Git::Version::Compare - Functions to compare Git versions
use Git::Version::Compare qw( cmp_git ); # result: 1.2.3 1.7.0.rc0 1.7.4.rc1 1.8.3.4 1.9.3 2.0.0.rc2 2.0.3 2.3.0.rc1 my @versions = sort cmp_git qw( 1.7.4.rc1 1.9.3 1.7.0.rc0 2.0.0.rc2 1.2.3 1.8.3.4 2.3.0.rc1 2.0.3 );
Git::Version::Compare contains a selection of subroutines that make dealing with Git-related things (like versions) a little bit easier.
The strings to compare can be version numbers, tags from git.git or the output of git version or git describe.
git.git
git version
git describe
These routines collect the knowledge about Git versions that was accumulated while developing Git::Repository.
By default Git::Version::Compare does not export any subroutines.
All the comparison version functions die when given strings that do not look like Git version numbers (the check is done with "looks_like_git").
if ( lt_git( $v1, $v2 ) ) { ... }
A Git-aware version of the lt operator.
lt
if ( gt_git( $v1, $v2 ) ) { ... }
A Git-aware version of the gt operator.
gt
if ( le_git( $v1, $v2 ) ) { ... }
A Git-aware version of the le operator.
le
if ( ge_git( $v1, $v2 ) ) { ... }
A Git-aware version of the ge operator.
ge
if ( eq_git( $v1, $v2 ) ) { ... }
A Git-aware version of the eq operator.
eq
if ( ne_git( $v1, $v2 ) ) { ... }
A Git-aware version of the ne operator.
ne
@versions = sort cmp_git @versions;
A Git-aware version of the cmp operator.
cmp
# true looks_like_git(`git version`); # duh # false looks_like_git('v1.7.3_02'); # no _ in git versions
Given a string, returns true if it looks like a Git version number (and can therefore be parsed by Git::Version::Number) and false otherwise.
Git::Version::Number
Exports lt_git, gt_git, le_git, ge_git, eq_git, and ne_git.
lt_git
gt_git
le_git
ge_git
eq_git
ne_git
Exports lt_git, gt_git, le_git, ge_git, eq_git, ne_git, cmp_git, and looks_like_git.
cmp_git
looks_like_git
Version numbers as returned by git version are in the following formats (since the 1.4 series, in 2006):
1.4
# stable version 1.6.0 2.7.1 # maintenance release 1.8.5.6 # release candidate 1.6.0.rc2 # development version # (the last two elements come from `git describe`) 1.7.1.209.gd60ad 1.8.5.1.21.gb2a0afd 2.3.0.rc0.36.g63a0e83
In the git.git repository, several commits have multiple tags (e.g. v1.0.1 and v1.0.2 point respectively to v1.0.0a and v1.0.0b). Pre-1.0.0 versions also have non-standard formats like 0.99.9j or 1.0rc2.
v1.0.1
v1.0.2
v1.0.0a
v1.0.0b
0.99.9j
1.0rc2
This explains why:
# this is true eq_git( '0.99.9l', '1.0rc4' ); eq_git( '1.0.0a', '1.0.1' ); # this is false ge_git( '1.0rc3', '0.99.9m' );
git version appeared in version 1.3.0. git --version appeared in version 0.99.7. Before that, there is no way to know which version of Git one is dealing with.
1.3.0
git --version
0.99.7
Git::Version::Compare converts all version numbers to an internal format before performing a simple string comparison.
Git::Version::Compare
Prior to 1.4.0-rc1 (June 2006), compiling a development version of Git would lead git --version to output 1.x-GIT (with x in 0 .. 3), which would make comparing versions that are very close a futile exercise.
1.4.0-rc1
1.x-GIT
x
0 .. 3
Other issues exist when comparing development version numbers with one another. For example, 1.7.1.1 is greater than both 1.7.1.1.gc8c07 and 1.7.1.1.g5f35a, and 1.7.1 is less than both. Obviously, 1.7.1.1.gc8c07 will compare as greater than 1.7.1.1.g5f35a (asciibetically), but in fact these two version numbers cannot be compared, as they are two siblings children of the commit tagged v1.7.1). For practical purposes, the version-comparison methods declares them equal.
1.7.1.1
1.7.1.1.gc8c07
1.7.1.1.g5f35a
1.7.1
v1.7.1
Therefore:
# this is true lt_git( '1.8.5.4.8.g7c9b668', '1.8.5.4.19.g5032098' ); gt_git( '1.3.GIT', '1.3.0' ); # this is false ne_git( '1.7.1.1.gc8c07', '1.7.1.1.g5f35a' ); gt_git( '1.3.GIT', '1.3.1' );
If one were to compute the set of all possible version numbers (as returned by git --version) for all git versions that can be compiled from each commit in the git.git repository, the result would not be a totally ordered set. Big deal.
Also, don't be too precise when requiring the minimum version of Git that supported a given feature. The precise commit in git.git at which a given feature was added doesn't mean as much as the release branch in which that commit was merged.
Test::Requires::Git, for defining Git version requirements in test scripts that need git.
Copyright 2016 Philippe Bruhat (BooK), all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Git::Version::Compare, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Git::Version::Compare
CPAN shell
perl -MCPAN -e shell install Git::Version::Compare
For more information on module installation, please visit the detailed CPAN module installation guide.