package strict;
+$strict::VERSION = "1.04";
+
+# Verify that we're called correctly so that strictures will work.
+unless ( __FILE__ =~ /(^|[\/\\])\Q${\__PACKAGE__}\E\.pmc?$/ ) {
+ # Can't use Carp, since Carp uses us!
+ my (undef, $f, $l) = caller;
+ die("Incorrect use of pragma '${\__PACKAGE__}' at $f line $l.\n");
+}
+
+my %bitmask = (
+refs => 0x00000002,
+subs => 0x00000200,
+vars => 0x00000400
+);
+
+sub bits {
+ my $bits = 0;
+ my @wrong;
+ foreach my $s (@_) {
+ push @wrong, $s unless exists $bitmask{$s};
+ $bits |= $bitmask{$s} || 0;
+ }
+ if (@wrong) {
+ require Carp;
+ Carp::croak("Unknown 'strict' tag(s) '@wrong'");
+ }
+ $bits;
+}
+
+my $default_bits = bits(qw(refs subs vars));
+
+sub import {
+ shift;
+ $^H |= @_ ? bits(@_) : $default_bits;
+}
+
+sub unimport {
+ shift;
+ $^H &= ~ (@_ ? bits(@_) : $default_bits);
+}
+
+1;
+__END__
+
=head1 NAME
strict - Perl pragma to restrict unsafe constructs
=item C<strict vars>
This generates a compile-time error if you access a variable that wasn't
-declared via "our" or C<use vars>,
+declared via C<our> or C<use vars>,
localized via C<my()>, or wasn't fully qualified. Because this is to avoid
variable suicide problems and subtle dynamic scoping issues, a merely
local() variable isn't good enough. See L<perlfunc/my> and
This disables the poetry optimization, generating a compile-time error if
you try to use a bareword identifier that's not a subroutine, unless it
-appears in curly braces or on the left hand side of the "=E<gt>" symbol.
-
+is a simple identifier (no colons) and that it appears in curly braces or
+on the left hand side of the C<< => >> symbol.
use strict 'subs';
$SIG{PIPE} = Plumber; # blows up
- $SIG{PIPE} = "Plumber"; # just fine: bareword in curlies always ok
+ $SIG{PIPE} = "Plumber"; # just fine: quoted string is always ok
$SIG{PIPE} = \&Plumber; # preferred form
-
-
=back
See L<perlmodlib/Pragmatic Modules>.
+=head1 HISTORY
-=cut
-
-$strict::VERSION = "1.02";
-
-my %bitmask = (
-refs => 0x00000002,
-subs => 0x00000200,
-vars => 0x00000400
-);
+C<strict 'subs'>, with Perl 5.6.1, erroneously permitted to use an unquoted
+compound identifier (e.g. C<Foo::Bar>) as a hash key (before C<< => >> or
+inside curlies), but without forcing it always to a literal string.
-sub bits {
- my $bits = 0;
- my @wrong;
- foreach my $s (@_) {
- push @wrong, $s unless exists $bitmask{$s};
- $bits |= $bitmask{$s} || 0;
- }
- if (@wrong) {
- my $useno = {
- __PACKAGE__.'::import' => 'use',
- __PACKAGE__.'::unimport' => 'no'
- }->{ (caller(1))[3] };
- require Carp;
- Carp::croak("Don't know how to '$useno ".__PACKAGE__." qw(@wrong)'");
- }
- $bits;
-}
+Starting with Perl 5.8.1 strict is strict about its restrictions:
+if unknown restrictions are used, the strict pragma will abort with
-sub import {
- shift;
- $^H |= bits(@_ ? @_ : qw(refs subs vars));
-}
+ Unknown 'strict' tag(s) '...'
-sub unimport {
- shift;
- $^H &= ~ bits(@_ ? @_ : qw(refs subs vars));
-}
+As of version 1.04 (Perl 5.10), strict verifies that it is used as
+"strict" to avoid the dreaded Strict trap on case insensitive file
+systems.
-1;
+=cut