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CPAN(3pm)              Perl Programmers Reference Guide              CPAN(3pm)


       CPAN - query, download and build perl modules from CPAN sites


       Interactive mode:

         perl -MCPAN -e shell



       Basic commands:

         # Modules:

         cpan> install Acme::Meta                       # in the shell

         CPAN::Shell->install("Acme::Meta");            # in perl

         # Distributions:

         cpan> install NWCLARK/Acme-Meta-0.02.tar.gz    # in the shell

           install("NWCLARK/Acme-Meta-0.02.tar.gz");    # in perl

         # module objects:

         $mo = CPAN::Shell->expandany($mod);
         $mo = CPAN::Shell->expand("Module",$mod);      # same thing

         # distribution objects:

         $do = CPAN::Shell->expand("Module",$mod)->distribution;
         $do = CPAN::Shell->expandany($distro);         # same thing
         $do = CPAN::Shell->expand("Distribution",
                                   $distro);            # same thing


       The CPAN module automates or at least simplifies the make and install
       of perl modules and extensions. It includes some primitive searching
       capabilities and knows how to use LWP, HTTP::Tiny, Net::FTP and certain
       external download clients to fetch distributions from the net.

       These are fetched from one or more mirrored CPAN (Comprehensive Perl
       Archive Network) sites and unpacked in a dedicated directory.

       The CPAN module also supports named and versioned bundles of modules.
       Bundles simplify handling of sets of related modules. See Bundles

       The package contains a session manager and a cache manager. The session
       manager keeps track of what has been fetched, built, and installed in
       the current session. The cache manager keeps track of the disk space
       occupied by the make processes and deletes excess space using a simple
       FIFO mechanism.

       All methods provided are accessible in a programmer style and in an
       interactive shell style.

   CPAN::shell([$prompt, $command]) Starting Interactive Mode
       Enter interactive mode by running

           perl -MCPAN -e shell



       which puts you into a readline interface. If "Term::ReadKey" and either
       of "Term::ReadLine::Perl" or "Term::ReadLine::Gnu" are installed,
       history and command completion are supported.

       Once at the command line, type "h" for one-page help screen; the rest
       should be self-explanatory.

       The function call "shell" takes two optional arguments: one the prompt,
       the second the default initial command line (the latter only works if a
       real ReadLine interface module is installed).

       The most common uses of the interactive modes are

       Searching for authors, bundles, distribution files and modules
         There are corresponding one-letter commands "a", "b", "d", and "m"
         for each of the four categories and another, "i" for any of the
         mentioned four. Each of the four entities is implemented as a class
         with slightly differing methods for displaying an object.

         Arguments to these commands are either strings exactly matching the
         identification string of an object, or regular expressions matched
         case-insensitively against various attributes of the objects. The
         parser only recognizes a regular expression when you enclose it with

         The principle is that the number of objects found influences how an
         item is displayed. If the search finds one item, the result is
         displayed with the rather verbose method "as_string", but if more
         than one is found, each object is displayed with the terse method


           cpan> m Acme::MetaSyntactic
           Module id = Acme::MetaSyntactic
               CPAN_USERID  BOOK (Philippe Bruhat (BooK) <[...]>)
               CPAN_VERSION 0.99
               CPAN_FILE    B/BO/BOOK/Acme-MetaSyntactic-0.99.tar.gz
               UPLOAD_DATE  2006-11-06
               MANPAGE      Acme::MetaSyntactic - Themed metasyntactic variables names
               INST_FILE    /usr/local/lib/perl/5.10.0/Acme/
               INST_VERSION 0.99
           cpan> a BOOK
           Author id = BOOK
               EMAIL        [...]
               FULLNAME     Philippe Bruhat (BooK)
           cpan> d BOOK/Acme-MetaSyntactic-0.99.tar.gz
           Distribution id = B/BO/BOOK/Acme-MetaSyntactic-0.99.tar.gz
               CPAN_USERID  BOOK (Philippe Bruhat (BooK) <[...]>)
               CONTAINSMODS Acme::MetaSyntactic Acme::MetaSyntactic::Alias [...]
               UPLOAD_DATE  2006-11-06
           cpan> m /lorem/
           Module  = Acme::MetaSyntactic::loremipsum (BOOK/Acme-MetaSyntactic-0.99.tar.gz)
           Module    Text::Lorem            (ADEOLA/Text-Lorem-0.3.tar.gz)
           Module    Text::Lorem::More      (RKRIMEN/Text-Lorem-More-0.12.tar.gz)
           Module    Text::Lorem::More::Source (RKRIMEN/Text-Lorem-More-0.12.tar.gz)
           cpan> i /berlin/
           Distribution    BEATNIK/Filter-NumberLines-0.02.tar.gz
           Module  = DateTime::TimeZone::Europe::Berlin (DROLSKY/DateTime-TimeZone-0.7904.tar.gz)
           Module    Filter::NumberLines    (BEATNIK/Filter-NumberLines-0.02.tar.gz)
           Author          [...]

         The examples illustrate several aspects: the first three queries
         target modules, authors, or distros directly and yield exactly one
         result. The last two use regular expressions and yield several
         results. The last one targets all of bundles, modules, authors, and
         distros simultaneously. When more than one result is available, they
         are printed in one-line format.

       "get", "make", "test", "install", "clean" modules or distributions
         These commands take any number of arguments and investigate what is
         necessary to perform the action. Argument processing is as follows:

           known module name in format Foo/   module
           other embedded slash                     distribution
             - with trailing slash dot              directory
           enclosing slashes                        regexp
           known module name in format Foo::Bar     module

         If the argument is a distribution file name (recognized by embedded
         slashes), it is processed. If it is a module, CPAN determines the
         distribution file in which this module is included and processes
         that, following any dependencies named in the module's META.yml or
         Makefile.PL (this behavior is controlled by the configuration
         parameter "prerequisites_policy"). If an argument is enclosed in
         slashes it is treated as a regular expression: it is expanded and if
         the result is a single object (distribution, bundle or module), this
         object is processed.


             install Dummy::Perl                   # installs the module
             install AUXXX/Dummy-Perl-3.14.tar.gz  # installs that distribution
             install /Dummy-Perl-3.14/             # same if the regexp is unambiguous

         "get" downloads a distribution file and untars or unzips it, "make"
         builds it, "test" runs the test suite, and "install" installs it.

         Any "make" or "test" is run unconditionally. An

           install <distribution_file>

         is also run unconditionally. But for

           install <module>

         CPAN checks whether an install is needed and prints module up to date
         if the distribution file containing the module doesn't need updating.

         CPAN also keeps track of what it has done within the current session
         and doesn't try to build a package a second time regardless of
         whether it succeeded or not. It does not repeat a test run if the
         test has been run successfully before. Same for install runs.

         The "force" pragma may precede another command (currently: "get",
         "make", "test", or "install") to execute the command from scratch and
         attempt to continue past certain errors. See the section below on the
         "force" and the "fforce" pragma.

         The "notest" pragma skips the test part in the build process.


             cpan> notest install Tk

         A "clean" command results in a

           make clean

         being executed within the distribution file's working directory.

       "readme", "perldoc", "look" module or distribution
         "readme" displays the README file of the associated distribution.
         "Look" gets and untars (if not yet done) the distribution file,
         changes to the appropriate directory and opens a subshell process in
         that directory. "perldoc" displays the module's pod documentation in
         html or plain text format.

       "ls" author
       "ls" globbing_expression
         The first form lists all distribution files in and below an author's
         CPAN directory as stored in the CHECKSUMS files distributed on CPAN.
         The listing recurses into subdirectories.

         The second form limits or expands the output with shell globbing as
         in the following examples:

               ls JV/make*
               ls GSAR/*make*
               ls */*make*

         The last example is very slow and outputs extra progress indicators
         that break the alignment of the result.

         Note that globbing only lists directories explicitly asked for, for
         example FOO/* will not list FOO/bar/Acme-Sthg-n.nn.tar.gz. This may
         be regarded as a bug that may be changed in some future version.

         The "failed" command reports all distributions that failed on one of
         "make", "test" or "install" for some reason in the currently running
         shell session.

       Persistence between sessions
         If the "YAML" or the "YAML::Syck" module is installed a record of the
         internal state of all modules is written to disk after each step.
         The files contain a signature of the currently running perl version
         for later perusal.

         If the configurations variable "build_dir_reuse" is set to a true
         value, then reads the collected YAML files. If the stored
         signature matches the currently running perl, the stored state is
         loaded into memory such that persistence between sessions is
         effectively established.

       The "force" and the "fforce" pragma
         To speed things up in complex installation scenarios, keeps
         track of what it has already done and refuses to do some things a
         second time. A "get", a "make", and an "install" are not repeated.  A
         "test" is repeated only if the previous test was unsuccessful. The
         diagnostic message when refuses to do something a second time
         is one of Has already been "unwrapped|made|tested successfully" or
         something similar. Another situation where CPAN refuses to act is an
         "install" if the corresponding "test" was not successful.

         In all these cases, the user can override this stubborn behaviour by
         prepending the command with the word force, for example:

           cpan> force get Foo
           cpan> force make AUTHOR/Bar-3.14.tar.gz
           cpan> force test Baz
           cpan> force install Acme::Meta

         Each forced command is executed with the corresponding part of its
         memory erased.

         The "fforce" pragma is a variant that emulates a "force get" which
         erases the entire memory followed by the action specified,
         effectively restarting the whole get/make/test/install procedure from

         Interactive sessions maintain a lockfile, by default "~/.cpan/.lock".
         Batch jobs can run without a lockfile and not disturb each other.

         The shell offers to run in downgraded mode when another process is
         holding the lockfile. This is an experimental feature that is not yet
         tested very well. This second shell then does not write the history
         file, does not use the metadata file, and has a different prompt.

       Signals installs signal handlers for SIGINT and SIGTERM. While you
         are in the cpan-shell, it is intended that you can press "^C" anytime
         and return to the cpan-shell prompt. A SIGTERM will cause the cpan-
         shell to clean up and leave the shell loop. You can emulate the
         effect of a SIGTERM by sending two consecutive SIGINTs, which usually
         means by pressing "^C" twice.
 ignores SIGPIPE. If the user sets "inactivity_timeout", a
         SIGALRM is used during the run of the "perl Makefile.PL" or "perl
         Build.PL" subprocess. A SIGALRM is also used during module version
         parsing, and is controlled by "version_timeout".

       The commands available in the shell interface are methods in the
       package CPAN::Shell. If you enter the shell command, your input is
       split by the Text::ParseWords::shellwords() routine, which acts like
       most shells do. The first word is interpreted as the method to be
       invoked, and the rest of the words are treated as the method's
       arguments.  Continuation lines are supported by ending a line with a
       literal backslash.

       "autobundle" writes a bundle file into the
       "$CPAN::Config->{cpan_home}/Bundle" directory. The file contains a list
       of all modules that are both available from CPAN and currently
       installed within @INC. Duplicates of each distribution are suppressed.
       The name of the bundle file is based on the current date and a counter,
       e.g. Bundle/ This is installed again by
       running "cpan Bundle::Snapshot_2012_05_21_00", or installing
       "Bundle::Snapshot_2012_05_21_00" from the CPAN shell.

       Return value: path to the written file.

       Note: this feature is still in alpha state and may change in future
       versions of

       This commands provides a statistical overview over recent download
       activities. The data for this is collected in the YAML file
       "FTPstats.yml" in your "cpan_home" directory. If no YAML module is
       configured or YAML not installed, no stats are provided.

           Install all distributions that have been tested successfully but
           have not yet been installed. See also "is_tested".

           List all build directories of distributions that have been tested
           successfully but have not yet been installed. See also

       mkmyconfig() writes your own CPAN::MyConfig file into your "~/.cpan/"
       directory so that you can save your own preferences instead of the
       system-wide ones.

   r [Module|/Regexp/]...
       scans current perl installation for modules that have a newer version
       available on CPAN and provides a list of them. If called without
       argument, all potential upgrades are listed; if called with arguments
       the list is filtered to the modules and regexps given as arguments.

       The listing looks something like this:

         Package namespace         installed    latest  in CPAN file
         CPAN                        1.94_64    1.9600  ANDK/CPAN-1.9600.tar.gz
         CPAN::Reporter               1.1801    1.1902  DAGOLDEN/CPAN-Reporter-1.1902.tar.gz
         YAML                           0.70      0.73  INGY/YAML-0.73.tar.gz
         YAML::Syck                     1.14      1.17  AVAR/YAML-Syck-1.17.tar.gz
         YAML::Tiny                     1.44      1.50  ADAMK/YAML-Tiny-1.50.tar.gz
         CGI                            3.43      3.55  MARKSTOS/
         Module::Build::YAML            1.40      1.41  DAGOLDEN/Module-Build-0.3800.tar.gz
         TAP::Parser::Result::YAML      3.22      3.23  ANDYA/Test-Harness-3.23.tar.gz
         YAML::XS                       0.34      0.35  INGY/YAML-LibYAML-0.35.tar.gz

       It suppresses duplicates in the column "in CPAN file" such that
       distributions with many upgradeable modules are listed only once.

       Note that the list is not sorted.

       The "recent" command downloads a list of recent uploads to CPAN and
       displays them slowly. While the command is running, a $SIG{INT} exits
       the loop after displaying the current item.

       Note: This command requires XML::LibXML installed.

       Note: This whole command currently is just a hack and will probably
       change in future versions of, but the general approach will
       likely remain.

       Note: See also smoke

       recompile() is a special command that takes no argument and runs the
       make/test/install cycle with brute force over all installed dynamically
       loadable extensions (a.k.a. XS modules) with 'force' in effect. The
       primary purpose of this command is to finish a network installation.
       Imagine you have a common source tree for two different architectures.
       You decide to do a completely independent fresh installation. You start
       on one architecture with the help of a Bundle file produced earlier.
       CPAN installs the whole Bundle for you, but when you try to repeat the
       job on the second architecture, CPAN responds with a "Foo up to date"
       message for all modules. So you invoke CPAN's recompile on the second
       architecture and you're done.

       Another popular use for "recompile" is to act as a rescue in case your
       perl breaks binary compatibility. If one of the modules that CPAN uses
       is in turn depending on binary compatibility (so you cannot run CPAN
       commands), then you should try the CPAN::Nox module for recovery.

   report Bundle|Distribution|Module
       The "report" command temporarily turns on the "test_report" config
       variable, then runs the "force test" command with the given arguments.
       The "force" pragma reruns the tests and repeats every step that might
       have failed before.

       *** WARNING: this command downloads and executes software from CPAN to
       your computer of completely unknown status. You should never do this
       with your normal account and better have a dedicated well separated and
       secured machine to do this. ***

       The "smoke" command takes the list of recent uploads to CPAN as
       provided by the "recent" command and tests them all. While the command
       is running $SIG{INT} is defined to mean that the current item shall be

       Note: This whole command currently is just a hack and will probably
       change in future versions of, but the general approach will
       likely remain.

       Note: See also recent

   upgrade [Module|/Regexp/]...
       The "upgrade" command first runs an "r" command with the given
       arguments and then installs the newest versions of all modules that
       were listed by that.

   The four "CPAN::*" Classes: Author, Bundle, Module, Distribution
       Although it may be considered internal, the class hierarchy does matter
       for both users and programmer. deals with the four classes
       mentioned above, and those classes all share a set of methods.
       Classical single polymorphism is in effect. A metaclass object
       registers all objects of all kinds and indexes them with a string. The
       strings referencing objects have a separated namespace (well, not
       completely separated):

                Namespace                         Class

          words containing a "/" (slash)      Distribution
           words starting with Bundle::          Bundle
                 everything else            Module or Author

       Modules know their associated Distribution objects. They always refer
       to the most recent official release. Developers may mark their releases
       as unstable development versions (by inserting an underscore into the
       module version number which will also be reflected in the distribution
       name when you run 'make dist'), so the really hottest and newest
       distribution is not always the default.  If a module Foo circulates on
       CPAN in both version 1.23 and 1.23_90, offers a convenient way
       to install version 1.23 by saying

           install Foo

       This would install the complete distribution file (say
       BAR/Foo-1.23.tar.gz) with all accompanying material. But if you would
       like to install version 1.23_90, you need to know where the
       distribution file resides on CPAN relative to the authors/id/
       directory. If the author is BAR, this might be BAR/Foo-1.23_90.tar.gz;
       so you would have to say

           install BAR/Foo-1.23_90.tar.gz

       The first example will be driven by an object of the class
       CPAN::Module, the second by an object of class CPAN::Distribution.

   Integrating local directories
       Note: this feature is still in alpha state and may change in future
       versions of

       Distribution objects are normally distributions from the CPAN, but
       there is a slightly degenerate case for Distribution objects, too, of
       projects held on the local disk. These distribution objects have the
       same name as the local directory and end with a dot. A dot by itself is
       also allowed for the current directory at the time was used.
       All actions such as "make", "test", and "install" are applied directly
       to that directory. This gives the command "cpan ." an interesting
       touch: while the normal mantra of installing a CPAN module without is one of

           perl Makefile.PL                 perl Build.PL
                  ( go and get prerequisites )
           make                             ./Build
           make test                        ./Build test
           make install                     ./Build install

       the command "cpan ." does all of this at once. It figures out which of
       the two mantras is appropriate, fetches and installs all prerequisites,
       takes care of them recursively, and finally finishes the installation
       of the module in the current directory, be it a CPAN module or not.

       The typical usage case is for private modules or working copies of
       projects from remote repositories on the local disk.

       The usual shell redirection symbols " | " and ">" are recognized by the
       cpan shell only when surrounded by whitespace. So piping to pager or
       redirecting output into a file works somewhat as in a normal shell,
       with the stipulation that you must type extra spaces.

   Plugin support ***EXPERIMENTAL***
       Plugins are objects that implement any of currently eight methods:


       The "plugin_list" configuration parameter holds a list of strings of
       the form




       At run time, each listed plugin is instantiated as a singleton object
       by running the equivalent of this pseudo code:

         my $plugin = <string representation from config>;
         <generate Modulename and arguments from $plugin>;
         my $p = $instance{$plugin} ||= Modulename->new($arg0,$arg1,...);

       The generated singletons are kept around from instantiation until the
       end of the shell session. <plugin_list> can be reconfigured at any time
       at run time. While the cpan shell is running, it checks all activated
       plugins at each of the 8 reference points listed above and runs the
       respective method if it is implemented for that object. The method is
       called with the active CPAN::Distribution object passed in as an


       When the CPAN module is used for the first time, a configuration
       dialogue tries to determine a couple of site specific options. The
       result of the dialog is stored in a hash reference  $CPAN::Config in a
       file CPAN/

       Default values defined in the CPAN/ file can be overridden in
       a user specific file: CPAN/ Such a file is best placed in
       "$HOME/.cpan/CPAN/", because "$HOME/.cpan" is added to the
       search path of the CPAN module before the use() or require()
       statements. The mkmyconfig command writes this file for you.

       The "o conf" command has various bells and whistles:

       completion support
           If you have a ReadLine module installed, you can hit TAB at any
           point of the commandline and "o conf" will offer you completion for
           the built-in subcommands and/or config variable names.

       displaying some help: o conf help
           Displays a short help

       displaying current values: o conf [KEY]
           Displays the current value(s) for this config variable. Without
           KEY, displays all subcommands and config variables.


             o conf shell

           If KEY starts and ends with a slash, the string in between is
           treated as a regular expression and only keys matching this regexp
           are displayed


             o conf /color/

       changing of scalar values: o conf KEY VALUE
           Sets the config variable KEY to VALUE. The empty string can be
           specified as usual in shells, with '' or ""


             o conf wget /usr/bin/wget

       changing of list values: o conf KEY SHIFT|UNSHIFT|PUSH|POP|SPLICE|LIST
           If a config variable name ends with "list", it is a list. "o conf
           KEY shift" removes the first element of the list, "o conf KEY pop"
           removes the last element of the list. "o conf KEYS unshift LIST"
           prepends a list of values to the list, "o conf KEYS push LIST"
           appends a list of valued to the list.

           Likewise, "o conf KEY splice LIST" passes the LIST to the
           corresponding splice command.

           Finally, any other list of arguments is taken as a new list value
           for the KEY variable discarding the previous value.


             o conf urllist unshift
             o conf urllist splice 3 1
             o conf urllist http://cpan1.local http://cpan2.local

       reverting to saved: o conf defaults
           Reverts all config variables to the state in the saved config file.

       saving the config: o conf commit
           Saves all config variables to the current config file
           (CPAN/ or CPAN/ that was loaded at start).

       The configuration dialog can be started any time later again by issuing
       the command " o conf init " in the CPAN shell. A subset of the
       configuration dialog can be run by issuing "o conf init WORD" where
       WORD is any valid config variable or a regular expression.

   Config Variables
       The following keys in the hash reference $CPAN::Config are currently

                            allow or disallow installing module downgrades
                            allow or disallow installing modules that are
                            indexed in the cpan index pointing to a distro
                            with a higher distro-version number
         applypatch         path to external prg
         auto_commit        commit all changes to config variables to disk
         build_cache        size of cache for directories to build modules
         build_dir          locally accessible directory to build modules
         build_dir_reuse    boolean if distros in build_dir are persistent
                            to install or not to install when a module is
                            only needed for building. yes|no|ask/yes|ask/no
         bzip2              path to external prg
         cache_metadata     use serializer to cache metadata
         check_sigs         if signatures should be verified
                            remove build directory immediately after a
                            successful install and remember that for the
                            duration of the session
         colorize_debug     Term::ANSIColor attributes for debugging output
         colorize_output    boolean if Term::ANSIColor should colorize output
         colorize_print     Term::ANSIColor attributes for normal output
         colorize_warn      Term::ANSIColor attributes for warnings
                            boolean if you want to see current command number
         commands_quote     preferred character to use for quoting external
                            commands when running them. Defaults to double
                            quote on Windows, single tick everywhere else;
                            can be set to space to disable quoting
                            whether to ask if opening a connection is ok before
                            urllist is specified
         cpan_home          local directory reserved for this package
         curl               path to external prg
         dontload_hash      DEPRECATED
         dontload_list      arrayref: modules in the list will not be
                            loaded by the CPAN::has_inst() routine
         ftp                path to external prg
         ftp_passive        if set, the environment variable FTP_PASSIVE is set
                            for downloads
         ftp_proxy          proxy host for ftp requests
         ftpstats_period    max number of days to keep download statistics
         ftpstats_size      max number of items to keep in the download statistics
         getcwd             see below
         gpg                path to external prg
         gzip               location of external program gzip
         halt_on_failure    stop processing after the first failure of queued
                            items or dependencies
         histfile           file to maintain history between sessions
         histsize           maximum number of lines to keep in histfile
         http_proxy         proxy host for http requests
         inactivity_timeout breaks interactive Makefile.PLs or Build.PLs
                            after this many seconds inactivity. Set to 0 to
                            disable timeouts.
         index_expire       refetch index files after this many days
                            if true, suppress the startup message
         keep_source_where  directory in which to keep the source (if we do)
                            report loading of optional modules used by
         lynx               path to external prg
         make               location of external make program
         make_arg           arguments that should always be passed to 'make'
                            the make command for running 'make install', for
                            example 'sudo make'
         make_install_arg   same as make_arg for 'make install'
         makepl_arg         arguments passed to 'perl Makefile.PL'
         mbuild_arg         arguments passed to './Build'
         mbuild_install_arg arguments passed to './Build install'
                            command to use instead of './Build' when we are
                            in the install stage, for example 'sudo ./Build'
         mbuildpl_arg       arguments passed to 'perl Build.PL'
         ncftp              path to external prg
         ncftpget           path to external prg
         no_proxy           don't proxy to these hosts/domains (comma separated list)
         pager              location of external program more (or any pager)
         password           your password if you CPAN server wants one
         patch              path to external prg
         patches_dir        local directory containing patch files
         perl5lib_verbosity verbosity level for PERL5LIB additions
         plugin_list        list of active hooks (see Plugin support above
                            and the CPAN::Plugin module)
                            per default all untar operations are done with
                            Archive::Tar; by setting this variable to true
                            the external tar command is used if available
         prefer_installer   legal values are MB and EUMM: if a module comes
                            with both a Makefile.PL and a Build.PL, use the
                            former (EUMM) or the latter (MB); if the module
                            comes with only one of the two, that one will be
                            used no matter the setting
                            what to do if you are missing module prerequisites
                            ('follow' automatically, 'ask' me, or 'ignore')
                            For 'follow', also sets PERL_AUTOINSTALL and
                            PERL_EXTUTILS_AUTOINSTALL for "--defaultdeps" if
                            not already set
         prefs_dir          local directory to store per-distro build options
         proxy_user         username for accessing an authenticating proxy
         proxy_pass         password for accessing an authenticating proxy
         randomize_urllist  add some randomness to the sequence of the urllist
         recommends_policy  whether recommended prerequisites should be included
         scan_cache         controls scanning of cache ('atstart', 'atexit' or 'never')
         shell              your favorite shell
                            boolean if r command tells which modules are versionless
         show_upload_date   boolean if commands should try to determine upload date
         show_zero_versions boolean if r command tells for which modules $version==0
         suggests_policy    whether suggested prerequisites should be included
         tar                location of external program tar
         tar_verbosity      verbosity level for the tar command
         term_is_latin      deprecated: if true Unicode is translated to ISO-8859-1
                            (and nonsense for characters outside latin range)
         term_ornaments     boolean to turn ReadLine ornamenting on/off
         test_report        email test reports (if CPAN::Reporter is installed)
                            skip testing when previously tested ok (according to
                            CPAN::Reporter history)
         unzip              location of external program unzip
         urllist            arrayref to nearby CPAN sites (or equivalent locations)
                            use external ping command when autoselecting mirrors
                            increase verbosity when autoselecting mirrors
         use_prompt_default set PERL_MM_USE_DEFAULT for configure/make/test/install
         use_sqlite         use CPAN::SQLite for metadata storage (fast and lean)
         username           your username if you CPAN server wants one
         version_timeout    stops version parsing after this many seconds.
                            Default is 15 secs. Set to 0 to disable.
         wait_list          arrayref to a wait server to try (See CPAN::WAIT)
         wget               path to external prg
         yaml_load_code     enable YAML code deserialisation via CPAN::DeferredCode
         yaml_module        which module to use to read/write YAML files

       You can set and query each of these options interactively in the cpan
       shell with the "o conf" or the "o conf init" command as specified

       "o conf <scalar option>"
         prints the current value of the scalar option

       "o conf <scalar option> <value>"
         Sets the value of the scalar option to value

       "o conf <list option>"
         prints the current value of the list option in MakeMaker's neatvalue

       "o conf <list option> [shift|pop]"
         shifts or pops the array in the list option variable

       "o conf <list option> [unshift|push|splice] <list>"
         works like the corresponding perl commands.

       interactive editing: o conf init [MATCH|LIST]
         Runs an interactive configuration dialog for matching variables.
         Without argument runs the dialog over all supported config variables.
         To specify a MATCH the argument must be enclosed by slashes.


           o conf init ftp_passive ftp_proxy
           o conf init /color/

         Note: this method of setting config variables often provides more
         explanation about the functioning of a variable than the manpage.

   CPAN::anycwd($path): Note on config variable getcwd changes the current working directory often and needs to
       determine its own current working directory. By default it uses
       Cwd::cwd, but if for some reason this doesn't work on your system,
       configure alternatives according to the following table:

       cwd Calls Cwd::cwd

           Calls Cwd::getcwd

           Calls Cwd::fastcwd

           Calls Cwd::getdcwd

           Calls the external command cwd.

   Note on the format of the urllist parameter
       urllist parameters are URLs according to RFC 1738. We do a little
       guessing if your URL is not compliant, but if you have problems with
       "file" URLs, please try the correct format. Either:




   The urllist parameter has CD-ROM support
       The "urllist" parameter of the configuration table contains a list of
       URLs used for downloading. If the list contains any "file" URLs, CPAN
       always tries there first. This feature is disabled for index files. So
       the recommendation for the owner of a CD-ROM with CPAN contents is:
       include your local, possibly outdated CD-ROM as a "file" URL at the end
       of urllist, e.g.

         o conf urllist push file://localhost/CDROM/CPAN will then fetch the index files from one of the CPAN sites that
       come at the beginning of urllist. It will later check for each module
       to see whether there is a local copy of the most recent version.

       Another peculiarity of urllist is that the site that we could
       successfully fetch the last file from automatically gets a preference
       token and is tried as the first site for the next request. So if you
       add a new site at runtime it may happen that the previously preferred
       site will be tried another time. This means that if you want to
       disallow a site for the next transfer, it must be explicitly removed
       from urllist.

   Maintaining the urllist parameter
       If you have (or some other YAML module configured in
       "yaml_module") installed, collects a few statistical data about
       recent downloads. You can view the statistics with the "hosts" command
       or inspect them directly by looking into the "FTPstats.yml" file in
       your "cpan_home" directory.

       To get some interesting statistics, it is recommended that
       "randomize_urllist" be set; this introduces some amount of randomness
       into the URL selection.

   The "requires" and "build_requires" dependency declarations
       Since version 1.88_51 modules declared as "build_requires" by a
       distribution are treated differently depending on the config variable
       "build_requires_install_policy". By setting
       "build_requires_install_policy" to "no", such a module is not
       installed. It is only built and tested, and then kept in the list of
       tested but uninstalled modules. As such, it is available during the
       build of the dependent module by integrating the path to the
       "blib/arch" and "blib/lib" directories in the environment variable
       PERL5LIB. If "build_requires_install_policy" is set to "yes", then both
       modules declared as "requires" and those declared as "build_requires"
       are treated alike. By setting to "ask/yes" or "ask/no", asks
       the user and sets the default accordingly.

   Configuration of the allow_installing_* parameters
       The "allow_installing_*" parameters are evaluated during the "make"
       phase. If set to "yes", they allow the testing and the installation of
       the current distro and otherwise have no effect. If set to "no", they
       may abort the build (preventing testing and installing), depending on
       the contents of the "blib/" directory. The "blib/" directory is the
       directory that holds all the files that would usually be installed in
       the "install" phase.

       "allow_installing_outdated_dists" compares the "blib/" directory with
       the CPAN index.  If it finds something there that belongs, according to
       the index, to a different dist, it aborts the current build.

       "allow_installing_module_downgrades" compares the "blib/" directory
       with already installed modules, actually their version numbers, as
       determined by ExtUtils::MakeMaker or equivalent. If a to-be-installed
       module would downgrade an already installed module, the current build
       is aborted.

       An interesting twist occurs when a distroprefs document demands the
       installation of an outdated dist via goto while
       "allow_installing_outdated_dists" forbids it. Without additional
       provisions, this would let the "allow_installing_outdated_dists" win
       and the distroprefs lose. So the proper arrangement in such a case is
       to write a second distroprefs document for the distro that "goto"
       points to and overrule the "cpanconfig" there. E.g.:

           distribution: "^MAUKE/Keyword-Simple-0.04.tar.gz"
         goto: "MAUKE/Keyword-Simple-0.03.tar.gz"
           distribution: "^MAUKE/Keyword-Simple-0.03.tar.gz"
           allow_installing_outdated_dists: yes

   Configuration for individual distributions (Distroprefs)
       (Note: This feature has been introduced in 1.8854)

       Distributions on CPAN usually behave according to what we call the CPAN
       mantra. Or since the advent of Module::Build we should talk about two

           perl Makefile.PL     perl Build.PL
           make                 ./Build
           make test            ./Build test
           make install         ./Build install

       But some modules cannot be built with this mantra. They try to get some
       extra data from the user via the environment, extra arguments, or
       interactively--thus disturbing the installation of large bundles like
       Phalanx100 or modules with many dependencies like Plagger.

       The distroprefs system of "" addresses this problem by allowing
       the user to specify extra informations and recipes in YAML files to

       o   pass additional arguments to one of the four commands,

       o   set environment variables

       o   instantiate an Expect object that reads from the console, waits for
           some regular expressions and enters some answers

       o   temporarily override assorted "" configuration variables

       o   specify dependencies the original maintainer forgot

       o   disable the installation of an object altogether

       See the YAML and Data::Dumper files that come with the ""
       distribution in the "distroprefs/" directory for examples.

       The YAML files themselves must have the ".yml" extension; all other
       files are ignored (for two exceptions see Fallback Data::Dumper and
       Storable below). The containing directory can be specified in ""
       in the "prefs_dir" config variable. Try "o conf init prefs_dir" in the
       CPAN shell to set and activate the distroprefs system.

       Every YAML file may contain arbitrary documents according to the YAML
       specification, and every document is treated as an entity that can
       specify the treatment of a single distribution.

       Filenames can be picked arbitrarily; "" always reads all files
       (in alphabetical order) and takes the key "match" (see below in
       Language Specs) as a hashref containing match criteria that determine
       if the current distribution matches the YAML document or not.

   Fallback Data::Dumper and Storable
       If neither your configured "yaml_module" nor is installed, falls back to using Data::Dumper and Storable and looks for
       files with the extensions ".dd" or ".st" in the "prefs_dir" directory.
       These files are expected to contain one or more hashrefs.  For
       Data::Dumper generated files, this is expected to be done with by
       defining $VAR1, $VAR2, etc. The YAML shell would produce these with the

           ysh < somefile.yml > somefile.dd

       For Storable files the rule is that they must be constructed such that
       "Storable::retrieve(file)" returns an array reference and the array
       elements represent one distropref object each. The conversion from YAML
       would look like so:

           perl -MYAML=LoadFile -MStorable=nstore -e '
               nstore(\@y, shift)' somefile.yml

       In bootstrapping situations it is usually sufficient to translate only
       a few YAML files to Data::Dumper for crucial modules like "YAML::Syck",
       "" and "". If you prefer Storable over Data::Dumper,
       remember to pull out a Storable version that writes an older format
       than all the other Storable versions that will need to read them.

       The following example contains all supported keywords and structures
       with the exception of "eexpect" which can be used instead of "expect".

         comment: "Demo"
           module: "Dancing::Queen"
           distribution: "^CHACHACHA/Dancing-"
           not_distribution: "\.zip$"
           perl: "/usr/local/cariba-perl/bin/perl"
             archname: "freebsd"
             not_cc: "gcc"
             DANCING_FLOOR: "Shubiduh"
         disabled: 1
           make: gmake
             - "--somearg=specialcase"

           env: {}

             - "Which is your favorite fruit"
             - "apple\n"

             - all
             - extra-all

           env: {}

           expect: []

           commandline: "echo SKIPPING make"

           args: []

           env: {}

           expect: []

           args: []

             WANT_TO_INSTALL: YES

             - "Do you really want to install"
             - "y\n"

           - "ABCDE/Fedcba-3.14-ABCDE-01.patch"

             LWP: 5.8
             Test::Exception: 0.25
             Spiffy: 0.30

   Language Specs
       Every YAML document represents a single hash reference. The valid keys
       in this hash are as follows:

       comment [scalar]
           A comment

       cpanconfig [hash]
           Temporarily override assorted "" configuration variables.

           Supported are: "build_requires_install_policy", "check_sigs",
           "make", "make_install_make_command", "prefer_installer",
           "test_report". Please report as a bug when you need another one

       depends [hash] *** EXPERIMENTAL FEATURE ***
           All three types, namely "configure_requires", "build_requires", and
           "requires" are supported in the way specified in the META.yml
           specification. The current implementation merges the specified
           dependencies with those declared by the package maintainer. In a
           future implementation this may be changed to override the original

       disabled [boolean]
           Specifies that this distribution shall not be processed at all.

       features [array] *** EXPERIMENTAL FEATURE ***
           Experimental implementation to deal with optional_features from
           META.yml. Still needs coordination with installer software and
           currently works only for META.yml declaring "dynamic_config=0". Use
           with caution.

       goto [string]
           The canonical name of a delegate distribution to install instead.
           Useful when a new version, although it tests OK itself, breaks
           something else or a developer release or a fork is already uploaded
           that is better than the last released version.

       install [hash]
           Processing instructions for the "make install" or "./Build install"
           phase of the CPAN mantra. See below under Processing Instructions.

       make [hash]
           Processing instructions for the "make" or "./Build" phase of the
           CPAN mantra. See below under Processing Instructions.

       match [hash]
           A hashref with one or more of the keys "distribution", "module",
           "perl", "perlconfig", and "env" that specify whether a document is
           targeted at a specific CPAN distribution or installation.  Keys
           prefixed with "not_" negates the corresponding match.

           The corresponding values are interpreted as regular expressions.
           The "distribution" related one will be matched against the
           canonical distribution name, e.g. "AUTHOR/Foo-Bar-3.14.tar.gz".

           The "module" related one will be matched against all modules
           contained in the distribution until one module matches.

           The "perl" related one will be matched against $^X (but with the
           absolute path).

           The value associated with "perlconfig" is itself a hashref that is
           matched against corresponding values in the %Config::Config hash
           living in the "" module.  Keys prefixed with "not_"
           negates the corresponding match.

           The value associated with "env" is itself a hashref that is matched
           against corresponding values in the %ENV hash.  Keys prefixed with
           "not_" negates the corresponding match.

           If more than one restriction of "module", "distribution", etc. is
           specified, the results of the separately computed match values must
           all match. If so, the hashref represented by the YAML document is
           returned as the preference structure for the current distribution.

       patches [array]
           An array of patches on CPAN or on the local disk to be applied in
           order via an external patch program. If the value for the "-p"
           parameter is 0 or 1 is determined by reading the patch beforehand.
           The path to each patch is either an absolute path on the local
           filesystem or relative to a patch directory specified in the
           "patches_dir" configuration variable or in the format of a
           canonical distro name. For examples please consult the distroprefs/
           directory in the distribution (these examples are not
           installed by default).

           Note: if the "applypatch" program is installed and "CPAN::Config"
           knows about it and a patch is written by the "makepatch" program,
           then "" lets "applypatch" apply the patch. Both "makepatch"
           and "applypatch" are available from CPAN in the "JV/makepatch-*"

       pl [hash]
           Processing instructions for the "perl Makefile.PL" or "perl
           Build.PL" phase of the CPAN mantra. See below under Processing

       test [hash]
           Processing instructions for the "make test" or "./Build test" phase
           of the CPAN mantra. See below under Processing Instructions.

   Processing Instructions
       args [array]
           Arguments to be added to the command line

           A full commandline to run via "system()".  During execution, the
           environment variable PERL is set to $^X (but with an absolute
           path). If "commandline" is specified, "args" is not used.

       eexpect [hash]
           Extended "expect". This is a hash reference with four allowed keys,
           "mode", "timeout", "reuse", and "talk".

           You must install the "Expect" module to use "eexpect". does
           not install it for you.

           "mode" may have the values "deterministic" for the case where all
           questions come in the order written down and "anyorder" for the
           case where the questions may come in any order. The default mode is

           "timeout" denotes a timeout in seconds. Floating-point timeouts are
           OK. With "mode=deterministic", the timeout denotes the timeout per
           question; with "mode=anyorder" it denotes the timeout per byte
           received from the stream or questions.

           "talk" is a reference to an array that contains alternating
           questions and answers. Questions are regular expressions and
           answers are literal strings. The Expect module watches the stream
           from the execution of the external program ("perl Makefile.PL",
           "perl Build.PL", "make", etc.).

           For "mode=deterministic", the injects the corresponding
           answer as soon as the stream matches the regular expression.

           For "mode=anyorder" answers a question as soon as the
           timeout is reached for the next byte in the input stream. In this
           mode you can use the "reuse" parameter to decide what will happen
           with a question-answer pair after it has been used. In the default
           case (reuse=0) it is removed from the array, avoiding being used
           again accidentally. If you want to answer the question "Do you
           really want to do that" several times, then it must be included in
           the array at least as often as you want this answer to be given.
           Setting the parameter "reuse" to 1 makes this repetition

       env [hash]
           Environment variables to be set during the command

       expect [array]
           You must install the "Expect" module to use "expect". does
           not install it for you.

           "expect: <array>" is a short notation for this "eexpect":

                           mode: deterministic
                           timeout: 15
                           talk: <array>

   Schema verification with "Kwalify"
       If you have the "Kwalify" module installed (which is part of the
       Bundle::CPANxxl), then all your distroprefs files are checked for
       syntactic correctness.

   Example Distroprefs Files
       "" comes with a collection of example YAML files. Note that
       these are really just examples and should not be used without care
       because they cannot fit everybody's purpose. After all, the authors of
       the packages that ask questions had a need to ask, so you should watch
       their questions and adjust the examples to your environment and your
       needs. You have been warned:-)


       If you do not enter the shell, shell commands are available both as
       methods ("CPAN::Shell->install(...)") and as functions in the calling
       package ("install(...)").  Before calling low-level commands, it makes
       sense to initialize components of CPAN you need, e.g.:


       High-level commands do such initializations automatically.

       There's currently only one class that has a stable interface -
       CPAN::Shell. All commands that are available in the CPAN shell are
       methods of the class CPAN::Shell. The arguments on the commandline are
       passed as arguments to the method.

       So if you take for example the shell command

         notest install A B C

       the actually executed command is


       Each of the commands that produce listings of modules ("r",
       "autobundle", "u") also return a list of the IDs of all modules within
       the list.

         The IDs of all objects available within a program are strings that
         can be expanded to the corresponding real objects with the
         "CPAN::Shell->expand("Module",@things)" method. Expand returns a list
         of CPAN::Module objects according to the @things arguments given. In
         scalar context, it returns only the first element of the list.

         Like expand, but returns objects of the appropriate type, i.e.
         CPAN::Bundle objects for bundles, CPAN::Module objects for modules,
         and CPAN::Distribution objects for distributions. Note: it does not
         expand to CPAN::Author objects.

       Programming Examples
         This enables the programmer to do operations that combine
         functionalities that are available in the shell.

             # install everything that is outdated on my disk:
             perl -MCPAN -e 'CPAN::Shell->install(CPAN::Shell->r)'

             # install my favorite programs if necessary:
             for $mod (qw(Net::FTP Digest::SHA Data::Dumper)) {

             # list all modules on my disk that have no VERSION number
             for $mod (CPAN::Shell->expand("Module","/./")) {
                 next unless $mod->inst_file;
                 # MakeMaker convention for undefined $VERSION:
                 next unless $mod->inst_version eq "undef";
                 print "No VERSION in ", $mod->id, "\n";

             # find out which distribution on CPAN contains a module:
             print CPAN::Shell->expand("Module","Apache::Constants")->cpan_file

         Or if you want to schedule a cron job to watch CPAN, you could list
         all modules that need updating. First a quick and dirty way:

             perl -e 'use CPAN; CPAN::Shell->r;'

         If you don't want any output should all modules be up to date, parse
         the output of above command for the regular expression "/modules are
         up to date/" and decide to mail the output only if it doesn't match.

         If you prefer to do it more in a programmerish style in one single
         process, something like this may better suit you:

           # list all modules on my disk that have newer versions on CPAN
           for $mod (CPAN::Shell->expand("Module","/./")) {
             next unless $mod->inst_file;
             next if $mod->uptodate;
             printf "Module %s is installed as %s, could be updated to %s from CPAN\n",
                 $mod->id, $mod->inst_version, $mod->cpan_version;

         If that gives too much output every day, you may want to watch only
         for three modules. You can write

           for $mod (CPAN::Shell->expand("Module","/Apache|LWP|CGI/")) {

         as the first line instead. Or you can combine some of the above

           # watch only for a new mod_perl module
           $mod = CPAN::Shell->expand("Module","mod_perl");
           exit if $mod->uptodate;
           # new mod_perl arrived, let me know all update recommendations

   Methods in the other Classes
           Returns a one-line description of the author

           Returns a multi-line description of the author

           Returns the author's email address

           Returns the author's name

           An alias for fullname

           Returns a one-line description of the bundle

           Returns a multi-line description of the bundle

           Recursively runs the "clean" method on all items contained in the

           Returns a list of objects' IDs contained in a bundle. The
           associated objects may be bundles, modules or distributions.

           Forces CPAN to perform a task that it normally would have refused
           to do. Force takes as arguments a method name to be called and any
           number of additional arguments that should be passed to the called
           method.  The internals of the object get the needed changes so that
  does not refuse to take the action. The "force" is passed
           recursively to all contained objects. See also the section above on
           the "force" and the "fforce" pragma.

           Recursively runs the "get" method on all items contained in the

           Returns the highest installed version of the bundle in either @INC
           or "$CPAN::Config->{cpan_home}". Note that this is different from

           Like CPAN::Bundle::inst_file, but returns the $VERSION

           Returns 1 if the bundle itself and all its members are up-to-date.

           Recursively runs the "install" method on all items contained in the

           Recursively runs the "make" method on all items contained in the

           Recursively runs the "readme" method on all items contained in the

           Recursively runs the "test" method on all items contained in the

           Returns a one-line description of the distribution

           Returns a multi-line description of the distribution

           Returns the CPAN::Author object of the maintainer who uploaded this

           Returns a string of the form "AUTHORID/TARBALL", where AUTHORID is
           the author's PAUSE ID and TARBALL is the distribution filename.

           Returns the distribution filename without any archive suffix.  E.g

           Changes to the directory where the distribution has been unpacked
           and runs "make clean" there.

           Returns a list of IDs of modules contained in a distribution file.
           Works only for distributions listed in the
           02packages.details.txt.gz file. This typically means that just most
           recent version of a distribution is covered.

           Changes to the directory where the distribution has been unpacked
           and runs something like

               cvs -d $cvs_root import -m $cvs_log $cvs_dir $userid v$version


           Returns the directory into which this distribution has been

           Forces CPAN to perform a task that it normally would have refused
           to do. Force takes as arguments a method name to be called and any
           number of additional arguments that should be passed to the called
           method.  The internals of the object get the needed changes so that
  does not refuse to take the action. See also the section
           above on the "force" and the "fforce" pragma.

           Downloads the distribution from CPAN and unpacks it. Does nothing
           if the distribution has already been downloaded and unpacked within
           the current session.

           Changes to the directory where the distribution has been unpacked
           and runs the external command "make install" there. If "make" has
           not yet been run, it will be run first. A "make test" is issued in
           any case and if this fails, the install is cancelled. The
           cancellation can be avoided by letting "force" run the "install"
           for you.

           This install method only has the power to install the distribution
           if there are no dependencies in the way. To install an object along
           with all its dependencies, use CPAN::Shell->install.

           Note that install() gives no meaningful return value. See

           Returns 1 if this distribution file seems to be a perl
           distribution.  Normally this is derived from the file name only,
           but the index from CPAN can contain a hint to achieve a return
           value of true for other filenames too.

           Changes to the directory where the distribution has been unpacked
           and opens a subshell there. Exiting the subshell returns.

           First runs the "get" method to make sure the distribution is
           downloaded and unpacked. Changes to the directory where the
           distribution has been unpacked and runs the external commands "perl
           Makefile.PL" or "perl Build.PL" and "make" there.

           Downloads the pod documentation of the file associated with a
           distribution (in HTML format) and runs it through the external
           command lynx specified in "$CPAN::Config->{lynx}". If lynx isn't
           available, it converts it to plain text with the external command
           html2text and runs it through the pager specified in

           Returns the hash reference from the first matching YAML file that
           the user has deposited in the "prefs_dir/" directory. The first
           succeeding match wins. The files in the "prefs_dir/" are processed
           alphabetically, and the canonical distro name (e.g.
           AUTHOR/Foo-Bar-3.14.tar.gz) is matched against the regular
           expressions stored in the $root->{match}{distribution} attribute
           value.  Additionally all module names contained in a distribution
           are matched against the regular expressions in the
           $root->{match}{module} attribute value. The two match values are
           ANDed together. Each of the two attributes are optional.

           Returns the hash reference that has been announced by a
           distribution as the "requires" and "build_requires" elements. These
           can be declared either by the "META.yml" (if authoritative) or can
           be deposited after the run of "Build.PL" in the file
           "./_build/prereqs" or after the run of "Makfile.PL" written as the
           "PREREQ_PM" hash in a comment in the produced "Makefile". Note:
           this method only works after an attempt has been made to "make" the
           distribution. Returns undef otherwise.

           Downloads the README file associated with a distribution and runs
           it through the pager specified in "$CPAN::Config->{pager}".

           Downloads report data for this distribution from
  and displays a subset of them.

           Returns the content of the META.yml of this distro as a hashref.
           Note: works only after an attempt has been made to "make" the
           distribution.  Returns undef otherwise. Also returns undef if the
           content of META.yml is not authoritative. (The rules about what
           exactly makes the content authoritative are still in flux.)

           Changes to the directory where the distribution has been unpacked
           and runs "make test" there.

           Returns 1 if all the modules contained in the distribution are up-
           to-date. Relies on containsmods.

           Forces a reload of all indices.

           Reloads all indices if they have not been read for more than
           "$CPAN::Config->{index_expire}" days.

           CPAN::Author, CPAN::Bundle, CPAN::Module, and CPAN::Distribution
           inherit this method. It prints the data structure associated with
           an object. Useful for debugging. Note: the data structure is
           considered internal and thus subject to change without notice.

           Returns a one-line description of the module in four columns: The
           first column contains the word "Module", the second column consists
           of one character: an equals sign if this module is already
           installed and up-to-date, a less-than sign if this module is
           installed but can be upgraded, and a space if the module is not
           installed. The third column is the name of the module and the
           fourth column gives maintainer or distribution information.

           Returns a multi-line description of the module

           Runs a clean on the distribution associated with this module.

           Returns the filename on CPAN that is associated with the module.

           Returns the latest version of this module available on CPAN.

           Runs a cvs_import on the distribution associated with this module.

           Returns a 44 character description of this module. Only available
           for modules listed in The Module List
           (CPAN/modules/00modlist.long.html or 00modlist.long.txt.gz)

           Returns the CPAN::Distribution object that contains the current
           version of this module.

           Returns a hash reference. The keys of the hash are the letters "D",
           "S", "L", "I", and <P>, for development status, support level,
           language, interface and public licence respectively. The data for
           the DSLIP status are collected by when authors
           register their namespaces. The values of the 5 hash elements are
           one-character words whose meaning is described in the table below.
           There are also 5 hash elements "DV", "SV", "LV", "IV", and <PV>
           that carry a more verbose value of the 5 status variables.

           Where the 'DSLIP' characters have the following meanings:

             D - Development Stage  (Note: *NO IMPLIED TIMESCALES*):
               i   - Idea, listed to gain consensus or as a placeholder
               c   - under construction but pre-alpha (not yet released)
               a/b - Alpha/Beta testing
               R   - Released
               M   - Mature (no rigorous definition)
               S   - Standard, supplied with Perl 5

             S - Support Level:
               m   - Mailing-list
               d   - Developer
               u   - Usenet newsgroup comp.lang.perl.modules
               n   - None known, try comp.lang.perl.modules
               a   - abandoned; volunteers welcome to take over maintenance

             L - Language Used:
               p   - Perl-only, no compiler needed, should be platform independent
               c   - C and perl, a C compiler will be needed
               h   - Hybrid, written in perl with optional C code, no compiler needed
               +   - C++ and perl, a C++ compiler will be needed
               o   - perl and another language other than C or C++

             I - Interface Style
               f   - plain Functions, no references used
               h   - hybrid, object and function interfaces available
               n   - no interface at all (huh?)
               r   - some use of unblessed References or ties
               O   - Object oriented using blessed references and/or inheritance

             P - Public License
               p   - Standard-Perl: user may choose between GPL and Artistic
               g   - GPL: GNU General Public License
               l   - LGPL: "GNU Lesser General Public License" (previously known as
                     "GNU Library General Public License")
               b   - BSD: The BSD License
               a   - Artistic license alone
               2   - Artistic license 2.0 or later
               o   - open source: approved by
               d   - allows distribution without restrictions
               r   - restricted distribution
               n   - no license at all

           Forces CPAN to perform a task it would normally refuse to do. Force
           takes as arguments a method name to be invoked and any number of
           additional arguments to pass that method.  The internals of the
           object get the needed changes so that does not refuse to
           take the action. See also the section above on the "force" and the
           "fforce" pragma.

           Runs a get on the distribution associated with this module.

           Returns the filename of the module found in @INC. The first file
           found is reported, just as perl itself stops searching @INC once it
           finds a module.

           Returns the filename of the module found in PERL5LIB or @INC. The
           first file found is reported. The advantage of this method over
           "inst_file" is that modules that have been tested but not yet
           installed are included because PERL5LIB keeps track of tested

           Returns the version number of the installed module in readable

           Returns the version number of the available module in readable

           Runs an "install" on the distribution associated with this module.

           Changes to the directory where the distribution associated with
           this module has been unpacked and opens a subshell there. Exiting
           the subshell returns.

           Runs a "make" on the distribution associated with this module.

           If module is installed, peeks into the module's manpage, reads the
           headline, and returns it. Moreover, if the module has been
           downloaded within this session, does the equivalent on the
           downloaded module even if it hasn't been installed yet.

           Runs a "perldoc" on this module.

           Runs a "readme" on the distribution associated with this module.

           Calls the reports() method on the associated distribution object.

           Runs a "test" on the distribution associated with this module.

           Returns 1 if the module is installed and up-to-date.

           Returns the author's ID of the module.

   Cache Manager
       Currently the cache manager only keeps track of the build directory
       ($CPAN::Config->{build_dir}). It is a simple FIFO mechanism that
       deletes complete directories below "build_dir" as soon as the size of
       all directories there gets bigger than $CPAN::Config->{build_cache} (in
       MB). The contents of this cache may be used for later re-installations
       that you intend to do manually, but will never be trusted by CPAN
       itself. This is due to the fact that the user might use these
       directories for building modules on different architectures.

       There is another directory ($CPAN::Config->{keep_source_where}) where
       the original distribution files are kept. This directory is not covered
       by the cache manager and must be controlled by the user. If you choose
       to have the same directory as build_dir and as keep_source_where
       directory, then your sources will be deleted with the same fifo

       A bundle is just a perl module in the namespace Bundle:: that does not
       define any functions or methods. It usually only contains

       It starts like a perl module with a package declaration and a $VERSION
       variable. After that the pod section looks like any other pod with the
       only difference being that one special pod section exists starting with

           =head1 CONTENTS

       In this pod section each line obeys the format

               Module_Name [Version_String] [- optional text]

       The only required part is the first field, the name of a module (e.g.
       Foo::Bar, i.e. not the name of the distribution file). The rest of the
       line is optional. The comment part is delimited by a dash just as in
       the man page header.

       The distribution of a bundle should follow the same convention as other

       Bundles are treated specially in the CPAN package. If you say 'install
       Bundle::Tkkit' (assuming such a bundle exists), CPAN will install all
       the modules in the CONTENTS section of the pod. You can install your
       own Bundles locally by placing a conformant Bundle file somewhere into
       your @INC path. The autobundle() command which is available in the
       shell interface does that for you by including all currently installed
       modules in a snapshot bundle file.


       The CPAN program is trying to depend on as little as possible so the
       user can use it in hostile environment. It works better the more
       goodies the environment provides. For example if you try in the CPAN

         install Bundle::CPAN


         install Bundle::CPANxxl

       you will find the shell more convenient than the bare shell before.

       If you have a local mirror of CPAN and can access all files with
       "file:" URLs, then you only need a perl later than perl5.003 to run
       this module. Otherwise Net::FTP is strongly recommended. LWP may be
       required for non-UNIX systems, or if your nearest CPAN site is
       associated with a URL that is not "ftp:".

       If you have neither Net::FTP nor LWP, there is a fallback mechanism
       implemented for an external ftp command or for an external lynx


   Finding packages and VERSION
       This module presumes that all packages on CPAN

       o declare their $VERSION variable in an easy to parse manner. This
         prerequisite can hardly be relaxed because it consumes far too much
         memory to load all packages into the running program just to
         determine the $VERSION variable. Currently all programs that are
         dealing with version use something like this

             perl -MExtUtils::MakeMaker -le \
                 'print MM->parse_version(shift)' filename

         If you are author of a package and wonder if your $VERSION can be
         parsed, please try the above method.

       o come as compressed or gzipped tarfiles or as zip files and contain a
         "Makefile.PL" or "Build.PL" (well, we try to handle a bit more, but
         with little enthusiasm).

       Debugging this module is more than a bit complex due to interference
       from the software producing the indices on CPAN, the mirroring process
       on CPAN, packaging, configuration, synchronicity, and even (gasp!) due
       to bugs within the module itself.

       For debugging the code of itself in interactive mode, some
       debugging aid can be turned on for most packages within with
       one of

       o debug package...
         sets debug mode for packages.

       o debug -package...
         unsets debug mode for packages.

       o debug all
         turns debugging on for all packages.

       o debug number

       which sets the debugging packages directly. Note that "o debug 0" turns
       debugging off.

       What seems a successful strategy is the combination of "reload cpan"
       and the debugging switches. Add a new debug statement while running in
       the shell and then issue a "reload cpan" and see the new debugging
       messages immediately without losing the current context.

       "o debug" without an argument lists the valid package names and the
       current set of packages in debugging mode. "o debug" has built-in
       completion support.

       For debugging of CPAN data there is the "dump" command which takes the
       same arguments as make/test/install and outputs each object's
       Data::Dumper dump. If an argument looks like a perl variable and
       contains one of "$", "@" or "%", it is eval()ed and fed to Data::Dumper

   Floppy, Zip, Offline Mode works nicely without network access, too. If you maintain
       machines that are not networked at all, you should consider working
       with "file:" URLs. You'll have to collect your modules somewhere first.
       So you might use to put together all you need on a networked
       machine. Then copy the $CPAN::Config->{keep_source_where} (but not
       $CPAN::Config->{build_dir}) directory on a floppy. This floppy is kind
       of a personal CPAN. on the non-networked machines works nicely
       with this floppy. See also below the paragraph about CD-ROM support.

   Basic Utilities for Programmers
         Returns true if the module is installed. Used to load all modules
         into the running that are considered optional. The config
         variable "dontload_list" intercepts the "has_inst()" call such that
         an optional module is not loaded despite being available. For
         example, the following command will prevent "" from being

             cpan> o conf dontload_list push YAML

         See the source for details.

         Similary to has_inst() tries to load optional library but also dies
         if library is not available

         Returns true if the module is installed and in a usable state. Only
         useful for a handful of modules that are used internally. See the
         source for details.

         The constructor for all the singletons used to represent modules,
         distributions, authors, and bundles. If the object already exists,
         this method returns the object; otherwise, it calls the constructor.

         Getter/setter for frontend object. Method just allows to subclass


       There's no strong security layer in helps you to
       install foreign, unmasked, unsigned code on your machine. We compare to
       a checksum that comes from the net just as the distribution file
       itself. But we try to make it easy to add security on demand:

   Cryptographically signed modules
       Since release 1.77, has been able to verify cryptographically
       signed module distributions using Module::Signature.  The CPAN modules
       can be signed by their authors, thus giving more security.  The simple
       unsigned MD5 checksums that were used before by CPAN protect mainly
       against accidental file corruption.

       You will need to have Module::Signature installed, which in turn
       requires that you have at least one of Crypt::OpenPGP module or the
       command-line gpg tool installed.

       You will also need to be able to connect over the Internet to the
       public key servers, like, and their port 11731 (the HKP

       The configuration parameter check_sigs is there to turn signature
       checking on or off.


       Most functions in package CPAN are exported by default. The reason for
       this is that the primary use is intended for the cpan shell or for one-


       When the CPAN shell enters a subshell via the look command, it sets the
       environment CPAN_SHELL_LEVEL to 1, or increments that variable if it is
       already set.

       When CPAN runs, it sets the environment variable PERL5_CPAN_IS_RUNNING
       to the ID of the running process. It also sets
       PERL5_CPANPLUS_IS_RUNNING to prevent runaway processes which could
       happen with older versions of Module::Install.

       When running "perl Makefile.PL", the environment variable
       "PERL5_CPAN_IS_EXECUTING" is set to the full path of the "Makefile.PL"
       that is being executed. This prevents runaway processes with newer
       versions of Module::Install.

       When the config variable ftp_passive is set, all downloads will be run
       with the environment variable FTP_PASSIVE set to this value. This is in
       general a good idea as it influences both Net::FTP and LWP based
       connections. The same effect can be achieved by starting the cpan shell
       with this environment variable set. For Net::FTP alone, one can also
       always set passive mode by running libnetcfg.


       Populating a freshly installed perl with one's favorite modules is
       pretty easy if you maintain a private bundle definition file. To get a
       useful blueprint of a bundle definition file, the command autobundle
       can be used on the CPAN shell command line. This command writes a
       bundle definition file for all modules installed for the current perl
       interpreter. It's recommended to run this command once only, and from
       then on maintain the file manually under a private name, say
       Bundle/ With a clever bundle file you can then simply say

           cpan> install Bundle::my_bundle

       then answer a few questions and go out for coffee (possibly even in a
       different city).

       Maintaining a bundle definition file means keeping track of two things:
       dependencies and interactivity. sometimes fails on calculating
       dependencies because not all modules define all MakeMaker attributes
       correctly, so a bundle definition file should specify prerequisites as
       early as possible. On the other hand, it's annoying that so many
       distributions need some interactive configuring. So what you can try to
       accomplish in your private bundle file is to have the packages that
       need to be configured early in the file and the gentle ones later, so
       you can go out for coffee after a few minutes and leave to
       churn away unattended.


       Thanks to Graham Barr for contributing the following paragraphs about
       the interaction between perl, and various firewall configurations. For
       further information on firewalls, it is recommended to consult the
       documentation that comes with the ncftp program. If you are unable to
       go through the firewall with a simple Perl setup, it is likely that you
       can configure ncftp so that it works through your firewall.

   Three basic types of firewalls
       Firewalls can be categorized into three basic types.

       http firewall
           This is when the firewall machine runs a web server, and to access
           the outside world, you must do so via that web server. If you set
           environment variables like http_proxy or ftp_proxy to values
           beginning with http://, or in your web browser you've proxy
           information set, then you know you are running behind an http

           To access servers outside these types of firewalls with perl (even
           for ftp), you need LWP or HTTP::Tiny.

       ftp firewall
           This where the firewall machine runs an ftp server. This kind of
           firewall will only let you access ftp servers outside the firewall.
           This is usually done by connecting to the firewall with ftp, then
           entering a username like "".

           To access servers outside these type of firewalls with perl, you
           need Net::FTP.

       One-way visibility
           One-way visibility means these firewalls try to make themselves
           invisible to users inside the firewall. An FTP data connection is
           normally created by sending your IP address to the remote server
           and then listening for the return connection. But the remote server
           will not be able to connect to you because of the firewall. For
           these types of firewall, FTP connections need to be done in a
           passive mode.

           There are two that I can think off.

               If you are using a SOCKS firewall, you will need to compile
               perl and link it with the SOCKS library.  This is what is
               normally called a 'socksified' perl. With this executable you
               will be able to connect to servers outside the firewall as if
               it were not there.

           IP Masquerade
               This is when the firewall implemented in the kernel (via NAT,
               or networking address translation), it allows you to hide a
               complete network behind one IP address. With this firewall no
               special compiling is needed as you can access hosts directly.

               For accessing ftp servers behind such firewalls you usually
               need to set the environment variable "FTP_PASSIVE" or the
               config variable ftp_passive to a true value.

   Configuring lynx or ncftp for going through a firewall
       If you can go through your firewall with e.g. lynx, presumably with a
       command such as

           /usr/local/bin/lynx -pscott:tiger

       then you would configure with the command

           o conf lynx "/usr/local/bin/lynx -pscott:tiger"

       That's all. Similarly for ncftp or ftp, you would configure something

           o conf ncftp "/usr/bin/ncftp -f /home/scott/ncftplogin.cfg"

       Your mileage may vary...


       1)  I installed a new version of module X but CPAN keeps saying, I have
           the old version installed

           Probably you do have the old version installed. This can happen if
           a module installs itself into a different directory in the @INC
           path than it was previously installed. This is not really a
           problem, you would have the same problem when installing the module
           manually. The easiest way to prevent this behaviour is to add the
           argument "UNINST=1" to the "make install" call, and that is why
           many people add this argument permanently by configuring

             o conf make_install_arg UNINST=1

       2)  So why is UNINST=1 not the default?

           Because there are people who have their precise expectations about
           who may install where in the @INC path and who uses which @INC
           array. In fine tuned environments "UNINST=1" can cause damage.

       3)  I want to clean up my mess, and install a new perl along with all
           modules I have. How do I go about it?

           Run the autobundle command for your old perl and optionally rename
           the resulting bundle file (e.g. Bundle/, install the
           new perl with the Configure option prefix, e.g.

               ./Configure -Dprefix=/usr/local/perl-

           Install the bundle file you produced in the first step with
           something like

               cpan> install Bundle::mybundle

           and you're done.

       4)  When I install bundles or multiple modules with one command there
           is too much output to keep track of.

           You may want to configure something like

             o conf make_arg "| tee -ai /root/.cpan/logs/make.out"
             o conf make_install_arg "| tee -ai /root/.cpan/logs/make_install.out"

           so that STDOUT is captured in a file for later inspection.

       5)  I am not root, how can I install a module in a personal directory?

           As of CPAN 1.9463, if you do not have permission to write the
           default perl library directories, CPAN's configuration process will
           ask you whether you want to bootstrap <local::lib>, which makes
           keeping a personal perl library directory easy.

           Another thing you should bear in mind is that the UNINST parameter
           can be dangerous when you are installing into a private area
           because you might accidentally remove modules that other people
           depend on that are not using the private area.

       6)  How to get a package, unwrap it, and make a change before building

           Have a look at the "look" (!) command.

       7)  I installed a Bundle and had a couple of fails. When I retried,
           everything resolved nicely. Can this be fixed to work on first try?

           The reason for this is that CPAN does not know the dependencies of
           all modules when it starts out. To decide about the additional
           items to install, it just uses data found in the META.yml file or
           the generated Makefile. An undetected missing piece breaks the
           process. But it may well be that your Bundle installs some
           prerequisite later than some depending item and thus your second
           try is able to resolve everything.  Please note, does not
           know the dependency tree in advance and cannot sort the queue of
           things to install in a topologically correct order. It resolves
           perfectly well if all modules declare the prerequisites correctly
           with the PREREQ_PM attribute to MakeMaker or the "requires" stanza
           of Module::Build. For bundles which fail and you need to install
           often, it is recommended to sort the Bundle definition file

       8)  In our intranet, we have many modules for internal use. How can I
           integrate these modules with but without uploading the
           modules to CPAN?

           Have a look at the CPAN::Site module.

       9)  When I run CPAN's shell, I get an error message about things in my
           "/etc/inputrc" (or "~/.inputrc") file.

           These are readline issues and can only be fixed by studying
           readline configuration on your architecture and adjusting the
           referenced file accordingly. Please make a backup of the
           "/etc/inputrc" or "~/.inputrc" and edit them. Quite often harmless
           changes like uppercasing or lowercasing some arguments solves the

       10) Some authors have strange characters in their names.

           Internally uses the UTF-8 charset. If your terminal is
           expecting ISO-8859-1 charset, a converter can be activated by
           setting term_is_latin to a true value in your config file. One way
           of doing so would be

               cpan> o conf term_is_latin 1

           If other charset support is needed, please file a bug report
           against at and describe your needs. Maybe we
           can extend the support or maybe UTF-8 terminals become widely

           Note: this config variable is deprecated and will be removed in a
           future version of It will be replaced with the conventions
           around the family of $LANG and $LC_* environment variables.

       11) When an install fails for some reason and then I correct the error
           condition and retry, refuses to install the module, saying
           "Already tried without success".

           Use the force pragma like so

             force install Foo::Bar

           Or you can use

             look Foo::Bar

           and then "make install" directly in the subshell.

       12) How do I install a "DEVELOPER RELEASE" of a module?

           By default, CPAN will install the latest non-developer release of a
           module. If you want to install a dev release, you have to specify
           the partial path starting with the author id to the tarball you
           wish to install, like so:

               cpan> install KWILLIAMS/Module-Build-0.27_07.tar.gz

           Note that you can use the "ls" command to get this path listed.

       13) How do I install a module and all its dependencies from the
           commandline, without being prompted for anything, despite my CPAN
           configuration (or lack thereof)?

           CPAN uses ExtUtils::MakeMaker's prompt() function to ask its
           questions, so if you set the PERL_MM_USE_DEFAULT environment
           variable, you shouldn't be asked any questions at all (assuming the
           modules you are installing are nice about obeying that variable as

               % PERL_MM_USE_DEFAULT=1 perl -MCPAN -e 'install My::Module'

       14) How do I create a Module::Build based Build.PL derived from an
           ExtUtils::MakeMaker focused Makefile.PL?


       15) I'm frequently irritated with the CPAN shell's inability to help me
           select a good mirror.

           CPAN can now help you select a "good" mirror, based on which ones
           have the lowest 'ping' round-trip times.  From the shell, use the
           command 'o conf init urllist' and allow CPAN to automatically
           select mirrors for you.

           Beyond that help, the urllist config parameter is yours. You can
           add and remove sites at will. You should find out which sites have
           the best up-to-dateness, bandwidth, reliability, etc. and are
           topologically close to you. Some people prefer fast downloads,
           others up-to-dateness, others reliability.  You decide which to try
           in which order.

           Henk P. Penning maintains a site that collects data about CPAN


           Also, feel free to play with experimental features. Run

             o conf init randomize_urllist ftpstats_period ftpstats_size

           and choose your favorite parameters. After a few downloads running
           the "hosts" command will probably assist you in choosing the best
           mirror sites.

       16) Why do I get asked the same questions every time I start the shell?

           You can make your configuration changes permanent by calling the
           command "o conf commit". Alternatively set the "auto_commit"
           variable to true by running "o conf init auto_commit" and answering
           the following question with yes.

       17) Older versions of had the original root directory of all
           tarballs in the build directory. Now there are always random
           characters appended to these directory names. Why was this done?

           The random characters are provided by File::Temp and ensure that
           each module's individual build directory is unique. This makes
           running in concurrent processes simultaneously safe.

       18) Speaking of the build directory. Do I have to clean it up myself?

           You have the choice to set the config variable "scan_cache" to
           "never". Then you must clean it up yourself. The other possible
           values, "atstart" and "atexit" clean up the build directory when
           you start (or more precisely, after the first extraction into the
           build directory) or exit the CPAN shell, respectively. If you never
           start up the CPAN shell, you probably also have to clean up the
           build directory yourself.

       19) How can I switch to sudo instead of local::lib?

           The following 5 environment veriables need to be reset to the
           previous values: PATH, PERL5LIB, PERL_LOCAL_LIB_ROOT, PERL_MB_OPT,
           PERL_MM_OPT; and these two config variables must be
           reconfigured: make_install_make_command and
           mbuild_install_build_command. The five env variables have probably
           been overwritten in your $HOME/.bashrc or some equivalent. You
           either find them there and delete their traces and logout/login or
           you override them temporarily, depending on your exact desire. The
           two cpanpm config variables can be set with:

             o conf init /install_.*_command/

           probably followed by

             o conf commit


   OLD PERL VERSIONS is regularly tested to run under 5.005 and assorted newer
       versions. It is getting more and more difficult to get the minimal
       prerequisites working on older perls. It is close to impossible to get
       the whole Bundle::CPAN working there. If you're in the position to have
       only these old versions, be advised that CPAN is designed to work fine
       without the Bundle::CPAN installed.

       To get things going, note that GBARR/Scalar-List-Utils-1.18.tar.gz is
       compatible with ancient perls and that File::Temp is listed as a
       prerequisite but CPAN has reasonable workarounds if it is missing.

       This module and its competitor, the CPANPLUS module, are both much
       cooler than the other. is older. CPANPLUS was designed to be
       more modular, but it was never intended to be compatible with

       In the year 2010 App::cpanminus was launched as a new approach to a
       cpan shell with a considerably smaller footprint. Very cool stuff.


       This software enables you to upgrade software on your computer and so
       is inherently dangerous because the newly installed software may
       contain bugs and may alter the way your computer works or even make it
       unusable. Please consider backing up your data before every upgrade.


       Please report bugs via <>

       Before submitting a bug, please make sure that the traditional method
       of building a Perl module package from a shell by following the
       installation instructions of that package still works in your


       Andreas Koenig "<>"


       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

       See <>


       Kawai,Takanori provides a Japanese translation of a very old version of
       this manpage at


       Many people enter the CPAN shell by running the cpan utility program
       which is installed in the same directory as perl itself. So if you have
       this directory in your PATH variable (or some equivalent in your
       operating system) then typing "cpan" in a console window will work for
       you as well. Above that the utility provides several commandline

       melezhik (Alexey) sent me a link where he published a chef recipe to
       work with

perl v5.34.0                      2020-10-24                         CPAN(3pm)

perl 5.34.0 - Generated Sun Feb 27 19:11:44 CST 2022
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