Add built local::lib

[catagits/Gitalist.git] / local-lib5 / man / man3 / local::lib.3pm

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.\" ========================================================================
.\"
.IX Title "local::lib 3"
.TH local::lib 3 "2009-11-08" "perl v5.8.7" "User Contributed Perl Documentation"
.SH "NAME"
local::lib \- create and use a local lib/ for perl modules with PERL5LIB
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
In code \-
.PP
.Vb 1
\&  use local::lib; # sets up a local lib at ~/perl5
.Ve
.PP
.Vb 1
\&  use local::lib '~/foo'; # same, but ~/foo
.Ve
.PP
.Vb 3
\&  # Or...
\&  use FindBin;
\&  use local::lib "$FindBin::Bin/../support";  # app\-local support library
.Ve
.PP
From the shell \-
.PP
.Vb 2
\&  # Install LWP and it's missing dependencies to the 'my_lwp' directory
\&  perl \-MCPAN \-Mlocal::lib=my_lwp \-e 'CPAN::install(LWP)'
.Ve
.PP
.Vb 2
\&  # Install LWP and *all non\-core* dependencies to the 'my_lwp' directory 
\&  perl \-MCPAN \-Mlocal::lib=\-\-self\-contained,my_lwp \-e 'CPAN::install(LWP)'
.Ve
.PP
.Vb 6
\&  # Just print out useful shell commands
\&  $ perl \-Mlocal::lib
\&  export MODULEBUILDRC=/home/username/perl/.modulebuildrc
\&  export PERL_MM_OPT='INSTALL_BASE=/home/username/perl'
\&  export PERL5LIB='/home/username/perl/lib/perl5:/home/username/perl/lib/perl5/i386\-linux'
\&  export PATH="/home/username/perl/bin:$PATH"
.Ve
.Sh "The bootstrapping technique"
.IX Subsection "The bootstrapping technique"
A typical way to install local::lib is using what is known as the
\&\*(L"bootstrapping\*(R" technique.  You would do this if your system administrator
hasn't already installed local::lib.  In this case, you'll need to install
local::lib in your home directory.
.PP
1. Download and unpack the local::lib tarball from \s-1CPAN\s0 (search for \*(L"Download\*(R"
on the \s-1CPAN\s0 page about local::lib).  Do this as an ordinary user, not as root
or administrator.  Unpack the file in your home directory or in any other
convenient location.
.PP
2. Run this:
.PP
.Vb 1
\&  perl Makefile.PL \-\-bootstrap
.Ve
.PP
If the system asks you whether it should automatically configure as much
as possible, you would typically answer yes.
.PP
3. Run this:
.PP
.Vb 1
\&  make test && make install
.Ve
.PP
4. Arrange for Perl to use your own packages instead of the system
packages.  If you are using bash, you can do this as follows:
.PP
.Vb 1
\&  echo 'eval $(perl \-I$HOME/perl5/lib/perl5 \-Mlocal::lib)' >>~/.bashrc
.Ve
.PP
If you are using C shell, you can do this as follows:
.PP
.Vb 4
\&  /bin/csh
\&  echo $SHELL
\&  /bin/csh
\&  perl \-I$HOME/perl5/lib/perl5 \-Mlocal::lib >> ~/.cshrc
.Ve
.PP
You can also pass \-\-bootstrap=~/foo to get a different location \-
.PP
.Vb 2
\&  perl Makefile.PL \-\-bootstrap=~/foo
\&  make test && make install
.Ve
.PP
.Vb 1
\&  echo 'eval $(perl \-I$HOME/foo/lib/perl5 \-Mlocal::lib=$HOME/foo)' >>~/.bashrc
.Ve
.PP
After writing your shell configuration file, be sure to re-read it to get the
changed settings into your current shell's environment.
.PP
.Vb 1
\&  . ~/.bashrc
.Ve
.PP
If you are using C shell, you can do this as follows:
.PP
.Vb 4
\&  /bin/csh
\&  echo $SHELL
\&  /bin/csh
\&  perl \-I$HOME/perl5/lib/perl5 \-Mlocal::lib >> ~/.cshrc
.Ve
.PP
.Vb 1
\&  source ~/.cshrc
.Ve
.PP
You can also pass \-\-bootstrap=~/foo to get a different location \-
.PP
.Vb 2
\&  perl Makefile.PL \-\-bootstrap=~/foo
\&  make test && make install
.Ve
.PP
.Vb 1
\&  echo 'eval $(perl \-I$HOME/foo/lib/perl5 \-Mlocal::lib=$HOME/foo)' >> ~/.bashrc
.Ve
.PP
.Vb 1
\&  . ~/.bashrc
.Ve
.PP
If you're on a slower machine, or are operating under draconian disk space
limitations, you can disable the automatic generation of manpages from \s-1POD\s0 when
installing modules by using the \f(CW\*(C`\-\-no\-manpages\*(C'\fR argument when bootstrapping:
.PP
.Vb 1
\&  perl Makefile.PL \-\-bootstrap \-\-no\-manpages
.Ve
.PP
If you want to install multiple Perl module environments, say for application evelopment, 
install local::lib globally and then:
.PP
.Vb 7
\&  cd ~/mydir1
\&  perl \-Mlocal::lib=./
\&  eval $(perl \-Mlocal::lib=./)  ### To set the environment for this shell alone
\&  printenv  ### You will see that ~/mydir1 is in the PERL5LIB
\&  perl \-MCPAN \-e install ...    ### whatever modules you want
\&  cd ../mydir2
\&  ... REPEAT ...
.Ve
.PP
For multiple environments for multiple apps you may need to include a modified
version of the \f(CW\*(C`use FindBin\*(C'\fR instructions in the \*(L"In code\*(R" sample above.
If you did something like the above, you have a set of Perl modules at \f(CW\*(C`~/mydir1/lib\*(C'\fR. If you have a script at \f(CW\*(C`~/mydir1/scripts/myscript.pl\*(C'\fR,
you need to tell it where to find the modules you installed for it at \f(CW\*(C`~/mydir1/lib\*(C'\fR.
.PP
In \f(CW\*(C`~/mydir1/scripts/myscript.pl\*(C'\fR:
.PP
.Vb 4
\&  use strict;
\&  use warnings;
\&  use local::lib "$FindBin::Bin/..";  ### points to ~/mydir1 and local::lib finds lib
\&  use lib "$FindBin::Bin/../lib";     ### points to ~/mydir1/lib
.Ve
.PP
Put this before any \s-1BEGIN\s0 { ... } blocks that require the modules you installed.
.Sh "Differences when using this module under Win32"
.IX Subsection "Differences when using this module under Win32"
.Vb 5
\&  C:\e>perl \-Mlocal::lib
\&  set MODULEBUILDRC=C:\eDOCUME~1\eADMINI~1\eperl5\e.modulebuildrc
\&  set PERL_MM_OPT=INSTALL_BASE=C:\eDOCUME~1\eADMINI~1\eperl5
\&  set PERL5LIB=C:\eDOCUME~1\eADMINI~1\eperl5\elib\eperl5;C:\eDOCUME~1\eADMINI~1\eperl5\elib\eperl5\eMSWin32\-x86\-multi\-thread
\&  set PATH=C:\eDOCUME~1\eADMINI~1\eperl5\ebin;%PATH%
.Ve
.PP
.Vb 3
\&    ### To set the environment for this shell alone
\&  C:\e>perl \-Mlocal::lib > %TEMP%\etmp.bat && %TEMP%\etmp.bat && del %TEMP%\etemp.bat
\&  ### instead of $(perl \-Mlocal::lib=./)
.Ve
.PP
If you want the environment entries to persist, you'll need to add then to the
Control Panel's System applet yourself at the moment.
.PP
The \*(L"~\*(R" is translated to the user's profile directory (the directory named for
the user under \*(L"Documents and Settings\*(R" (Windows \s-1XP\s0 or earlier) or \*(L"Users\*(R"
(Windows Vista or later) unless \f(CW$ENV\fR{\s-1HOME\s0} exists. After that, the home
directory is translated to a short name (which means the directory must exist)
and the subdirectories are created.
.SH "RATIONALE"
.IX Header "RATIONALE"
The version of a Perl package on your machine is not always the version you
need.  Obviously, the best thing to do would be to update to the version you
need.  However, you might be in a situation where you're prevented from doing
this.  Perhaps you don't have system administrator privileges; or perhaps you
are using a package management system such as Debian, and nobody has yet gotten
around to packaging up the version you need.
.PP
local::lib solves this problem by allowing you to create your own directory of
Perl packages downloaded from \s-1CPAN\s0 (in a multi-user system, this would typically
be within your own home directory).  The existing system Perl installation is
not affected; you simply invoke Perl with special options so that Perl uses the
packages in your own local package directory rather than the system packages.
local::lib arranges things so that your locally installed version of the Perl
packages takes precedence over the system installation.
.PP
If you are using a package management system (such as Debian), you don't need to
worry about Debian and \s-1CPAN\s0 stepping on each other's toes.  Your local version
of the packages will be written to an entirely separate directory from those
installed by Debian.  
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This module provides a quick, convenient way of bootstrapping a user-local Perl
module library located within the user's home directory. It also constructs and
prints out for the user the list of environment variables using the syntax
appropriate for the user's current shell (as specified by the \f(CW\*(C`SHELL\*(C'\fR
environment variable), suitable for directly adding to one's shell
configuration file.
.PP
More generally, local::lib allows for the bootstrapping and usage of a
directory containing Perl modules outside of Perl's \f(CW@INC\fR. This makes it
easier to ship an application with an app-specific copy of a Perl module, or
collection of modules. Useful in cases like when an upstream maintainer hasn't
applied a patch to a module of theirs that you need for your application.
.PP
On import, local::lib sets the following environment variables to appropriate
values:
.IP "\s-1MODULEBUILDRC\s0" 4
.IX Item "MODULEBUILDRC"
.PD 0
.IP "\s-1PERL_MM_OPT\s0" 4
.IX Item "PERL_MM_OPT"
.IP "\s-1PERL5LIB\s0" 4
.IX Item "PERL5LIB"
.IP "\s-1PATH\s0" 4
.IX Item "PATH"
.PD
\&\s-1PATH\s0 is appended to, rather than clobbered.
.PP
These values are then available for reference by any code after import.
.SH "METHODS"
.IX Header "METHODS"
.Sh "ensure_directory_structure_for"
.IX Subsection "ensure_directory_structure_for"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Attempts to create the given path, and all required parent directories. Throws
an exception on failure.
.Sh "print_environment_vars_for"
.IX Subsection "print_environment_vars_for"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Prints to standard output the variables listed above, properly set to use the
given path as the base directory.
.Sh "setup_env_hash_for"
.IX Subsection "setup_env_hash_for"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Constructs the \f(CW%ENV\fR keys for the given path, by calling
\&\f(CW\*(C`build_environment_vars_for\*(C'\fR.
.Sh "install_base_perl_path"
.IX Subsection "install_base_perl_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Returns a path describing where to install the Perl modules for this local
library installation. Appends the directories \f(CW\*(C`lib\*(C'\fR and \f(CW\*(C`perl5\*(C'\fR to the given
path.
.Sh "install_base_arch_path"
.IX Subsection "install_base_arch_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Returns a path describing where to install the architecture-specific Perl
modules for this local library installation. Based on the
\&\*(L"install_base_perl_path\*(R" method's return value, and appends the value of
\&\f(CW$Config{archname}\fR.
.Sh "install_base_bin_path"
.IX Subsection "install_base_bin_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Returns a path describing where to install the executable programs for this
local library installation. Based on the \*(L"install_base_perl_path\*(R" method's
return value, and appends the directory \f(CW\*(C`bin\*(C'\fR.
.Sh "modulebuildrc_path"
.IX Subsection "modulebuildrc_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Returns a path describing where to install the \f(CW\*(C`.modulebuildrc\*(C'\fR file, based on
the given path.
.Sh "resolve_empty_path"
.IX Subsection "resolve_empty_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Builds and returns the base path into which to set up the local module
installation. Defaults to \f(CW\*(C`~/perl5\*(C'\fR.
.Sh "resolve_home_path"
.IX Subsection "resolve_home_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Attempts to find the user's home directory. If installed, uses \f(CW\*(C`File::HomeDir\*(C'\fR
for this purpose. If no definite answer is available, throws an exception.
.Sh "resolve_relative_path"
.IX Subsection "resolve_relative_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Translates the given path into an absolute path.
.Sh "resolve_path"
.IX Subsection "resolve_path"
.IP "Arguments: path" 4
.IX Item "Arguments: path"
.PP
Calls the following in a pipeline, passing the result from the previous to the
next, in an attempt to find where to configure the environment for a local
library installation: \*(L"resolve_empty_path\*(R", \*(L"resolve_home_path\*(R",
\&\*(L"resolve_relative_path\*(R". Passes the given path argument to
\&\*(L"resolve_empty_path\*(R" which then returns a result that is passed to
\&\*(L"resolve_home_path\*(R", which then has its result passed to
\&\*(L"resolve_relative_path\*(R". The result of this final call is returned from
\&\*(L"resolve_path\*(R".
.SH "A WARNING ABOUT UNINST=1"
.IX Header "A WARNING ABOUT UNINST=1"
Be careful about using local::lib in combination with \*(L"make install UNINST=1\*(R".
The idea of this feature is that will uninstall an old version of a module
before installing a new one. However it lacks a safety check that the old
version and the new version will go in the same directory. Used in combination
with local::lib, you can potentially delete a globally accessible version of a
module while installing the new version in a local place. Only combine \*(L"make
install UNINST=1\*(R" and local::lib if you understand these possible consequences.
.SH "LIMITATIONS"
.IX Header "LIMITATIONS"
Rather basic shell detection. Right now anything with csh in its name is
assumed to be a C shell or something compatible, and everything else is assumed
to be Bourne, except on Win32 systems. If the \f(CW\*(C`SHELL\*(C'\fR environment variable is
not set, a Bourne-compatible shell is assumed.
.PP
Bootstrap is a hack and will use \s-1CPAN\s0.pm for ExtUtils::MakeMaker even if you
have \s-1CPANPLUS\s0 installed.
.PP
Kills any existing \s-1PERL5LIB\s0, \s-1PERL_MM_OPT\s0 or \s-1MODULEBUILDRC\s0.
.PP
Should probably auto-fixup \s-1CPAN\s0 config if not already done.
.PP
Patches very much welcome for any of the above.
.PP
On Win32 systems, does not have a way to write the created environment variables
to the registry, so that they can persist through a reboot.
.SH "TROUBLESHOOTING"
.IX Header "TROUBLESHOOTING"
If you've configured local::lib to install \s-1CPAN\s0 modules somewhere in to your
home directory, and at some point later you try to install a module with \f(CW\*(C`cpan
\&\-i Foo::Bar\*(C'\fR, but it fails with an error like: \f(CW\*(C`Warning: You do not have
permissions to install into /usr/lib64/perl5/site_perl/5.8.8/x86_64\-linux at
/usr/lib64/perl5/5.8.8/Foo/Bar.pm\*(C'\fR and buried within the install log is an
error saying \f(CW\*(C`'INSTALL_BASE' is not a known MakeMaker parameter name\*(C'\fR, then
you've somehow lost your updated ExtUtils::MakeMaker module.
.PP
To remedy this situation, rerun the bootstrapping procedure documented above.
.PP
Then, run \f(CW\*(C`rm \-r ~/.cpan/build/Foo\-Bar*\*(C'\fR
.PP
Finally, re-run \f(CW\*(C`cpan \-i Foo::Bar\*(C'\fR and it should install without problems.
.SH "ENVIRONMENT"
.IX Header "ENVIRONMENT"
.IP "\s-1SHELL\s0" 4
.IX Item "SHELL"
.PD 0
.IP "\s-1COMSPEC\s0" 4
.IX Item "COMSPEC"
.PD
local::lib looks at the user's \f(CW\*(C`SHELL\*(C'\fR environment variable when printing out
commands to add to the shell configuration file.
.Sp
On Win32 systems, \f(CW\*(C`COMSPEC\*(C'\fR is also examined.
.SH "AUTHOR"
.IX Header "AUTHOR"
Matt S Trout <mst@shadowcat.co.uk> http://www.shadowcat.co.uk/
.PP
auto_install fixes kindly sponsored by http://www.takkle.com/
.SH "CONTRIBUTORS"
.IX Header "CONTRIBUTORS"
Chris Nehren <apeiron@cpan.org> now oversees maintenance of local::lib, in
addition to providing doc patches and bootstrap fixes to prevent users from
shooting themselves in the foot (it's more likely than you think).
.PP
Patches to correctly output commands for csh style shells, as well as some
documentation additions, contributed by Christopher Nehren <apeiron@cpan.org>.
.PP
\&'\-\-self\-contained' feature contributed by Mark Stosberg <mark@summersault.com>.
.PP
Ability to pass '\-\-self\-contained' without a directory inspired by frew on
irc.perl.org/#catalyst.
.PP
Doc patches for a custom local::lib directory contributed by Torsten Raudssus
<torsten@raudssus.de>.
.PP
Hans Dieter Pearcey <hdp@cpan.org> sent in some additional tests for ensuring
things will install properly, submitted a fix for the bug causing problems with
writing Makefiles during bootstrapping, contributed an example program, and
submitted yet another fix to ensure that local::lib can install and bootstrap
properly. Many, many thanks!
.PP
pattern of Freenode \s-1IRC\s0 contributed the beginnings of the Troubleshooting
section. Many thanks!
.PP
Patch to add Win32 support contributed by Curtis Jewell <csjewell@cpan.org>.
.PP
kgish/#perl\-help@irc.perl.org suggested revamping the section on sourcing the
shell file to make it clearer to those quickly reading the \s-1POD\s0.
.PP
t0m and chrisa on #local\-lib@irc.perl.org pointed out a \s-1PERL5LIB\s0 ordering issue
with \f(CW\*(C`\-\-self\-contained\*(C'\fR.
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright (c) 2007 \- 2009 the local::lib \*(L"\s-1AUTHOR\s0\*(R" and \*(L"\s-1CONTRIBUTORS\s0\*(R" as
listed above.
.SH "LICENSE"
.IX Header "LICENSE"
This library is free software and may be distributed under the same terms
as perl itself.