CPAN - query, download and build perl modules from CPAN sites
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
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 Net::FTP, LWP, 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.
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
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. 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
.)
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.
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.
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.
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.
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.
The commands available in the shell interface are methods in the package CPAN::Shell. If you enter the shell command, your input is split by the Text::ParseWords::shellwords() routine, which acts like most shells do. The first word is interpreted as the method to be invoked, and the rest of the words are treated as the method's arguments. Continuation lines are supported by ending a line with a literal backslash.
autobundle
writes a bundle file into the
$CPAN::Config->{cpan_home}/Bundle
directory. The file contains
a list of all modules that are both available from CPAN and currently
installed within @INC. The name of the bundle file is based on the
current date and a counter.
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() writes your own CPAN::MyConfig file into your ~/.cpan/
directory so that you can save your own preferences instead of the
system-wide ones.
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() is a special command that takes no argument and
runs the make/test/install cycle with brute force over all installed
dynamically loadable extensions (aka 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.
The report
command temporarily turns on the test_report
config
variable, then runs the force test
command with the given
arguments. The force
pragma reruns the tests and repeats
every step that might have failed before.
*** WARNING: this command downloads and executes software from CPAN to your computer of completely unknown status. You should never do this with your normal account and better have a dedicated well separated and secured machine to do this. ***
The smoke
command takes the list of recent uploads to CPAN as
provided by the recent
command and tests them all. While the
command is running $SIG{INT} is defined to mean that the current item
shall be 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
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.
CPAN::*
Classes: Author, Bundle, Module, DistributionAlthough 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.
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.
The usual shell redirection symbols | and > are recognized
by the cpan shell only when surrounded by whitespace. So piping to
pager or redirecting output into a file works somewhat as in a normal
shell, with the stipulation that you must type extra spaces.
When the CPAN module is used for the first time, a configuration
dialogue tries to determine a couple of site specific options. The
result of the dialog is stored in a hash reference $CPAN::Config
in a file CPAN/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:
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.
Displays a short help
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 regex are displayed
Example:
- o conf /color/
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
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
Reverts all config variables to the state in the saved config file.
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.
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 envariable 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_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')
- 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' 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
- 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.
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.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:
Calls Cwd::cwd
Calls Cwd::getcwd
Calls Cwd::fastcwd
Calls the external command cwd.
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 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.
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.
requires
and build_requires
dependency declarationsSince 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.
(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.
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.
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
, $VAR2
, etc. The YAML shell would produce these
with the command
- ysh < somefile.yml > somefile.dd
For Storable files the rule is that they must be constructed such that
Storable::retrieve(file)
returns an array reference and the array
elements represent one distropref object each. The conversion from
YAML would look like so:
- perl -MYAML=LoadFile -MStorable=nstore -e '
- @y=LoadFile(shift);
- nstore(\@y, shift)' somefile.yml somefile.st
In bootstrapping situations it is usually sufficient to translate only
a few YAML files to Data::Dumper for crucial modules like
YAML::Syck
, YAML.pm
and Expect.pm
. If you prefer Storable
over Data::Dumper, remember to pull out a Storable version that writes
an older format than all the other Storable versions that will need to
read them.
The following example contains all supported keywords and structures
with the exception of eexpect
which can be used instead of
expect
.
- ---
- comment: "Demo"
- match:
- module: "Dancing::Queen"
- distribution: "^CHACHACHA/Dancing-"
- not_distribution: "\.zip$"
- 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: []
- commendline: "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
Every YAML document represents a single hash reference. The valid keys in this hash are as follows:
A comment
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.
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.
Specifies that this distribution shall not be processed at all.
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.
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.
Processing instructions for the make install
or ./Build install
phase of the CPAN mantra. See below under Processing Instructions.
Processing instructions for the make
or ./Build phase of the
CPAN mantra. See below under Processing Instructions.
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.
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
distroname. 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.
Processing instructions for the perl Makefile.PL
or perl
Build.PL
phase of the CPAN mantra. See below under Processing
Instructions.
Processing instructions for the make test
or ./Build test phase
of the CPAN mantra. See below under Processing Instructions.
Arguments to be added to the command line
A full commandline to run via system().
During execution, the environment variable PERL is set
to $^X (but with an absolute path). If commandline
is specified,
args
is not used.
Extended expect
. This is a hash reference with four allowed keys,
mode
, timeout
, reuse
, and talk
.
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.
Environment variables to be set during the command
expect: <array>
is a short notation for
eexpect: mode: deterministic timeout: 15 talk: <array>
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.
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:-)
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. Each of the commands that produce
listings of modules (r
, autobundle
, u
) also return a list of
the IDs of all modules within the list.
The IDs of all objects available within a program are strings that can
be expanded to the corresponding real objects with the
CPAN::Shell->expand("Module",@things)
method. Expand returns a
list of CPAN::Module objects according to the @things
arguments
given. In scalar context, it returns only the first element of the
list.
Like expand, but returns objects of the appropriate type, i.e. CPAN::Bundle objects for bundles, CPAN::Module objects for modules, and CPAN::Distribution objects for distributions. Note: it does not expand to CPAN::Author objects.
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:
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;
Returns a one-line description of the author
Returns a multi-line description of the author
Returns the author's email address
Returns the author's name
An alias for fullname
Returns a one-line description of the bundle
Returns a multi-line description of the bundle
Recursively runs the clean
method on all items contained in the bundle.
Returns a list of objects' IDs contained in a bundle. The associated objects may be bundles, modules or distributions.
Forces CPAN to perform a task that it normally would have refused to
do. Force takes as arguments a method name to be called and any number
of additional arguments that should be passed to the called method.
The internals of the object get the needed changes so that 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.
Recursively runs the get
method on all items contained in the bundle
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.
Like CPAN::Bundle::inst_file, but returns the $VERSION
Returns 1 if the bundle itself and all its members are uptodate.
Recursively runs the install
method on all items contained in the bundle
Recursively runs the make
method on all items contained in the bundle
Recursively runs the readme
method on all items contained in the bundle
Recursively runs the test
method on all items contained in the bundle
Returns a one-line description of the distribution
Returns a multi-line description of the distribution
Returns the CPAN::Author object of the maintainer who uploaded this distribution
Returns a string of the form "AUTHORID/TARBALL", where AUTHORID is the author's PAUSE ID and TARBALL is the distribution filename.
Returns the distribution filename without any archive suffix. E.g "Foo-Bar-0.01"
Changes to the directory where the distribution has been unpacked and
runs make clean
there.
Returns a list of IDs of modules contained in a distribution file. Works only for distributions listed in the 02packages.details.txt.gz file. This typically means that just most recent version of a distribution is covered.
Changes to the directory where the distribution has been unpacked and runs something like
- cvs -d $cvs_root import -m $cvs_log $cvs_dir $userid v$version
there.
Returns the directory into which this distribution has been unpacked.
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.
Downloads the distribution from CPAN and unpacks it. Does nothing if the distribution has already been downloaded and unpacked within the current session.
Changes to the directory where the distribution has been unpacked and
runs the external command make install
there. If make
has not
yet been run, it will be run first. A make test
is issued in
any case and if this fails, the install is cancelled. The
cancellation can be avoided by letting force
run the install
for
you.
This install method only has the power to install the distribution if there are no dependencies in the way. To install an object along with all its dependencies, use CPAN::Shell->install.
Note that install() gives no meaningful return value. See uptodate().
Install all distributions that have tested sucessfully but
not yet installed. See also is_tested
.
Returns 1 if this distribution file seems to be a perl distribution. Normally this is derived from the file name only, but the index from CPAN can contain a hint to achieve a return value of true for other filenames too.
Changes to the directory where the distribution has been unpacked and opens a subshell there. Exiting the subshell returns.
First runs the get
method to make sure the distribution is
downloaded and unpacked. Changes to the directory where the
distribution has been unpacked and runs the external commands perl
Makefile.PL
or perl Build.PL
and make
there.
Downloads the pod documentation of the file associated with a
distribution (in HTML format) and runs it through the external
command lynx specified in $CPAN::Config-
{lynx}>. If lynx
isn't available, it converts it to plain text with the external
command html2text and runs it through the pager specified
in $CPAN::Config-
{pager}>
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 distroname (e.g.
AUTHOR/Foo-Bar-3.14.tar.gz) is matched against the regular expressions
stored in the $root->{match}{distribution} attribute value.
Additionally all module names contained in a distribution are matched
against the regular expressions in the $root->{match}{module} attribute
value. The two match values are ANDed together. Each of the two
attributes are optional.
Returns the hash reference that has been announced by a distribution
as the requires
and build_requires
elements. These can be
declared either by the META.yml
(if authoritative) or can be
deposited after the run of Build.PL
in the file ./_build/prereqs
or after the run of Makfile.PL
written as the PREREQ_PM
hash in
a comment in the produced Makefile
. Note: this method only works
after an attempt has been made to make
the distribution. Returns
undef otherwise.
Downloads the README file associated with a distribution and runs it
through the pager specified in $CPAN::Config-
{pager}>.
Downloads report data for this distribution from www.cpantesters.org and displays a subset of them.
Returns the content of the META.yml of this distro as a hashref. Note:
works only after an attempt has been made to make
the distribution.
Returns undef otherwise. Also returns undef if the content of META.yml
is not authoritative. (The rules about what exactly makes the content
authoritative are still in flux.)
Changes to the directory where the distribution has been unpacked and
runs make test
there.
Returns 1 if all the modules contained in the distribution are uptodate. Relies on containsmods.
Forces a reload of all indices.
Reloads all indices if they have not been read for more than
$CPAN::Config-
{index_expire}> days.
CPAN::Author, CPAN::Bundle, CPAN::Module, and CPAN::Distribution inherit this method. It prints the data structure associated with an object. Useful for debugging. Note: the data structure is considered internal and thus subject to change without notice.
Returns a one-line description of the module in four columns: The
first column contains the word Module
, the second column consists
of one character: an equals sign if this module is already installed
and uptodate, a less-than sign if this module is installed but can be
upgraded, and a space if the module is not installed. The third column
is the name of the module and the fourth column gives maintainer or
distribution information.
Returns a multi-line description of the module
Runs a clean on the distribution associated with this module.
Returns the filename on CPAN that is associated with the module.
Returns the latest version of this module available on CPAN.
Runs a cvs_import on the distribution associated with this module.
Returns a 44 character description of this module. Only available for modules listed in The Module List (CPAN/modules/00modlist.long.html or 00modlist.long.txt.gz)
Returns the CPAN::Distribution object that contains the current version of this module.
Returns a hash reference. The keys of the hash are the letters D
,
S
, L
, I
, and <P>, for development status, support level,
language, interface and public licence respectively. The data for the
DSLIP status are collected by 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 maintainance
- 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: appoved by www.opensource.org
- d - allows distribution without restrictions
- r - restricted distribtion
- n - no license at all
Forces CPAN to perform a task it would normally refuse to
do. Force takes as arguments a method name to be invoked and any number
of additional arguments to pass that method.
The internals of the object get the needed changes so that CPAN.pm
does not refuse to take the action. See also the section above on the
force
and the fforce
pragma.
Runs a get on the distribution associated with this module.
Returns the filename of the module found in @INC. The first file found is reported, just as perl itself stops searching @INC once it finds a module.
Returns the filename of the module found in PERL5LIB or @INC. The
first file found is reported. The advantage of this method over
inst_file
is that modules that have been tested but not yet
installed are included because PERL5LIB keeps track of tested modules.
Returns the version number of the installed module in readable format.
Returns the version number of the available module in readable format.
Runs an install
on the distribution associated with this module.
Changes to the directory where the distribution associated with this module has been unpacked and opens a subshell there. Exiting the subshell returns.
Runs a make
on the distribution associated with this module.
If module is installed, peeks into the module's manpage, reads the headline, and returns it. Moreover, if the module has been downloaded within this session, does the equivalent on the downloaded module even if it hasn't been installed yet.
Runs a perldoc
on this module.
Runs a readme
on the distribution associated with this module.
Calls the reports() method on the associated distribution object.
Runs a test
on the distribution associated with this module.
Returns 1 if the module is installed and up-to-date.
Returns the author's ID of the module.
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.
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, ie. 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.
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.
This module presumes that all packages on CPAN
declare their $VERSION variable in an easy to parse manner. This prerequisite can hardly be relaxed because it consumes far too much memory to load all packages into the running program just to determine the $VERSION variable. Currently all programs that are dealing with version use something like this
- perl -MExtUtils::MakeMaker -le \
- 'print MM->parse_version(shift)' filename
If you are author of a package and wonder if your $VERSION can be parsed, please try the above method.
come as compressed or gzipped tarfiles or as zip files and contain a
Makefile.PL
or Build.PL
(well, we try to handle a bit more, but
with little enthusiasm).
Debugging this module is more than a bit complex due to interference from the software producing the indices on CPAN, the mirroring process on CPAN, packaging, configuration, synchronicity, and even (gasp!) due to bugs within the 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
sets debug mode for packages.
unsets debug mode for packages.
turns debugging on for all packages.
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.
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.
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.
Returns true if the module is installed and in a usable state. Only useful for a handful of modules that are used internally. See the source for details.
The constructor for all the singletons used to represent modules, distributions, authors, and bundles. If the object already exists, this method returns the object; otherwise, it calls the constructor.
There's no strong security layer in 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:
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 keyservers, 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.
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.
When the CPAN shell enters a subshell via the look command, it sets the environment CPAN_SHELL_LEVEL to 1, or increments that variable if it is already set.
When CPAN runs, it sets the environment variable PERL5_CPAN_IS_RUNNING to the ID of the running process. It also sets PERL5_CPANPLUS_IS_RUNNING to prevent runaway processes which could happen with older versions of Module::Install.
When running perl Makefile.PL
, the environment variable
PERL5_CPAN_IS_EXECUTING
is set to the full path of the
Makefile.PL
that is being executed. This prevents runaway processes
with newer versions of Module::Install.
When the config variable ftp_passive is set, all downloads will be run with the environment variable FTP_PASSIVE set to this value. This is in general a good idea as it influences both Net::FTP and LWP based connections. The same effect can be achieved by starting the cpan shell with this environment variable set. For Net::FTP alone, one can also always set passive mode by running libnetcfg.
Populating a freshly installed perl with one's favorite modules is pretty easy if you maintain a private bundle definition file. To get a useful blueprint of a bundle definition file, the command autobundle can be used on the CPAN shell command line. This command writes a bundle definition file for all modules installed for the current perl interpreter. It's recommended to run this command once only, and from then on maintain the file manually under a private name, say Bundle/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 cofeee after a few minutes and leave CPAN.pm to churn away untended.
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.
Firewalls can be categorized into three basic types.
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.
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 means these firewalls try to make themselves invisible to users inside the firewall. An FTP data connection is normally created by sending your IP address to the remote server and then listening for the return connection. But the remote server will not be able to connect to you because of the firewall. For these types of firewall, FTP connections need to be done in a passive mode.
There are two that I can think off.
If you are using a SOCKS firewall, you will need to compile perl and link it with the SOCKS library. This is what is normally called a 'socksified' perl. With this executable you will be able to connect to servers outside the firewall as if it were not there.
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.
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...
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
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.
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.
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.
I am not root, how can I install a module in a personal directory?
First of all, you will want to use your own configuration, not the one that your root user installed. If you do not have permission to write in the cpan directory that root has configured, you will be asked if you want to create your own config. Answering "yes" will bring you into CPAN's configuration stage, using the system config for all defaults except things that have to do with CPAN's work directory, saving your choices to your MyConfig.pm file.
You can also manually initiate this process with the following command:
- % perl -MCPAN -e 'mkmyconfig'
or by running
- mkmyconfig
from the CPAN shell.
You will most probably also want to configure something like this:
- o conf makepl_arg "LIB=~/myperl/lib \
- INSTALLMAN1DIR=~/myperl/man/man1 \
- INSTALLMAN3DIR=~/myperl/man/man3 \
- INSTALLSCRIPT=~/myperl/bin \
- INSTALLBIN=~/myperl/bin"
and then the equivalent command for Module::Build, which is
- o conf mbuildpl_arg "--lib=~/myperl/lib \
- --installman1dir=~/myperl/man/man1 \
- --installman3dir=~/myperl/man/man3 \
- --installscript=~/myperl/bin \
- --installbin=~/myperl/bin"
You can make this setting permanent like all o conf
settings with
o conf commit
or by setting auto_commit
beforehand.
You will have to add ~/myperl/man to the MANPATH environment variable and also tell your perl programs to look into ~/myperl/lib, e.g. by including
- use lib "$ENV{HOME}/myperl/lib";
or setting the PERL5LIB environment variable.
While we're speaking about $ENV{HOME}, it might be worth mentioning, that for Windows we use the File::HomeDir module that provides an equivalent to the concept of the home directory on Unix.
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.
How to get a package, unwrap it, and make a change before building it?
Have a look at the look
(!) command.
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.
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.
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.
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 bugreport 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.
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.
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.
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'
How do I create a Module::Build based Build.PL derived from an ExtUtils::MakeMaker focused Makefile.PL?
I'm frequently irritated with the CPAN shell's inability to help me select a good mirror.
The urllist config parameter is yours. You can add and remove sites at will. You should find out which sites have the best uptodateness, bandwidth, reliability, etc. and are topologically close to you. Some people prefer fast downloads, others uptodateness, 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.
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.
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.
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
value, atstart
only cleans up the build directory when you start
the CPAN shell. If you never start up the CPAN shell, you probably
also have to clean up the build directory yourself.
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.
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.
This software enables you to upgrade software on your computer and so is inherently dangerous because the newly installed software may contain bugs and may alter the way your computer works or even make it unusable. Please consider backing up your data before every upgrade.
Please report bugs via 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.
Andreas Koenig <andk@cpan.org>
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
Kawai,Takanori provides a Japanese translation of this manpage at http://homepage3.nifty.com/hippo2000/perltips/CPAN.htm
cpan, CPAN::Nox, CPAN::Version