Jethro, you are the man.
You saved my day, the concept of Finite-state machine is perfect!
I modified a little few things and the script now works.
living and learning.
thanks again brother
here is the final script: 

#! /usr/local/bin/perl
# must add service_description inside "define service{" only in defini
+tions that do not have it
#Version 6


my $state="outside";
my @servicelines;
my $desc_flag;         #is 1 if description found(already exists, if i
+ts 0 then call parse and output sd)
my $file = "<test.txt";
my $sd = "";
open (MYFILE, '>services2.cfg');
open (TEXT_FILE, $file) || die "Can't open $file for read: $!";


while ($line = <TEXT_FILE>) {

  if ($state eq "outside") {

    if ($line=~/^\s*define service/) {
      $state="inside";
      @servicelines=();  #reset array
      push(@servicelines,$line );
      $desc_flag=0;
    }
  }
  elsif ($state eq "inside") {
    if ($line=~/^\s*}/) {
    if ($desc_flag eq 0){
    foreach $l(@servicelines) {
        if ($l=~/^\s*use/) {
        $sd = removesem($l);
        #print $sd;
        push(@servicelines,$sd);
        }        
     }      
    }
    push(@servicelines, "}\n");

# go thru entire array and print to file     
    foreach $i(@servicelines) {
      print $i;
      print MYFILE $i;
      }      

      $state="outside";
    }
    elsif ($line=~/^\s*service_description/) {
      push(@servicelines, $line);
        $desc_flag=1;
    }
    else {
      push(@servicelines, $line);
    }
  }
}

close (TEXT_FILE);
close (MYFILE);

sub removesem($)
{
     my $use = shift;
    $use =~ s/use/service_description/;    
    #print "test: " . $use . " \n";
    if($use =~ m/sem/ )
    {
        #remove sem
        $use =~s/sem_//;
        return $use;
        
    }else{
            return $use;
    } 
    
}

# Perl trim function to remove whitespace from the start and end of th
+e string
sub trim($)
{
    my $string = shift;
    $string =~ s/^\s+//;
    $string =~ s/\s+$//;
    return $string;
}

[download]

In reply to Re^4: How to parse a text file by xoroz
in thread How to parse a text file by xoroz

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