NAME

       Dpkg::Substvars - handle variable substitution in strings

DESCRIPTION

       It provides some an object which is able to substitute variables in strings.

METHODS

       $s = Dpkg::Substvars->new($file)
               Create a new object that can do substitutions. By default it contains generic
               substitutions like ${Newline}, ${Space}, ${Tab}, ${dpkg:Version} and
               ${dpkg:Upstream-Version}.

               Additional substitutions will be read from the $file passed as parameter.

               It keeps track of which substitutions were actually used (only counting
               substvars(), not get()), and warns about unused substvars when asked to. The
               substitutions that are always present are not included in these warnings.

       $s->set($key, $value)
               Add/replace a substitution.

       $s->set_as_used($key, $value)
               Add/replace a substitution and mark it as used (no warnings will be produced even
               if unused).

       $s->set_as_auto($key, $value)
               Add/replace a substitution and mark it as used and automatic (no warnings will be
               produced even if unused).

       $s->get($key)
               Get the value of a given substitution.

       $s->delete($key)
               Remove a given substitution.

       $s->mark_as_used($key)
               Prevents warnings about a unused substitution, for example if it is provided by
               default.

       $s->no_warn($key)
               Obsolete function, use mark_as_used() instead.

       $s->load($file)
               Add new substitutions read from $file.

       $s->parse($fh, $desc)
               Add new substitutions read from the filehandle. $desc is used to identify the
               filehandle in error messages.

       $s->set_version_substvars($sourceversion, $binaryversion)
               Defines ${binary:Version}, ${source:Version} and ${source:Upstream-Version} based
               on the given version strings.

               These will never be warned about when unused.

       $s->set_arch_substvars()
               Defines architecture variables: ${Arch}.

               This will never be warned about when unused.

       $newstring = $s->substvars($string)
               Substitutes variables in $string and return the result in $newstring.

       $s->warn_about_unused()
               Issues warning about any variables that were set, but not used.

       $s->set_msg_prefix($prefix)
               Define a prefix displayed before all warnings/error messages output by the module.

       $s->filter(remove => $rmfunc) =item $s->filter(keep => $keepfun)
               Filter the substitution variables, either removing or keeping all those that
               return true when &$rmfunc($key) or &keepfunc($key) is called.

       $s->save($file)
               Store all substitutions variables except the automatic ones in the indicated file.

       "$s"    Return a string representation of all substitutions variables except the automatic
               ones.

       $str = $s->output($fh)
               Print all substitutions variables except the automatic ones in the filehandle and
               return the content written.

CHANGES

   Version 1.04 (dpkg 1.18.0)
       New method: $s->filter().

   Version 1.03 (dpkg 1.17.11)
       New method: $s->set_as_auto().

   Version 1.02 (dpkg 1.16.5)
       New argument: Accept a $binaryversion in $s->set_version_substvars(), passing a single
       argument is still supported.

       New method: $s->mark_as_used().

       Deprecated method: $s->no_warn(), use $s->mark_as_used() instead.

   Version 1.01 (dpkg 1.16.4)
       New method: $s->set_as_used().

   Version 1.00 (dpkg 1.15.6)
       Mark the module as public.

AUTHOR

       Raphaël Hertzog <hertzog@debian.org>.