Perl Require

extern: index | reference
intern: preamble | sample | end

Preamble

For a long time I have regularly using Perl's 'require' to include a set of library type functions. This works very well, and now just about every perl script I write begins with :-

use strict;
use warnings;
require 'logfile.pl' or die "Unable to load logfile.pl!\n";

So much so, that it is included in my 'template' to create every new perl file.

But up until recently I have never tried to put 'variables' in these 'include' library files. The problem was how to access these 'external' variables! Since Perl 5.6, the great 'our' comes to the rescue ;=))

Of course, if you read the PERLDOC information on this 'require', you will only find a very brief mention that is can be used to 'include' external 'library' like files, and no mention of how to access the 'variables' ;=() But then the use of 'our' is quite 'new', and maybe has not yet percolated through the massive amount of perl documentation...

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Sample

The 'variable' include (require) file called 'test_req2.pl' ... in this case defining values for '$testv1', and '$testv2'...

code:

# test_req2.pl - test values
use strict;
our $testv1 = <<EOF;
string 1
EOF
our $testv2 = <<EOF;
string 2
EOF
1; # so the 'require' succeeds

And then a file, test_req1.pl, to use these two(2), sort of 'external' variables ...

# test_req1.pl - 25 August 2009 - testing 'require', for variables
use strict;
use warnings;
require 'test_req2.pl' or die "Unable to load test_req2.pl!\n";
our($testv1, $testv2);
my $test = $testv1;
print $test;
$test = $testv2;
print $test;

output:

string 1
string 2

For a little more on 'our'. That is it, for now ...

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EOF - perl_require.htm