CPAN(3pm) Perl Programmers Reference Guide CPAN(3pm)
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.
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.
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
o pass additional arguments to one of the four commands,
o set environment variables
o instantiate an Expect object that reads from the console, waits for
some regular expressions and enters some answers
o temporarily override assorted "CPAN.pm" configuration variables
o specify dependencies the original maintainer forgot
o disable the installation of an object altogether
See the YAML and Data::Dumper files that come with the "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", "modules",
"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::install_tested()
Install all distributions that have tested successfully but not yet
installed. See also "is_tested".
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
o declare their $VERSION variable in an easy to parse manner. This
prerequisite can hardly be relaxed because it consumes far too much
memory to load all packages into the running program just to
determine the $VERSION variable. Currently all programs that are
dealing with version use something like this
perl -MExtUtils::MakeMaker -le \
'print MM->parse_version(shift)' filename
If you are author of a package and wonder if your $VERSION can be
parsed, please try the above method.
o come as compressed or gzipped tarfiles or as zip files and contain a
"Makefile.PL" or "Build.PL" (well, we try to handle a bit more, but
with little enthusiasm).
Debugging
Debugging this module is more than a bit complex due to interference
from the software producing the indices on CPAN, the mirroring process
on CPAN, packaging, configuration, synchronicity, and even (gasp!) due
to bugs within the CPAN.pm module itself.
For debugging the code of CPAN.pm itself in interactive mode, some
debugging aid can be turned on for most packages within CPAN.pm with
one of
o debug package...
sets debug mode for packages.
o debug -package...
unsets debug mode for packages.
o debug all
turns debugging on for all packages.
o debug number
which sets the debugging packages directly. Note that "o debug 0" turns
debugging off.
What seems a successful strategy is the combination of "reload cpan"
and the debugging switches. Add a new debug statement while running in
the shell and then issue a "reload cpan" and see the new debugging
messages immediately without losing the current context.
"o debug" without an argument lists the valid package names and the
current set of packages in debugging mode. "o debug" has built-in
completion support.
For debugging of CPAN data there is the "dump" command which takes the
same arguments as make/test/install and outputs each object's
Data::Dumper dump. If an argument looks like a perl variable and
contains one of "$", "@" 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 untended.
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 AT outside.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 5.004, 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 AT 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.
perl v5.16.3 2013-03-04 CPAN(3pm)
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