2.5 Download Options

‘--bind-address=ADDRESS’

When making client TCP/IP connections, bind to ADDRESS on the local machine. ADDRESS may be specified as a hostname or IP address. This option can be useful if your machine is bound to multiple IPs.

‘-t number’

‘--tries=number’

Set number of tries to number. Specify 0 or ‘inf’ for infinite retrying. The default is to retry 20 times, with the exception of fatal errors like “connection refused” or “not found” (404), which are not retried.

‘-O file’

‘--output-document=file’

The documents will not be written to the appropriate files, but all will be concatenated together and written to file. If ‘-’ is used as file, documents will be printed to standard output, disabling link conversion. (Use ‘./-’ to print to a file literally named ‘-’.)

Use of ‘-O’ is not intended to mean simply “use the name file instead of the one in the URL;” rather, it is analogous to shell redirection: ‘wget -O file http://foo’ is intended to work like ‘wget -O - http://foo > file’; ‘file’ will be truncated immediately, and all downloaded content will be written there.

For this reason, ‘-N’ (for timestamp-checking) is not supported in combination with ‘-O’: since file is always newly created, it will always have a very new timestamp. A warning will be issued if this combination is used.

Similarly, using ‘-r’ or ‘-p’ with ‘-O’ may not work as you expect: Wget won’t just download the first file to file and then download the rest to their normal names: all downloaded content will be placed in file. This was disabled in version 1.11, but has been reinstated (with a warning) in 1.11.2, as there are some cases where this behavior can actually have some use.

Note that a combination with ‘-k’ is only permitted when downloading a single document, as in that case it will just convert all relative URIs to external ones; ‘-k’ makes no sense for multiple URIs when they’re all being downloaded to a single file; ‘-k’ can be used only when the output is a regular file.

‘-nc’

‘--no-clobber’

If a file is downloaded more than once in the same directory, Wget’s behavior depends on a few options, including ‘-nc’. In certain cases, the local file will be clobbered, or overwritten, upon repeated download. In other cases it will be preserved.

When running Wget without ‘-N’, ‘-nc’, ‘-r’, or ‘-p’, downloading the same file in the same directory will result in the original copy of file being preserved and the second copy being named ‘file.1’. If that file is downloaded yet again, the third copy will be named ‘file.2’, and so on. (This is also the behavior with ‘-nd’, even if ‘-r’ or ‘-p’ are in effect.) When ‘-nc’ is specified, this behavior is suppressed, and Wget will refuse to download newer copies of ‘file’. Therefore, “no-clobber” is actually a misnomer in this mode—it’s not clobbering that’s prevented (as the numeric suffixes were already preventing clobbering), but rather the multiple version saving that’s prevented.

When running Wget with ‘-r’ or ‘-p’, but without ‘-N’, ‘-nd’, or ‘-nc’, re-downloading a file will result in the new copy simply overwriting the old. Adding ‘-nc’ will prevent this behavior, instead causing the original version to be preserved and any newer copies on the server to be ignored.

When running Wget with ‘-N’, with or without ‘-r’ or ‘-p’, the decision as to whether or not to download a newer copy of a file depends on the local and remote timestamp and size of the file (see section Time-Stamping). ‘-nc’ may not be specified at the same time as ‘-N’.

Note that when ‘-nc’ is specified, files with the suffixes ‘.html’ or ‘.htm’ will be loaded from the local disk and parsed as if they had been retrieved from the Web.

‘--backups=backups’

Before (over)writing a file, back up an existing file by adding a ‘.1’ suffix (‘_1’ on VMS) to the file name. Such backup files are rotated to ‘.2’, ‘.3’, and so on, up to backups (and lost beyond that).

‘-c’

‘--continue’

Continue getting a partially-downloaded file. This is useful when you want to finish up a download started by a previous instance of Wget, or by another program. For instance:

wget -c ftp://sunsite.doc.ic.ac.uk/ls-lR.Z

If there is a file named ‘ls-lR.Z’ in the current directory, Wget will assume that it is the first portion of the remote file, and will ask the server to continue the retrieval from an offset equal to the length of the local file.

Note that you don’t need to specify this option if you just want the current invocation of Wget to retry downloading a file should the connection be lost midway through. This is the default behavior. ‘-c’ only affects resumption of downloads started prior to this invocation of Wget, and whose local files are still sitting around.

Without ‘-c’, the previous example would just download the remote file to ‘ls-lR.Z.1’, leaving the truncated ‘ls-lR.Z’ file alone.

Beginning with Wget 1.7, if you use ‘-c’ on a non-empty file, and it turns out that the server does not support continued downloading, Wget will refuse to start the download from scratch, which would effectively ruin existing contents. If you really want the download to start from scratch, remove the file.

Also beginning with Wget 1.7, if you use ‘-c’ on a file which is of equal size as the one on the server, Wget will refuse to download the file and print an explanatory message. The same happens when the file is smaller on the server than locally (presumably because it was changed on the server since your last download attempt)—because “continuing” is not meaningful, no download occurs.

On the other side of the coin, while using ‘-c’, any file that’s bigger on the server than locally will be considered an incomplete download and only (length(remote) - length(local)) bytes will be downloaded and tacked onto the end of the local file. This behavior can be desirable in certain cases—for instance, you can use ‘wget -c’ to download just the new portion that’s been appended to a data collection or log file.

However, if the file is bigger on the server because it’s been changed, as opposed to just appended to, you’ll end up with a garbled file. Wget has no way of verifying that the local file is really a valid prefix of the remote file. You need to be especially careful of this when using ‘-c’ in conjunction with ‘-r’, since every file will be considered as an "incomplete download" candidate.

Another instance where you’ll get a garbled file if you try to use ‘-c’ is if you have a lame HTTP proxy that inserts a “transfer interrupted” string into the local file. In the future a “rollback” option may be added to deal with this case.

Note that ‘-c’ only works with FTP servers and with HTTP servers that support the Range header.

‘--progress=type’

Select the type of the progress indicator you wish to use. Legal indicators are “dot” and “bar”.

The “bar” indicator is used by default. It draws an ASCII progress bar graphics (a.k.a “thermometer” display) indicating the status of retrieval. If the output is not a TTY, the “dot” bar will be used by default.

Use ‘--progress=dot’ to switch to the “dot” display. It traces the retrieval by printing dots on the screen, each dot representing a fixed amount of downloaded data.

When using the dotted retrieval, you may also set the style by specifying the type as ‘dot:style’. Different styles assign different meaning to one dot. With the default style each dot represents 1K, there are ten dots in a cluster and 50 dots in a line. The binary style has a more “computer”-like orientation—8K dots, 16-dots clusters and 48 dots per line (which makes for 384K lines). The mega style is suitable for downloading large files—each dot represents 64K retrieved, there are eight dots in a cluster, and 48 dots on each line (so each line contains 3M). If mega is not enough then you can use the giga style—each dot represents 1M retrieved, there are eight dots in a cluster, and 32 dots on each line (so each line contains 32M).

Note that you can set the default style using the progress command in ‘.wgetrc’. That setting may be overridden from the command line. The exception is that, when the output is not a TTY, the “dot” progress will be favored over “bar”. To force the bar output, use ‘--progress=bar:force’.

‘-N’

‘--timestamping’

Turn on time-stamping. See section Time-Stamping, for details.

‘--no-use-server-timestamps’

Don’t set the local file’s timestamp by the one on the server.

By default, when a file is downloaded, its timestamps are set to match those from the remote file. This allows the use of ‘--timestamping’ on subsequent invocations of wget. However, it is sometimes useful to base the local file’s timestamp on when it was actually downloaded; for that purpose, the ‘--no-use-server-timestamps’ option has been provided.

‘-S’

‘--server-response’

Print the headers sent by HTTP servers and responses sent by FTP servers.

‘--spider’

When invoked with this option, Wget will behave as a Web spider, which means that it will not download the pages, just check that they are there. For example, you can use Wget to check your bookmarks:

wget --spider --force-html -i bookmarks.html

This feature needs much more work for Wget to get close to the functionality of real web spiders.

‘-T seconds’

‘--timeout=seconds’

Set the network timeout to seconds seconds. This is equivalent to specifying ‘--dns-timeout’, ‘--connect-timeout’, and ‘--read-timeout’, all at the same time.

When interacting with the network, Wget can check for timeout and abort the operation if it takes too long. This prevents anomalies like hanging reads and infinite connects. The only timeout enabled by default is a 900-second read timeout. Setting a timeout to 0 disables it altogether. Unless you know what you are doing, it is best not to change the default timeout settings.

All timeout-related options accept decimal values, as well as subsecond values. For example, ‘0.1’ seconds is a legal (though unwise) choice of timeout. Subsecond timeouts are useful for checking server response times or for testing network latency.

‘--dns-timeout=seconds’

Set the DNS lookup timeout to seconds seconds. DNS lookups that don’t complete within the specified time will fail. By default, there is no timeout on DNS lookups, other than that implemented by system libraries.

‘--connect-timeout=seconds’

Set the connect timeout to seconds seconds. TCP connections that take longer to establish will be aborted. By default, there is no connect timeout, other than that implemented by system libraries.

‘--read-timeout=seconds’

Set the read (and write) timeout to seconds seconds. The “time” of this timeout refers to idle time: if, at any point in the download, no data is received for more than the specified number of seconds, reading fails and the download is restarted. This option does not directly affect the duration of the entire download.

Of course, the remote server may choose to terminate the connection sooner than this option requires. The default read timeout is 900 seconds.

‘--limit-rate=amount’

Limit the download speed to amount bytes per second. Amount may be expressed in bytes, kilobytes with the ‘k’ suffix, or megabytes with the ‘m’ suffix. For example, ‘--limit-rate=20k’ will limit the retrieval rate to 20KB/s. This is useful when, for whatever reason, you don’t want Wget to consume the entire available bandwidth.

This option allows the use of decimal numbers, usually in conjunction with power suffixes; for example, ‘--limit-rate=2.5k’ is a legal value.

Note that Wget implements the limiting by sleeping the appropriate amount of time after a network read that took less time than specified by the rate. Eventually this strategy causes the TCP transfer to slow down to approximately the specified rate. However, it may take some time for this balance to be achieved, so don’t be surprised if limiting the rate doesn’t work well with very small files.

‘-w seconds’

‘--wait=seconds’

Wait the specified number of seconds between the retrievals. Use of this option is recommended, as it lightens the server load by making the requests less frequent. Instead of in seconds, the time can be specified in minutes using the m suffix, in hours using h suffix, or in days using d suffix.

Specifying a large value for this option is useful if the network or the destination host is down, so that Wget can wait long enough to reasonably expect the network error to be fixed before the retry. The waiting interval specified by this function is influenced by --random-wait, which see.

‘--waitretry=seconds’

If you don’t want Wget to wait between every retrieval, but only between retries of failed downloads, you can use this option. Wget will use linear backoff, waiting 1 second after the first failure on a given file, then waiting 2 seconds after the second failure on that file, up to the maximum number of seconds you specify.

By default, Wget will assume a value of 10 seconds.

‘--random-wait’

Some web sites may perform log analysis to identify retrieval programs such as Wget by looking for statistically significant similarities in the time between requests. This option causes the time between requests to vary between 0.5 and 1.5 * wait seconds, where wait was specified using the ‘--wait’ option, in order to mask Wget’s presence from such analysis.

A 2001 article in a publication devoted to development on a popular consumer platform provided code to perform this analysis on the fly. Its author suggested blocking at the class C address level to ensure automated retrieval programs were blocked despite changing DHCP-supplied addresses.

The ‘--random-wait’ option was inspired by this ill-advised recommendation to block many unrelated users from a web site due to the actions of one.

‘--no-proxy’

Don’t use proxies, even if the appropriate *_proxy environment variable is defined.

For more information about the use of proxies with Wget, See section Proxies.

‘-Q quota’

‘--quota=quota’

Specify download quota for automatic retrievals. The value can be specified in bytes (default), kilobytes (with ‘k’ suffix), or megabytes (with ‘m’ suffix).

Note that quota will never affect downloading a single file. So if you specify ‘wget -Q10k ftp://wuarchive.wustl.edu/ls-lR.gz’, all of the ‘ls-lR.gz’ will be downloaded. The same goes even when several URLs are specified on the command-line. However, quota is respected when retrieving either recursively, or from an input file. Thus you may safely type ‘wget -Q2m -i sites’—download will be aborted when the quota is exceeded.

Setting quota to 0 or to ‘inf’ unlimits the download quota.

‘--no-dns-cache’

Turn off caching of DNS lookups. Normally, Wget remembers the IP addresses it looked up from DNS so it doesn’t have to repeatedly contact the DNS server for the same (typically small) set of hosts it retrieves from. This cache exists in memory only; a new Wget run will contact DNS again.

However, it has been reported that in some situations it is not desirable to cache host names, even for the duration of a short-running application like Wget. With this option Wget issues a new DNS lookup (more precisely, a new call to gethostbyname or getaddrinfo) each time it makes a new connection. Please note that this option will not affect caching that might be performed by the resolving library or by an external caching layer, such as NSCD.

If you don’t understand exactly what this option does, you probably won’t need it.

‘--restrict-file-names=modes’

Change which characters found in remote URLs must be escaped during generation of local filenames. Characters that are restricted by this option are escaped, i.e. replaced with ‘%HH’, where ‘HH’ is the hexadecimal number that corresponds to the restricted character. This option may also be used to force all alphabetical cases to be either lower- or uppercase.

By default, Wget escapes the characters that are not valid or safe as part of file names on your operating system, as well as control characters that are typically unprintable. This option is useful for changing these defaults, perhaps because you are downloading to a non-native partition, or because you want to disable escaping of the control characters, or you want to further restrict characters to only those in the ASCII range of values.

The modes are a comma-separated set of text values. The acceptable values are ‘unix’, ‘windows’, ‘nocontrol’, ‘ascii’, ‘lowercase’, and ‘uppercase’. The values ‘unix’ and ‘windows’ are mutually exclusive (one will override the other), as are ‘lowercase’ and ‘uppercase’. Those last are special cases, as they do not change the set of characters that would be escaped, but rather force local file paths to be converted either to lower- or uppercase.

When “unix” is specified, Wget escapes the character ‘/’ and the control characters in the ranges 0–31 and 128–159. This is the default on Unix-like operating systems.

When “windows” is given, Wget escapes the characters ‘\’, ‘|’, ‘/’, ‘:’, ‘?’, ‘"’, ‘*’, ‘<’, ‘>’, and the control characters in the ranges 0–31 and 128–159. In addition to this, Wget in Windows mode uses ‘+’ instead of ‘:’ to separate host and port in local file names, and uses ‘@’ instead of ‘?’ to separate the query portion of the file name from the rest. Therefore, a URL that would be saved as ‘www.xemacs.org:4300/search.pl?input=blah’ in Unix mode would be saved as ‘www.xemacs.org+4300/search.pl@input=blah’ in Windows mode. This mode is the default on Windows.

If you specify ‘nocontrol’, then the escaping of the control characters is also switched off. This option may make sense when you are downloading URLs whose names contain UTF-8 characters, on a system which can save and display filenames in UTF-8 (some possible byte values used in UTF-8 byte sequences fall in the range of values designated by Wget as “controls”).

The ‘ascii’ mode is used to specify that any bytes whose values are outside the range of ASCII characters (that is, greater than 127) shall be escaped. This can be useful when saving filenames whose encoding does not match the one used locally.

‘-4’

‘--inet4-only’

‘-6’

‘--inet6-only’

Force connecting to IPv4 or IPv6 addresses. With ‘--inet4-only’ or ‘-4’, Wget will only connect to IPv4 hosts, ignoring AAAA records in DNS, and refusing to connect to IPv6 addresses specified in URLs. Conversely, with ‘--inet6-only’ or ‘-6’, Wget will only connect to IPv6 hosts and ignore A records and IPv4 addresses.

Neither options should be needed normally. By default, an IPv6-aware Wget will use the address family specified by the host’s DNS record. If the DNS responds with both IPv4 and IPv6 addresses, Wget will try them in sequence until it finds one it can connect to. (Also see --prefer-family option described below.)

These options can be used to deliberately force the use of IPv4 or IPv6 address families on dual family systems, usually to aid debugging or to deal with broken network configuration. Only one of ‘--inet6-only’ and ‘--inet4-only’ may be specified at the same time. Neither option is available in Wget compiled without IPv6 support.

‘--prefer-family=none/IPv4/IPv6’

When given a choice of several addresses, connect to the addresses with specified address family first. The address order returned by DNS is used without change by default.

This avoids spurious errors and connect attempts when accessing hosts that resolve to both IPv6 and IPv4 addresses from IPv4 networks. For example, ‘www.kame.net’ resolves to ‘2001:200:0:8002:203:47ff:fea5:3085’ and to ‘203.178.141.194’. When the preferred family is IPv4, the IPv4 address is used first; when the preferred family is IPv6, the IPv6 address is used first; if the specified value is none, the address order returned by DNS is used without change.

Unlike ‘-4’ and ‘-6’, this option doesn’t inhibit access to any address family, it only changes the order in which the addresses are accessed. Also note that the reordering performed by this option is stable—it doesn’t affect order of addresses of the same family. That is, the relative order of all IPv4 addresses and of all IPv6 addresses remains intact in all cases.

‘--retry-connrefused’

Consider “connection refused” a transient error and try again. Normally Wget gives up on a URL when it is unable to connect to the site because failure to connect is taken as a sign that the server is not running at all and that retries would not help. This option is for mirroring unreliable sites whose servers tend to disappear for short periods of time.

‘--user=user’

‘--password=password’

Specify the username user and password password for both FTP and HTTP file retrieval. These parameters can be overridden using the ‘--ftp-user’ and ‘--ftp-password’ options for FTP connections and the ‘--http-user’ and ‘--http-password’ options for HTTP connections.

‘--ask-password’

Prompt for a password for each connection established. Cannot be specified when ‘--password’ is being used, because they are mutually exclusive.

‘--no-iri’

Turn off internationalized URI (IRI) support. Use ‘--iri’ to turn it on. IRI support is activated by default.

You can set the default state of IRI support using the iri command in ‘.wgetrc’. That setting may be overridden from the command line.

‘--local-encoding=encoding’

Force Wget to use encoding as the default system encoding. That affects how Wget converts URLs specified as arguments from locale to UTF-8 for IRI support.

Wget use the function nl_langinfo() and then the CHARSET environment variable to get the locale. If it fails, ASCII is used.

You can set the default local encoding using the local_encoding command in ‘.wgetrc’. That setting may be overridden from the command line.

‘--remote-encoding=encoding’

Force Wget to use encoding as the default remote server encoding. That affects how Wget converts URIs found in files from remote encoding to UTF-8 during a recursive fetch. This options is only useful for IRI support, for the interpretation of non-ASCII characters.

For HTTP, remote encoding can be found in HTTP Content-Type header and in HTML Content-Type http-equiv meta tag.

You can set the default encoding using the remoteencoding command in ‘.wgetrc’. That setting may be overridden from the command line.

‘--unlink’

Force Wget to unlink file instead of clobbering existing file. This option is useful for downloading to the directory with hardlinks.

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