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

       CPAN::FirstTime - Utility for CPAN::Config file Initialization


       The init routine asks a few questions and writes a CPAN/ or
       CPAN/ file (depending on what it is currently using).

       In the following all questions and explanations regarding config
       variables are collected.

         Normally keeps config variables in memory and changes need to
         be saved in a separate 'o conf commit' command to make them permanent
         between sessions. If you set the 'auto_commit' option to true,
         changes to a config variable are always automatically committed to

         Always commit changes to config variables to disk?

       build_cache can limit the size of the disk area for keeping the build
         directories with all the intermediate files.

         Cache size for build directory (in MB)?

         Directory where the build process takes place?

         Until version 1.88 never trusted the contents of the
         build_dir directory between sessions. Since 1.88_58 has a
         YAML-based mechanism that makes it possible to share the contents of
         the build_dir/ directory between different sessions with the same
         version of perl. People who prefer to test things several days before
         installing will like this feature because it saves a lot of time.

         If you say yes to the following question, CPAN will try to store
         enough information about the build process so that it can pick up in
         future sessions at the same state of affairs as it left a previous

         Store and re-use state information about distributions between sessions?

         When a module declares another one as a 'build_requires' prerequisite
         this means that the other module is only needed for building or
         testing the module but need not be installed permanently. In this
         case you may wish to install that other module nonetheless or just
         keep it in the 'build_dir' directory to have it available only
         temporarily.  Installing saves time on future installations but makes
         the perl installation bigger.

         You can choose if you want to always install (yes), never install
         (no) or be always asked. In the latter case you can set the default
         answer for the question to yes (ask/yes) or no (ask/no).

         Policy on installing 'build_requires' modules (yes, no, ask/yes,

         To considerably speed up the initial CPAN shell startup, it is
         possible to use Storable to create a cache of metadata. If Storable
         is not available, the normal index mechanism will be used.

         Note: this mechanism is not used when use_sqlite is on and SQLLite is

         Cache metadata (yes/no)?

         CPAN packages can be digitally signed by authors and thus verified
         with the security provided by strong cryptography. The exact
         mechanism is defined in the Module::Signature module. While this is
         generally considered a good thing, it is not always convenient to the
         end user to install modules that are signed incorrectly or where the
         key of the author is not available or where some prerequisite for
         Module::Signature has a bug and so on.

         With the check_sigs parameter you can turn signature checking on and
         off. The default is off for now because the whole tool chain for the
         functionality is not yet considered mature by some. The author of would recommend setting it to true most of the time and
         turning it off only if it turns out to be annoying.

         Note that if you do not have Module::Signature installed, no
         signature checks will be performed at all.

         Always try to check and verify signatures if a SIGNATURE file is in
         the package and Module::Signature is installed (yes/no)?

         Users who install modules and do not intend to look back, can free
         occupied disk space quickly by letting cleanup each build
         directory immediately after a successful install.

         Remove build directory after a successful install? (yes/no)?

         When you have Term::ANSIColor installed, you can turn on colorized
         output to have some visual differences between normal output,
         warnings, debugging output, and the output of the modules being
         installed. Set your favorite colors after some experimenting with the
         Term::ANSIColor module.

         Please note that on Windows platforms colorized output also requires
         the Win32::Console::ANSI module.

         Do you want to turn on colored output?

         Color for normal output?

         Color for warnings?

         Color for debugging messages?

         The prompt of the cpan shell can contain the current command number
         for easier tracking of the session or be a plain string.

         Do you want the command number in the prompt (yes/no)?

         If you have never defined your own "urllist" in your configuration
         then "" will be hesitant to use the built in default sites for
         downloading. It will ask you once per session if a connection to the
         internet is OK and only if you say yes, it will try to connect. But
         to avoid this question, you can choose your favorite download sites
         once and get away with it. Or, if you have no favorite download sites
         answer yes to the following question.

         If no urllist has been chosen yet, would you prefer to
         connect to the built-in default sites without asking? (yes/no)?

         Shall we always set the FTP_PASSIVE environment variable when dealing
         with ftp download (yes/no)?

         Statistics about downloads are truncated by size and period

         How many days shall we keep statistics about downloads?

         Statistics about downloads are truncated by size and period

         How many items shall we keep in the statistics about downloads?

       getcwd changes the current working directory often and needs to
         determine its own current working directory. Per default it uses
         Cwd::cwd but if this doesn't work on your system for some reason,
         alternatives can be configured according to the following table:

             cwd         Cwd::cwd
             getcwd      Cwd::getcwd
             fastcwd     Cwd::fastcwd
             getdcwd     Cwd::getdcwd
             backtickcwd external command cwd

         Preferred method for determining the current working directory?

         Normally, continues processing the full list of targets and
         dependencies, even if one of them fails.  However, you can specify
         that CPAN should halt after the first failure.  (Note that optional
         recommended or suggested modules that fail will not cause a halt.)

         Do you want to halt on failure (yes/no)?

         If you have one of the readline packages (Term::ReadLine::Perl,
         Term::ReadLine::Gnu, possibly others) installed, the interactive CPAN
         shell will have history support. The next two questions deal with the
         filename of the history file and with its size. If you do not want to
         set this variable, please hit SPACE ENTER to the following question.

         File to save your history?

         Number of lines to save?

         Sometimes you may wish to leave the processes run by CPAN alone
         without caring about them. Because the Makefile.PL or the Build.PL
         sometimes contains question you're expected to answer, you can set a
         timer that will kill a 'perl Makefile.PL' process after the specified
         time in seconds.

         If you set this value to 0, these processes will wait forever. This
         is the default and recommended setting.

         Timeout for inactivity during {Makefile,Build}.PL?

         The CPAN indexes are usually rebuilt once or twice per hour, but the
         typical CPAN mirror mirrors only once or twice per day. Depending on
         the quality of your mirror and your desire to be on the bleeding
         edge, you may want to set the following value to more or less than
         one day (which is the default). It determines after how many days downloads new indexes.

         Let the index expire after how many days?

         When the CPAN shell is started it normally displays a greeting
         message that contains the running version and the status of readline

         Do you want to turn this message off?

         Unless you are accessing the CPAN on your filesystem via a file: URL, needs to keep the source files it downloads somewhere. Please
         supply a directory where the downloaded files are to be kept.

         Download target directory?

         When loads a module it needs for some optional feature, it
         usually reports about module name and version. Choose 'v' to get this
         message, 'none' to suppress it.

         Verbosity level for loading modules (none or v)?

         Every Makefile.PL is run by perl in a separate process. Likewise we
         run 'make' and 'make install' in separate processes. If you have any
         parameters (e.g. PREFIX, UNINST or the like) you want to pass to the
         calls, please specify them here.

         If you don't understand this question, just press ENTER.

         Typical frequently used settings:

             PREFIX=~/perl    # non-root users (please see manual for more hints)

         Parameters for the 'perl Makefile.PL' command?

         Parameters for the 'make' command? Typical frequently used setting:

             -j3              # dual processor system (on GNU make)

         Your choice:

         Parameters for the 'make install' command?  Typical frequently used

             UNINST=1         # to always uninstall potentially conflicting files
                              # (but do NOT use with local::lib or INSTALL_BASE)

         Your choice:

         Do you want to use a different make command for 'make install'?
         Cautious people will probably prefer:

             su root -c make
             sudo make
             /path1/to/sudo -u admin_account /path2/to/make

         or some such. Your choice:

         A Build.PL is run by perl in a separate process. Likewise we run
         './Build' and './Build install' in separate processes. If you have
         any parameters you want to pass to the calls, please specify them

         Typical frequently used settings:

             --install_base /home/xxx             # different installation directory

         Parameters for the 'perl Build.PL' command?

         Parameters for the './Build' command? Setting might be:

             --extra_linker_flags -L/usr/foo/lib  # non-standard library location

         Your choice:

         Parameters for the './Build install' command? Typical frequently used

             --uninst 1       # uninstall conflicting files
                              # (but do NOT use with local::lib or INSTALL_BASE)

         Your choice:

         Do you want to use a different command for './Build install'? Sudo
         users will probably prefer:

             su root -c ./Build
             sudo ./Build
             /path1/to/sudo -u admin_account ./Build

         or some such. Your choice:

         What is your favorite pager program?

         When you have Module::Build installed and a module comes with both a
         Makefile.PL and a Build.PL, which shall have precedence?

         The main two standard installer modules are the old and well
         established ExtUtils::MakeMaker (for short: EUMM) which uses the
         Makefile.PL. And the next generation installer Module::Build (MB)
         which works with the Build.PL (and often comes with a Makefile.PL
         too). If a module comes only with one of the two we will use that one
         but if both are supplied then a decision must be made between EUMM
         and MB. See also for
         a discussion about the right default.

         Or, as a third option you can choose RAND which will make a random
         decision (something regular CPAN testers will enjoy).

         In case you can choose between running a Makefile.PL or a Build.PL,
         which installer would you prefer (EUMM or MB or RAND)?

       prefs_dir can store customized build environments based on regular
         expressions for distribution names. These are YAML files where the
         default options for and the environment can be overridden and
         dialog sequences can be stored that can later be executed by an object. The distribution comes with some prefab
         YAML files that cover sample distributions that can be used as
         blueprints to store your own prefs. Please check out the distroprefs/
         directory of the distribution to get a quick start into the
         prefs system.

         Directory where to store default options/environment/dialogs for
         building modules that need some customization?

         The CPAN module can detect when a module which you are trying to
         build depends on prerequisites. If this happens, it can build the
         prerequisites for you automatically ('follow'), ask you for
         confirmation ('ask'), or just ignore them ('ignore').  Choosing
         'follow' also sets PERL_AUTOINSTALL and PERL_EXTUTILS_AUTOINSTALL for
         "--defaultdeps" if not already set.

         Please set your policy to one of the three values.

         Policy on building prerequisites (follow, ask or ignore)?

       randomize_urllist can introduce some randomness when using hosts for download
         that are configured in the urllist parameter. Enter a numeric value
         between 0 and 1 to indicate how often you want to let try a
         random host from the urllist. A value of one specifies to always use
         a random host as the first try. A value of zero means no randomness
         at all. Anything in between specifies how often, on average, a random
         host should be tried first.

         Randomize parameter

         (Experimental feature!) Some CPAN modules recommend additional,
         optional dependencies.  These should generally be installed except in
         resource constrained environments.  When this policy is true,
         recommended modules will be included with required modules.

         Include recommended modules?

         By default, each time the CPAN module is started, cache scanning is
         performed to keep the cache size in sync ('atstart'). Alternatively,
         scanning and cleanup can happen when CPAN exits ('atexit'). To
         prevent any cache cleanup, answer 'never'.

         Perform cache scanning ('atstart', 'atexit' or 'never')?

         What is your favorite shell?

         During the 'r' command finds modules without version number.
         When the command finishes, it prints a report about this. If you want
         this report to be very verbose, say yes to the following variable.

         Show all individual modules that have no $VERSION?

         The 'd' and the 'm' command normally only show you information they
         have in their in-memory database and thus will never connect to the
         internet. If you set the 'show_upload_date' variable to true, 'm' and
         'd' will additionally show you the upload date of the module or
         distribution. Per default this feature is off because it may require
         a net connection to get at the upload date.

         Always try to show upload date with 'd' and 'm' command (yes/no)?

         During the 'r' command finds modules with a version number of
         zero. When the command finishes, it prints a report about this. If
         you want this report to be very verbose, say yes to the following

         Show all individual modules that have a $VERSION of zero?

         (Experimental feature!) Some CPAN modules suggest additional,
         optional dependencies.  These 'suggest' dependencies provide enhanced
         operation.  When this policy is true, suggested modules will be
         included with required modules.

         Include suggested modules?

         When uses the tar command, which switch for the verbosity
         shall be used? Choose 'none' for quiet operation, 'v' for file name
         listing, 'vv' for full listing.

         Tar command verbosity level (none or v or vv)?

         The next option deals with the charset (a.k.a. character set) your
         terminal supports. In general, CPAN is English speaking territory, so
         the charset does not matter much but some CPAN have names that are
         outside the ASCII range. If your terminal supports UTF-8, you should
         say no to the next question. If it expects ISO-8859-1 (also known as
         LATIN1) then you should say yes. If it supports neither, your answer
         does not matter because you will not be able to read the names of
         some authors anyway. If you answer no, names will be output in UTF-8.

         Your terminal expects ISO-8859-1 (yes/no)?

         When using Term::ReadLine, you can turn ornaments on so that your
         input stands out against the output from

         Do you want to turn ornaments on?

         The goal of the CPAN Testers project ( is to
         test as many CPAN packages as possible on as many platforms as
         possible.  This provides valuable feedback to module authors and
         potential users to identify bugs or platform compatibility issues and
         improves the overall quality and value of CPAN.

         One way you can contribute is to send test results for each module
         that you install.  If you install the CPAN::Reporter module, you have
         the option to automatically generate and deliver test reports to CPAN
         Testers whenever you run tests on a CPAN package.

         See the CPAN::Reporter documentation for additional details and
         configuration settings.  If your firewall blocks outgoing traffic,
         you may need to configure CPAN::Reporter before sending reports.

         Generate test reports if CPAN::Reporter is installed (yes/no)?

         When extends @INC via PERL5LIB, it prints a list of
         directories added (or a summary of how many directories are added).
         Choose 'v' to get this message, 'none' to suppress it.

         Verbosity level for PERL5LIB changes (none or v)?

         Per default all untar operations are done with the perl module
         Archive::Tar; by setting this variable to true the external tar
         command is used if available; on Unix this is usually preferred
         because they have a reliable and fast gnutar implementation.

         Use the external tar program instead of Archive::Tar?

         When a distribution has already been tested by CPAN::Reporter on this
         machine, CPAN can skip the test phase and just rely on the test
         report history instead.

         Note that this will not apply to distributions that failed tests
         because of missing dependencies.  Also, tests can be run regardless
         of the history using "force".

         Do you want to rely on the test report history (yes/no)?

         When this is true, CPAN will set PERL_MM_USE_DEFAULT to a true value.
         This causes ExtUtils::MakeMaker (and compatible) prompts to use
         default values instead of stopping to prompt you to answer questions.
         It also sets NONINTERACTIVE_TESTING to a true value to signal more
         generally that distributions should not try to interact with you.

         Do you want to use prompt defaults (yes/no)?

         CPAN::SQLite is a layer between the index files that are downloaded
         from the CPAN and that speeds up metadata queries and reduces
         memory consumption of considerably.

         Use CPAN::SQLite if available? (yes/no)?

         This timeout prevents CPAN from hanging when trying to parse a
         pathologically coded $VERSION from a module.

         The default is 15 seconds.  If you set this value to 0, no timeout
         will occur, but this is not recommended.

         Timeout for parsing module versions?

         Both and YAML::Syck are capable of deserialising code. As
         this requires a string eval, which might be a security risk, you can
         use this option to enable or disable the deserialisation of code via
         CPAN::DeferredCode. (Note: This does not work under perl 5.6)

         Do you want to enable code deserialisation (yes/no)?

         At the time of this writing (2009-03) there are three YAML
         implementations working: YAML, YAML::Syck, and YAML::XS. The latter
         two are faster but need a C compiler installed on your system. There
         may be more alternative YAML conforming modules. When I tried two
         other players, YAML::Tiny and YAML::Perl, they seemed not powerful
         enough to work with This may have changed in the meantime.

         Which YAML implementation would you prefer?

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

perl v5.30.1                      2019-11-11            CPAN::FirstTime(3perl)