open (RUNSET, "<text.txt" ) || die "Can't access test\n";

while (<RUNSET>) {
    if (/^\*DESCRIPTION$/ .. /^\*END$/) {
        # do any substitutions
    }
}

close RUNSET;
[download]

######untested code
#should be close in theory though

#!/usr/bin/perl -w

use strict;

my $keyword='';
my %file_hash=();
while(<>) {
   chomp;
   next if (/^\;/);
   if ( /\*/) {
         $keyword=(split /\*/)[1];
   }
   if ($keyword ne "END") {
      push @{$file_hash{$keyword}},$_;
   }
}

foreach my $line (@{$file_hash{'DESCRIPTION'})
{
   #do what ever you want with each line that falls in
   # the description block

   print "$line\n";

}
[download]

#!/bin/perl -w
use strict;

open (DATA, "text.txt") || die "Can't access test\n";
#each element in the array is a single line
my @data = <DATA>;
close(DATA);

#vars to manipulate the data
my $line="";
my @description = ("");
my $found = "false";

#while it is not the end of the file
while($line = shift @data){
  chomp $line;
  if($line =~ "DESCRIPTION"){
    $line = shift @data;
    chomp $line;
    while(!($line =~ "END")){
      if(!($line =~ ";")){
        push @description, $line;
      }
      $line = shift(@data);
      chomp $line;
    }
    print "[",@description, "]\n";

    #if there's going to be more descriptions in the same file
    #then we can clear the array and keep going through the 
    #file until we run out of lines.  Otherwise @description 
    #will continue to accumulate strings

    #@description = ("");
  }
}
if($found eq "false"){
  #then we didn't find a description
  #add it here
}
[download]

Yours is closest to the way I would do it. My approach would probably be to use a Finite State Machine, but otherwise works the same way.

Since Rhodium has said s/he wants to do a search and replace, I presume that the rest of the file should be preserved. For example, run this script with 'prog file >out_file':

#!/usr/local/bin/perl -w
my $inblock = 0;

while (<>) {
 if ($inblock ) {
  if (/^\*END/ ) {
   $inblock = 0;
  }
  else {
   s/expression_to_find/replace_with/g;   # e.g.
  }
 }
 elsif ( /^\*DESCRIPTION ) {
  $inblock = 1;
 }
 print;   # print $_ implicitly
}
[download]

Nothing fancy, just does the job

dmm

GIVE a man a fish and you feed him for a day
TEACH him to fish and you feed him for a lifetime

First off thanks a lot!

Now, I like this one because it allows me to verify that I am in fact working on the right block. But this presents the problem that I don't know how to deal with.

FYI - I know that I will only have one DESCRIPTION block but the stuff inside of DESCRIPTION is what may be elsewhere in the file.

My problem is ok now I have an array @description now If do my search and replaces does this get reflected in @data? I need to play with this..

And like you said now I need to work the "crap the variable I want to change isn't in there"

#!/usr/bin/perl -w

use strict;

$/ = undef;
open (FILE, "< input.txt") or die $!;
my $file = <FILE>;
close FILE;
# only standard stuff so far..

# this will hold the key's value
my $value;

# remove comments..
$file =~ s/;.*$//g;

# check for the block we want
if ($file =~ m/\*DESCRIPTION.+?\*END/s)
{
    my $block = $&;
    # look for the keyword within the block
    if ($block =~ m/^$keyword\s*=\s*(.+)$/)
    {
        $value = $1;
    }
    else
    {
        $value = "Pattern not found, sorry";
    }
}
else
{
    $value = "Block not found.. Please check!";
}

print $value . "\n";
[download]

This code will parse the whole file into a hash. Then you can manipulate it via the supplied subroutines (add_keyword, del_keyword, get_keyword). You can find examples to their usages to the end of the code.

#!/usr/bin/perl -w

use strict;
use Data::Dumper;

sub read_config {
  my $file = shift;

  # Slurp in the file
  open (RUNSET, "<$file") or die "Can't access '$file': $!";

  my %conf;
  my $handle;

  while (<RUNSET>) {
    chomp;
    next if $_ eq '' or /^;/;

    if (/^\*(.*)$/) {
      if ($1 eq 'END') {
        undef($handle);
      } else {
        $handle   = $1;
        %{$conf{$handle}} = ();
      }

      next;
    }

    if ($handle) {
      my($var, $value) = split('\s*=\s*', $_, 2);
      next unless defined $var;
      $conf{$handle}{$var} = $value;
    }
  }

  close RUNSET;

  return \%conf;
}

sub check_params {
  my ($config, $block, $keyword, $value) = @_;

  return unless ref($config) eq 'HASH';
  return unless defined($block);
  return unless ref($config->{$block}) eq 'HASH';

  return unless defined($keyword);

  return @_;
}

sub add_keyword {
  my ($config, $block, $keyword, $value) = check_params(@_);
  return unless defined($config);

  if (defined(${$config->{$block}}{$keyword})) {
    print "Replacing value of $keyword in $block (previously "
          . ${$config->{$block}}{$keyword} . ").\n";
  } else {
    print "Adding the new $keyword keyword to $block block.\n";
  }

  ${$config->{$block}}{$keyword} = $value;
}

sub del_keyword {
  my ($config, $block, $keyword) = check_params(@_);
  return unless defined($config);

  if (defined(${$config->{$block}}{$keyword})) {
    print "Deleting $keyword from $block.\n";
    return delete(${$config->{$block}}{$keyword});
  } else {
    print "Tried to delete a nonexistant key $keyword in $block block.
+\n";
  }
}

sub get_keyword {
  my ($config, $block, $keyword) = check_params(@_);
  return unless defined($config);

  if (defined(${$config->{$block}}{$keyword})) {
    return ${$config->{$block}}{$keyword};
  } else {
    print "Tried to access a nonexistant key $keyword in $block block.
+\n";
  }
}

my $config = read_config('test.txt');

add_keyword($config, 'DESCRIPTION', 'test', 10);
add_keyword($config, 'DESCRIPTION', 'keyword', 'aa');
del_keyword($config, 'DESCRIPTION', 'keyword2');
del_keyword($config, 'DESCRIPTION', 'keyword3');

print Dumper($config);

exit;
[download]

I hope this helps.