Hello Everyone,

I occasionally like to download perl programs off the web to see how they work. And if there are any bugs I try to report back to the original author.

This code was found verbatim (except for the file name) in two different files.

my $conf = which_conf($configuration_file);
if (-f $conf) {
    my @conf_args;
    open(my $conffile, '<', "$conf")
        or warn "$P: Can't find a readable $configuration_file file $!
+\n";

    while (<$conffile>) {
        my $line = $_;

        $line =~ s/\s*\n?$//g;
        $line =~ s/^\s*//g;
        $line =~ s/\s+/ /g;

        next if ($line =~ m/^\s*#/);
        next if ($line =~ m/^\s*$/);

        my @words = split(" ", $line);
        foreach my $word (@words) {
            last if ($word =~ m/^#/);
            push (@conf_args, $word);
        }
    }
    close($conffile);
    unshift(@ARGV, @conf_args) if @conf_args;
}
[download]

my $conf = which_conf($configuration_file);
if (-f $conf) {
    my @conf_args;
    open(my $conffile, '<', "$conf")
        or warn "$P: Can't find a readable $configuration_file file $!
+\n";
[download]

It looks like there is a race condition between the file test and the file open.

The file test does not print a message if the file is not found but the file open does.

If the file cannot be opened a message is printed and then another message is printed when readline tries to read from an invalid file handle.

The file name is copied to a string.

    while (<$conffile>) {
        my $line = $_;
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Data is assigned to $_ and then copied to $line but $_ is never used inside the loop.

        $line =~ s/\s*\n?$//g;
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This is the line that gobsmacked me. I ran some tests with Benchmark and re 'debug' compared to the FAQ answer "s/\s+$//;" and it turns out that this is a good example of what not to do.

This substitution was found in five places in one file and two places in the other file.

        $line =~ s/^\s*//g;
[download]

Not as bad as the previous line but still not as good as the FAQ answer.

        $line =~ s/\s+/ /g;
[download]

Correct code, nothing to see here.

        next if ($line =~ m/^\s*#/);
        next if ($line =~ m/^\s*$/);
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Why check for whitespace after you've just removed it?

        my @words = split(" ", $line);
        foreach my $word (@words) {
            last if ($word =~ m/^#/);
            push (@conf_args, $word);
        }
[download]

This code is where the work is done and obviates the need for the previous five lines. split(" ", $line) removes all whitespace. foreach will not loop if @words is empty. $word =~ m/^#/ will skip to the next line if a '#' comment is found.

    close($conffile);
[download]

Correct code, nothing to see here.

    unshift(@ARGV, @conf_args) if @conf_args;
[download]

The conditional is not really required.

Where I found this code: