Dpkg::Version

Section: libdpkg-perl (3perl)
Updated: 2021-02-15
Page Index

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.

METHODS

$v = Dpkg::Version->new($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 ? \''$v\`` : 'default''') it returns true if the version stored is valid ($v->is_valid()) and false otherwise.

Notice: Between dpkg 1.15.7.2 and 1.19.1 this overload used to return $v->as_string() if $v->is_valid(), a breaking change in behavior that caused ``0'' versions to be evaluated as false. To catch any possibly intended code that relied on those semantics, this overload will emit a warning with category ``Dpkg::Version::semantic_change::overload::bool'' until dpkg 1.20.x. Once fixed, or for already valid code the warning can be quiesced with

  no if $Dpkg::Version::VERSION ge '1.02',
     warnings => qw(Dpkg::Version::semantic_change::overload::bool);

added after the "use Dpkg::Version".

$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.

$v->is_native()

Returns true if the version is native, false if it has a revision.

$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(), $v->as_string(%options)

Accepts an optional option hash reference, affecting the string conversion.

Options:

omit_epoch (defaults to 0): Omit the epoch, if present, in the output string.
omit_revision (defaults to 0): Omit the revision, if present, in the output 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.
$rel = version_normalize_relation($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 $b.
The ``~'' character always sort lower than anything else. Digits sort lower than non-digits. Among remaining characters alphabetic characters (A-Z, a-z) sort lower than the other ones. Within each range, the ASCII decimal value of the character is used to sort between characters.
version_compare_part($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 $b.
@items = version_split_digits($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'').
($ok, $msg) = version_check($version)
$ok = version_check($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.

CHANGES

Version 1.03 (dpkg 1.20.0)

Remove deprecation warning from semantic change in 1.02.

Version 1.02 (dpkg 1.19.1)

Semantic change: bool evaluation semantics restored to their original behavior.

Version 1.01 (dpkg 1.17.0)

New argument: Accept an options argument in $v->as_string().

New method: $v->is_native().

Version 1.00 (dpkg 1.15.6)

Mark the module as public.