My code is shown below. After locating the keyword(stored in $first) I need to check the value of the variable stored in $first. $first = SEL_BLOCK. But I need to check the value of the SEL_BLOCK. How can it be done?

open(OUT,">Output.txt") or die "Can't open output.txt for writing:$!\n
+";
open(IN, "<Input.txt") or die "Can't open input.txt for reading:$!\n";


@array = <IN>;

foreach $line (@array) {
  chomp ($line);

  if ($line =~ /^OPT:/) {
    $var = $';
    @param = split / /, $var;
    $first = $param[1];
    print "$first\n";
    if ($first==1) { # This is not working as desired
        $start = 1;
    }
    else {
      $skip = 1;
    } 
  } 
  
  elsif ($start == 1 || $skip==1) {
    
    if ($line =~ /^]/) {
      $start = 0;
      $skip = 0;
    }
    elsif ($skip == 0) {
      printf (OUT "$line\n");
    }  

  }  
  else  {
    printf (OUT "$line\n");
 
  }

}
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I also like to point out that in the input file the keyword will be declared as below

Input.txt(input file) 
OPT: SEL_BLOCK [ 
 some text to be copied to output file
 if SEL_BLOCK = 1
]
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SEL_BLOCK will be defined in a config file which can be included in the perl script. The script will have visibilty of the value of SEL_BLOCK and take appropriate actions(copying contents from input to output file).