The following fragment is extracted from your program:
sub sep_id {
...

         open (TMPFILE, "> $tmp_file") or (die "Could not open $tmp_fi
+le: $!");
         select TMPFILE;
         foreach $water (keys %wat_freq) {
            $freq=0;
            $code=undef;
            if ($wat_freq{$water} >= $C_NETSIZE) {
               @ids=();
               foreach (@info) {
                  if (substr($_,13,5,) == $water ) {
                     push @ids, substr($_,8,5);
                  }
               }
               @ids=sort {$a <=> $b} @ids;
               $code = join ":", $water . "+", @ids;
               $code =~ s/ /0/g;
               printf "%02d:+%s:\n",$wat_freq{$water}, $code;
            }
         }
         select STDOUT;

[download]

You are missing a close TMPFILE after you created the file. Now what happens is that the last file created will not closed properly, although files created earlier are automatically closed by the next open of the TMPFILE in your loop.

Update:
Having looked at your code, which is ugly, I just want to add a few comments:

1) Add use strict; to the beginning of your code to prevent autovivification of variables.

2) Avoid using global variables. And if you must, try to make your intension clear on how the global variables are used. For example, instead of doing
  my $SOME_GLOBAL_VARIABLE = 0;
  some_sub_with_side_effects();

  ...
  sub some_sub_with_side_effects {
    $SOME_GLOBAL_VARIABLE = 1;
  }

[download]

Do this instead:
  my $SOME_GLOBAL_VARIABLE = some_sub_without_side_effects();

  ...
  sub some_sub_without_side_effects {
    return 1;
  }

[download]

3) Remove the { } around the function calls, they are unnecessary and ugly.

4) Use IO::File my $f = new IO::File "file.txt", "w" or open my $f, "< file.txt" when openning your files. In other words, avoid using direct file handles, use lexical/anonymous file handles that are associated to the variables they are attached to. The lexical file handles are closed automatically when the associated variables fall out of scope, so you don't have to worry about closing them.

5) When modifying a Perl built-in variable, always create a scope and localize it first. You had a $| = 1; in your sub that turned off bufferring, however the effect is not cancelled when your sub finishes, this side effect carries on to other subs. This will not happen if you do local $| = 1;

Anyway, good luck and happy Perl programming.

In reply to Re: Error not reported while processing an open file by Roger
in thread Error not reported while processing an open file by qhayaal

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