Provided by: perl-doc_5.18.2-2ubuntu1.7_all 
NAME
CPAN - query, download and build perl modules from CPAN sites
SYNOPSIS
Interactive mode:
perl -MCPAN -e shell
--or--
cpan
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
CPAN::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",
$distro); # same thing
DESCRIPTION
The CPAN module automates or at least simplifies the make and install of perl modules and extensions. It
includes some primitive searching capabilities and knows how to use LWP, HTTP::Tiny, Net::FTP and certain
external download clients to fetch distributions from the net.
These are fetched from one or more mirrored CPAN (Comprehensive Perl Archive Network) sites and unpacked
in a dedicated directory.
The CPAN module also supports named and versioned bundles of modules. Bundles simplify handling of sets
of related modules. See Bundles below.
The package contains a session manager and a cache manager. The session manager keeps track of what has
been fetched, built, and installed in the current session. The cache manager keeps track of the disk
space occupied by the make processes and deletes excess space using a simple FIFO mechanism.
All methods provided are accessible in a programmer style and in an interactive shell style.
CPAN::shell([$prompt, $command]) Starting Interactive Mode
Enter interactive mode by running
perl -MCPAN -e shell
or
cpan
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 slashes.
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 "as_glimpse".
Examples:
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/MetaSyntactic.pm
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/Bar.pm 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.
Example:
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.
Example:
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.
"failed"
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 CPAN.pm 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, CPAN.pm 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 CPAN.pm
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 scratch.
Lockfile
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
CPAN.pm 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.
CPAN.pm 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".
CPAN::Shell
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
"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/Snapshot_2012_05_21_00.pm. 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.
hosts
Note: this feature is still in alpha state and may change in future versions of CPAN.pm
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_tested
Install all distributions that have been tested successfully but have not yet been installed. See
also "is_tested".
is_tested
List all buid directories of distributions that have been tested successfully but have not yet been
installed. See also "install_tested".
mkmyconfig
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/CGI.pm-3.55.tar.gz
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.
recent ***EXPERIMENTAL COMMAND***
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 CPAN.pm,
but the general approach will likely remain.
Note: See also smoke
recompile
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.
smoke ***EXPERIMENTAL COMMAND***
*** 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
skipped.
Note: This whole command currently is just a hack and will probably change in future versions of CPAN.pm,
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.
CPAN.pm 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, CPAN.pm 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 CPAN.pm
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 CPAN.pm 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 CPAN.pm 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.
Redirection
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.
CONFIGURATION
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 $CPAN::Config in a file
CPAN/Config.pm.
Default values defined in the CPAN/Config.pm file can be overridden in a user specific file:
CPAN/MyConfig.pm. Such a file is best placed in "$HOME/.cpan/CPAN/MyConfig.pm", 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.
Example:
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
Example:
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 ""
Example:
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.
Examples:
o conf urllist unshift http://cpan.dev.local/CPAN
o conf urllist splice 3 1
o conf urllist http://cpan1.local http://cpan2.local ftp://ftp.perl.org
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/Config.pm or CPAN/MyConfig.pm 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 defined:
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
build_requires_install_policy
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
commandnumber_in_prompt
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
connect_to_internet_ok
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
inhibit_startup_message
if true, suppress the startup message
keep_source_where directory in which to keep the source (if we do)
load_module_verbosity
report loading of optional modules used by CPAN.pm
lynx path to external prg
make location of external make program
make_arg arguments that should always be passed to 'make'
make_install_make_command
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'
mbuild_install_build_command
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
prefer_external_tar
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
prerequisites_policy
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
show_unparsable_versions
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)
trust_test_report_history
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 below.
"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 format.
"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.
Examples:
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
CPAN.pm 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
getcwd
Calls Cwd::getcwd
fastcwd
Calls Cwd::fastcwd
backtickcwd
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:
file://localhost/whatever/ftp/pub/CPAN/
or
file:///home/ftp/pub/CPAN/
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
CPAN.pm 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 YAML.pm (or some other YAML module configured in "yaml_module") installed, CPAN.pm 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 CPAN.pm 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",
CPAN.pm asks the user and sets the default accordingly.
Configuration for individual distributions (Distroprefs)
(Note: This feature has been introduced in CPAN.pm 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 mantras:
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 "CPAN.pm" addresses this problem by allowing the user to specify extra
informations and recipes in YAML files to either
• 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 "CPAN.pm" 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 "CPAN.pm" distribution in the "distroprefs/"
directory for examples.
Filenames
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 "CPAN.pm" 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; "CPAN.pm" 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 YAML.pm is installed, CPAN.pm 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, $VAR2, etc. The YAML shell would produce these with
the command
ysh < somefile.yml > somefile.dd
For Storable files the rule is that they must be constructed such that "Storable::retrieve(file)" returns
an array reference and the array elements represent one distropref object each. The conversion from YAML
would look like so:
perl -MYAML=LoadFile -MStorable=nstore -e '
@y=LoadFile(shift);
nstore(\@y, shift)' somefile.yml somefile.st
In bootstrapping situations it is usually sufficient to translate only a few YAML files to Data::Dumper
for crucial modules like "YAML::Syck", "YAML.pm" and "Expect.pm". If you prefer Storable over
Data::Dumper, remember to pull out a Storable version that writes an older format than all the other
Storable versions that will need to read them.
Blueprint
The following example contains all supported keywords and structures with the exception of "eexpect"
which can be used instead of "expect".
---
comment: "Demo"
match:
module: "Dancing::Queen"
distribution: "^CHACHACHA/Dancing-"
not_distribution: "\.zip$"
perl: "/usr/local/cariba-perl/bin/perl"
perlconfig:
archname: "freebsd"
not_cc: "gcc"
env:
DANCING_FLOOR: "Shubiduh"
disabled: 1
cpanconfig:
make: gmake
pl:
args:
- "--somearg=specialcase"
env: {}
expect:
- "Which is your favorite fruit"
- "apple\n"
make:
args:
- all
- extra-all
env: {}
expect: []
commandline: "echo SKIPPING make"
test:
args: []
env: {}
expect: []
install:
args: []
env:
WANT_TO_INSTALL: YES
expect:
- "Do you really want to install"
- "y\n"
patches:
- "ABCDE/Fedcba-3.14-ABCDE-01.patch"
depends:
configure_requires:
LWP: 5.8
build_requires:
Test::Exception: 0.25
requires:
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 "CPAN.pm" 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 supported.
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 declaration.
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 "Config.pm" 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 CPAN.pm 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 "CPAN.pm" lets "applypatch" apply the patch. Both
"makepatch" and "applypatch" are available from CPAN in the "JV/makepatch-*" distribution.
pl [hash]
Processing instructions for the "perl Makefile.PL" or "perl Build.PL" phase of the CPAN mantra. See
below under Processing Instructions.
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
commandline
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". CPAN.pm 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
"deterministic".
"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 CPAN.pm injects the corresponding answer as soon as the stream matches
the regular expression.
For "mode=anyorder" CPAN.pm 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 unnecessary.
env [hash]
Environment variables to be set during the command
expect [array]
You must install the "Expect" module to use "expect". CPAN.pm does not install it for you.
"expect: <array>" is a short notation for this "eexpect":
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
"CPAN.pm" 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:-)
PROGRAMMER'S INTERFACE
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.:
CPAN::HandleConfig->load;
CPAN::Shell::setup_output;
CPAN::Index->reload;
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
CPAN::Shell->notest("install","A","B","C");
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.
expand($type,@things)
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.
expandany(@things)
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 $mod (qw(Net::FTP Digest::SHA Data::Dumper)) {
CPAN::Shell->install($mod);
}
# 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 tricks:
# watch only for a new mod_perl module
$mod = CPAN::Shell->expand("Module","mod_perl");
exit if $mod->uptodate;
# new mod_perl arrived, let me know all update recommendations
CPAN::Shell->r;
Methods in the other Classes
CPAN::Author::as_glimpse()
Returns a one-line description of the author
CPAN::Author::as_string()
Returns a multi-line description of the author
CPAN::Author::email()
Returns the author's email address
CPAN::Author::fullname()
Returns the author's name
CPAN::Author::name()
An alias for fullname
CPAN::Bundle::as_glimpse()
Returns a one-line description of the bundle
CPAN::Bundle::as_string()
Returns a multi-line description of the bundle
CPAN::Bundle::clean()
Recursively runs the "clean" method on all items contained in the bundle.
CPAN::Bundle::contains()
Returns a list of objects' IDs contained in a bundle. The associated objects may be bundles, modules
or distributions.
CPAN::Bundle::force($method,@args)
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 CPAN.pm 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.
CPAN::Bundle::get()
Recursively runs the "get" method on all items contained in the bundle
CPAN::Bundle::inst_file()
Returns the highest installed version of the bundle in either @INC or "$CPAN::Config->{cpan_home}".
Note that this is different from CPAN::Module::inst_file.
CPAN::Bundle::inst_version()
Like CPAN::Bundle::inst_file, but returns the $VERSION
CPAN::Bundle::uptodate()
Returns 1 if the bundle itself and all its members are up-to-date.
CPAN::Bundle::install()
Recursively runs the "install" method on all items contained in the bundle
CPAN::Bundle::make()
Recursively runs the "make" method on all items contained in the bundle
CPAN::Bundle::readme()
Recursively runs the "readme" method on all items contained in the bundle
CPAN::Bundle::test()
Recursively runs the "test" method on all items contained in the bundle
CPAN::Distribution::as_glimpse()
Returns a one-line description of the distribution
CPAN::Distribution::as_string()
Returns a multi-line description of the distribution
CPAN::Distribution::author
Returns the CPAN::Author object of the maintainer who uploaded this distribution
CPAN::Distribution::pretty_id()
Returns a string of the form "AUTHORID/TARBALL", where AUTHORID is the author's PAUSE ID and TARBALL
is the distribution filename.
CPAN::Distribution::base_id()
Returns the distribution filename without any archive suffix. E.g "Foo-Bar-0.01"
CPAN::Distribution::clean()
Changes to the directory where the distribution has been unpacked and runs "make clean" there.
CPAN::Distribution::containsmods()
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.
CPAN::Distribution::cvs_import()
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
there.
CPAN::Distribution::dir()
Returns the directory into which this distribution has been unpacked.
CPAN::Distribution::force($method,@args)
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 CPAN.pm does not refuse to take
the action. See also the section above on the "force" and the "fforce" pragma.
CPAN::Distribution::get()
Downloads the distribution from CPAN and unpacks it. Does nothing if the distribution has already
been downloaded and unpacked within the current session.
CPAN::Distribution::install()
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 uptodate().
CPAN::Distribution::isa_perl()
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.
CPAN::Distribution::look()
Changes to the directory where the distribution has been unpacked and opens a subshell there. Exiting
the subshell returns.
CPAN::Distribution::make()
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.
CPAN::Distribution::perldoc()
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 "$CPAN::Config->{pager}".
CPAN::Distribution::prefs()
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
$root->{match}{module} attribute value. The two match values are ANDed together. Each of the two
attributes are optional.
CPAN::Distribution::prereq_pm()
Returns the hash reference that has been announced by a distribution as the "requires" and
"build_requires" elements. These can be declared either by the "META.yml" (if authoritative) or can
be deposited after the run of "Build.PL" in the file "./_build/prereqs" or after the run of
"Makfile.PL" written as the "PREREQ_PM" hash in a comment in the produced "Makefile". Note: this
method only works after an attempt has been made to "make" the distribution. Returns undef otherwise.
CPAN::Distribution::readme()
Downloads the README file associated with a distribution and runs it through the pager specified in
"$CPAN::Config->{pager}".
CPAN::Distribution::reports()
Downloads report data for this distribution from www.cpantesters.org and displays a subset of them.
CPAN::Distribution::read_yaml()
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.)
CPAN::Distribution::test()
Changes to the directory where the distribution has been unpacked and runs "make test" there.
CPAN::Distribution::uptodate()
Returns 1 if all the modules contained in the distribution are up-to-date. Relies on containsmods.
CPAN::Index::force_reload()
Forces a reload of all indices.
CPAN::Index::reload()
Reloads all indices if they have not been read for more than "$CPAN::Config->{index_expire}" days.
CPAN::InfoObj::dump()
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.
CPAN::Module::as_glimpse()
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.
CPAN::Module::as_string()
Returns a multi-line description of the module
CPAN::Module::clean()
Runs a clean on the distribution associated with this module.
CPAN::Module::cpan_file()
Returns the filename on CPAN that is associated with the module.
CPAN::Module::cpan_version()
Returns the latest version of this module available on CPAN.
CPAN::Module::cvs_import()
Runs a cvs_import on the distribution associated with this module.
CPAN::Module::description()
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)
CPAN::Module::distribution()
Returns the CPAN::Distribution object that contains the current version of this module.
CPAN::Module::dslip_status()
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 pause.perl.org 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 www.opensource.org
d - allows distribution without restrictions
r - restricted distribution
n - no license at all
CPAN::Module::force($method,@args)
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 CPAN.pm does not refuse to take the action. See also the
section above on the "force" and the "fforce" pragma.
CPAN::Module::get()
Runs a get on the distribution associated with this module.
CPAN::Module::inst_file()
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.
CPAN::Module::available_file()
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 modules.
CPAN::Module::inst_version()
Returns the version number of the installed module in readable format.
CPAN::Module::available_version()
Returns the version number of the available module in readable format.
CPAN::Module::install()
Runs an "install" on the distribution associated with this module.
CPAN::Module::look()
Changes to the directory where the distribution associated with this module has been unpacked and
opens a subshell there. Exiting the subshell returns.
CPAN::Module::make()
Runs a "make" on the distribution associated with this module.
CPAN::Module::manpage_headline()
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.
CPAN::Module::perldoc()
Runs a "perldoc" on this module.
CPAN::Module::readme()
Runs a "readme" on the distribution associated with this module.
CPAN::Module::reports()
Calls the reports() method on the associated distribution object.
CPAN::Module::test()
Runs a "test" on the distribution associated with this module.
CPAN::Module::uptodate()
Returns 1 if the module is installed and up-to-date.
CPAN::Module::userid()
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 mechanism.
Bundles
A bundle is just a perl module in the namespace Bundle:: that does not define any functions or methods.
It usually only contains documentation.
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 (verbatim):
=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 distributions.
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.
PREREQUISITES
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 shell
install Bundle::CPAN
or
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 command.
UTILITIES
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 $VERSION can be parsed, please try the above method.
• come as compressed or gzipped tarfiles or as zip files and contain a "Makefile.PL" or "Build.PL" (well,
we try to handle a bit more, but with little enthusiasm).
Debugging
Debugging this module is more than a bit complex due to interference from the software producing the
indices on CPAN, the mirroring process on CPAN, packaging, configuration, synchronicity, and even (gasp!)
due to bugs within the CPAN.pm module itself.
For debugging the code of CPAN.pm itself in interactive mode, some debugging aid can be turned on for
most packages within CPAN.pm with one of
o debug package...
sets debug mode for packages.
o debug -package...
unsets debug mode for packages.
o debug all
turns debugging on for all packages.
o debug number
which sets the debugging packages directly. Note that "o debug 0" turns debugging off.
What seems a successful strategy is the combination of "reload cpan" and the debugging switches. Add a
new debug statement while running in the shell and then issue a "reload cpan" and see the new debugging
messages immediately without losing the current context.
"o debug" without an argument lists the valid package names and the current set of packages in debugging
mode. "o debug" has built-in completion support.
For debugging of CPAN data there is the "dump" command which takes the same arguments as
make/test/install and outputs each object's Data::Dumper dump. If an argument looks like a perl variable
and contains one of "$", "@" or "%", it is eval()ed and fed to Data::Dumper directly.
Floppy, Zip, Offline Mode
CPAN.pm 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 CPAN.pm to put together all you need on a networked machine. Then copy the
$CPAN::Config->{keep_source_where} (but not $CPAN::Config->{build_dir}) directory on a floppy. This
floppy is kind of a personal CPAN. CPAN.pm on the non-networked machines works nicely with this floppy.
See also below the paragraph about CD-ROM support.
Basic Utilities for Programmers
has_inst($module)
Returns true if the module is installed. Used to load all modules into the running CPAN.pm 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
"YAML.pm" from being loaded:
cpan> o conf dontload_list push YAML
See the source for details.
has_usable($module)
Returns true if the module is installed and in a usable state. Only useful for a handful of modules
that are used internally. See the source for details.
instance($module)
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.
SECURITY
There's no strong security layer in CPAN.pm. CPAN.pm 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, CPAN.pm 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 pgp.mit.edu,
and their port 11731 (the HKP protocol).
The configuration parameter check_sigs is there to turn signature checking on or off.
EXPORT
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-liners.
ENVIRONMENT
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.
POPULATE AN INSTALLATION WITH LOTS OF MODULES
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/my_bundle.pm. 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.
CPAN.pm 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
CPAN.pm to churn away unattended.
WORKING WITH CPAN.pm BEHIND FIREWALLS
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 firewall.
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 "user@outside.host.com".
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.
SOCKS
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 CPAN.pm with the command
o conf lynx "/usr/local/bin/lynx -pscott:tiger"
That's all. Similarly for ncftp or ftp, you would configure something like
o conf ncftp "/usr/bin/ncftp -f /home/scott/ncftplogin.cfg"
Your mileage may vary...
FAQ
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 CPAN.pm
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/mybundle.pm), install the new perl with the Configure option prefix, e.g.
./Configure -Dprefix=/usr/local/perl-5.6.78.9
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 it?
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, CPAN.pm 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 manually.
8) In our intranet, we have many modules for internal use. How can I integrate these modules with
CPAN.pm 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 problem.
10) Some authors have strange characters in their names.
Internally CPAN.pm 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 CPAN.pm at rt.cpan.org and
describe your needs. Maybe we can extend the support or maybe UTF-8 terminals become widely
available.
Note: this config variable is deprecated and will be removed in a future version of CPAN.pm. 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, CPAN.pm
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 well):
% 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?
http://search.cpan.org/dist/Module-Build-Convert/
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 sites:
http://www.cs.uu.nl/people/henkp/mirmon/cpan.html
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 CPAN.pm 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 CPAN.pm 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.
COMPATIBILITY
OLD PERL VERSIONS
CPAN.pm 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.
CPANPLUS
This module and its competitor, the CPANPLUS module, are both much cooler than the other. CPAN.pm is
older. CPANPLUS was designed to be more modular, but it was never intended to be compatible with CPAN.pm.
CPANMINUS
In the year 2010 App::cpanminus was launched as a new approach to a cpan shell with a considerably
smaller footprint. Very cool stuff.
SECURITY ADVICE
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.
BUGS
Please report bugs via <http://rt.cpan.org/>
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 environment.
AUTHOR
Andreas Koenig "<andk@cpan.org>"
LICENSE
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.
See <http://www.perl.com/perl/misc/Artistic.html>
TRANSLATIONS
Kawai,Takanori provides a Japanese translation of a very old version of this manpage at
<http://homepage3.nifty.com/hippo2000/perltips/CPAN.htm>
SEE ALSO
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 shortcuts.
melezhik (Alexey) sent me a link where he published a chef recipe to work with CPAN.pm:
http://community.opscode.com/cookbooks/cpan.