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Manual Reference Pages  - Dpkg::Version (3)


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



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.


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.


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. 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.


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

1.16.12 Dpkg::Version (3) 2013-09-30
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