# Copyright (C) 2002 Richard Clamp.  All Rights Reserved.
#
# This module is free software; you can redistribute it and/or modify it
# under the same terms as Perl itself.

package Text::Glob;
use strict;
use Exporter;
use vars qw/$VERSION @ISA @EXPORT_OK
            $strict_leading_dot $strict_wildcard_slash/;
$VERSION = '0.06';
@ISA = 'Exporter';
@EXPORT_OK = qw( glob_to_regex match_glob );

$strict_leading_dot    = 1;
$strict_wildcard_slash = 1;

use constant debug => 0;

sub glob_to_regex {
    my $glob = shift;
    my ($regex, $in_curlies, $escaping);
    local $_;
    my $first_byte = 1;
    for ($glob =~ m/(.)/gs) {
        if ($first_byte) {
            if ($strict_leading_dot) {
                $regex .= '(?=[^\.])' unless $_ eq '.';
            }
            $first_byte = 0;
        }
        if ($_ eq '/') {
            $first_byte = 1;
        }
        if ($_ eq '.' || $_ eq '(' || $_ eq ')' || $_ eq '|' ||
            $_ eq '+' || $_ eq '^' || $_ eq '$' ) {
            $regex .= "\\$_";
        }
        elsif ($_ eq '*') {
            $regex .= $escaping ? "\\*" :
              $strict_wildcard_slash ? "[^/]*" : ".*";
        }
        elsif ($_ eq '?') {
            $regex .= $escaping ? "\\?" :
              $strict_wildcard_slash ? "[^/]" : ".";
        }
        elsif ($_ eq '{') {
            $regex .= $escaping ? "\\{" : "(";
            ++$in_curlies unless $escaping;
        }
        elsif ($_ eq '}' && $in_curlies) {
            $regex .= $escaping ? "}" : ")";
            --$in_curlies unless $escaping;
        }
        elsif ($_ eq ',' && $in_curlies) {
            $regex .= $escaping ? "," : "|";
        }
        elsif ($_ eq "\\") {
            if ($escaping) {
                $regex .= "\\\\";
                $escaping = 0;
            }
            else {
                $escaping = 1;
            }
            next;
        }
        else {
            $regex .= $_;
            $escaping = 0;
        }
        $escaping = 0;
    }
    print "# $glob $regex\n" if debug;
    qr/^$regex$/;
}

sub match_glob {
    print "# ", join(', ', map { "'$_'" } @_), "\n" if debug;
    my $glob = shift;
    my $regex = glob_to_regex $glob;
    local $_;
    grep { $_ =~ $regex } @_;
}

1;
__END__

=head1 NAME

Text::Glob - match globbing patterns against text

=head1 SYNOPSIS

 use Text::Glob qw( match_glob glob_to_regex );

 print "matched\n" if match_glob( "foo.*", "foo.bar" );

 # prints foo.bar and foo.baz
 my $regex = glob_to_regex( "foo.*" );
 for ( qw( foo.bar foo.baz foo bar ) ) {
     print "matched: $_\n" if /$regex/;
 }

=head1 DESCRIPTION

Text::Glob implements glob(3) style matching that can be used to match
against text, rather than fetching names from a filesystem.  If you
want to do full file globbing use the File::Glob module instead.

=head2 Routines

=over

=item match_glob( $glob, @things_to_test )

Returns the list of things which match the glob from the source list.

=item glob_to_regex( $glob )

Returns a compiled regex which is the equiavlent of the globbing
pattern.

=back

=head1 SYNTAX

The following metacharacters and rules are respected.

=over

=item C<*> - match zero or more characters

C<a*> matches C<a>, C<aa>, C<aaaa> and many many more.

=item C<?> - match exactly one character

C<a?> matches C<aa>, but not C<a>, or C<aa>

=item Character sets/ranges

C<example.[ch]> matches C<example.c> and C<example.h>

C<demo.[a-c]> matches C<demo.a>, C<demo.b>, and C<demo.c>

=item alternation

C<example.{foo,bar,baz}> matches C<example.foo>, C<example.bar>, and
C<example.baz>

=item leading . must be explictly matched

C<*.foo> does not match C<.bar.foo>.  For this you must either specify
the leading . in the glob pattern (C<.*.foo>), or set
C<$Text::Glob::strict_leading_dot> to a false value while compiling
the regex.

=item C<*> and C<?> do not match /

C<*.foo> does not match C<bar/baz.foo>.  For this you must either
explicitly match the / in the glob (C<*/*.foo>), or set
C<$Text::Glob::strict_wildcard_slash> to a false value with compiling
the regex.

=back

=head1 BUGS

The code uses qr// to produce compiled regexes, therefore this module
requires perl version 5.005_03 or newer.

=head1 AUTHOR

Richard Clamp <richardc@unixbeard.net>

=head1 COPYRIGHT

Copyright (C) 2002 Richard Clamp.  All Rights Reserved.

This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

=head1 SEE ALSO

L<File::Glob>, glob(3)

=cut