First, you should always use strict; and use warnings;. Second, you should use lexical file handles. Third, you can perform this in one loop over the file. And fourth, you can use unlink to delete the file, and rename to rename the temp file.

This should do what you want:

#!/usr/bin/perl
use strict;
use warnings;

open my $file, "<", "petpages" or die "Could not open petpages: $!";
open my $new, ">", "petpages.new" or die "Could not open petpages.new:
+ $!";

while (my $line = <$file>) {
   $line =~ tr/A-Z/a-z/;
   print $new "http://$line";
}

close $file;
close $new;
rename "petpages.new", "petpages";

[download]

Update:I forgot to mention that exec doesn't do what you think. As the first line in the doc says, exec never returns. That is why you got the warning: Statement unlikely to be reached at c.pl line 11. (Maybe you meant system() when you said exec()?). Since the rest of the code is never executed, that is why the "http://" never gets prepended.

In reply to Re: File manipulation only works when I split it into two files. by lostjimmy
in thread File manipulation only works when I split it into two files. by Vonunov

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