Sys-Path - README

NAME

Sys::Path - supply autoconf style installation directories

SYNOPSIS

Paths for basic Unix instalation when Perl is in /usr/bin:

use Sys::Path;

        print Sys::Path->sysconfdir, "\n";
        # /etc
        print Sys::Path->datadir, "\n";
        # /usr/share
        print Sys::Path->logdir, "\n";
        # /var/log
        print Sys::Path->sharedstatedir, "\n";
        # /var/lib

Paths for Unix when Perl is in home dir /home/daxim/local/bin:

        print Sys::Path->sysconfdir, "\n";
        # /home/daxim/local/etc
        print Sys::Path->datadir, "\n";
        # /home/daxim/local/share
        print Sys::Path->logdir, "\n";
        # /home/daxim/local/log
        print Sys::Path->sharedstatedir, "\n";
        # /home/daxim/local/lib

Paths for MS Windows Strawberry Perl when installed to C:\Strawberry\

        print Sys::Path->sysconfdir, "\n";
        # C:\Strawberry\etc
        print Sys::Path->datadir, "\n";
        # C:\Strawberry\share
        print Sys::Path->logdir, "\n";
        # C:\Strawberry\log
        print Sys::Path->sharedstatedir, "\n";
        # C:\Strawberry\lib

DESCRIPTION

The goal is that Sys::Path provides autoconf style system paths.

The default paths for file locations are based on http://www.pathname.com/fhs/ (Filesystem Hierarchy Standard) if the Perl was installed in /usr. For all other non-standard Perl installations or systems the default prefix is the prefix of Perl it self. Still those are just defaults and can be changed during `perl Build.PL' prompting. After Sys::Path is configured and installed all programs using it can just read/use the paths.

In addition Sys::Path includes some functions that are related to modules build or instalation. For now there is only Module::Build based Module::Build::SysPath that uses Sys::Path.

BUILD TIME CONFIGURATION

        PERL_MM_USE_DEFAULT=1 perl Build.PL \
            --sp-prefix=/usr/local \
            --sp-sysconfdir=/usr/local/etc \
            --sp-localstatedir=/var/local

NOTE

This is an experiment and lot of questions and concerns can come out about the paths configuration. Distributions build systems integration and the naming. And as this is early version thinks may change. For these purposes there is a mailing list http://lists.meon.sk/mailman/listinfo/sys-path.

WHY?
The filesystem standard has been designed to be used by Unix distribution developers, package developers, and system implementors. However, it is primarily intended to be a reference and is not a tutorial on how to manage a Unix filesystem or directory hierarchy.

Sys::Path follows this standard when it is possible. Or when Perl follows. Perl can be installed in many places. Most Linux distributions place Perl in /usr/bin/perl where FHS suggest. In this case the FHS folders are suggested in prompt when doing ``perl Build.PL'`. In other cases for other folders or home-dir Perl distributions Sys::Path will suggest folders under Perl install prefix. (ex. c:\strawerry\ for the ones using Windows).

PATHS
Here is the list of paths. First the default FHS path, then (to compare) a suggested path when Perl is not installed in /usr.

prefix
/usr - `$Config::Config{'prefix'}'

Is a helper function and should not be used directly.

localstatedir
/var - `$Config::Config{'prefix'}'

Is a helper function and should not be used directly.

sysconfdir
/etc - $prefix/etc

The /etc hierarchy contains configuration files. See http://www.pathname.com/fhs/pub/fhs-2.3.html#ETCHOSTSPECIFICSYSTEMCONFIG URATION.

datadir
/usr/share - $prefix/share

The /usr/share hierarchy is for all read-only architecture independent data files. See
http://www.pathname.com/fhs/pub/fhs-2.3.html#USRSHAREARCHITECTUREINDEPEN DENTDATA.

docdir
/usr/share/doc - $prefix/share/doc

See datadir

localedir
/usr/share/locale - $prefix/share/locale

See datadir

cachedir
/var/cache - $localstatedir/cache

/var/cache is intended for cached data from applications. See http://www.pathname.com/fhs/pub/fhs-2.3.html#VARCACHEAPPLICATIONCACHEDAT A.

logdir
/var/log - $localstatedir/logdir

This directory contains miscellaneous log files. Most logs must be written to this directory or an appropriate subdirectory. See http://www.pathname.com/fhs/pub/fhs-2.3.html#VARLOGLOGFILESANDDIRECTORIE S.

spooldir
/var/spool - $localstatedir/spool

Contains data which is awaiting some kind of later processing. See http://www.pathname.com/fhs/pub/fhs-2.3.html#VARSPOOLAPPLICATIONSPOOLDAT A.

rundir
/var/run - $localstatedir/rundir

This directory contains system information data describing the system since it was booted. See
http://www.pathname.com/fhs/pub/fhs-2.3.html#VARRUNRUNTIMEVARIABLEDATA.

lockdir
/var/lock - $localstatedir/lock

Lock files folder. See
http://www.pathname.com/fhs/pub/fhs-2.3.html#VARLOCKLOCKFILES.

sharedstatedir
/var/lib - $localstatedir/lib

The directory for installing modifiable architecture-independent data. See
http://www.pathname.com/fhs/pub/fhs-2.3.html#VARLIBVARIABLESTATEINFORMAT ION.

webdir
/var/www - $localstatedir/www

Not defined by FHS but it is a place to put web page related (html, js, css, ...) files.

HOW IT WORKS
The heart of Sys::Path is just:

        use Config;
        if ($Config::Config{'prefix'} eq '/usr') { ... do stuff ... }

The idea is that if the Perl was installed to /usr it is FHS type installation and all path defaults are made based on FHS. For the rest of the installations `prefix' and `localstatedir' is set exactly to `$Config::Config{'prefix'}' which is the prefix of Perl that was used to install. In this case `sysconfdir' is set to `prefix+'etc''. See Sys::Path::SPc for the implementation.

METHODS

        prefix
        localstatedir
        sysconfdir
        datadir
        docdir
        localedir
        cachedir
        logdir
        spooldir
        rundir
        lockdir
        sharedstatedir
        webdir

BUILDERS/INSTALLERS helper methods
find_distribution_root(__PACKAGE__)
Find the root folder of distribution by going up the folder structure.

prompt_cfg_file_changed($src_file, $dst_file, $prompt_function) Will prompt if to overwrite `$dst_file' with `$src_file'. Returns true for "yes" and false for "no".

changed_since_install($dest_file, $file) Return if `$dest_file' changed since install. If optional `$file' is set then this one is compared agains install `$dest_file' checksum.

install_checksums(%filenames_with_checksums) Getter and setter for files checksums recording.

SEE ALSO

Module::Build::SysPath

FAQ
Why "SPc" ?

it is short (much more than SysPatchConfig)
it is weird
it's so weird that it is uniq, so there will be no conflict. (hopefully)

AUTHOR

Jozef Kutej, `<jkutej at cpan.org>'

CONTRIBUTORS

The following people have contributed to the Sys::Path by commiting their code, sending patches, reporting bugs, asking questions, suggesting useful advices, nitpicking, chatting on IRC or commenting on my blog (in no particular order):

        Lars DÉªá´Зá´Дá´Лá´Пá´¡ è¿ªæЛЙæЦ&hibar;
        Emmanuel Rodriguez

BUGS

Please report any bugs or feature requests to `bug-sys-path at rt.cpan.org', or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Sys-Path. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT
Mailing list
http://lists.meon.sk/mailman/listinfo/sys-path

The rest
You can find documentation for this module with the perldoc command.

perldoc Sys::Path

You can also look for information at:

RT: CPAN's request tracker http://rt.cpan.org/NoAuth/Bugs.html?Dist=Sys-Path
AnnoCPAN: Annotated CPAN documentation http://annocpan.org/dist/Sys-Path
CPAN Ratings http://cpanratings.perl.org/d/Sys-Path
Search CPAN http://search.cpan.org/dist/Sys-Path

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