Dpkg::Version(3)						   libdpkg-perl 						  Dpkg::Version(3)

NAME

       Dpkg::Version - handling and comparing dpkg-style version numbers

DESCRIPTION

       The Dpkg::Version module provides pure-Perl routines to compare dpkg-style version numbers (as used in Debian packages) and also an object
       oriented interface overriding perl operators to do the right thing when you compare Dpkg::Version object between them.

OBJECT INTERFACE

       my $v = Dpkg::Version->new($version, %opts)
	   Create a new Dpkg::Version object corresponding to the version indicated in the string (scalar) $version. By default it will accepts
	   any string and consider it as a valid version. If you pass the option "check => 1", it will return undef if the version is invalid (see
	   version_check for details).

	   You can always call $v->is_valid() later on to verify that the version is valid.

       boolean evaluation
	   When the Dpkg::Version object is used in a boolean evaluation (for example in "if ($v)" or "$v || 'default'") it returns its string
	   representation if the version stored is valid ($v->is_valid()) and undef otherwise.

       $v->is_valid()
	   Returns true if the version is valid, false otherwise.

       $v->epoch(), $v->version(), $v->revision()
	   Returns the corresponding part of the full version string.

       $v1 <=> $v2, $v1 < $v2, $v1 <= $v2, $v1 > $v2, $v1 >= $v2
	   Numerical comparison of various versions numbers. One of the two operands needs to be a Dpkg::Version, the other one can be anything
	   provided that its string representation is a version number.

       "$v", $v->as_string()
	   Returns the string representation of the version number.

FUNCTIONS

       All the functions are exported by default.

       version_compare($a, $b)
	   Returns -1 if $a is earlier than $b, 0 if they are equal and 1 if $a is later than $b.

	   If $a or $b are not valid version numbers, it dies with an error.

       version_compare_relation($a, $rel, $b)
	   Returns the result (0 or 1) of the given comparison operation. This function is implemented on top of version_compare().

	   Allowed values for $rel are the exported constants REL_GT, REL_GE, REL_EQ, REL_LE, REL_LT. Use version_normalize_relation() if you have
	   an input string containing the operator.

       my $rel = version_normalize_relation($rel_string)
	   Returns the normalized constant of the relation $rel (a value among REL_GT, REL_GE, REL_EQ, REL_LE and REL_LT). Supported relations
	   names in input are: "gt", "ge", "eq", "le", "lt", ">>", ">=", "=", "<=", "<<". ">" and "<" are also supported but should not be used as
	   they are obsolete aliases of ">=" and "<=".

       version_compare_string($a, $b)
	   String comparison function used for comparing non-numerical parts of version numbers. Returns -1 if $a is earlier than $b, 0 if they
	   are equal and 1 if $a is later than $b.

	   The "~" character always sort lower than anything else. Digits sort lower than non-digits. Among remaining characters alphabetic
	   characters (A-Za-z) sort lower than the other ones. Within each range, the ASCII decimal value of the character is used to sort between
	   characters.

       version_compare_part($a, $b)
	   Compare two corresponding sub-parts of a version number (either upstream version or debian revision).

	   Each parameter is split by version_split_digits() and resulting items are compared together.in digits and non-digits items that are
	   compared together. As soon as a difference happens, it returns -1 if $a is earlier than $b, 0 if they are equal and 1 if $a is later
	   than $b.

       my @items = version_split_digits($version)
	   Splits a string in items that are each entirely composed either of digits or of non-digits. For instance for "1.024~beta1+svn234" it
	   would return ("1", ".", "024", "~beta", "1", "+svn", "234").

       my ($ok, $msg) = version_check($version)
       my $ok = version_check($version)
	   Checks the validity of $version as a version number. Returns 1 in $ok if the version is valid, 0 otherwise. In the latter case, $msg
	   contains a description of the problem with the $version scalar.

AUTHOR

       Don Armstrong <don@donarmstrong.com>, Colin Watson <cjwatson@debian.org> and Raphael Hertzog <hertzog@debian.org>, based on the
       implementation in "dpkg/lib/vercmp.c" by Ian Jackson and others.

1.16.0.3							    2012-04-17							  Dpkg::Version(3)