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curl(1)                           Curl Manual                          curl(1)




NAME

       curl - transfer a URL


SYNOPSIS

       curl [options] [URL...]


DESCRIPTION

       curl  is  a tool to transfer data from or to a server, using one of the
       supported protocols (DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS,  IMAP,
       IMAPS,  LDAP,  LDAPS,  POP3,  POP3S,  RTMP, RTSP, SCP, SFTP, SMB, SMBS,
       SMTP, SMTPS, TELNET and TFTP). The command is designed to work  without
       user interaction.

       curl offers a busload of useful tricks like proxy support, user authen-
       tication, FTP upload, HTTP post, SSL connections, cookies, file  trans-
       fer  resume,  Metalink,  and more. As you will see below, the number of
       features will make your head spin!

       curl is powered by  libcurl  for  all  transfer-related  features.  See
       libcurl(3) for details.


URL

       The  URL  syntax is protocol-dependent. You'll find a detailed descrip-
       tion in RFC 3986.

       You can specify multiple URLs or parts of URLs  by  writing  part  sets
       within braces as in:

         http://site.{one,two,three}.com

       or you can get sequences of alphanumeric series by using [] as in:

         ftp://ftp.example.com/file[1-100].txt

         ftp://ftp.example.com/file[001-100].txt    (with leading zeros)

         ftp://ftp.example.com/file[a-z].txt

       Nested  sequences  are not supported, but you can use several ones next
       to each other:

         http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html

       You can specify any amount of URLs on the command line.  They  will  be
       fetched in a sequential manner in the specified order.

       You  can  specify a step counter for the ranges to get every Nth number
       or letter:

         http://example.com/file[1-100:10].txt

         http://example.com/file[a-z:2].txt

       When using [] or {} sequences when invoked from a command line  prompt,
       you probably have to put the full URL within double quotes to avoid the
       shell from interfering with it. This also  goes  for  other  characters
       treated special, like for example '&', '?' and '*'.

       Provide  the IPv6 zone index in the URL with an escaped percentage sign
       and the interface name. Like in

         http://[fe80::3%25eth0]/

       If you specify URL without protocol:// prefix,  curl  will  attempt  to
       guess  what  protocol  you might want. It will then default to HTTP but
       try other protocols based on often-used host name prefixes.  For  exam-
       ple,  for  host names starting with "ftp." curl will assume you want to
       speak FTP.

       curl will do its best to use what you pass to it as a URL.  It  is  not
       trying  to  validate it as a syntactically correct URL by any means but
       is instead very liberal with what it accepts.

       curl will attempt to re-use connections for multiple file transfers, so
       that  getting many files from the same server will not do multiple con-
       nects / handshakes. This improves speed. Of course this is only done on
       files  specified  on  a  single command line and cannot be used between
       separate curl invokes.


PROGRESS METER

       curl normally displays a progress meter during  operations,  indicating
       the  amount  of  transferred  data,  transfer speeds and estimated time
       left, etc. The progress meter displays number of bytes and  the  speeds
       are  in  bytes per second. The suffixes (k, M, G, T, P) are 1024 based.
       For example 1k is 1024 bytes. 1M is 1048576 bytes.

       curl displays this data to the terminal by default, so  if  you  invoke
       curl  to do an operation and it is about to write data to the terminal,
       it disables the progress meter as otherwise it would mess up the output
       mixing progress meter and response data.

       If you want a progress meter for HTTP POST or PUT requests, you need to
       redirect the response output to a file, using shell redirect  (>),  -o,
       --output or similar.

       It  is not the same case for FTP upload as that operation does not spit
       out any response data to the terminal.

       If you prefer a progress  "bar"  instead  of  the  regular  meter,  -#,
       --progress-bar  is your friend. You can also disable the progress meter
       completely with the -s, --silent option.


OPTIONS

       Options start with one or two dashes. Many of the  options  require  an
       additional value next to them.

       The  short  "single-dash"  form  of the options, -d for example, may be
       used with or without a space between it and its value, although a space
       is a recommended separator. The long "double-dash" form, -d, --data for
       example, requires a space between it and its value.

       Short version options that don't need any additional values can be used
       immediately  next  to  each other, like for example you can specify all
       the options -O, -L and -v at once as -OLv.

       In general, all boolean options are enabled with --option and yet again
       disabled  with --no-option. That is, you use the exact same option name
       but prefix it with "no-". However, in this list we mostly only list and
       show  the --option version of them. (This concept with --no options was
       added in  7.19.0.  Previously  most  options  were  toggled  on/off  on
       repeated use of the same command line option.)

       --abstract-unix-socket <path>
              (HTTP)  Connect  through an abstract Unix domain socket, instead
              of using the network.   Note:  netstat  shows  the  path  of  an
              abstract  socket  prefixed with '@', however the <path> argument
              should not have this leading character.

              Added in 7.53.0.

       --anyauth
              (HTTP) Tells curl to figure out authentication method by itself,
              and  use  the most secure one the remote site claims to support.
              This is done by first doing a request and checking the response-
              headers,  thus  possibly  inducing  an extra network round-trip.
              This is  used  instead  of  setting  a  specific  authentication
              method,  which  you  can  do with --basic, --digest, --ntlm, and
              --negotiate.

              Using --anyauth is not recommended if you do uploads from stdin,
              since  it  may require data to be sent twice and then the client
              must be able to rewind. If the need should arise when  uploading
              from stdin, the upload operation will fail.

              Used together with -u, --user.

              See also --proxy-anyauth and --basic and --digest.

       -a, --append
              (FTP SFTP) When used in an upload, this makes curl append to the
              target file instead  of  overwriting  it.  If  the  remote  file
              doesn't  exist,  it  will  be  created.   Note that this flag is
              ignored by some SFTP servers (including OpenSSH).

       --basic
              (HTTP) Tells curl to use  HTTP  Basic  authentication  with  the
              remote  host.  This  is  the  default and this option is usually
              pointless, unless you use it to override a previously set option
              that  sets  a  different  authentication method (such as --ntlm,
              --digest, or --negotiate).

              Used together with -u, --user.

              See also --proxy-basic.

       --cacert <CA certificate>
              (TLS) Tells curl to use the specified certificate file to verify
              the  peer.  The  file  may contain multiple CA certificates. The
              certificate(s) must be in PEM format. Normally curl is built  to
              use a default file for this, so this option is typically used to
              alter that default file.

              curl recognizes the environment variable named  'CURL_CA_BUNDLE'
              if  it  is  set,  and uses the given path as a path to a CA cert
              bundle. This option overrides that variable.

              The windows version of curl will automatically  look  for  a  CA
              certs file named 'curl-ca-bundle.crt', either in the same direc-
              tory as curl.exe, or in the Current Working Directory, or in any
              folder along your PATH.

              If  curl  is  built  against  the  NSS  SSL library, the NSS PEM
              PKCS#11 module (libnsspem.so) needs to  be  available  for  this
              option to work properly.

              (iOS  and macOS only) If curl is built against Secure Transport,
              then this option is supported for  backward  compatibility  with
              other  SSL  engines,  but it should not be set. If the option is
              not set, then curl will use the certificates in the  system  and
              user  Keychain to verify the peer, which is the preferred method
              of verifying the peer's certificate chain.

              If this option is used several times, the last one will be used.

       --capath <dir>
              (TLS)  Tells  curl to use the specified certificate directory to
              verify the peer. Multiple paths can be  provided  by  separating
              them with ":" (e.g.  "path1:path2:path3"). The certificates must
              be in PEM format, and if curl  is  built  against  OpenSSL,  the
              directory  must  have  been processed using the c_rehash utility
              supplied with OpenSSL. Using --capath can allow  OpenSSL-powered
              curl  to  make  SSL-connections much more efficiently than using
              --cacert if the --cacert file contains many CA certificates.

              If this option is set, the default capath value will be ignored,
              and if it is used several times, the last one will be used.

       --cert-status
              (TLS)  Tells curl to verify the status of the server certificate
              by using the Certificate Status Request (aka. OCSP stapling) TLS
              extension.

              If  this option is enabled and the server sends an invalid (e.g.
              expired) response, if the response suggests that the server cer-
              tificate  has  been  revoked, or no response at all is received,
              the verification fails.

              This is currently only implemented in the  OpenSSL,  GnuTLS  and
              NSS backends.

              Added in 7.41.0.

       --cert-type <type>
              (TLS)  Tells curl what certificate type the provided certificate
              is in. PEM, DER and ENG are recognized types.  If not specified,
              PEM is assumed.

              If this option is used several times, the last one will be used.

              See also -E, --cert and --key and --key-type.

       -E, --cert <certificate[:password]>
              (TLS) Tells curl to use the specified  client  certificate  file
              when getting a file with HTTPS, FTPS or another SSL-based proto-
              col. The certificate must be in PKCS#12 format if  using  Secure
              Transport,  or  PEM  format  if  using any other engine.  If the
              optional password isn't specified, it will be queried for on the
              terminal.  Note  that  this  option assumes a "certificate" file
              that is the private key and the client certificate concatenated!
              See -E, --cert and --key to specify them independently.

              If  curl  is  built against the NSS SSL library then this option
              can tell curl the nickname of the certificate to use within  the
              NSS  database defined by the environment variable SSL_DIR (or by
              default /etc/pki/nssdb). If the NSS  PEM  PKCS#11  module  (lib-
              nsspem.so)  is  available  then  PEM files may be loaded. If you
              want to use a file from the current directory, please precede it
              with  "./"  prefix, in order to avoid confusion with a nickname.
              If the nickname contains ":", it needs to be preceded by "\"  so
              that  it  is not recognized as password delimiter.  If the nick-
              name contains "\", it needs to be escaped as "\\" so that it  is
              not recognized as an escape character.

              (iOS  and macOS only) If curl is built against Secure Transport,
              then the certificate string can either be the name of a certifi-
              cate/private  key in the system or user keychain, or the path to
              a PKCS#12-encoded certificate and private key. If  you  want  to
              use  a  file  from the current directory, please precede it with
              "./" prefix, in order to avoid confusion with a nickname.

              If this option is used several times, the last one will be used.

              See also --cert-type and --key and --key-type.

       --ciphers <list of ciphers>
              (TLS) Specifies which ciphers to use in the connection. The list
              of ciphers must specify valid ciphers. Read  up  on  SSL  cipher
              list details on this URL:

               https://curl.haxx.se/docs/ssl-ciphers.html

              If this option is used several times, the last one will be used.

       --compressed
              (HTTP) Request a compressed response using one of the algorithms
              curl  supports,  and  save  the  uncompressed document.  If this
              option is used and the server  sends  an  unsupported  encoding,
              curl will report an error.

       -K, --config <file>
              Specify  which config file to read curl arguments from. The con-
              fig file is a text file in which command line arguments  can  be
              written  which  then will be used as if they were written on the
              actual command line.

              Options and their parameters must be specified on the same  con-
              fig  file  line,  separated  by whitespace, colon, or the equals
              sign. Long option names can optionally be given  in  the  config
              file  without  the initial double dashes and if so, the colon or
              equals characters can be used as separators. If  the  option  is
              specified  with  one  or  two  dashes,  there can be no colon or
              equals character between the option and its parameter.

              If the parameter is to contain whitespace, the parameter must be
              enclosed  within  quotes.  Within  double  quotes, the following
              escape sequences are available: \\, \", \t, \n,  \r  and  \v.  A
              backslash  preceding  any  other letter is ignored. If the first
              column of a config line is a '#' character, the rest of the line
              will be treated as a comment. Only write one option per physical
              line in the config file.

              Specify the filename to -K, --config as '-' to  make  curl  read
              the file from stdin.

              Note  that  to  be able to specify a URL in the config file, you
              need to specify it using the --url option,  and  not  by  simply
              writing  the  URL  on its own line. So, it could look similar to
              this:

              url = "https://curl.haxx.se/docs/"

              When curl is invoked, it always (unless -q, --disable  is  used)
              checks  for  a  default  config  file  and uses it if found. The
              default config file is checked for in the  following  places  in
              this order:

              1)  curl  tries  to find the "home dir": It first checks for the
              CURL_HOME and then the HOME environment variables. Failing that,
              it  uses getpwuid() on Unix-like systems (which returns the home
              dir given the current user in your system). On Windows, it  then
              checks for the APPDATA variable, or as a last resort the '%USER-
              PROFILE%\Application Data'.

              2) On windows, if there is no _curlrc file in the home  dir,  it
              checks for one in the same dir the curl executable is placed. On
              Unix-like systems, it will simply try to load .curlrc  from  the
              determined home dir.

              # --- Example file ---
              # this is a comment
              url = "example.com"
              output = "curlhere.html"
              user-agent = "superagent/1.0"

              # and fetch another URL too
              url = "example.com/docs/manpage.html"
              -O
              referer = "http://nowhereatall.example.com/"
              # --- End of example file ---

              This  option  can be used multiple times to load multiple config
              files.

       --connect-timeout <seconds>
              Maximum time in seconds that  you  allow  curl's  connection  to
              take.   This  only  limits the connection phase, so if curl con-
              nects within the given period it will continue - if not it  will
              exit.  Since version 7.32.0, this option accepts decimal values.

              If this option is used several times, the last one will be used.

              See also -m, --max-time.

       --connect-to <HOST1:PORT1:HOST2:PORT2>

              For  a  request to the given HOST:PORT pair, connect to CONNECT-
              TO-HOST:CONNECT-TO-PORT instead.  This  option  is  suitable  to
              direct requests at a specific server, e.g. at a specific cluster
              node in a cluster of servers.   This  option  is  only  used  to
              establish  the  network connection. It does NOT affect the host-
              name/port that is used for TLS/SSL (e.g. SNI, certificate  veri-
              fication)  or  for the application protocols.  "host" and "port"
              may be the empty string, meaning "any host/port".   "connect-to-
              host"  and "connect-to-port" may also be the empty string, mean-
              ing "use the request's original host/port".

              This option can be used many times to add many connect rules.

              See also --resolve and -H, --header. Added in 7.49.0.

       -C, --continue-at <offset>
              Continue/Resume a previous file transfer at  the  given  offset.
              The  given  offset  is  the  exact  number of bytes that will be
              skipped, counting from the beginning of the source  file  before
              it is transferred to the destination.  If used with uploads, the
              FTP server command SIZE will not be used by curl.

              Use "-C -" to tell curl to automatically find out  where/how  to
              resume  the  transfer. It then uses the given output/input files
              to figure that out.

              If this option is used several times, the last one will be used.

              See also -r, --range.

       -c, --cookie-jar <filename>
              (HTTP)  Specify to which file you want curl to write all cookies
              after a completed operation. Curl writes all  cookies  from  its
              in-memory  cookie storage to the given file at the end of opera-
              tions. If no cookies are known, no data  will  be  written.  The
              file  will  be written using the Netscape cookie file format. If
              you set the file name to a single dash, "-", the cookies will be
              written to stdout.

              This  command  line  option will activate the cookie engine that
              makes curl record and use cookies. Another way to activate it is
              to use the -b, --cookie option.

              If the cookie jar can't be created or written to, the whole curl
              operation won't fail or even report an error clearly. Using  -v,
              --verbose  will  get  a  warning displayed, but that is the only
              visible feedback you get about this possibly lethal situation.

              If this option is used several times, the  last  specified  file
              name will be used.

       -b, --cookie <data>
              (HTTP) Pass the data to the HTTP server in the Cookie header. It
              is supposedly the data previously received from the server in  a
              "Set-Cookie:"   line.    The   data  should  be  in  the  format
              "NAME1=VALUE1; NAME2=VALUE2".

              If no '=' symbol is used in the argument, it is instead  treated
              as a filename to read previously stored cookie from. This option
              also activates the cookie engine which  will  make  curl  record
              incoming  cookies,  which  may  be handy if you're using this in
              combination with the -L, --location option or  do  multiple  URL
              transfers on the same invoke.

              The file format of the file to read cookies from should be plain
              HTTP headers (Set-Cookie style) or the  Netscape/Mozilla  cookie
              file format.

              The  file  specified with -b, --cookie is only used as input. No
              cookies will be written to the file. To store cookies,  use  the
              -c, --cookie-jar option.

              Exercise  caution  if  you  are  using  this option and multiple
              transfers may occur.  If you use the NAME1=VALUE1; format, or in
              a  file  use  the  Set-Cookie format and don't specify a domain,
              then the cookie is sent for any domain (even after redirects are
              followed)  and cannot be modified by a server-set cookie. If the
              cookie engine is enabled and a server sets a cookie of the  same
              name then both will be sent on a future transfer to that server,
              likely not what you intended.  To address  these  issues  set  a
              domain  in  Set-Cookie  (doing that will include sub domains) or
              use the Netscape format.

              If this option is used several times, the last one will be used.

              Users very often want to both read cookies from a file and write
              updated cookies back to a file, so using both -b,  --cookie  and
              -c, --cookie-jar in the same command line is common.

       --create-dirs
              When used in conjunction with the -o, --output option, curl will
              create the necessary local directory hierarchy as  needed.  This
              option  creates the dirs mentioned with the -o, --output option,
              nothing else. If the --output file name uses no dir  or  if  the
              dirs it mentions already exist, no dir will be created.

              To  create remote directories when using FTP or SFTP, try --ftp-
              create-dirs.

       --crlf (FTP SMTP)  Convert  LF  to  CRLF  in  upload.  Useful  for  MVS
              (OS/390).

              (SMTP added in 7.40.0)

       --crlfile <file>
              (TLS) Provide a file using PEM format with a Certificate Revoca-
              tion List that may specify peer certificates that are to be con-
              sidered revoked.

              If this option is used several times, the last one will be used.

              Added in 7.19.7.

       --data-ascii <data>
              (HTTP) This is just an alias for -d, --data.

       --data-binary <data>
              (HTTP) This posts data exactly as specified with no  extra  pro-
              cessing whatsoever.

              If  you  start  the data with the letter @, the rest should be a
              filename.  Data is posted in a  similar  manner  as  -d,  --data
              does,  except  that  newlines and carriage returns are preserved
              and conversions are never done.

              If this option is used several times,  the  ones  following  the
              first will append data as described in -d, --data.

       --data-raw <data>
              (HTTP)  This  posts data similarly to -d, --data but without the
              special interpretation of the @ character.

              See also -d, --data. Added in 7.43.0.

       --data-urlencode <data>
              (HTTP) This posts data, similar to the other -d, --data  options
              with the exception that this performs URL-encoding.

              To  be  CGI-compliant,  the <data> part should begin with a name
              followed by a separator and a content specification. The  <data>
              part can be passed to curl using one of the following syntaxes:

              content
                     This  will make curl URL-encode the content and pass that
                     on. Just be careful so that the content  doesn't  contain
                     any  =  or  @  symbols, as that will then make the syntax
                     match one of the other cases below!

              =content
                     This will make curl URL-encode the content and pass  that
                     on. The preceding = symbol is not included in the data.

              name=content
                     This  will make curl URL-encode the content part and pass
                     that on. Note that the name part is expected to  be  URL-
                     encoded already.

              @filename
                     This  will  make  curl  load  data  from  the  given file
                     (including any newlines), URL-encode that data  and  pass
                     it on in the POST.

              name@filename
                     This  will  make  curl  load  data  from  the  given file
                     (including any newlines), URL-encode that data  and  pass
                     it  on  in  the  POST.  The  name part gets an equal sign
                     appended, resulting in name=urlencoded-file-content. Note
                     that the name is expected to be URL-encoded already.

       See also -d, --data and --data-raw. Added in 7.18.0.

       -d, --data <data>
              (HTTP)  Sends  the  specified data in a POST request to the HTTP
              server, in the same way that a browser  does  when  a  user  has
              filled  in an HTML form and presses the submit button. This will
              cause curl to pass the data to the server using the content-type
              application/x-www-form-urlencoded.  Compare to -F, --form.

              --data-raw is almost the same but does not have a special inter-
              pretation of the @ character. To post data  purely  binary,  you
              should  instead use the --data-binary option.  To URL-encode the
              value of a form field you may use --data-urlencode.

              If any of these options is used more than once on the same  com-
              mand  line,  the  data  pieces specified will be merged together
              with a separating  &-symbol.  Thus,  using  '-d  name=daniel  -d
              skill=lousy'  would  generate  a  post  chunk  that  looks  like
              'name=daniel&skill=lousy'.

              If you start the data with the letter @, the rest  should  be  a
              file  name  to read the data from, or - if you want curl to read
              the data from stdin. Multiple files can also be specified. Post-
              ing  data  from  a  file  named  from a file like that, carriage
              returns and newlines will be stripped out. If you don't want the
              @  character  to  have  a  special interpretation use --data-raw
              instead.

              See also --data-binary and --data-urlencode and --data-raw. This
              option overrides -F, --form and -I, --head and --upload.

       --delegation <LEVEL>
              (GSS/kerberos)  Set  LEVEL to tell the server what it is allowed
              to delegate when it comes to user credentials.

              none   Don't allow any delegation.

              policy Delegates if and only if the OK-AS-DELEGATE flag  is  set
                     in  the  Kerberos  service  ticket,  which is a matter of
                     realm policy.

              always Unconditionally allow the server to delegate.

       --digest
              (HTTP) Enables HTTP Digest authentication. This is an  authenti-
              cation  scheme  that  prevents the password from being sent over
              the wire in clear text. Use this in combination with the  normal
              -u, --user option to set user name and password.

              If  this  option  is  used  several times, only the first one is
              used.

              See also -u,  --user  and  --proxy-digest  and  --anyauth.  This
              option overrides --basic and --ntlm and --negotiate.

       --disable-eprt
              (FTP) Tell curl to disable the use of the EPRT and LPRT commands
              when doing active FTP transfers. Curl will normally always first
              attempt  to use EPRT, then LPRT before using PORT, but with this
              option, it will use PORT right away. EPRT and  LPRT  are  exten-
              sions  to  the  original  FTP  protocol, and may not work on all
              servers, but they enable more functionality in a better way than
              the traditional PORT command.

              --eprt can be used to explicitly enable EPRT again and --no-eprt
              is an alias for --disable-eprt.

              If the server is accessed using IPv6, this option will  have  no
              effect as EPRT is necessary then.

              Disabling  EPRT only changes the active behavior. If you want to
              switch to passive mode you need to not  use  -P,  --ftp-port  or
              force it with --ftp-pasv.

       --disable-epsv
              (FTP)  (FTP)  Tell  curl  to disable the use of the EPSV command
              when doing passive FTP  transfers.  Curl  will  normally  always
              first  attempt to use EPSV before PASV, but with this option, it
              will not try using EPSV.

              --epsv can be used to explicitly enable EPSV again and --no-epsv
              is an alias for --disable-epsv.

              If  the  server is an IPv6 host, this option will have no effect
              as EPSV is necessary then.

              Disabling EPSV only changes the passive behavior. If you want to
              switch to active mode you need to use -P, --ftp-port.

       -q, --disable
              If  used  as the first parameter on the command line, the curlrc
              config file will not be read and used. See the -K, --config  for
              details on the default config file search path.

       --dns-interface <interface>
              (DNS)  Tell  curl  to send outgoing DNS requests through <inter-
              face>. This option is a counterpart to --interface  (which  does
              not  affect  DNS). The supplied string must be an interface name
              (not an address).

              See also --dns-ipv4-addr  and  --dns-ipv6-addr.  --dns-interface
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv4-addr <address>
              (DNS) Tell curl to bind to <ip-address>  when  making  IPv4  DNS
              requests,  so that the DNS requests originate from this address.
              The argument should be a single IPv4 address.

              See also --dns-interface  and  --dns-ipv6-addr.  --dns-ipv4-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-ipv6-addr <address>
              (DNS) Tell curl to bind to <ip-address>  when  making  IPv6  DNS
              requests,  so that the DNS requests originate from this address.
              The argument should be a single IPv6 address.

              See also --dns-interface  and  --dns-ipv4-addr.  --dns-ipv6-addr
              requires  that  the  underlying  libcurl was built to support c-
              ares. Added in 7.33.0.

       --dns-servers <addresses>
              Set the list of DNS servers to be used  instead  of  the  system
              default.  The list of IP addresses should be separated with com-
              mas. Port numbers may also optionally be given as :<port-number>
              after each IP address.

              --dns-servers  requires that the underlying libcurl was built to
              support c-ares. Added in 7.33.0.

       -D, --dump-header <filename>
              (HTTP FTP) Write the received protocol headers to the  specified
              file.

              This  option  is handy to use when you want to store the headers
              that an HTTP site sends to you. Cookies from the  headers  could
              then  be  read  in  a  second  curl  invocation by using the -b,
              --cookie option! The -c, --cookie-jar option is a better way  to
              store cookies.

              When  used  in FTP, the FTP server response lines are considered
              being "headers" and thus are saved there.

              If this option is used several times, the last one will be used.

              See also -o, --output.

       --egd-file <file>
              (TLS)  Specify  the  path  name  to the Entropy Gathering Daemon
              socket. The socket is used to seed the  random  engine  for  SSL
              connections.

              See also --random-file.

       --engine <name>
              (TLS)  Select the OpenSSL crypto engine to use for cipher opera-
              tions. Use --engine list to print a list of build-time supported
              engines.  Note  that  not  all  (or  none) of the engines may be
              available at run-time.

       --environment
              Sets a range of environment variables, using the names  the  -w,
              --write-out  option supports, to allow easier extraction of use-
              ful information after having run curl.

              --environment requires that the underlying libcurl was built  to
              support RISC OS.

       --expect100-timeout <seconds>
              (HTTP) Maximum time in seconds that you allow curl to wait for a
              100-continue response when curl emits an  Expects:  100-continue
              header  in  its  request.  By default curl will wait one second.
              This option accepts decimal values! When curl stops waiting,  it
              will continue as if the response has been received.

              See also --connect-timeout. Added in 7.47.0.

       --fail-early
              Fail and exit on first detected error.

              When  curl is used to do multiple transfers on the command line,
              it will attempt to operate on each given URL,  one  by  one.  By
              default,  it will ignore errors if there are more URLs given and
              the last URL's  success  will  determine  the  error  code  curl
              returns.  So  early failures will be "hidden" by subsequent suc-
              cessful transfers.

              Using this option, curl will instead  return  an  error  on  the
              first  transfers  that  fails, independent on the amount of more
              URLs that are given on the command line. This way,  no  transfer
              failures go undetected by scripts and similar.

              This  option  will  apply for all given URLs even if you use -:,
              --next.

              Added in 7.52.0.

       -f, --fail
              (HTTP) Fail silently (no output at all) on server  errors.  This
              is  mostly done to better enable scripts etc to better deal with
              failed attempts. In normal cases when an HTTP  server  fails  to
              deliver  a  document,  it  returns  an  HTML document stating so
              (which often also describes why and more). This flag  will  pre-
              vent curl from outputting that and return error 22.

              This  method is not fail-safe and there are occasions where non-
              successful response codes will  slip  through,  especially  when
              authentication is involved (response codes 401 and 407).

       --false-start
              (TLS)  Tells  curl  to use false start during the TLS handshake.
              False start is a mode where a  TLS  client  will  start  sending
              application data before verifying the server's Finished message,
              thus saving a round trip when performing a full handshake.

              This is currently only implemented in the NSS and Secure  Trans-
              port (on iOS 7.0 or later, or OS X 10.9 or later) backends.

              Added in 7.42.0.

       --form-string <name=string>
              (HTTP)  Similar  to  -F, --form except that the value string for
              the named parameter is used literally. Leading '@' and '<' char-
              acters,  and  the  ';type='  string in the value have no special
              meaning. Use this in preference to -F,  --form  if  there's  any
              possibility  that  the string value may accidentally trigger the
              '@' or '<' features of -F, --form.

              See also -F, --form.

       -F, --form <name=content>
              (HTTP) This lets curl emulate a filled-in form in which  a  user
              has  pressed  the  submit  button. This causes curl to POST data
              using the  Content-Type  multipart/form-data  according  to  RFC
              2388.  This  enables uploading of binary files etc. To force the
              'content' part to be a file, prefix the  file  name  with  an  @
              sign.  To just get the content part from a file, prefix the file
              name with the symbol <. The difference between @ and <  is  then
              that  @  makes a file get attached in the post as a file upload,
              while the < makes a text field and just  get  the  contents  for
              that text field from a file.

              Example:  to  send  an image to a server, where 'profile' is the
              name of the form-field to which portrait.jpg will be the input:

               curl -F profile=@portrait.jpg https://example.com/upload.cgi

              To read content from stdin instead of a file, use - as the file-
              name.  This  goes  for both @ and < constructs. Unfortunately it
              does not support reading the file from a named pipe or  similar,
              as it needs the full size before the transfer starts.

              You  can  also  tell  curl  what  Content-Type  to  use by using
              'type=', in a manner similar to:

               curl -F "web=@index.html;type=text/html" example.com

              or

               curl -F "name=daniel;type=text/foo" example.com

              You can also explicitly change the name field of a  file  upload
              part by setting filename=, like this:

               curl -F "file=@localfile;filename=nameinpost" example.com

              If  filename/path contains ',' or ';', it must be quoted by dou-
              ble-quotes like:

               curl  -F  "file=@\"localfile\";filename=\"nameinpost\""   exam-
              ple.com

              or

               curl -F 'file=@"localfile";filename="nameinpost"' example.com

              Note  that  if  a  filename/path is quoted by double-quotes, any
              double-quote or backslash within the filename must be escaped by
              backslash.

              See further examples and details in the MANUAL.

              This option can be used multiple times.

              This option overrides -d, --data and -I, --head and --upload.

       --ftp-account <data>
              (FTP) When an FTP server asks for "account data" after user name
              and password has been provided, this data is sent off using  the
              ACCT command.

              If this option is used several times, the last one will be used.

              Added in 7.13.0.

       --ftp-alternative-to-user <command>
              (FTP) If authenticating with the USER and PASS  commands  fails,
              send  this  command.   When  connecting  to  Tumbleweed's Secure
              Transport server over FTPS using  a  client  certificate,  using
              "SITE  AUTH"  will tell the server to retrieve the username from
              the certificate.

              Added in 7.15.5.

       --ftp-create-dirs
              (FTP SFTP) When an FTP or SFTP URL/operation uses  a  path  that
              doesn't  currently exist on the server, the standard behavior of
              curl is to fail. Using this option, curl will instead attempt to
              create missing directories.

              See also --create-dirs.

       --ftp-method <method>
              (FTP)  Control what method curl should use to reach a file on an
              FTP(S) server. The method argument should be one of the  follow-
              ing alternatives:

              multicwd
                     curl  does  a  single CWD operation for each path part in
                     the given URL. For deep hierarchies this means very  many
                     commands.  This  is  how RFC 1738 says it should be done.
                     This is the default but the slowest behavior.

              nocwd  curl does no CWD at all. curl will do  SIZE,  RETR,  STOR
                     etc and give a full path to the server for all these com-
                     mands. This is the fastest behavior.

              singlecwd
                     curl does one CWD with the full target directory and then
                     operates  on  the  file  "normally" (like in the multicwd
                     case). This is somewhat  more  standards  compliant  than
                     'nocwd' but without the full penalty of 'multicwd'.

       Added in 7.15.1.

       --ftp-pasv
              (FTP)  Use  passive mode for the data connection. Passive is the
              internal default behavior, but using this option can be used  to
              override a previous -P, --ftp-port option.

              If  this  option  is  used  several times, only the first one is
              used. Undoing an enforced passive really isn't  doable  but  you
              must then instead enforce the correct -P, --ftp-port again.

              Passive mode means that curl will try the EPSV command first and
              then PASV, unless --disable-epsv is used.

              See also --disable-epsv. Added in 7.11.0.

       -P, --ftp-port <address>
              (FTP) Reverses the default initiator/listener  roles  when  con-
              necting  with  FTP. This option makes curl use active mode. curl
              then tells the server to connect back to the client's  specified
              address and port, while passive mode asks the server to setup an
              IP address and port for it to connect to.  <address>  should  be
              one of:

              interface
                     i.e  "eth0"  to  specify which interface's IP address you
                     want to use (Unix only)

              IP address
                     i.e "192.168.10.1" to specify the exact IP address

              host name
                     i.e "my.host.domain" to specify the machine

              -      make curl pick the same IP address that is  already  used
                     for the control connection

       If  this  option is used several times, the last one will be used. Dis-
       able the use of PORT with --ftp-pasv. Disable the attempt  to  use  the
       EPRT  command  instead  of PORT by using --disable-eprt. EPRT is really
       PORT++.

       Since 7.19.5, you can append  ":[start]-[end]"  to  the  right  of  the
       address,  to tell curl what TCP port range to use. That means you spec-
       ify a port range, from a lower to a  higher  number.  A  single  number
       works  as well, but do note that it increases the risk of failure since
       the port may not be available.

       See also --ftp-pasv and --disable-eprt.

       --ftp-pret
              (FTP) Tell curl to send a PRET command before PASV  (and  EPSV).
              Certain  FTP  servers,  mainly drftpd, require this non-standard
              command for directory listings as well as up  and  downloads  in
              PASV mode.

              Added in 7.20.0.

       --ftp-skip-pasv-ip
              (FTP) Tell curl to not use the IP address the server suggests in
              its response to curl's PASV command when curl connects the  data
              connection.  Instead  curl  will  re-use  the same IP address it
              already uses for the control connection.

              This option has no effect if PORT, EPRT or EPSV is used  instead
              of PASV.

              See also --ftp-pasv. Added in 7.14.2.

       --ftp-ssl-ccc-mode <active/passive>
              (FTP)  Sets the CCC mode. The passive mode will not initiate the
              shutdown, but instead wait for the server to do it, and will not
              reply to the shutdown from the server. The active mode initiates
              the shutdown and waits for a reply from the server.

              See also --ftp-ssl-ccc. Added in 7.16.2.

       --ftp-ssl-ccc
              (FTP) Use CCC (Clear Command Channel)  Shuts  down  the  SSL/TLS
              layer after authenticating. The rest of the control channel com-
              munication will be unencrypted. This allows NAT routers to  fol-
              low the FTP transaction. The default mode is passive.

              See also --ssl and --ftp-ssl-ccc-mode. Added in 7.16.1.

       --ftp-ssl-control
              (FTP)  Require  SSL/TLS  for  the FTP login, clear for transfer.
              Allows secure authentication, but non-encrypted  data  transfers
              for  efficiency.   Fails the transfer if the server doesn't sup-
              port SSL/TLS.

              Added in 7.16.0.

       -G, --get
              When used, this option will make all  data  specified  with  -d,
              --data,  --data-binary or --data-urlencode to be used in an HTTP
              GET request instead of the POST request that otherwise would  be
              used. The data will be appended to the URL with a '?' separator.

              If used in combination with  -I,  --head,  the  POST  data  will
              instead be appended to the URL with a HEAD request.

              If  this  option  is  used  several times, only the first one is
              used. This is because undoing a GET doesn't make sense, but  you
              should then instead enforce the alternative method you prefer.

       -g, --globoff
              This option switches off the "URL globbing parser". When you set
              this option, you can specify URLs that contain the letters  {}[]
              without  having them being interpreted by curl itself. Note that
              these letters are not normal legal URL contents but they  should
              be encoded according to the URI standard.

       -I, --head
              (HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the
              command HEAD which this uses to get nothing but the header of  a
              document.  When  used  on an FTP or FILE file, curl displays the
              file size and last modification time only.

       -H, --header <header>
              (HTTP) Extra header to include in the request when sending  HTTP
              to  a  server. You may specify any number of extra headers. Note
              that if you should add a custom header that has the same name as
              one  of  the  internal  ones curl would use, your externally set
              header will be used instead of the internal one. This allows you
              to  make  even  trickier  stuff than curl would normally do. You
              should not replace internally set headers without  knowing  per-
              fectly well what you're doing. Remove an internal header by giv-
              ing a replacement without content  on  the  right  side  of  the
              colon, as in: -H "Host:". If you send the custom header with no-
              value then its header must be terminated with a semicolon,  such
              as -H "X-Custom-Header;" to send "X-Custom-Header:".

              curl  will  make  sure  that each header you add/replace is sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              See also the -A, --user-agent and -e, --referer options.

              Starting in 7.37.0, you need --proxy-header to send custom head-
              ers intended for a proxy.

              Example:

               curl -H "X-First-Name: Joe" http://example.com/

              WARNING:  headers  set  with  this  option  will  be  set in all
              requests - even after redirects are  followed,  like  when  told
              with  -L,  --location. This can lead to the header being sent to
              other hosts than the original host, so sensitive headers  should
              be used with caution combined with following redirects.

              This  option  can  be  used multiple times to add/replace/remove
              multiple headers.

       -h, --help
              Usage help. This lists all current command line options  with  a
              short description.

       --hostpubmd5 <md5>
              (SFTP  SCP)  Pass a string containing 32 hexadecimal digits. The
              string should be the 128 bit MD5 checksum of the  remote  host's
              public key, curl will refuse the connection with the host unless
              the md5sums match.

              Added in 7.17.1.

       -0, --http1.0
              (HTTP) Tells curl to use HTTP version 1.0 instead of  using  its
              internally preferred HTTP version.

              This option overrides --http1.1 and --http2.

       --http1.1
              (HTTP) Tells curl to use HTTP version 1.1.

              This  option  overrides  -0,  --http1.0  and  --http2.  Added in
              7.33.0.

       --http2-prior-knowledge
              (HTTP) Tells curl to  issue  its  non-TLS  HTTP  requests  using
              HTTP/2  without  HTTP/1.1  Upgrade.  It requires prior knowledge
              that the server supports HTTP/2 straight  away.  HTTPS  requests
              will  still  do HTTP/2 the standard way with negotiated protocol
              version in the TLS handshake.

              --http2-prior-knowledge requires that the underlying libcurl was
              built to support HTTP/2. This option overrides --http1.1 and -0,
              --http1.0 and --http2. Added in 7.49.0.

       --http2
              (HTTP) Tells curl to use HTTP version 2.

              See also --no-alpn. --http2 requires that the underlying libcurl
              was built to support HTTP/2. This option overrides --http1.1 and
              -0, --http1.0 and --http2-prior-knowledge. Added in 7.33.0.

       --ignore-content-length
              (FTP HTTP) For HTTP, Ignore the Content-Length header.  This  is
              particularly  useful  for servers running Apache 1.x, which will
              report incorrect Content-Length for files larger  than  2  giga-
              bytes.

              For  FTP (since 7.46.0), skip the RETR command to figure out the
              size before downloading a file.

       -i, --include
              Include the HTTP-header in the output. The HTTP-header  includes
              things  like server-name, date of the document, HTTP-version and
              more...

              See also -v, --verbose.

       -k, --insecure
              (TLS) This option explicitly allows curl to  perform  "insecure"
              SSL connections and transfers. All SSL connections are attempted
              to be made secure by using the CA certificate  bundle  installed
              by  default.  This  makes  all connections considered "insecure"
              fail unless -k, --insecure is used.

              See this online resource for further details:
               https://curl.haxx.se/docs/sslcerts.html

       --interface <name>

              Perform an operation using a specified interface. You can  enter
              interface  name,  IP address or host name. An example could look
              like:

               curl --interface eth0:1 https://www.example.com/

              If this option is used several times, the last one will be used.

              See also --dns-interface.

       -4, --ipv4
              This  option tells curl to resolve names to IPv4 addresses only,
              and not for example try IPv6.

              See also  --http1.1  and  --http2.  This  option  overrides  -6,
              --ipv6.

       -6, --ipv6
              This  option tells curl to resolve names to IPv6 addresses only,
              and not for example try IPv4.

              See also  --http1.1  and  --http2.  This  option  overrides  -6,
              --ipv6.

       -j, --junk-session-cookies
              (HTTP) When curl is told to read cookies from a given file, this
              option will make it discard all  "session  cookies".  This  will
              basically  have  the same effect as if a new session is started.
              Typical browsers always discard  session  cookies  when  they're
              closed down.

              See also -b, --cookie and -c, --cookie-jar.

       --keepalive-time <seconds>
              This  option  sets  the  time  a connection needs to remain idle
              before sending keepalive probes and the time between  individual
              keepalive probes. It is currently effective on operating systems
              offering  the  TCP_KEEPIDLE  and  TCP_KEEPINTVL  socket  options
              (meaning  Linux, recent AIX, HP-UX and more). This option has no
              effect if --no-keepalive is used.

              If this option is used several times, the last one will be used.
              If unspecified, the option defaults to 60 seconds.

              Added in 7.18.0.

       --key-type <type>
              (TLS)  Private key file type. Specify which type your --key pro-
              vided private key is. DER, PEM, and ENG are  supported.  If  not
              specified, PEM is assumed.

              If this option is used several times, the last one will be used.

       --key <key>
              (TLS SSH) Private key file name. Allows you to provide your pri-
              vate  key in this separate file. For SSH, if not specified, curl
              tries the following candidates in order:

              If this option is used several times, the last one will be used.

       --krb <level>
              (FTP)  Enable Kerberos authentication and use. The level must be
              entered and should be one of 'clear', 'safe', 'confidential', or
              'private'.  Should  you  use  a  level that is not one of these,
              'private' will instead be used.

              If this option is used several times, the last one will be used.

              --krb  requires that the underlying libcurl was built to support
              Kerberos.

       --libcurl <file>
              Append this option to any ordinary curl command  line,  and  you
              will  get a libcurl-using C source code written to the file that
              does the equivalent of what your command-line operation does!

              If this option is used several times, the last given  file  name
              will be used.

              Added in 7.16.1.

       --limit-rate <speed>
              Specify  the  maximum  transfer  rate you want curl to use - for
              both downloads and uploads. This feature is useful if you have a
              limited pipe and you'd like your transfer not to use your entire
              bandwidth. To make it slower than it otherwise would be.

              The given speed is measured in bytes/second, unless a suffix  is
              appended.   Appending  'k' or 'K' will count the number as kilo-
              bytes, 'm' or M' makes it megabytes, while 'g' or 'G'  makes  it
              gigabytes. Examples: 200K, 3m and 1G.

              If  you  also use the -Y, --speed-limit option, that option will
              take precedence and might cripple the rate-limiting slightly, to
              help keeping the speed-limit logic working.

              If this option is used several times, the last one will be used.

       -l, --list-only
              (FTP POP3) (FTP) When listing  an  FTP  directory,  this  switch
              forces  a  name-only view. This is especially useful if the user
              wants to machine-parse the contents of an  FTP  directory  since
              the normal directory view doesn't use a standard look or format.
              When used like this, the option causes a NLST command to be sent
              to the server instead of LIST.

              Note:  Some  FTP  servers  list  only files in their response to
              NLST; they do not include sub-directories and symbolic links.

              (POP3) When retrieving a specific email from POP3,  this  switch
              forces  a  LIST command to be performed instead of RETR. This is
              particularly useful if the user wants to see if a specific  mes-
              sage id exists on the server and what size it is.

              Note:  When combined with -X, --request, this option can be used
              to send an UIDL command instead, so the user may use the email's
              unique  identifier  rather  than  it's  message  id  to make the
              request.

              Added in 7.21.5.

       --local-port <num/range>
              Set a preferred single number or range (FROM-TO) of  local  port
              numbers to use for the connection(s).  Note that port numbers by
              nature are a scarce resource that will be busy at times so  set-
              ting  this range to something too narrow might cause unnecessary
              connection setup failures.

              Added in 7.15.2.

       --location-trusted
              (HTTP) Like -L, --location, but will allow sending  the  name  +
              password to all hosts that the site may redirect to. This may or
              may not introduce a security breach if the site redirects you to
              a  site  to which you'll send your authentication info (which is
              plaintext in the case of HTTP Basic authentication).

              See also -u, --user.

       -L, --location
              (HTTP) If the server reports that the requested page  has  moved
              to a different location (indicated with a Location: header and a
              3XX response code), this option will make curl redo the  request
              on  the  new  place.  If used together with -i, --include or -I,
              --head, headers from all requested pages  will  be  shown.  When
              authentication  is  used, curl only sends its credentials to the
              initial host. If a redirect takes curl to a different  host,  it
              won't  be  able to intercept the user+password. See also --loca-
              tion-trusted on how to change this. You can limit the amount  of
              redirects to follow by using the --max-redirs option.

              When  curl follows a redirect and the request is not a plain GET
              (for example POST or PUT), it will do the following request with
              a GET if the HTTP response was 301, 302, or 303. If the response
              code was any other 3x code, curl  will  re-send  the  following
              request using the same unmodified method.

              You  can  tell  curl to not change the non-GET request method to
              GET after a 30x response by  using  the  dedicated  options  for
              that: --post301, --post302 and --post303.

       --login-options <options>
              (IMAP  POP3 SMTP) Specify the login options to use during server
              authentication.

              You can use the  login  options  to  specify  protocol  specific
              options  that may be used during authentication. At present only
              IMAP, POP3 and SMTP support login options. For more  information
              about  the  login options please see RFC 2384, RFC 5092 and IETF
              draft draft-earhart-url-smtp-00.txt

              If this option is used several times, the last one will be used.

              Added in 7.34.0.

       --mail-auth <address>
              (SMTP)  Specify  a  single address. This will be used to specify
              the authentication address (identity)  of  a  submitted  message
              that is being relayed to another server.

              See also --mail-rcpt and --mail-from. Added in 7.25.0.

       --mail-from <address>
              (SMTP)  Specify  a single address that the given mail should get
              sent from.

              See also --mail-rcpt and --mail-auth. Added in 7.20.0.

       --mail-rcpt <address>
              (SMTP) Specify a single address, user name or mailing list name.
              Repeat this option several times to send to multiple recipients.

              When performing a mail transfer, the recipient should specify  a
              valid email address to send the mail to.

              When  performing  an  address  verification  (VRFY command), the
              recipient should be specified as the user name or user name  and
              domain (as per Section 3.5 of RFC5321). (Added in 7.34.0)

              When performing a mailing list expand (EXPN command), the recip-
              ient should be specified using the mailing list  name,  such  as
              "Friends" or "London-Office".  (Added in 7.34.0)

              Added in 7.20.0.

       -M, --manual
              Manual. Display the huge help text.

       --max-filesize <bytes>
              Specify  the  maximum  size (in bytes) of a file to download. If
              the file requested is larger than this value, the transfer  will
              not start and curl will return with exit code 63.

              NOTE:  The  file size is not always known prior to download, and
              for such files this option has no effect even if the file trans-
              fer  ends  up  being larger than this given limit. This concerns
              both FTP and HTTP transfers.

              See also --limit-rate.

       --max-redirs <num>
              (HTTP) Set maximum  number  of  redirection-followings  allowed.
              When  -L,  --location is used, is used to prevent curl from fol-
              lowing redirections "in absurdum". By default, the limit is  set
              to  50 redirections. Set this option to -1 to make it unlimited.

              If this option is used several times, the last one will be used.

       -m, --max-time <time>
              Maximum  time  in  seconds that you allow the whole operation to
              take.  This is useful for preventing your batch jobs from  hang-
              ing  for  hours due to slow networks or links going down.  Since
              7.32.0, this option accepts decimal values, but the actual time-
              out will decrease in accuracy as the specified timeout increases
              in decimal precision.

              If this option is used several times, the last one will be used.

              See also --connect-timeout.

       --metalink
              This  option  can  tell curl to parse and process a given URI as
              Metalink file (both version 3 and 4 (RFC  5854)  are  supported)
              and  make use of the mirrors listed within for failover if there
              are errors (such as the file or server not being available).  It
              will  also  verify  the hash of the file after the download com-
              pletes. The Metalink file itself is downloaded and processed  in
              memory and not stored in the local file system.

              Example to use a remote Metalink file:

               curl --metalink http://www.example.com/example.metalink

              To use a Metalink file in the local file system, use FILE proto-
              col (file://):

               curl --metalink file://example.metalink

              Please note that if FILE protocol is disabled, there is  no  way
              to  use  a local Metalink file at the time of this writing. Also
              note that if --metalink and -i,  --include  are  used  together,
              --include  will be ignored. This is because including headers in
              the response will break Metalink parser and if the  headers  are
              included in the file described in Metalink file, hash check will
              fail.


              --metalink requires that the underlying  libcurl  was  built  to
              support metalink. Added in 7.27.0.

       --negotiate
              (HTTP) Enables Negotiate (SPNEGO) authentication.

              This  option  requires a library built with GSS-API or SSPI sup-
              port. Use -V, --version  to  see  if  your  curl  supports  GSS-
              API/SSPI or SPNEGO.

              When  using this option, you must also provide a fake -u, --user
              option to activate the authentication code properly.  Sending  a
              '-u  :'  is  enough  as  the user name and password from the -u,
              --user option aren't actually used.

              If this option is used several times,  only  the  first  one  is
              used.

              See also --basic and --ntlm and --anyauth and --proxy-negotiate.

       --netrc-file <filemame>
              This option is similar to -n, --netrc, except that  you  provide
              the  path  (absolute  or  relative)  to the netrc file that Curl
              should use.  You can only specify one netrc file per invocation.
              If  several --netrc-file options are provided, the last one will
              be used.

              It will abide by --netrc-optional if specified.

              This option overrides -n, --netrc. Added in 7.21.5.

       --netrc-optional
              Very similar to -n, --netrc, but this option  makes  the  .netrc
              usage optional and not mandatory as the -n, --netrc option does.

              See also --netrc-file. This option overrides -n, --netrc.

       -n, --netrc
              Makes curl scan the .netrc  (_netrc  on  Windows)  file  in  the
              user's home directory for login name and password. This is typi-
              cally used for FTP on Unix. If used with HTTP, curl will  enable
              user authentication. See netrc(5) ftp(1) for details on the file
              format. Curl will not complain if that  file  doesn't  have  the
              right permissions (it should not be either world- or group-read-
              able). The environment variable "HOME" is used to find the  home
              directory.

              A  quick  and  very  simple  example of how to setup a .netrc to
              allow curl to FTP to the machine host.domain.com with user  name
              'myself' and password 'secret' should look similar to:

              machine host.domain.com login myself password secret

       -:, --next
              Tells curl to use a separate operation for the following URL and
              associated  options.  This  allows  you  to  send  several   URL
              requests,  each  with  their  own specific options, for example,
              such as different user names or custom requests for each.

              -:, --next will reset all local options  and  only  global  ones
              will  have  their values survive over to the operation following
              the -:, --next instruction. Global options  include  -v,  --ver-
              bose, --trace, --trace-ascii and --fail-early.

              For  example,  you can do both a GET and a POST in a single com-
              mand line:

               curl www1.example.com --next -d postthis www2.example.com

              Added in 7.36.0.

       --no-alpn
              (HTTPS) Disable the ALPN  TLS  extension.  ALPN  is  enabled  by
              default  if  libcurl was built with an SSL library that supports
              ALPN. ALPN is used by a libcurl that supports HTTP/2 to  negoti-
              ate HTTP/2 support with the server during https sessions.

              See  also  --no-npn  and  --http2.  --no-alpn  requires that the
              underlying libcurl was built to support TLS. Added in 7.36.0.

       -N, --no-buffer
              Disables the buffering of the output stream. In normal work sit-
              uations,  curl  will  use a standard buffered output stream that
              will have the effect that it will output the data in chunks, not
              necessarily  exactly  when  the data arrives.  Using this option
              will disable that buffering.

              Note that this is the negated option name  documented.  You  can
              thus use --buffer to enforce the buffering.

       --no-keepalive
              Disables  the  use  of keepalive messages on the TCP connection.
              curl otherwis enables them by default.

              Note that this is the negated option name  documented.  You  can
              thus use --keepalive to enforce keepalive.

       --no-npn
              (HTTPS) Disable the NPN TLS extension. NPN is enabled by default
              if libcurl was built with an SSL library that supports NPN.  NPN
              is  used  by  a libcurl that supports HTTP/2 to negotiate HTTP/2
              support with the server during https sessions.

              See also --no-alpn  and  --http2.  --no-npn  requires  that  the
              underlying libcurl was built to support TLS. Added in 7.36.0.

       --no-sessionid
              (TLS)  Disable curl's use of SSL session-ID caching.  By default
              all transfers are done using the cache. Note that while  nothing
              should  ever  get  hurt  by attempting to reuse SSL session-IDs,
              there seem to be broken SSL implementations in the wild that may
              require you to disable this in order for you to succeed.

              Note  that  this  is the negated option name documented. You can
              thus use --sessionid to enforce session-ID caching.

              Added in 7.16.0.

       --noproxy <no-proxy-list>
              Comma-separated list of hosts which do not use a proxy,  if  one
              is  specified.  The only wildcard is a single * character, which
              matches all hosts, and effectively disables the proxy. Each name
              in  this  list  is matched as either a domain which contains the
              hostname, or the hostname itself. For example,  local.com  would
              match   local.com,  local.com:80,  and  www.local.com,  but  not
              www.notlocal.com.

              Since 7.53.0, This option overrides  the  environment  variables
              that  disable the proxy. If there's an environment variable dis-
              abling a proxy, you can set noproxy list to "" to override it.

              Added in 7.19.4.

       --ntlm-wb
              (HTTP) Enables NTLM much in the style --ntlm does, but hand over
              the  authentication  to the separate binary ntlmauth application
              that is executed when needed.

              See also --ntlm and --proxy-ntlm.

       --ntlm (HTTP) Enables  NTLM  authentication.  The  NTLM  authentication
              method was designed by Microsoft and is used by IIS web servers.
              It is a proprietary protocol, reverse-engineered by clever  peo-
              ple and implemented in curl based on their efforts. This kind of
              behavior should not be endorsed, you should  encourage  everyone
              who  uses  NTLM to switch to a public and documented authentica-
              tion method instead, such as Digest.

              If you want to enable NTLM for your proxy  authentication,  then
              use --proxy-ntlm.

              If  this  option  is  used  several times, only the first one is
              used.

              See also  --proxy-ntlm.  --ntlm  requires  that  the  underlying
              libcurl  was built to support TLS. This option overrides --basic
              and --negotiated and --digest and --anyauth.

       --oauth2-bearer
              (IMAP POP3 SMTP) Specify the Bearer Token for OAUTH  2.0  server
              authentication. The Bearer Token is used in conjunction with the
              user name which can be specified as part of  the  --url  or  -u,
              --user options.

              The  Bearer  Token  and user name are formatted according to RFC
              6750.

              If this option is used several times, the last one will be used.

       -o, --output <file>
              Write output to <file> instead of stdout. If you are using {} or
              [] to fetch multiple documents, you can use '#'  followed  by  a
              number  in  the <file> specifier. That variable will be replaced
              with the current string for the URL being fetched. Like in:

               curl http://{one,two}.example.com -o "file_#1.txt"

              or use several variables like:

               curl http://{site,host}.host[1-5].com -o "#1_#2"

              You may use this option as many times as the number of URLs  you
              have.  For  example, if you specify two URLs on the same command
              line, you can use it like this:

                curl -o aa example.com -o bb example.net

              and the order of the -o options and  the  URLs  doesn't  matter,
              just  that  the  first -o is for the first URL and so on, so the
              above command line can also be written as

                curl example.com example.net -o aa -o bb

              See also the --create-dirs option to create the  local  directo-
              ries  dynamically.  Specifying the output as '-' (a single dash)
              will force the output to be done to stdout.

              See  also  -O,  --remote-name  and  --remote-name-all  and   -J,
              --remote-header-name.

       --pass <phrase>
              (SSH TLS) Passphrase for the private key

              If this option is used several times, the last one will be used.

       --path-as-is
              Tell curl to not handle sequences of /../ or /./  in  the  given
              URL  path.  Normally curl will squash or merge them according to
              standards but with this option set you tell it not to do that.

              Added in 7.42.0.

       --pinnedpubkey <hashes>
              (TLS) Tells curl to  use  the  specified  public  key  file  (or
              hashes)  to  verify the peer. This can be a path to a file which
              contains a single public key in PEM or DER format, or any number
              of base64 encoded sha256 hashes preceded by 'sha256//' and sepa-
              rated by ';'

              When negotiating a TLS or SSL connection,  the  server  sends  a
              certificate  indicating  its identity. A public key is extracted
              from this certificate and if it does not exactly match the  pub-
              lic  key provided to this option, curl will abort the connection
              before sending or receiving any data.

              PEM/DER support:
                7.39.0: OpenSSL, GnuTLS and GSKit
                7.43.0: NSS and wolfSSL/CyaSSL
                7.47.0: mbedtls
                7.49.0: PolarSSL sha256 support:
                7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL/CyaSSL.
                7.47.0: mbedtls
                7.49.0: PolarSSL Other SSL backends not supported.

              If this option is used several times, the last one will be used.

       --post301
              (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST
              requests into GET requests when following a 301 redirection. The
              non-RFC  behaviour  is  ubiquitous in web browsers, so curl does
              the conversion by default to maintain  consistency.  However,  a
              server  may  require  a POST to remain a POST after such a redi-
              rection. This option is meaningful only when using  -L,  --loca-
              tion.

              See  also  --post302  and --post303 and -L, --location. Added in
              7.17.1.

       --post302
              (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST
              requests into GET requests when following a 302 redirection. The
              non-RFC behaviour is ubiquitous in web browsers,  so  curl  does
              the  conversion  by  default to maintain consistency. However, a
              server may require a POST to remain a POST after  such  a  redi-
              rection.  This  option is meaningful only when using -L, --loca-
              tion.

              See also --post301 and --post303 and -L,  --location.  Added  in
              7.19.1.

       --post303
              (HTTP) Tells curl to respect RFC 7231/6.4.4 and not convert POST
              requests into GET requests when following a 303 redirection. The
              non-RFC  behaviour  is  ubiquitous in web browsers, so curl does
              the conversion by default to maintain  consistency.  However,  a
              server  may  require  a POST to remain a POST after such a redi-
              rection. This option is meaningful only when using  -L,  --loca-
              tion.

              See  also  --post302  and --post301 and -L, --location. Added in
              7.26.0.

       --preproxy [protocol://]host[:port]
              Use the specified SOCKS proxy before connecting to  an  HTTP  or
              HTTPS  -x,  --proxy.  In  such a case curl first connects to the
              SOCKS proxy and then connects (through SOCKS)  to  the  HTTP  or
              HTTPS proxy. Hence pre proxy.

              The pre proxy string should be specified with a protocol:// pre-
              fix to  specify  alternative  proxy  protocols.  Use  socks4://,
              socks4a://,  socks5://  or  socks5h://  to  request the specific
              SOCKS version to be used. No protocol specified will  make  curl
              default to SOCKS4.

              If  the  port number is not specified in the proxy string, it is
              assumed to be 1080.

              User and password that might be provided in the proxy string are
              URL  decoded by curl. This allows you to pass in special charac-
              ters such as @ by using %40 or pass in a colon with %3a.

              If this option is used several times, the last one will be used.

              Added in 7.52.0.

       -#, --progress-bar
              Make  curl  display  transfer  progress as a simple progress bar
              instead of the standard, more informational, meter.

              This progress bar draws a single line of '#'  characters  across
              the screen and shows a percentage if the transfer size is known.
              For transfers without a known size, it will instead  output  one
              '#' character for every 1024 bytes transferred.

       --proto-default <protocol>
              Tells curl to use protocol for any URL missing a scheme name.

              Example:

               curl --proto-default https ftp.mozilla.org

              An  unknown  or  unsupported  protocol causes error CURLE_UNSUP-
              PORTED_PROTOCOL (1).

              This option does not change the default proxy protocol (http).

              Without this option curl would make a guess based on  the  host,
              see --url for details.

              Added in 7.45.0.

       --proto-redir <protocols>
              Tells  curl to limit what protocols it may use on redirect. Pro-
              tocols denied by --proto are not overridden by this option.  See
              --proto for how protocols are represented.

              Example, allow only HTTP and HTTPS on redirect:

               curl --proto-redir -all,http,https http://example.com

              By default curl will allow all protocols on redirect except sev-
              eral disabled for security reasons: Since 7.19.4  FILE  and  SCP
              are  disabled,  and since 7.40.0 SMB and SMBS are also disabled.
              Specifying all  or  +all  enables  all  protocols  on  redirect,
              including those disabled for security.

              Added in 7.20.2.

       --proto <protocols>
              Tells  curl  to limit what protocols it may use in the transfer.
              Protocols are evaluated left to right, are comma separated,  and
              are each a protocol name or

              +  Permit this protocol in addition to protocols already permit-
                 ted (this is the default if no modifier is used).

              -  Deny this protocol, removing it from the  list  of  protocols
                 already permitted.

              =  Permit  only this protocol (ignoring the list already permit-
                 ted), though subject  to  later  modification  by  subsequent
                 entries in the comma separated list.

              For example:

              --proto -ftps  uses the default protocols, but disables ftps

              --proto -all,https,+http
                             only enables http and https

              --proto =http,https
                             also only enables http and https

       Unknown protocols produce a warning. This allows scripts to safely rely
       on being able to disable potentially dangerous protocols, without rely-
       ing  upon  support  for that protocol being built into curl to avoid an
       error.

       This option can be used multiple times, in which case the effect is the
       same as concatenating the protocols into one instance of the option.

       See also --proto-redir and --proto-default. Added in 7.20.2.

       --proxy-anyauth
              Tells  curl to pick a suitable authentication method when commu-
              nicating with the given HTTP proxy. This might  cause  an  extra
              request/response round-trip.

              See also -x, --proxy and --proxy-basic and --proxy-digest. Added
              in 7.13.2.

       --proxy-basic
              Tells curl to use HTTP Basic authentication  when  communicating
              with the given proxy. Use --basic for enabling HTTP Basic with a
              remote host. Basic is the  default  authentication  method  curl
              uses with proxies.

              See also -x, --proxy and --proxy-anyauth and --proxy-digest.

       --proxy-cacert <file>
              Same as --cacert but used in HTTPS proxy context.

              See  also  --proxy-capath  and  --cacert  and  --capath  and -x,
              --proxy. Added in 7.52.0.

       --proxy-capath <dir>
              Same as --capath but used in HTTPS proxy context.

              See also --proxy-cacert and -x, --proxy and --capath.  Added  in
              7.52.0.

       --proxy-cert-type <type>
              Same as --cert-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-cert <cert[:passwd]>
              Same as -E, --cert but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-ciphers <list>
              Same as --ciphers but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-crlfile <file>
              Same as --crlfile but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-digest
              Tells  curl to use HTTP Digest authentication when communicating
              with the given proxy. Use --digest for enabling HTTP Digest with
              a remote host.

              See also -x, --proxy and --proxy-anyauth and --proxy-basic.

       --proxy-header <header>
              (HTTP)  Extra header to include in the request when sending HTTP
              to a proxy. You may specify any number of extra headers. This is
              the  equivalent option to -H, --header but is for proxy communi-
              cation only like in CONNECT requests when you  want  a  separate
              header  sent  to  the proxy to what is sent to the actual remote
              host.

              curl will make sure that each header  you  add/replace  is  sent
              with the proper end-of-line marker, you should thus not add that
              as a part of the header content: do not add newlines or carriage
              returns, they will only mess things up for you.

              Headers  specified  with  this  option  will  not be included in
              requests that curl knows will not be sent to a proxy.

              This option can be used  multiple  times  to  add/replace/remove
              multiple headers.

              Added in 7.37.0.

       --proxy-insecure
              Same as -k, --insecure but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key-type <type>
              Same as --key-type but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-key <key>
              Same as --key but used in HTTPS proxy context.

       --proxy-negotiate
              Tells  curl  to  use HTTP Negotiate (SPNEGO) authentication when
              communicating with the given proxy. Use --negotiate for enabling
              HTTP Negotiate (SPNEGO) with a remote host.

              See also --proxy-anyauth and --proxy-basic. Added in 7.17.1.

       --proxy-ntlm
              Tells  curl  to  use HTTP NTLM authentication when communicating
              with the given proxy. Use --ntlm for enabling NTLM with a remote
              host.

              See also --proxy-negotiate and --proxy-anyauth.

       --proxy-pass <phrase>
              Same as --pass but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-service-name <name>
              This  option  allows  you  to  change the service name for proxy
              negotiation.

              Added in 7.43.0.

       --proxy-ssl-allow-beast
              Same as --ssl-allow-beast but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsauthtype <type>
              Same as --tlsauthtype but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlspassword <string>
              Same as --tlspassword but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsuser <name>
              Same as --tlsuser but used in HTTPS proxy context.

              Added in 7.52.0.

       --proxy-tlsv1
              Same as -1, --tlsv1 but used in HTTPS proxy context.

              Added in 7.52.0.

       -U, --proxy-user <user:password>
              Specify the user name and password to use for proxy  authentica-
              tion.

              If  you  use  a  Windows  SSPI-enabled curl binary and do either
              Negotiate or NTLM authentication  then  you  can  tell  curl  to
              select the user name and password from your environment by spec-
              ifying a single colon with this option: "-U :".

              If this option is used several times, the last one will be used.

       -x, --proxy [protocol://]host[:port]
              Use the specified proxy.

              The  proxy string can be specified with a protocol:// prefix. No
              protocol specified or http:// will be treated as HTTP proxy. Use
              socks4://, socks4a://, socks5:// or socks5h:// to request a spe-
              cific SOCKS version to be used.  (The protocol support was added
              in curl 7.21.7)

              HTTPS  proxy  support  via https:// protocol prefix was added in
              7.52.0 for OpenSSL, GnuTLS and NSS.

              Unrecognized and unsupported  proxy  protocols  cause  an  error
              since  7.52.0.   Prior  versions may ignore the protocol and use
              http:// instead.

              If the port number is not specified in the proxy string,  it  is
              assumed to be 1080.

              This  option  overrides  existing environment variables that set
              the proxy to use. If there's an environment variable  setting  a
              proxy, you can set proxy to "" to override it.

              All operations that are performed over an HTTP proxy will trans-
              parently be converted to HTTP. It means  that  certain  protocol
              specific operations might not be available. This is not the case
              if you can tunnel through the proxy, as one with the -p, --prox-
              ytunnel option.

              User and password that might be provided in the proxy string are
              URL decoded by curl. This allows you to pass in special  charac-
              ters such as @ by using %40 or pass in a colon with %3a.

              The  proxy host can be specified the exact same way as the proxy
              environment variables, including the protocol  prefix  (http://)
              and the embedded user + password.

              If this option is used several times, the last one will be used.

       --proxy1.0 <host[:port]>
              Use the specified HTTP 1.0 proxy. If  the  port  number  is  not
              specified, it is assumed at port 1080.

              The  only  difference between this and the HTTP proxy option -x,
              --proxy, is that attempts to use CONNECT through the proxy  will
              specify an HTTP 1.0 protocol instead of the default HTTP 1.1.

       -p, --proxytunnel
              When  an  HTTP proxy is used -x, --proxy, this option will cause
              non-HTTP protocols  to  attempt  to  tunnel  through  the  proxy
              instead  of merely using it to do HTTP-like operations. The tun-
              nel approach is made with the HTTP  proxy  CONNECT  request  and
              requires that the proxy allows direct connect to the remote port
              number curl wants to tunnel through to.

              See also -x, --proxy.

       --pubkey <key>
              (SFTP SCP) Public key file name. Allows you to provide your pub-
              lic key in this separate file.

              If this option is used several times, the last one will be used.

              (As of 7.39.0, curl attempts to automatically extract the public
              key  from the private key file, so passing this option is gener-
              ally not required. Note that this public key extraction requires
              libcurl  to  be linked against a copy of libssh2 1.2.8 or higher
              that is itself linked against OpenSSL.)

       -Q, --quote
              (FTP SFTP) Send an arbitrary command to the remote FTP  or  SFTP
              server.  Quote commands are sent BEFORE the transfer takes place
              (just after the initial PWD command in an FTP  transfer,  to  be
              exact). To make commands take place after a successful transfer,
              prefix them with a dash '-'.  To make  commands  be  sent  after
              curl has changed the working directory, just before the transfer
              command(s), prefix the command with a '+'  (this  is  only  sup-
              ported for FTP). You may specify any number of commands.

              If  the  server  returns  failure  for  one of the commands, the
              entire operation will be aborted. You  must  send  syntactically
              correct  FTP  commands as RFC 959 defines to FTP servers, or one
              of the commands listed below to SFTP servers.

              This option can be used multiple times. When speaking to an  FTP
              server,  prefix  the  command  with an asterisk (*) to make curl
              continue even if the command fails as by default curl will  stop
              at first failure.

              SFTP  is a binary protocol. Unlike for FTP, curl interprets SFTP
              quote commands itself before sending them to the  server.   File
              names may be quoted shell-style to embed spaces or special char-
              acters.  Following is the list of all supported SFTP quote  com-
              mands:

              chgrp group file
                     The  chgrp command sets the group ID of the file named by
                     the file operand to the group ID specified by  the  group
                     operand. The group operand is a decimal integer group ID.

              chmod mode file
                     The chmod command modifies the  file  mode  bits  of  the
                     specified file. The mode operand is an octal integer mode
                     number.

              chown user file
                     The chown command sets the owner of the file named by the
                     file  operand  to the user ID specified by the user oper-
                     and. The user operand is a decimal integer user ID.

              ln source_file target_file
                     The ln and symlink commands create a symbolic link at the
                     target_file  location  pointing  to the source_file loca-
                     tion.

              mkdir directory_name
                     The mkdir command creates  the  directory  named  by  the
                     directory_name operand.

              pwd    The pwd command returns the absolute pathname of the cur-
                     rent working directory.

              rename source target
                     The rename command renames the file or directory named by
                     the  source  operand to the destination path named by the
                     target operand.

              rm file
                     The rm command removes the file specified by the file op-
                     erand.

              rmdir directory
                     The  rmdir  command removes the directory entry specified
                     by the directory operand, provided it is empty.

              symlink source_file target_file
                     See ln.

       --random-file <file>
              Specify the path name to file containing what will be considered
              as  random  data. The data may be used to seed the random engine
              for SSL connections.  See also the --egd-file option.

       -r, --range <range>
              (HTTP FTP SFTP FILE) Retrieve a byte range (i.e a partial  docu-
              ment)  from  a  HTTP/1.1,  FTP  or  SFTP server or a local FILE.
              Ranges can be specified in a number of ways.

              0-499     specifies the first 500 bytes

              500-999   specifies the second 500 bytes

              -500      specifies the last 500 bytes

              9500-     specifies the bytes from offset 9500 and forward

              0-0,-1    specifies the first and last byte only(*)(HTTP)

              100-199,500-599
                        specifies two separate 100-byte ranges(*) (HTTP)

              (*) = NOTE that this will cause the server to reply with a  mul-
              tipart response!

              Only  digit characters (0-9) are valid in the 'start' and 'stop'
              fields of the 'start-stop' range syntax. If a non-digit  charac-
              ter is given in the range, the server's response will be unspec-
              ified, depending on the server's configuration.

              You should also be aware that many HTTP/1.1 servers do not  have
              this  feature  enabled, so that when you attempt to get a range,
              you'll instead get the whole document.

              FTP and SFTP range downloads only  support  the  simple  'start-
              stop'  syntax  (optionally with one of the numbers omitted). FTP
              use depends on the extended FTP command SIZE.

              If this option is used several times, the last one will be used.

       --raw  (HTTP) When used, it disables all internal HTTP decoding of con-
              tent or transfer encodings and  instead  makes  them  passed  on
              unaltered, raw.

              Added in 7.16.2.

       -e, --referer <URL>
              (HTTP) Sends the "Referrer Page" information to the HTTP server.
              This can also be set with the -H, --header flag of course.  When
              used  with  -L,  --location  you  can  append ";auto" to the -e,
              --referer URL to make curl automatically set  the  previous  URL
              when  it  follows  a Location: header. The ";auto" string can be
              used alone, even if you don't set an initial -e, --referer.

              If this option is used several times, the last one will be used.

              See also -A, --user-agent and -H, --header.

       -J, --remote-header-name
              (HTTP) This option tells the -O, --remote-name option to use the
              server-specified   Content-Disposition   filename   instead   of
              extracting a filename from the URL.

              If  the  server  specifies a file name and a file with that name
              already exists in the current working directory it will  not  be
              overwritten and an error will occur. If the server doesn't spec-
              ify a file name then this option has no effect.

              There's no attempt to decode %-sequences (yet) in  the  provided
              file name, so this option may provide you with rather unexpected
              file names.

              WARNING: Exercise judicious use of this  option,  especially  on
              Windows.  A  rogue  server  could  send you the name of a DLL or
              other file that could possibly be loaded automatically  by  Win-
              dows or some third party software.

       --remote-name-all
              This  option changes the default action for all given URLs to be
              dealt with as if -O, --remote-name were used for each one. So if
              you want to disable that for a specific URL after --remote-name-
              all has been used, you must use "-o -" or --no-remote-name.

              Added in 7.19.0.

       -O, --remote-name
              Write output to a local file named like the remote file we  get.
              (Only  the file part of the remote file is used, the path is cut
              off.)

              The file will be saved in the current working directory. If  you
              want  the  file  saved  in  a different directory, make sure you
              change the current working directory before invoking  curl  with
              this option.

              The  remote  file  name  to use for saving is extracted from the
              given URL, nothing else, and if it already  exists  it  will  be
              overwritten.  If  you  want  the server to be able to choose the
              file name refer to -J, --remote-header-name which can be used in
              addition  to  this option. If the server chooses a file name and
              that name already exists it will not be overwritten.

              There is no URL decoding done on the file name. If it has %20 or
              other  URL  encoded parts of the name, they will end up as-is as
              file name.

              You may use this option as many times as the number of URLs  you
              have.

       -R, --remote-time
              When  used,  this will make curl attempt to figure out the time-
              stamp of the remote file, and if  that  is  available  make  the
              local file get that same timestamp.

       -X, --request <command>
              (HTTP) Specifies a custom request method to use when communicat-
              ing with the HTTP server.  The specified request method will  be
              used  instead  of  the  method otherwise used (which defaults to
              GET). Read the HTTP 1.1 specification for details  and  explana-
              tions.  Common  additional HTTP requests include PUT and DELETE,
              but related technologies like WebDAV offers PROPFIND, COPY, MOVE
              and more.

              Normally  you  don't  need  this option. All sorts of GET, HEAD,
              POST and PUT requests are rather invoked by using dedicated com-
              mand line options.

              This  option  only  changes  the  actual  word  used in the HTTP
              request, it does not alter the way curl behaves. So for  example
              if  you  want  to make a proper HEAD request, using -X HEAD will
              not suffice. You need to use the -I, --head option.

              The method string you set with -X, --request will  be  used  for
              all  requests,  which  if you for example use -L, --location may
              cause unintended side-effects when curl doesn't  change  request
              method according to the HTTP 30x response codes - and similar.

              (FTP) Specifies a custom FTP command to use instead of LIST when
              doing file lists with FTP.

              (POP3) Specifies a custom POP3 command to use instead of LIST or
              RETR. (Added in 7.26.0)

              (IMAP)  Specifies  a custom IMAP command to use instead of LIST.
              (Added in 7.30.0)

              (SMTP) Specifies a custom SMTP command to use instead of HELP or
              VRFY. (Added in 7.34.0)

              If this option is used several times, the last one will be used.

       --resolve <host:port:address>
              Provide a custom address for a  specific  host  and  port  pair.
              Using  this,  you  can make the curl requests(s) use a specified
              address and prevent the otherwise normally resolved  address  to
              be  used.  Consider it a sort of /etc/hosts alternative provided
              on the command line. The port number should be the  number  used
              for  the  specific  protocol the host will be used for. It means
              you need several entries if you want to provide address for  the
              same host but different ports.

              The provided address set by this option will be used even if -4,
              --ipv4 or -6, --ipv6 is set to make curl use another IP version.

              This  option  can  be  used many times to add many host names to
              resolve.

              Added in 7.21.3.

       --retry-connrefused
              In addition to the other conditions, consider ECONNREFUSED as  a
              transient  error  too  for --retry. This option is used together
              with --retry.

              Added in 7.52.0.

       --retry-delay <seconds>
              Make curl sleep this amount of time before  each  retry  when  a
              transfer  has  failed  with  a  transient  error (it changes the
              default backoff time algorithm between retries). This option  is
              only  interesting if --retry is also used. Setting this delay to
              zero will make curl use the default backoff time.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry-max-time <seconds>
              The  retry  timer  is  reset  before the first transfer attempt.
              Retries will be done as usual (see --retry) as long as the timer
              hasn't reached this given limit. Notice that if the timer hasn't
              reached the limit, the request will be made and  while  perform-
              ing,  it may take longer than this given time period. To limit a
              single request's maximum time, use  -m,  --max-time.   Set  this
              option to zero to not timeout retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --retry <num>
              If a transient error is returned when curl tries  to  perform  a
              transfer,  it  will retry this number of times before giving up.
              Setting the number to 0 makes curl do no retries (which  is  the
              default).  Transient  error  means either: a timeout, an FTP 4xx
              response code or an HTTP 5xx response code.

              When curl is about to retry a transfer, it will first  wait  one
              second  and  then for all forthcoming retries it will double the
              waiting time until it reaches 10 minutes which then will be  the
              delay  between  the rest of the retries.  By using --retry-delay
              you  disable  this  exponential  backoff  algorithm.  See   also
              --retry-max-time to limit the total time allowed for retries.

              If this option is used several times, the last one will be used.

              Added in 7.12.3.

       --sasl-ir
              Enable initial response in SASL authentication.

              Added in 7.31.0.

       --service-name <name>
              This option allows you to change the service name for SPNEGO.

              Examples:   --negotiate   --service-name   sockd    would    use
              sockd/server-name.

              Added in 7.43.0.

       -S, --show-error
              When used with -s, --silent, it makes curl show an error message
              if it fails.

       -s, --silent
              Silent or quiet mode. Don't show progress meter  or  error  mes-
              sages.   Makes  Curl mute. It will still output the data you ask
              for, potentially even to the terminal/stdout unless you redirect
              it.

              Use  -S,  --show-error  in  addition  to  this option to disable
              progress meter but still show error messages.

              See also -v, --verbose and --stderr.

       --socks4 <host[:port]>
              Use the specified SOCKS4 proxy. If the port number is not speci-
              fied, it is assumed at port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks4 proxy with -x, --proxy using a socks4:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.15.2.

       --socks4a <host[:port]>
              Use the specified SOCKS4a proxy. If the port number is not spec-
              ified, it is assumed at port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks4a  proxy with -x, --proxy using a socks4a:// protocol pre-
              fix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5-gssapi-nec
              As part of the GSS-API negotiation a protection mode is  negoti-
              ated.  RFC  1961 says in section 4.3/4.4 it should be protected,
              but the NEC  reference  implementation  does  not.   The  option
              --socks5-gssapi-nec  allows the unprotected exchange of the pro-
              tection mode negotiation.

              Added in 7.19.4.

       --socks5-gssapi-service <name>
              The default service name for a socks server is rcmd/server-fqdn.
              This option allows you to change it.

              Examples:   --socks5  proxy-name  --socks5-gssapi-service  sockd
              would use sockd/proxy-name --socks5 proxy-name  --socks5-gssapi-
              service  sockd/real-name  would  use  sockd/real-name  for cases
              where the proxy-name does not match the principal name.

              Added in 7.19.4.

       --socks5-hostname <host[:port]>
              Use the specified SOCKS5 proxy (and let the  proxy  resolve  the
              host  name).  If the port number is not specified, it is assumed
              at port 1080.

              This option overrides any previous use of -x, --proxy,  as  they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks5 hostname proxy with -x, --proxy using a socks5h:// proto-
              col prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the same time -x, --proxy is used with an HTTP/HTTPS  proxy.  In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              Added in 7.18.0.

       --socks5 <host[:port]>
              Use  the  specified  SOCKS5  proxy  -  but resolve the host name
              locally. If the port number is not specified, it is  assumed  at
              port 1080.

              This  option  overrides any previous use of -x, --proxy, as they
              are mutually exclusive.

              Since 7.21.7, this option is superfluous since you can specify a
              socks5 proxy with -x, --proxy using a socks5:// protocol prefix.

              Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at
              the  same  time -x, --proxy is used with an HTTP/HTTPS proxy. In
              such a case curl first connects to the SOCKS proxy and then con-
              nects (through SOCKS) to the HTTP or HTTPS proxy.

              If this option is used several times, the last one will be used.

              This option (as well as --socks4) does not work with IPV6,  FTPS
              or LDAP.

              Added in 7.18.0.

       -Y, --speed-limit <speed>
              If a download is slower than this given speed (in bytes per sec-
              ond) for speed-time seconds it gets aborted. speed-time  is  set
              with -y, --speed-time and is 30 if not set.

              If this option is used several times, the last one will be used.

       -y, --speed-time <seconds>
              If a download is slower than speed-limit bytes per second during
              a speed-time period, the download gets aborted. If speed-time is
              used, the default speed-limit will be  1  unless  set  with  -Y,
              --speed-limit.

              This  option  controls  transfers  and thus will not affect slow
              connects etc. If this is a concern for you, try  the  --connect-
              timeout option.

              If this option is used several times, the last one will be used.

       --ssl-allow-beast
              This option tells curl to not work around a security flaw in the
              SSL3  and TLS1.0 protocols known as BEAST.  If this option isn't
              used, the SSL layer may use workarounds known to cause  interop-
              erability problems with some older SSL implementations. WARNING:
              this option loosens the SSL security, and by using this flag you
              ask for exactly that.

              Added in 7.25.0.

       --ssl-no-revoke
              (WinSSL)  This  option tells curl to disable certificate revoca-
              tion checks.  WARNING: this option loosens the SSL security, and
              by using this flag you ask for exactly that.

              Added in 7.44.0.

       --ssl-reqd
              (FTP IMAP POP3 SMTP) Require SSL/TLS for the connection.  Termi-
              nates the connection if the server doesn't support SSL/TLS.

              This option was formerly known as --ftp-ssl-reqd.

              Added in 7.20.0.

       --ssl  (FTP IMAP POP3 SMTP) Try to  use  SSL/TLS  for  the  connection.
              Reverts to a non-secure connection if the server doesn't support
              SSL/TLS.  See also --ftp-ssl-control and --ssl-reqd for  differ-
              ent levels of encryption required.

              This  option  was formerly known as --ftp-ssl (Added in 7.11.0).
              That option name can still be used but  will  be  removed  in  a
              future version.

              Added in 7.20.0.

       -2, --sslv2
              (SSL)  Forces  curl to use SSL version 2 when negotiating with a
              remote SSL server. Sometimes curl is built  without  SSLv2  sup-
              port. SSLv2 is widely considered insecure (see RFC 6176).

              See  also  --http1.1  and --http2. -2, --sslv2 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides -3, --sslv3 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       -3, --sslv3
              (SSL)  Forces  curl to use SSL version 3 when negotiating with a
              remote SSL server. Sometimes curl is built  without  SSLv3  sup-
              port. SSLv3 is widely considered insecure (see RFC 7568).

              See  also  --http1.1  and --http2. -3, --sslv3 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides -2, --sslv2 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.

       --stderr
              Redirect  all writes to stderr to the specified file instead. If
              the file name is a plain '-', it is instead written to stdout.

              If this option is used several times, the last one will be used.

              See also -v, --verbose and -s, --silent.

       --tcp-fastopen
              Enable use of TCP Fast Open (RFC7413).

              Added in 7.49.0.

       --tcp-nodelay
              Turn  on the TCP_NODELAY option. See the curl_easy_setopt(3) man
              page for details about this option.

              Since 7.50.2, curl sets this option by default and you  need  to
              explictitly switch it off if you don't want it on.

              Added in 7.11.2.

       -t, --telnet-option <opt=val>
              Pass options to the telnet protocol. Supported options are:

              TTYPE=<term> Sets the terminal type.

              XDISPLOC=<X display> Sets the X display location.

              NEW_ENV=<var,val> Sets an environment variable.

       --tftp-blksize <value>
              (TFTP) Set TFTP BLKSIZE option (must be >512). This is the block
              size that curl will try to use when transferring data to or from
              a TFTP server. By default 512 bytes will be used.

              If this option is used several times, the last one will be used.

              Added in 7.20.0.

       --tftp-no-options
              (TFTP) Tells curl not to send TFTP options requests.

              This option improves interop with some legacy  servers  that  do
              not  acknowledge  or  properly implement TFTP options. When this
              option is used --tftp-blksize is ignored.

              Added in 7.48.0.

       -z, --time-cond <time>
              (HTTP FTP) Request a file that has been modified later than  the
              given  time  and date, or one that has been modified before that
              time. The <date expression> can be all sorts of date strings  or
              if it doesn't match any internal ones, it is taken as a filename
              and tries to get  the  modification  date  (mtime)  from  <file>
              instead.  See  the curl_getdate(3) man pages for date expression
              details.

              Start the date expression with a dash (-) to make it request for
              a  document that is older than the given date/time, default is a
              document that is newer than the specified date/time.

              If this option is used several times, the last one will be used.

       --tlsauthtype <type>
              Set  TLS  authentication  type.  Currently,  the  only supported
              option is "SRP",  for  TLS-SRP  (RFC  5054).  If  --tlsuser  and
              --tlspassword  are specified but --tlsauthtype is not, then this
              option defaults to "SRP".

              Added in 7.21.4.

       --tlspassword
              Set password for use with the TLS authentication  method  speci-
              fied with --tlsauthtype. Requires that --tlsuser also be set.

              Added in 7.21.4.

       --tlsuser <name>
              Set  username  for use with the TLS authentication method speci-
              fied with --tlsauthtype. Requires  that  --tlspassword  also  is
              set.

              Added in 7.21.4.

       --tlsv1.0
              (TLS)  Forces  curl  to use TLS version 1.0 when connecting to a
              remote TLS server.

              Added in 7.34.0.

       --tlsv1.1
              (TLS) Forces curl to use TLS version 1.1 when  connecting  to  a
              remote TLS server.

              Added in 7.34.0.

       --tlsv1.2
              (TLS)  Forces  curl  to use TLS version 1.2 when connecting to a
              remote TLS server.

              Added in 7.34.0.

       --tlsv1.3
              (TLS) Forces curl to use TLS version 1.3 when  connecting  to  a
              remote TLS server.

              Note that TLS 1.3 is only supported by a subset of TLS backends.
              At the time of writing this, those are BoringSSL and NSS only.

              Added in 7.52.0.

       -1, --tlsv1
              (SSL) Tells curl to use TLS version 1.x when negotiating with  a
              remote TLS server. That means TLS version 1.0, 1.1 or 1.2.

              See  also  --http1.1  and --http2. -1, --tlsv1 requires that the
              underlying libcurl was built to support TLS. This  option  over-
              rides --tlsv1.1 and --tlsv1.2 and --tlsv1.3.

       --tr-encoding
              (HTTP) Request a compressed Transfer-Encoding response using one
              of the algorithms curl supports, and uncompress the  data  while
              receiving it.

              Added in 7.21.6.

       --trace-ascii <file>
              Enables  a  full  trace  dump of all incoming and outgoing data,
              including descriptive information, to the given output file. Use
              "-" as filename to have the output sent to stdout.

              This is very similar to --trace, but leaves out the hex part and
              only shows the ASCII part of the dump. It makes  smaller  output
              that might be easier to read for untrained humans.

              If this option is used several times, the last one will be used.

              This option overrides --trace and -v, --verbose.

       --trace-time
              Prepends a time stamp to each trace or verbose  line  that  curl
              displays.

              Added in 7.14.0.

       --trace <file>
              Enables  a  full  trace  dump of all incoming and outgoing data,
              including descriptive information, to the given output file. Use
              "-"  as  filename  to have the output sent to stdout. Use "%" as
              filename to have the output sent to stderr.

              If this option is used several times, the last one will be used.

              This option overrides -v, --verbose and --trace-ascii.

       --unix-socket <path>
              (HTTP) Connect through this Unix domain socket, instead of using
              the network.

              Added in 7.40.0.

       -T, --upload-file <file>
              This transfers the specified local file to the  remote  URL.  If
              there is no file part in the specified URL, curl will append the
              local file name. NOTE that you must use a trailing / on the last
              directory  to really prove to Curl that there is no file name or
              curl will think that your last directory name is the remote file
              name to use. That will most likely cause the upload operation to
              fail. If this is used on an HTTP(S) server, the PUT command will
              be used.

              Use  the file name "-" (a single dash) to use stdin instead of a
              given file.  Alternately, the file name "."  (a  single  period)
              may  be  specified  instead  of "-" to use stdin in non-blocking
              mode to  allow  reading  server  output  while  stdin  is  being
              uploaded.

              You  can  specify one -T, --upload-file for each URL on the com-
              mand line. Each -T, --upload-file + URL pair specifies  what  to
              upload  and  to  where. curl also supports "globbing" of the -T,
              --upload-file argument, meaning that  you  can  upload  multiple
              files  to a single URL by using the same URL globbing style sup-
              ported in the URL, like this:

               curl --upload-file "{file1,file2}" http://www.example.com

              or even

               curl -T "img[1-1000].png" ftp://ftp.example.com/upload/

              When uploading to an SMTP server: the uploaded data  is  assumed
              to be RFC 5322 formatted. It has to feature the necessary set of
              headers and mail body formatted correctly by the  user  as  curl
              will not transcode nor encode it further in any way.

       --url <url>
              Specify  a  URL  to  fetch. This option is mostly handy when you
              want to specify URL(s) in a config file.

              If the given URL is missing a scheme name (such as "http://"  or
              "ftp://"  etc) then curl will make a guess based on the host. If
              the outermost sub-domain name matches  DICT,  FTP,  IMAP,  LDAP,
              POP3  or  SMTP  then  that protocol will be used, otherwise HTTP
              will be used. Since 7.45.0 guessing can be disabled by setting a
              default protocol, see --proto-default for details.

              This  option  may  be used any number of times. To control where
              this URL is written, use the -o, --output or the  -O,  --remote-
              name options.

       -B, --use-ascii
              (FTP  LDAP)  Enable  ASCII  transfer.  For FTP, this can also be
              enforced by using a URL that ends with  ";type=A".  This  option
              causes data sent to stdout to be in text mode for win32 systems.

       -A, --user-agent <name>
              (HTTP) Specify the User-Agent string to send to the HTTP server.
              To  encode blanks in the string, surround the string with single
              quote marks. This can also be set with the -H,  --header  option
              of course.

              If this option is used several times, the last one will be used.

       -u, --user <user:password>
              Specify the user name and password to use for server authentica-
              tion. Overrides -n, --netrc and --netrc-optional.

              If  you  simply  specify  the  user name, curl will prompt for a
              password.

              The user name and passwords are split up  on  the  first  colon,
              which  makes  it impossible to use a colon in the user name with
              this option. The password can, still.

              When using Kerberos V5 with a Windows based  server  you  should
              include  the  Windows domain name in the user name, in order for
              the server to successfully obtain  a  Kerberos  Ticket.  If  you
              don't then the initial authentication handshake may fail.

              When  using  NTLM,  the user name can be specified simply as the
              user name, without the domain, if there is a single  domain  and
              forest in your setup for example.

              To  specify  the domain name use either Down-Level Logon Name or
              UPN (User Principal Name) formats. For example, EXAMPLE\user and
              user@example.com respectively.

              If  you  use a Windows SSPI-enabled curl binary and perform Ker-
              beros V5, Negotiate, NTLM or Digest authentication then you  can
              tell  curl  to select the user name and password from your envi-
              ronment by specifying a single colon with this option: "-u :".

              If this option is used several times, the last one will be used.

       -v, --verbose
              Makes  curl  verbose  during the operation. Useful for debugging
              and seeing what's going on "under the  hood".  A  line  starting
              with  '>'  means  "header  data" sent by curl, '<' means "header
              data" received by curl that is hidden in  normal  cases,  and  a
              line starting with '*' means additional info provided by curl.

              If you only want HTTP headers in the output, -i, --include might
              be the option you're looking for.

              If you think this option still doesn't give you enough  details,
              consider using --trace or --trace-ascii instead.

              Use -s, --silent to make curl really quiet.

              See  also  -i,  --include.  This  option  overrides  --trace and
              --trace-ascii.

       -V, --version
              Displays information about curl and the libcurl version it uses.

              The  first  line  includes the full version of curl, libcurl and
              other 3rd party libraries linked with the executable.

              The second line (starts with "Protocols:") shows  all  protocols
              that libcurl reports to support.

              The third line (starts with "Features:") shows specific features
              libcurl reports to offer. Available features include:

              IPv6   You can use IPv6 with this.

              krb4   Krb4 for FTP is supported.

              SSL    SSL versions of various protocols are supported, such  as
                     HTTPS, FTPS, POP3S and so on.

              libz   Automatic  decompression of compressed files over HTTP is
                     supported.

              NTLM   NTLM authentication is supported.

              Debug  This curl uses a libcurl built with Debug.  This  enables
                     more  error-tracking  and memory debugging etc. For curl-
                     developers only!

              AsynchDNS
                     This curl uses asynchronous name  resolves.  Asynchronous
                     name  resolves can be done using either the c-ares or the
                     threaded resolver backends.

              SPNEGO SPNEGO authentication is supported.

              Largefile
                     This curl supports transfers of large files, files larger
                     than 2GB.

              IDN    This curl supports IDN - international domain names.

              GSS-API
                     GSS-API is supported.

              SSPI   SSPI is supported.

              TLS-SRP
                     SRP  (Secure Remote Password) authentication is supported
                     for TLS.

              HTTP2  HTTP/2 support has been built-in.

              UnixSockets
                     Unix sockets support is provided.

              HTTPS-proxy
                     This curl is built to support HTTPS proxy.

              Metalink
                     This curl supports Metalink (both version 3  and  4  (RFC
                     5854)),  which  describes  mirrors and hashes.  curl will
                     use mirrors for failover if there are errors (such as the
                     file or server not being available).

              PSL    PSL  is  short for Public Suffix List and means that this
                     curl has been built with  knowledge  about  "public  suf-
                     fixes".

       -w, --write-out <format>
              Make curl display information on stdout after a completed trans-
              fer. The format is a string that may contain  plain  text  mixed
              with  any  number of variables. The format can be specified as a
              literal "string", or you can have curl read the  format  from  a
              file  with  "@filename" and to tell curl to read the format from
              stdin you write "@-".

              The variables present in the output format will  be  substituted
              by  the  value or text that curl thinks fit, as described below.
              All variables are specified as %{variable_name} and to output  a
              normal  % you just write them as %%. You can output a newline by
              using \n, a carriage return with \r and a tab space with \t.

              NOTE: The %-symbol is a special symbol in the win32-environment,
              where  all  occurrences  of  %  must  be doubled when using this
              option.

              The variables available are:

              content_type   The Content-Type of the  requested  document,  if
                             there was any.

              filename_effective
                             The  ultimate  filename  that curl writes out to.
                             This is only meaningful if curl is told to  write
                             to  a  file  with  the  -O,  --remote-name or -o,
                             --output option. It's most useful in  combination
                             with  the -J, --remote-header-name option. (Added
                             in 7.26.0)

              ftp_entry_path The initial path curl ended up in when logging on
                             to the remote FTP server. (Added in 7.15.4)

              http_code      The numerical response code that was found in the
                             last retrieved HTTP(S)  or  FTP(s)  transfer.  In
                             7.18.2  the alias response_code was added to show
                             the same info.

              http_connect   The numerical code that was  found  in  the  last
                             response   (from  a  proxy)  to  a  curl  CONNECT
                             request. (Added in 7.12.4)

              http_version   The  http  version  that  was  effectively  used.
                             (Added in 7.50.0)

              local_ip       The  IP  address  of  the  local  end of the most
                             recently done connection - can be either IPv4  or
                             IPv6 (Added in 7.29.0)

              local_port     The  local  port number of the most recently done
                             connection (Added in 7.29.0)

              num_connects   Number of new connects made in the recent  trans-
                             fer. (Added in 7.12.3)

              num_redirects  Number  of  redirects  that  were followed in the
                             request. (Added in 7.12.3)

              proxy_ssl_verify_result
                             The result of the HTTPS proxy's SSL peer certifi-
                             cate verification that was requested. 0 means the
                             verification was successful. (Added in 7.52.0)

              redirect_url   When an HTTP request was made without -L to  fol-
                             low redirects, this variable will show the actual
                             URL a redirect  would  take  you  to.  (Added  in
                             7.18.2)

              remote_ip      The  remote  IP address of the most recently done
                             connection - can be either IPv4 or IPv6 (Added in
                             7.29.0)

              remote_port    The  remote port number of the most recently done
                             connection (Added in 7.29.0)

              scheme         The URL scheme (sometimes called  protocol)  that
                             was effectively used (Added in 7.52.0)

              size_download  The total amount of bytes that were downloaded.

              size_header    The total amount of bytes of the downloaded head-
                             ers.

              size_request   The total amount of bytes that were sent  in  the
                             HTTP request.

              size_upload    The total amount of bytes that were uploaded.

              speed_download The average download speed that curl measured for
                             the complete download. Bytes per second.

              speed_upload   The average upload speed that curl  measured  for
                             the complete upload. Bytes per second.

              ssl_verify_result
                             The  result of the SSL peer certificate verifica-
                             tion that was requested. 0 means the verification
                             was successful. (Added in 7.19.0)

              time_appconnect
                             The  time,  in  seconds,  it  took from the start
                             until the SSL/SSH/etc  connect/handshake  to  the
                             remote host was completed. (Added in 7.19.0)

              time_connect   The  time,  in  seconds,  it  took from the start
                             until the TCP connect  to  the  remote  host  (or
                             proxy) was completed.

              time_namelookup
                             The  time,  in  seconds,  it  took from the start
                             until the name resolving was completed.

              time_pretransfer
                             The time, in seconds,  it  took  from  the  start
                             until  the file transfer was just about to begin.
                             This includes all pre-transfer commands and nego-
                             tiations that are specific to the particular pro-
                             tocol(s) involved.

              time_redirect  The time, in seconds, it took for all redirection
                             steps  include  name lookup, connect, pretransfer
                             and transfer before  the  final  transaction  was
                             started.  time_redirect shows the complete execu-
                             tion time for multiple  redirections.  (Added  in
                             7.12.3)

              time_starttransfer
                             The  time,  in  seconds,  it  took from the start
                             until the first byte was just about to be  trans-
                             ferred.  This  includes time_pretransfer and also
                             the time  the  server  needed  to  calculate  the
                             result.

              time_total     The  total time, in seconds, that the full opera-
                             tion lasted.

              url_effective  The URL that was fetched last. This is most mean-
                             ingful  if  you've  told curl to follow location:
                             headers.

              If this option is used several times, the last one will be used.

       --xattr
              When  saving  output  to a file, this option tells curl to store
              certain file metadata in extended  file  attributes.  Currently,
              the URL is stored in the xdg.origin.url attribute and, for HTTP,
              the content type is stored in the mime_type  attribute.  If  the
              file  system  does not support extended attributes, a warning is
              issued.


FILES

       ~/.curlrc
              Default config file, see -K, --config for details.


ENVIRONMENT

       The environment variables can be specified in lower case or upper case.
       The lower case version has precedence. http_proxy is an exception as it
       is only available in lower case.

       Using an environment variable to set the proxy has the same  effect  as
       using the -x, --proxy option.


       http_proxy [protocol://]<host>[:port]
              Sets the proxy server to use for HTTP.

       HTTPS_PROXY [protocol://]<host>[:port]
              Sets the proxy server to use for HTTPS.

       [url-protocol]_PROXY [protocol://]<host>[:port]
              Sets  the proxy server to use for [url-protocol], where the pro-
              tocol is a protocol that curl supports and  as  specified  in  a
              URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP etc.

       ALL_PROXY [protocol://]<host>[:port]
              Sets  the  proxy  server to use if no protocol-specific proxy is
              set.

       NO_PROXY <comma-separated list of hosts>
              list of host names that shouldn't go through any proxy.  If  set
              to a asterisk '*' only, it matches all hosts.

              Since  7.53.0,  this environment variable disable the proxy even
              if specify -x, --proxy  option.  That  is  NO_PROXY=direct.exam-
              ple.com  curl  -x  http://proxy.example.com  http://direct.exam-
              ple.com    accesses    the    target    URL    directly,     and
              NO_PROXY=direct.example.com   curl  -x  http://proxy.example.com
              http://somewhere.example.com accesses  the  target  URL  through
              proxy.



PROXY PROTOCOL PREFIXES

       Since  curl  version  7.21.7,  the proxy string may be specified with a
       protocol:// prefix to specify alternative proxy protocols.

       If no protocol is specified in  the  proxy  string  or  if  the  string
       doesn't  match  a  supported  one, the proxy will be treated as an HTTP
       proxy.

       The supported proxy protocol prefixes are as follows:

       socks4://
              Makes it the equivalent of --socks4

       socks4a://
              Makes it the equivalent of --socks4a

       socks5://
              Makes it the equivalent of --socks5

       socks5h://
              Makes it the equivalent of --socks5-hostname


EXIT CODES

       There are a bunch of different  error  codes  and  their  corresponding
       error  messages  that  may appear during bad conditions. At the time of
       this writing, the exit codes are:

       1      Unsupported protocol. This build of curl has no support for this
              protocol.

       2      Failed to initialize.

       3      URL malformed. The syntax was not correct.

       4      A  feature  or  option  that  was  needed to perform the desired
              request was not enabled or was  explicitly  disabled  at  build-
              time.  To  make  curl able to do this, you probably need another
              build of libcurl!

       5      Couldn't resolve proxy.  The  given  proxy  host  could  not  be
              resolved.

       6      Couldn't resolve host. The given remote host was not resolved.

       7      Failed to connect to host.

       8      Weird server reply. The server sent data curl couldn't parse.

       9      FTP  access  denied. The server denied login or denied access to
              the particular resource or directory you wanted to  reach.  Most
              often  you  tried to change to a directory that doesn't exist on
              the server.

       10     FTP accept failed. While waiting for the server to connect  back
              when  an active FTP session is used, an error code was sent over
              the control connection or similar.

       11     FTP weird PASS reply. Curl couldn't parse the reply sent to  the
              PASS request.

       12     During  an  active  FTP  session while waiting for the server to
              connect back to curl, the timeout expired.

       13     FTP weird PASV reply, Curl couldn't parse the reply sent to  the
              PASV request.

       14     FTP  weird  227  format.  Curl  couldn't  parse the 227-line the
              server sent.

       15     FTP can't get host. Couldn't resolve the host IP we got  in  the
              227-line.

       16     HTTP/2 error. A problem was detected in the HTTP2 framing layer.
              This is somewhat generic and can be one out of several problems,
              see the error message for details.

       17     FTP  couldn't  set  binary.  Couldn't  change transfer method to
              binary.

       18     Partial file. Only a part of the file was transferred.

       19     FTP couldn't download/access the given file, the RETR (or  simi-
              lar) command failed.

       21     FTP quote error. A quote command returned error from the server.

       22     HTTP page not retrieved. The requested  url  was  not  found  or
              returned  another  error  with  the HTTP error code being 400 or
              above. This return code only appears if -f, --fail is used.

       23     Write error. Curl couldn't write data to a local  filesystem  or
              similar.

       25     FTP  couldn't  STOR  file. The server denied the STOR operation,
              used for FTP uploading.

       26     Read error. Various reading problems.

       27     Out of memory. A memory allocation request failed.

       28     Operation timeout. The specified  time-out  period  was  reached
              according to the conditions.

       30     FTP  PORT  failed.  The PORT command failed. Not all FTP servers
              support the PORT  command,  try  doing  a  transfer  using  PASV
              instead!

       31     FTP  couldn't use REST. The REST command failed. This command is
              used for resumed FTP transfers.

       33     HTTP range error. The range "command" didn't work.

       34     HTTP post error. Internal post-request generation error.

       35     SSL connect error. The SSL handshaking failed.

       36     Bad download resume. Couldn't continue an earlier aborted  down-
              load.

       37     FILE couldn't read file. Failed to open the file. Permissions?

       38     LDAP cannot bind. LDAP bind operation failed.

       39     LDAP search failed.

       41     Function not found. A required LDAP function was not found.

       42     Aborted by callback. An application told curl to abort the oper-
              ation.

       43     Internal error. A function was called with a bad parameter.

       45     Interface error. A specified outgoing  interface  could  not  be
              used.

       47     Too many redirects. When following redirects, curl hit the maxi-
              mum amount.

       48     Unknown option specified to libcurl.  This  indicates  that  you
              passed  a weird option to curl that was passed on to libcurl and
              rejected. Read up in the manual!

       49     Malformed telnet option.

       51     The peer's SSL certificate or SSH MD5 fingerprint was not OK.

       52     The server didn't reply anything, which here  is  considered  an
              error.

       53     SSL crypto engine not found.

       54     Cannot set SSL crypto engine as default.

       55     Failed sending network data.

       56     Failure in receiving network data.

       58     Problem with the local certificate.

       59     Couldn't use specified SSL cipher.

       60     Peer  certificate cannot be authenticated with known CA certifi-
              cates.

       61     Unrecognized transfer encoding.

       62     Invalid LDAP URL.

       63     Maximum file size exceeded.

       64     Requested FTP SSL level failed.

       65     Sending the data requires a rewind that failed.

       66     Failed to initialise SSL Engine.

       67     The user name, password, or similar was not  accepted  and  curl
              failed to log in.

       68     File not found on TFTP server.

       69     Permission problem on TFTP server.

       70     Out of disk space on TFTP server.

       71     Illegal TFTP operation.

       72     Unknown TFTP transfer ID.

       73     File already exists (TFTP).

       74     No such user (TFTP).

       75     Character conversion failed.

       76     Character conversion functions required.

       77     Problem with reading the SSL CA cert (path? access rights?).

       78     The resource referenced in the URL does not exist.

       79     An unspecified error occurred during the SSH session.

       80     Failed to shut down the SSL connection.

       82     Could  not  load  CRL  file,  missing  or wrong format (added in
              7.19.0).

       83     Issuer check failed (added in 7.19.0).

       84     The FTP PRET command failed

       85     RTSP: mismatch of CSeq numbers

       86     RTSP: mismatch of Session Identifiers

       87     unable to parse FTP file list

       88     FTP chunk callback reported error

       89     No connection available, the session will be queued

       90     SSL public key does not matched pinned public key

       XX     More error codes will appear here in future releases. The exist-
              ing ones are meant to never change.


AUTHORS / CONTRIBUTORS

       Daniel  Stenberg is the main author, but the whole list of contributors
       is found in the separate THANKS file.


WWW

       https://curl.haxx.se


SEE ALSO

       ftp(1), wget(1)



Curl 7.52.0                       16 Dec 2016                          curl(1)

curl 7.53.0 - Generated Fri Feb 24 18:56:58 CST 2017
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Individual documents may contain additional copyright information.