Explain this code please?

über

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          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:

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

über

I will post my friends whole script now

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 #!/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

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          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

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 #!/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_directory" and all sub directories of the "start_directory" 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.

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 #!/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:

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#!/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

Explain this code please?

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