| 1 | package vars; |
| 2 | |
| 3 | use 5.006; |
| 4 | |
| 5 | our $VERSION = '1.01'; |
| 6 | |
| 7 | use warnings::register; |
| 8 | use strict qw(vars subs); |
| 9 | |
| 10 | sub 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 | |
| 46 | 1; |
| 47 | __END__ |
| 48 | |
| 49 | =head1 NAME |
| 50 | |
| 51 | vars - Perl pragma to predeclare global variable names (obsolete) |
| 52 | |
| 53 | =head1 SYNOPSIS |
| 54 | |
| 55 | use vars qw($frob @mung %seen); |
| 56 | |
| 57 | =head1 DESCRIPTION |
| 58 | |
| 59 | NOTE: For variables in the current package, the functionality provided |
| 60 | by this pragma has been superseded by C<our> declarations, available |
| 61 | in Perl v5.6.0 or later. See L<perlfunc/our>. |
| 62 | |
| 63 | This will predeclare all the variables whose names are |
| 64 | in the list, allowing you to use them under "use strict", and |
| 65 | disabling any typo warnings. |
| 66 | |
| 67 | Unlike pragmas that affect the C<$^H> hints variable, the C<use vars> and |
| 68 | C<use subs> declarations are not BLOCK-scoped. They are thus effective |
| 69 | for the entire file in which they appear. You may not rescind such |
| 70 | declarations with C<no vars> or C<no subs>. |
| 71 | |
| 72 | Packages such as the B<AutoLoader> and B<SelfLoader> that delay |
| 73 | loading of subroutines within packages can create problems with |
| 74 | package lexicals defined using C<my()>. While the B<vars> pragma |
| 75 | cannot duplicate the effect of package lexicals (total transparency |
| 76 | outside of the package), it can act as an acceptable substitute by |
| 77 | pre-declaring global symbols, ensuring their availability to the |
| 78 | later-loaded routines. |
| 79 | |
| 80 | See L<perlmodlib/Pragmatic Modules>. |
| 81 | |
| 82 | =cut |