NAME

       Lintian::Relation::Version - Comparison operators on Debian versions

SYNOPSIS

           print encode_utf8("yes\n") if versions_equal('1.0', '1.00');
           print encode_utf8("yes\n") if versions_gte('1.1', '1.0');
           print encode_utf8("no\n") if versions_lte('1.1', '1.0');
           print encode_utf8("yes\n") if versions_gt('1.1', '1.0');
           print encode_utf8("no\n") if versions_lt('1.1', '1.1');
           print encode_utf8("yes\n") if versions_compare('1.1', '<=', '1.1');

DESCRIPTION

       This module provides five functions for comparing version numbers.  The underlying
       implementation uses "libapt-pkg-perl" to ensure that the results match what dpkg will
       expect.

FUNCTIONS

       versions_equal(A, B)
           Returns true if A is equal to B ("=") and false otherwise.

       versions_lte(A, B)
           Returns true if A is less than or equal ("<=") to B and false otherwise.

       versions_gte(A, B)
           Returns true if A is greater than or equal (">=") to B and false otherwise.

       versions_lt(A, B)
           Returns true if A is less than ("<<") B and false otherwise.

       versions_gt(A, B)
           Returns true if A is greater than (">>") B and false otherwise.

       versions_compare(A, OP, B)
           Returns true if A OP B, where OP is one of "=", "<=", ">=", "<<", or ">>", and false
           otherwise.

       versions_comparator (A, B)
           Returns -1, 0 or 1 if the version A is (respectively) less than, equal to or greater
           than B.  This is useful for (e.g.) sorting a list of versions:

            foreach my $version (sort versions_comparator @versions) {
               ...
            }

AUTHOR

       Originally written by Russ Allbery <rra@debian.org> for Lintian and adapted to use libapt-
       pkg-perl by Adam D. Barratt <adam@adam-barratt-org.uk>.

SEE ALSO

       lintian(1)