init III

Perl OTRS/Kernel/cpan-lib/Set/Crontab.pm

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+# Copyright 2001 Abhijit Menon-Sen <ams@toroid.org>
+
+package Set::Crontab;
+
+use strict;
+use Carp;
+use vars qw( $VERSION );
+
+$VERSION = '1.03';
+
+sub _expand
+{
+    my (@list, @and, @not);
+    my ($self, $spec, $range) = @_;
+
+    # 1,2-4,*/3,!13,>9,<15
+    foreach (split /,/, $spec) {
+        my @pick;
+        my $step = $1 if s#/(\d+)$##;
+
+        # 0+"01" == 1
+        if    (/^(\d+)$/)       { push @pick, 0+$1;          }
+        elsif (/^\*$/)          { push @pick, @$range;       }
+        elsif (/^(\d+)-(\d+)$/) { push @pick, 0+$1..0+$2;    } 
+        elsif (/^!(\d+)$/)      { push @not,  "\$_ != 0+$1"; }
+        elsif (/^([<>])(\d+)$/) { push @and,  "\$_ $1 0+$2"; }
+
+        if ($step) {
+            my $i;
+            @pick = grep { defined $_ if $i++ % $step == 0 } @pick;
+        }
+
+        push @list, @pick;
+    }
+
+    if (@and) {
+        my $and = join q{ && }, @and;
+        push @list, grep { defined $_ if eval $and } @$range;
+    }
+
+    if (@not) {
+        my $not = join q{ && }, @not;
+        @list = grep { defined $_ if eval $not } (@list ? @list : @$range);
+    }
+
+    @list = sort { $a <=> $b } @list;
+    return \@list;
+}
+
+sub _initialise
+{
+    my ($self, $spec, $range) = @_;
+    return undef unless ref($self);
+
+    croak "Usage: ".__PACKAGE__."->new(\$spec, [\@range])"
+        unless defined $spec && ref($range) eq "ARRAY";
+
+    $self->{LIST} = $self->_expand($spec, $range);
+    $self->{HASH} = {map {$_ => 1} @{$self->{LIST}}};
+
+    return $self;
+};
+
+sub new
+{
+    my $class = shift;
+    my $self  = bless {}, ref($class) || $class;
+    return $self->_initialise(@_);
+}
+
+sub contains
+{
+    my ($self, $num) = @_;
+
+    croak "Usage: \$set->contains(\$num)" unless ref($self) && defined $num;
+    return exists $self->{HASH}{$num};
+}
+
+sub list
+{
+    my $self = shift;
+
+    croak "Usage: \$set->list()" unless ref($self);
+    return @{$self->{LIST}};
+}
+
+1;
+__END__
+
+=head1 NAME
+
+Set::Crontab - Expand crontab(5)-style integer lists
+
+=head1 SYNOPSIS
+
+$s = Set::Crontab->new("1-9/3,>15,>30,!23", [0..30]);
+
+if ($s->contains(3)) { ... }
+
+=head1 DESCRIPTION
+
+Set::Crontab parses crontab-style lists of integers and defines some
+utility functions to make it easier to deal with them.
+
+=head2 Syntax
+
+Numbers, ranges, *, and step values all work exactly as described in
+L<crontab(5)>. A few extensions to the standard syntax are described
+below.
+
+=over 4
+
+=item < and >
+
+<N selects the elements smaller than N from the entire range, and adds
+them to the set. >N does likewise for elements larger than N.
+
+=item !
+
+!N excludes N from the set. It applies to the other specified 
+range; otherwise it applies to the specified ranges (i.e. "!3" with a
+range of "1-10" corresponds to "1-2,4-10", but ">3,!7" in the same range
+means "4-6,8-10").
+
+=back
+
+=head2 Functions
+
+=over 4
+
+=item new($spec, [@range])
+
+Creates a new Set::Crontab object and returns a reference to it.
+
+=item contains($num)
+
+Returns true if C<$num> exists in the set.
+
+=item list()
+
+Returns the expanded list corresponding to the set. Elements are in
+ascending order.
+
+=back
+
+The functions described above croak if they are called with incorrect
+arguments.
+
+=head1 SEE ALSO
+
+L<crontab(5)>
+
+=head1 AUTHOR
+
+Abhijit Menon-Sen <ams@toroid.org>
+
+Copyright 2001 Abhijit Menon-Sen <ams@toroid.org>
+
+This module is free software; you can redistribute it and/or modify it
+under the same terms as Perl itself.