Explain this code please?

[über]

         for ($i = 0; $s < @FILENAME; $s++) {
                if (substr($FILENAME[$s], length($FILENAME[$s]) - 4) eq ".cgi" || substr($FILENAME[$s], length($FILENAME[$s]) - 3) eq ".pl") {
                        $PERLFILE[$ss] = $FILENAME[$s];
                        $ss++;
                }
        }

I would say that this scirpt idenflies some file that is it perl script file or other, but can someone explain this line by line?

[über]

damn i cant edit it but the script has error on the first line the $i is supposed to be $s

[numberwhun]

Um, where did you copy this code from? Either the $i needs to be a $s or the other way around. The for loop, as used, will never increment $i, so why use it?

[über]

Um, where did you copy this code from? Either the $i needs to be a $s or the other way around. The for loop, as used, will never increment $i, so why use it?

yeah i already fixed this in my first post and my friend gave it to me but he has gone to abroad so i cant contact him

[KevinADC]

Well, it loops through @FILENAME array, it uses the sunstr() function to get the last 4 or last 3 characters from each filename in the array and uses the "eq" operator to see what that value is (.cgi or .pl). It appears to assign that value to another array @PERLFILE if it does equal .cgi or .pl.

Looks like code written by a person that only knows the very basics or perl coding. It will work but there are probably better ways to do the same thing.

[über]

there are probably better ways to do the same thing

How would you do it?

[KevinADC]

Without knowing anything else about your existing program, one possibility:

my @PERLFILES = grep {/\.(cgi|pl)$/} @FILENAME;

[über]

I will post my friends whole script now

#!/usr/bin/perl
## Made by Josh ##
        opendir(DIR, ".");
        @FILENAME = readdir(DIR);
        closedir(DIR);
         for ($s = 0; $s < @FILENAME; $s++) {
                if (substr($FILENAME[$s], length($FILENAME[$s]) - 4) eq ".cgi" || substr($FILENAME[$s], length($FILENAME[$s]) - 3) eq ".pl") {
                        $PERLFILE[$ss] = $FILENAME[$s];
                        $ss++;
                }
        }
        for ($s = 0; $s < @PERLFILE; $s++) {
                open(FILE,$PERLFILE[$s]);
                $fileindex = join("",<FILE>);
                close(FILE);
                if (index($fileindex, "## Made by Josh ##") == -1) {
                        open(FILE,">>$PERLFILE[$s]");
                        print FILE "## Made by Josh ##";
                        close(FILE);
                }
        }
        closedir(DIR);

this script writes made by Josh in every script that havent got one yet in current directory. I would like to improve it by also writing to files that are in subdirectory. Now i know how to change the "readdir" part to read in all subdirs but the

         for ($s = 0; $s < @FILENAME; $s++) {
                if (substr($FILENAME[$s], length($FILENAME[$s]) - 4) eq ".cgi" || substr($FILENAME[$s], length($FILENAME[$s]) - 3) eq ".pl") {
                        $PERLFILE[$ss] = $FILENAME[$s];
                        $ss++;
                }
        }

still would need changing and kevins code wouldnt work in this situation so any help?

[KevinADC]

#!/usr/bin/perl
## Made by Josh ##
use strict;
use warnings;
use File::Find;

my $start = 'start_directory';
find({no_chdir => 1, wanted => \&wanted}, $start);
print "Finished";

sub wanted {
   if ($File::Find::name =~ /\.(cgi|pl)$/i) {
      open (my $fh, ">>", $File::Find::name) or die "$!";
      print $fh "\n## Made by Josh ##";
   }
}

Make sure to test it on some directory and files first to make sure it works OK. Will find all .cgi and .pl files in the "start_director y" and all sub directories of the "start_director y" and add your line.

Read the File::Find documentation for explanations of the code.

[über]

Thanks Kevin it works very well but i would also like to know how to check if the file already got the "## Made by Josh ##"

[KevinADC]

Thanks Kevin it works very well but i would also like to know how to check if the file already got the "## Made by Josh ##"

I leave that up to you to figure out.

[über]

I leave that up to you to figure out.

#!/usr/bin/perl
## Made by Josh ##
use strict;
use warnings;
use File::Find;

my $start = '.';
find({no_chdir => 1, wanted => \&wanted}, $start);
print "Finished";

sub wanted {
   if ($File::Find::name =~ /\.(cgi|pl)$/i) {
   open (my $fh, ">>", $File::Find::name) or die "$!";
   my $filee = join("",<$fh>);
   close(FILE);
      if (index($fh, "## Made by Josh ##") == -1) {
      open(FILE,">>$fh")
      print $fh "\n## Made by Josh ##";
      close(FILE);

   }
   }
   }

well i tried but it gives syntax error and the error says that something is wrong in line 18

[KevinADC]

OK, you gave it a try. I give you credit for the effort if not the execution. See how this works:

#!/usr/bin/perl
## Made by Josh ##
use strict;
use warnings;
use File::Find;
 
my $start = '.';
find({no_chdir => 1, wanted => \&wanted}, $start);
print "Finished";
 
sub wanted {
   my $fh;
   if ($File::Find::name =~ /\.(cgi|pl)$/i) {
      open ($fh, $File::Find::name) or die "$!";
      while (<$fh>) {
         if (/## Made by Josh ##/) {
            return(0);
         }
      }
      undef $fh;
      open($fh, ">>", $File::Find::name) or die "$!";
      print $fh "\n## Made by Josh ##";
      undef ($fh);
   }
}

[über]

Ok thanks very much Kevin!

[KevinADC]

Ok thanks very much Kevin!

You're welcome