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RedHat 9 (Linux i386) - man page for strict (redhat section 3pm)

strict(3pm)			 Perl Programmers Reference Guide		      strict(3pm)

NAME
       strict - Perl pragma to restrict unsafe constructs

SYNOPSIS
	   use strict;

	   use strict "vars";
	   use strict "refs";
	   use strict "subs";

	   use strict;
	   no strict "vars";

DESCRIPTION
       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".

       "strict refs"
	     This generates a runtime error if you use symbolic references (see perlref).

		 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 "goto &$AUTOLOAD" would not break under stricture.

       "strict vars"
	     This generates a compile-time error if you access a variable that wasn't declared
	     via "our" or "use vars", localized via "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 "my" in perlfunc and "local" in
	     perlfunc.

		 use strict 'vars';
		 $X::foo = 1;	      # ok, fully qualified
		 my $foo = 10;	      # ok, my() var
		 local $foo = 9;      # blows up

		 package Cinna;
		 our $bar;		     # Declares $bar in current package
		 $bar = 'HgS';		     # ok, global declared via pragma

	     The local() generated a compile-time error because you just touched a global name
	     without fully qualifying it.

	     Because of their special use by sort(), the variables $a and $b are exempted from
	     this check.

       "strict subs"
	     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 "=>" symbol.

		 use strict 'subs';
		 $SIG{PIPE} = Plumber;	     # blows up
		 $SIG{PIPE} = "Plumber";     # just fine: bareword in curlies always ok
		 $SIG{PIPE} = \&Plumber;     # preferred form

       See "Pragmatic Modules" in perlmodlib.

perl v5.8.0				    2002-06-01				      strict(3pm)


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