http://www.perlmonks.org?node_id=999381


in reply to Increaing a field size for a record

Here's a substitution option:

use strict; use warnings; use File::Slurp qw/read_file write_file/; write_file 'rij1.txt', map s/^(\S+) (\S+ )/"$1 $2" . ' ' x 39/er, read_file 'rij1.txt';

Have assumed the second field isn't empty, as it seems that the OP's suggesting it's currently fixed at 11 non-space characters to which 39 spaces are to be added.