juergenkemeter has asked for the wisdom of the Perl Monks concerning the following question:

Hi, the following code 
use List::Compare;
use strict;
open (GEN, "general.txt")||die("general.txt File cannot open\n");
open (SEA, "search.txt")||die("search.txt File cannot open\n");
my @gen=<GEN>;
my @sea=<SEA>;

for $a ($gen)
{
    @result = grep/^\Q$a\E$/, @sea;
    push (@final , @result);
}

open(OUT, ">textCompare3Output.txt")||die("cannot create\n");
print OUT "\nSearch string that matches against general data:\t@final"
+;

[download]
gives back the error message: 
Global symbol "$gen" requires explicit package name at textCompare3.pl
+ line 8.
Global symbol "@result" requires explicit package name at textCompare3
+.pl line 10.
Global symbol "@final" requires explicit package name at textCompare3.
+pl line 11.
Global symbol "@result" requires explicit package name at textCompare3
+.pl line 11.
Global symbol "@final" requires explicit package name at textCompare3.
+pl line 15.
Execution of textCompare3.pl aborted due to compilation errors.

[download]

Replies are listed 'Best First'.
Re: error message txtFile comparison with output in another txtfile
by BaldPenguin (Friar) on Jul 14, 2005 at 22:03 UTC
    You don't have a $gen declared only an array, @result and @final are not declared, try: 
    use List::Compare;
use strict;
open (GEN, "general.txt")||die("general.txt File cannot open\n");
open (SEA, "search.txt")||die("search.txt File cannot open\n");
my @gen=<GEN>;
my @sea=<SEA>;
my @final = ();

for $a (@gen)
{
    my @result = grep/^\Q$a\E$/, @sea;
    push (@final , @result);
}

open(OUT, ">textCompare3Output.txt")||die("cannot create\n");
print OUT "\nSearch string that matches against general data:\t@final"
+;

    [download]

    Don
    WHITEPAGES.COM | INC
    Everything I've learned in life can be summed up in a small perl script!
[reply]
[d/l]

      The variable in the foreach loop should also be properly declared, and preferably not called $a.

      for my $pattern (@gen)
{
    my @result = grep/^\Q$pattern\E$/, @sea;
    push (@final , @result);
}

      [download]
[reply]
[d/l]
      the code has no errors now, but the comparison doesnt work properly, there is no output in the new textfile except 'Search string that matches against general data:' Even if I have two same entries in 'search.txt' and 'general.txt', there is still no output. Perhaps the @final variable does not work properly? Jurgen
[reply]
Re: error message txtFile comparison with output in another txtfile
by GrandFather (Saint) on Jul 14, 2005 at 22:10 UTC

    Global symbol "..." requires explicit package name is telling you that ... is undefined. For $gen that is because it should be @gen. For the others you need a

    my ...;

    in each case.

    Read more... Fixed code (785 Bytes)
    Perl is Huffman encoded by design.
[reply]
[d/l]
[select]
      Thanks, but there is (still) no output in the new produced textfile (see also my upper message) although 'general.txt' and 'search.txt' have both the same content. Jurgen
[reply]

        You should provide sample data (file contents) in a <readmore>...</readmore> block in your original post so that others can reproduce your problem.

        Perl is Huffman encoded by design.
[reply]
[d/l]

        and now that the "compile" errors are fixed you should state your new problem: what do you expect to see and what do you actually see.

        For test purposes it would be better to print to STDOUT rather than to a file.

        Perl is Huffman encoded by design.
[reply]

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