Edit: /usr/share/perl5/strict.pm (4738B)
package strict;
$strict::VERSION = "1.11";
my ( %bitmask, %explicit_bitmask );
BEGIN {
# Verify that we're called correctly so that strictures will work.
# Can't use Carp, since Carp uses us!
# see also warnings.pm.
die sprintf "Incorrect use of pragma '%s' at %s line %d.\n", __PACKAGE__, +(caller)[1,2]
if __FILE__ !~ ( '(?x) \b '.__PACKAGE__.' \.pmc? \z' )
&& __FILE__ =~ ( '(?x) \b (?i:'.__PACKAGE__.') \.pmc? \z' );
%bitmask = (
refs => 0x00000002,
subs => 0x00000200,
vars => 0x00000400,
);
%explicit_bitmask = (
refs => 0x00000020,
subs => 0x00000040,
vars => 0x00000080,
);
my $bits = 0;
$bits |= $_ for values %bitmask;
my $inline_all_bits = $bits;
*all_bits = sub () { $inline_all_bits };
$bits = 0;
$bits |= $_ for values %explicit_bitmask;
my $inline_all_explicit_bits = $bits;
*all_explicit_bits = sub () { $inline_all_explicit_bits };
}
sub bits {
my $bits = 0;
my @wrong;
foreach my $s (@_) {
if (exists $bitmask{$s}) {
$^H |= $explicit_bitmask{$s};
$bits |= $bitmask{$s};
}
else {
push @wrong, $s;
}
}
if (@wrong) {
require Carp;
Carp::croak("Unknown 'strict' tag(s) '@wrong'");
}
$bits;
}
sub import {
shift;
$^H |= @_ ? &bits : all_bits | all_explicit_bits;
}
sub unimport {
shift;
if (@_) {
$^H &= ~&bits;
}
else {
$^H &= ~all_bits;
$^H |= all_explicit_bits;
}
}
1;
__END__
=head1 NAME
strict - Perl pragma to restrict unsafe constructs
=head1 SYNOPSIS
use strict;
use strict "vars";
use strict "refs";
use strict "subs";
use strict;
no strict "vars";
=head1 DESCRIPTION
The C
pragma disables certain Perl expressions that could behave
unexpectedly or are difficult to debug, turning them into errors. The
effect of this pragma is limited to the current file or scope block.
If no import list is supplied, all possible restrictions are assumed.
(This is the safest mode to operate in, but is sometimes too strict for
casual programming.) Currently, there are three possible things to be
strict about: "subs", "vars", and "refs".
=over 6
=item C
This generates a runtime error if you
use symbolic references (see L).
use strict 'refs';
$ref = \$foo;
print $$ref; # ok
$ref = "foo";
print $$ref; # runtime error; normally ok
$file = "STDOUT";
print $file "Hi!"; # error; note: no comma after $file
There is one exception to this rule:
$bar = \&{'foo'};
&$bar;
is allowed so that C would not break under stricture.
=item C
This generates a compile-time error if you access a variable that was
neither explicitly declared (using any of C, C, C, or C