1package vars; 2 3use 5.006; 4 5our $VERSION = '1.01'; 6 7use warnings::register; 8use strict qw(vars subs); 9 10sub import { 11 my $callpack = caller; 12 my ($pack, @imports) = @_; 13 my ($sym, $ch); 14 foreach (@imports) { 15 if (($ch, $sym) = /^([\$\@\%\*\&])(.+)/) { 16 if ($sym =~ /\W/) { 17 # time for a more-detailed check-up 18 if ($sym =~ /^\w+[[{].*[]}]$/) { 19 require Carp; 20 Carp::croak("Can't declare individual elements of hash or array"); 21 } elsif (warnings::enabled() and length($sym) == 1 and $sym !~ tr/a-zA-Z//) { 22 warnings::warn("No need to declare built-in vars"); 23 } elsif (($^H &= strict::bits('vars'))) { 24 require Carp; 25 Carp::croak("'$_' is not a valid variable name under strict vars"); 26 } 27 } 28 $sym = "${callpack}::$sym" unless $sym =~ /::/; 29 *$sym = 30 ( $ch eq "\$" ? \$$sym 31 : $ch eq "\@" ? \@$sym 32 : $ch eq "\%" ? \%$sym 33 : $ch eq "\*" ? \*$sym 34 : $ch eq "\&" ? \&$sym 35 : do { 36 require Carp; 37 Carp::croak("'$_' is not a valid variable name"); 38 }); 39 } else { 40 require Carp; 41 Carp::croak("'$_' is not a valid variable name"); 42 } 43 } 44}; 45 461; 47__END__ 48 49=head1 NAME 50 51vars - Perl pragma to predeclare global variable names (obsolete) 52 53=head1 SYNOPSIS 54 55 use vars qw($frob @mung %seen); 56 57=head1 DESCRIPTION 58 59NOTE: For variables in the current package, the functionality provided 60by this pragma has been superseded by C<our> declarations, available 61in Perl v5.6.0 or later. See L<perlfunc/our>. 62 63This will predeclare all the variables whose names are 64in the list, allowing you to use them under "use strict", and 65disabling any typo warnings. 66 67Unlike pragmas that affect the C<$^H> hints variable, the C<use vars> and 68C<use subs> declarations are not BLOCK-scoped. They are thus effective 69for the entire file in which they appear. You may not rescind such 70declarations with C<no vars> or C<no subs>. 71 72Packages such as the B<AutoLoader> and B<SelfLoader> that delay 73loading of subroutines within packages can create problems with 74package lexicals defined using C<my()>. While the B<vars> pragma 75cannot duplicate the effect of package lexicals (total transparency 76outside of the package), it can act as an acceptable substitute by 77pre-declaring global symbols, ensuring their availability to the 78later-loaded routines. 79 80See L<perlmodlib/Pragmatic Modules>. 81 82=cut 83