There's no magic that would allow expand field in place.

What? No magic? But this is Perl — of course there’s magic!

#! perl
use strict;
use warnings;
use Tie::File;

my $filename = 'data.txt';

tie  my @lines, 'Tie::File', $filename or die "Cannot tie file '$filen
+ame' to array: $!";

for (my $i = 0; $i < @lines; ++$i)
{
    my @fields  = split ' ', $lines[$i];
    $fields[1] .= ' ' x (50 - length $fields[1]);
    $lines[$i]  = join(' ', @fields);
}

untie @lines;

[download]

Test file “data.txt” before running the script:

DSE 1232123456 ABCDEF96DS0 20100722 20120827KJHLK LKEDX 058305574 IAC 
+8 S73 WERTYU
DSE 987 ABCDEF96DS0 20100722 20120827KJHLK LKEDX 058305574 IAC 8 S73 W
+ERTYU
DSE 12321234567890 ABCDEF96DS0 20100722 20120827KJHLK LKEDX 058305574 
+IAC 8 S73 WERTYU

[download]

and after:

DSE 1232123456                                         ABCDEF96DS0 201
+00722 20120827KJHLK LKEDX 058305574 IAC 8 S73 WERTYU
DSE 987                                                ABCDEF96DS0 201
+00722 20120827KJHLK LKEDX 058305574 IAC 8 S73 WERTYU
DSE 12321234567890                                     ABCDEF96DS0 201
+00722 20120827KJHLK LKEDX 058305574 IAC 8 S73 WERTYU

[download]

;-)

Athanasius <°(((>< contra mundum

In reply to Re^2: Increasing a field size for a record by Athanasius
in thread Increaing a field size for a record by Thomas Kennll

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