Cool. Thanks for the C-code lookup! Glad I'm not crazy. I have been trying to limit dependencies, but I could look at that module to see how they handle the '{}' expressions. My code should handle multiple occurrences, and assuming that there are no spaces and no nested expressions, I think it should theoretically work in every case. I'm not 100% on that though. Well, it doesn't handle escape curlies, but I'm not even sure a filename could have that... Whoops, yes they can. I just renamed a file to "tmpdelete{test}.txt". I dragged it to my terminal and it pasted it with escape characters. I guess I should make a minor edit to my code:

    #Keep updating an array to be the expansion of a file pattern to
    #separate files
    my @expanded = ($nospace_string);

    #If there exists a '{X,Y,...}' pattern in the string
    if($nospace_string =~ /(?<!\\)\{.+?(?<!\\)\}/)
      {
    #While the first element still has a '{X,Y,...}' pattern
    #(assuming everything else has the same pattern structure)
    while($expanded[0] =~ /(?<!\\)\{.+?(?<!\\)\}/)
      {
        #Accumulate replaced file patterns in @g
        my @buffer = ();
        foreach my $str (@expanded)
          {
        #If there's a '{X,Y,...}' pattern, split on ','
        if($str =~ /(?<!\\)\{(.+?)(?<!\\)\}/)
          {
            my $substr     = $1;
            my $before     = $`;
            my $after      = $';
            my @expansions = split(/,/,$substr);
            push(@buffer,map {$before . $_ . $after} @expansions);
          }
        #Otherwise, push on the whole string
        else
          {push(@buffer,$str)}
          }

        #Reset @f with the newly expanded file strings so that we
        #can handle additional '{X,Y,...}' patterns
        @expanded = @buffer;
      }
      }

    #Pass the newly expanded file strings through
    return(wantarray ? @expanded : [@expanded]);
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Although, I just tested that nested expressions are possible too, so I would definitely like to check out that module.