lib/perl5/5.6.1/msys/ops.pm

   1 package ops;
   2
   3 use Opcode qw(opmask_add opset invert_opset);
   4
   5 sub import {
   6     shift;
   7     # Not that unimport is the prefered form since import's don't
   8         # accumulate well owing to the 'only ever add opmask' rule.
   9         # E.g., perl -Mops=:set1 -Mops=:setb is unlikely to do as expected.
  10     opmask_add(invert_opset opset(@_)) if @_;
  11 }
  12
  13 sub unimport {
  14     shift;
  15     opmask_add(opset(@_)) if @_;
  16 }
  17
  18 1;
  19
  20 __END__
  21
  22 =head1 NAME
  23
  24 ops - Perl pragma to restrict unsafe operations when compiling
  25
  26 =head1 SYNOPSIS
  27
  28   perl -Mops=:default ...    # only allow reasonably safe operations
  29
  30   perl -M-ops=system ...     # disable the 'system' opcode
  31
  32 =head1 DESCRIPTION
  33
  34 Since the ops pragma currently has an irreversible global effect, it is
  35 only of significant practical use with the C<-M> option on the command line.
  36
  37 See the L<Opcode> module for information about opcodes, optags, opmasks
  38 and important information about safety.
  39
  40 =head1 SEE ALSO
  41
  42 Opcode(3), Safe(3), perlrun(3)
  43
  44 =cut
  45