in reply to Evolution of a Perl Programmer (new backup script)

I'll avoid repeating what's already been said. As a point of note though: 
foreach my $file (@$exc) { 
    if($_ eq $file) {
        $skip =1;
    }
}

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is broken, since it'll keep looping through checking for exclusions even if it's already found that this file or directory is in fact excluded from being backed up. Realistically, in a small, simple backup script like this, run on your own computer most of the time, it probably wouldn't matter. But it IS generally a good idea to leave a loop when you no longer need it to execute. :) 

foreach my $file (@$exc) {
    if($_ eq $file) {
        $skip =1;
    }
    last if $skip;
}

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Re: Re: Evolution of a Perl Programmer (new backup script)
by extremely (Priest) on Dec 21, 2000 at 16:48 UTC
    Don't test an exit flag, just set the flag and exit. 
    foreach my $file (@$exc) {
  $skip=1, last if ($_ eq $file);
}

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    --
    $you = new YOU;
    honk() if $you->love(perl)

[reply]
[d/l]
      Ah, but the only reason for the flag is to immediately skip to the next iteration of the while loop, which can be done without a flag at all: 
        FILE:
    while (defined(local $_ = readdir(LS))) {
        foreach my $file (@$exc) {
            next FILE if ($_ eq $file);
        }
        my $file = $dir . $_;
        my $append = "tar -rf $tarfile $file 2>> $ERRORFILE";
        system($append);
        print "\t$file\n";
    }

      [download]
      Although I would use a hash for the excludes, instead of looping over an array for each file in the directory, especially since the most common case of a file not being in the exclude list would also be the slowest case.

      I also recommend testing the readdir() assignment with defined, as I did above, so that the while loop will not stop prematurely if there's a file named '0'.

[reply]
[d/l]
      Thank you!!!
[reply]

In Section Cool Uses for Perl