version(3p) Perl Programmers Reference Guide version(3p)

version(3p) Perl Programmers Reference Guide version(3p) #

version(3p) Perl Programmers Reference Guide version(3p)

NNAAMMEE #

 version - Perl extension for Version Objects

SSYYNNOOPPSSIISS #

   # Parsing version strings (decimal or dotted-decimal)

   use version 0.77; # get latest bug-fixes and API
   $ver = version->parse($string)

   # Declaring a dotted-decimal $VERSION (keep on one line!)

   use version; our $VERSION = version->declare("v1.2.3"); # formal
   use version; our $VERSION = qv("v1.2.3");               # deprecated
   use version; our $VERSION = qv("v1.2_3");               # deprecated

   # Declaring an old-style decimal $VERSION (use quotes!)

   our $VERSION = "1.0203";                                # recommended
   use version; our $VERSION = version->parse("1.0203");   # formal
   use version; our $VERSION = version->parse("1.02_03");  # alpha

   # Comparing mixed version styles (decimals, dotted-decimals, objects)

   if ( version->parse($v1) == version->parse($v2) ) {
     # do stuff
   }

   # Sorting mixed version styles

   @ordered = sort { version->parse($a) <=> version->parse($b) } @list;

DDEESSCCRRIIPPTTIIOONN #

 Version objects were added to Perl in 5.10.  This module implements
 version objects for older version of Perl and provides the version object
 API for all versions of Perl.  All previous releases before 0.74 are
 deprecated and should not be used due to incompatible API changes.
 Version 0.77 introduces the new 'parse' and 'declare' methods to
 standardize usage.  You are strongly urged to set 0.77 as a minimum in
 your code, e.g.

   use version 0.77; # even for Perl v.5.10.0

TTYYPPEESS OOFF VVEERRSSIIOONN OOBBJJEECCTTSS #

 There are two different types of version objects, corresponding to the
 two different styles of versions in use:

 Decimal Versions
   The classic floating-point number $VERSION.  The advantage to this
   style is that you don't need to do anything special, just type a number
   into your source file.  Quoting is recommended, as it ensures that
   trailing zeroes ("1.50") are preserved in any warnings or other output.

 Dotted Decimal Versions
   The more modern form of version assignment, with 3 (or potentially
   more) integers separated by decimal points (e.g. v1.2.3).  This is the
   form that Perl itself has used since 5.6.0 was released.  The leading
   'v' is now strongly recommended for clarity, and will throw a warning
   in a future release if omitted.  A leading 'v' character is required to
   pass the "iiss__ssttrriicctt(())" test.

DDEECCLLAARRIINNGG VVEERRSSIIOONNSS #

 If you have a module that uses a decimal $VERSION (floating point), and
 you do not intend to ever change that, this module is not for you.  There
 is nothing that version.pm gains you over a simple $VERSION assignment:

   our $VERSION = "1.02";

 Since Perl v5.10.0 includes the version.pm comparison logic anyways, you
 don't need to do anything at all.

HHooww ttoo ccoonnvveerrtt aa mmoodduullee ffrroomm ddeecciimmaall ttoo ddootttteedd--ddeecciimmaall If you have used a decimal $VERSION in the past and wish to switch to a dotted-decimal $VERSION, then you need to make a one-time conversion to the new format.

 IImmppoorrttaanntt NNoottee: you must ensure that your new $VERSION is numerically
 greater than your current decimal $VERSION; this is not always obvious.
 First, convert your old decimal version (e.g. 1.02) to a normalized
 dotted-decimal form:

   $ perl -Mversion -e 'print version->parse("1.02")->normal'
   v1.20.0

 Then increment any of the dotted-decimal components (v1.20.1 or v1.21.0).

HHooww ttoo “"ddeeccllaarree(())“” aa ddootttteedd--ddeecciimmaall vveerrssiioonn use version; our $VERSION = version->declare(“v1.2.3”);

 The "declare()" method always creates dotted-decimal version objects.
 When used in a module, you mmuusstt put it on the same line as "use version"
 to ensure that $VERSION is read correctly by PAUSE and installer tools.
 You should also add 'version' to the 'configure_requires' section of your
 module metadata file.  See instructions in ExtUtils::MakeMaker or
 Module::Build for details.

 IImmppoorrttaanntt NNoottee: Even if you pass in what looks like a decimal number
 ("1.2"), a dotted-decimal will be created ("v1.200.0"). To avoid
 confusion or unintentional errors on older Perls, follow these
 guidelines:

 • Always use a dotted-decimal with (at least) three components

 • Always use a leading-v

 • Always quote the version

 If you really insist on using version.pm with an ordinary decimal
 version, use "parse()" instead of declare.  See the "PARSING AND
 COMPARING VERSIONS" for details.

 See also version::Internals for more on version number conversion,
 quoting, calculated version numbers and declaring developer or "alpha"
 version numbers.

PPAARRSSIINNGG AANNDD CCOOMMPPAARRIINNGG VVEERRSSIIOONNSS #

 If you need to compare version numbers, but can't be sure whether they
 are expressed as numbers, strings, v-strings or version objects,  then
 you should use version.pm to parse them all into objects for comparison.

HHooww ttoo “"ppaarrssee(())“” aa vveerrssiioonn The “parse()” method takes in anything that might be a version and returns a corresponding version object, doing any necessary conversion along the way.

 • Dotted-decimal: bare v-strings (v1.2.3) and strings with more than one
   decimal point and a leading 'v' ("v1.2.3"); NOTE you can technically
   use a v-string or strings with a leading-v and only one decimal point
   (v1.2 or "v1.2"), but you will confuse both yourself and others.

 • Decimal: regular decimal numbers (literal or in a string)

 Some examples:

   $variable   version->parse($variable)
   ---------   -------------------------
   1.23        v1.230.0
   "1.23"      v1.230.0
   v1.23       v1.23.0
   "v1.23"     v1.23.0
   "1.2.3"     v1.2.3
   "v1.2.3"    v1.2.3

 See version::Internals for more on version number conversion.

HHooww ttoo cchheecckk ffoorr aa lleeggaall vveerrssiioonn ssttrriinngg If you do not want to actually create a full blown version object, but would still like to verify that a given string meets the criteria to be parsed as a version, there are two helper functions that can be employed directly:

 "is_lax()"
     The lax criteria corresponds to what is currently allowed by the
     version parser.  All of the following formats are acceptable for
     dotted-decimal formats strings:

         v1.2
         1.2345.6
         v1.23_4
         1.2345
         1.2345_01

 "is_strict()"
     If you want to limit yourself to a much more narrow definition of
     what a version string constitutes, "is_strict()" is limited to
     version strings like the following list:

         v1.234.5
         2.3456

 See version::Internals for details of the regular expressions that define
 the legal version string forms, as well as how to use those regular
 expressions in your own code if "is_lax()" and "is_strict()" are not
 sufficient for your needs.

HHooww ttoo ccoommppaarree vveerrssiioonn oobbjjeeccttss Version objects overload the “cmp” and “<=>” operators. Perl automatically generates all of the other comparison operators based on those two so all the normal logical comparisons will work.

   if ( version->parse($v1) == version->parse($v2) ) {
     # do stuff
   }

 If a version object is compared against a non-version object, the non-
 object term will be converted to a version object using "parse()".  This
 may give surprising results:

   $v1 = version->parse("v0.95.0");
   $bool = $v1 < 0.94; # TRUE since 0.94 is v0.940.0

 Always comparing to a version object will help avoid surprises:

   $bool = $v1 < version->parse("v0.94.0"); # FALSE

 Note that "alpha" version objects (where the version string contains a
 trailing underscore segment) compare as less than the equivalent version
 without an underscore:

   $bool = version->parse("1.23_45") < version->parse("1.2345"); # TRUE

 See version::Internals for more details on "alpha" versions.

OOBBJJEECCTT MMEETTHHOODDSS #

iiss__aallpphhaa(()) True if and only if the version object was created with a underscore, e.g.

   version->parse('1.002_03')->is_alpha;  # TRUE
   version->declare('1.2.3_4')->is_alpha; # TRUE

iiss__qqvv(()) True only if the version object is a dotted-decimal version, e.g.

   version->parse('v1.2.0')->is_qv;       # TRUE
   version->declare('v1.2')->is_qv;       # TRUE
   qv('1.2')->is_qv;                      # TRUE
   version->parse('1.2')->is_qv;          # FALSE

nnoorrmmaall(()) Returns a string with a standard ’normalized’ dotted-decimal form with a leading-v and at least 3 components.

  version->declare('v1.2')->normal;  # v1.2.0
  version->parse('1.2')->normal;     # v1.200.0

nnuummiiffyy(()) Returns a value representing the object in a pure decimal.

  version->declare('v1.2')->numify;  # 1.002000
  version->parse('1.2')->numify;     # 1.200

ssttrriinnggiiffyy(()) Returns a string that is as close to the original representation as possible. If the original representation was a numeric literal, it will be returned the way perl would normally represent it in a string. This method is used whenever a version object is interpolated into a string.

  version->declare('v1.2')->stringify;    # v1.2
  version->parse('1.200')->stringify;     # 1.2
  version->parse(1.02_30)->stringify;     # 1.023

EEXXPPOORRTTEEDD FFUUNNCCTTIIOONNSS #

qqvv(()) This function is no longer recommended for use, but is maintained for compatibility with existing code. If you do not want to have it exported to your namespace, use this form:

   use version 0.77 ();

iiss__llaaxx(()) (Not exported by default)

 This function takes a scalar argument and returns a boolean value
 indicating whether the argument meets the "lax" rules for a version
 number.  Leading and trailing spaces are not allowed.

iiss__ssttrriicctt(()) (Not exported by default)

 This function takes a scalar argument and returns a boolean value
 indicating whether the argument meets the "strict" rules for a version
 number.  Leading and trailing spaces are not allowed.

AAUUTTHHOORR #

 John Peacock <jpeacock@cpan.org>

SSEEEE AALLSSOO #

 version::Internals.

 perl.

perl v5.36.3 2023-02-15 version(3p)