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Dpkg::Version.3perl - Man Page

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.


$v = Dpkg::Version->new($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 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 emitted a warning with category "Dpkg::Version::semantic_change::overload::bool" between dpkg 1.19.1 and 1.20.0. Once fixed, or for already valid code the warning could be quiesced for that specific versions with

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

added after the use Dpkg::Version.


Returns true if the version is valid, false otherwise.

$v->epoch(), $v->version(), $v->revision()

Returns the corresponding part of the full version string.


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.


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.


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.


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.


2024-03-10 1.22.6 libdpkg-perl