Hello again anirbanphys,

If you want to write the output to the file in one line you can do it like this:

io('out.txt')->appendln($_) for @lines;

__END__

$ perl test.pl
$ cat out.txt
library(and_gate) {
  delay_model : table_lookup ;
  date : "Fri Mar 15 03:44:39 " ;
  time_unit : 1ms ;
  voltage_unit : 1V ;
  current_unit : 1A ;

  operating_conditions       ("AB0.5v45c") {
    process : 1 ;
    temperature : 45 ;
    voltage : 0.5 ;
  }
default_operating_conditions : "AB0.5v45c"

  input_voltage(default) {
    vi : 0 ;
    vh : 0.5 ;
    vim : 0 ;
    vin : 0.5 ;
  }

}
[download]

You can use the method IO::All/appendln from the same package as you do for reading.

Hope this helps, BR.