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

       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 CHECKUMS 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 buid 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 underbar 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.

       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

	 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
	 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
			    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
	 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
	 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_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 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 ti "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 for individual distributions (Distroprefs)
       (Note: This feature has been introduced in 1.8854 and is still
       considered beta quality)

       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

       ·   pass additional arguments to one of the four commands,

       ·   set environment variables

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

       ·   temporarily override assorted "" configuration variables

       ·   specify dependencies the original maintainer forgot

       ·   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: []


	     - "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

       · 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.

       · 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.

	 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.

       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 exit the CPAN shell, respectively. If you never start
	   up the CPAN shell, you probably also have to clean up the build
	   directory yourself.

   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 v5.18.2			  2014-01-06			   CPAN(3perl)

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