Re^3: header footer

[gupr1980]

hmm.. i just realized some of the responses are not shown in full. Just the header :) Sry i am reading through those now. Thanks.

[gupr1980]

So this is the one that i tried and it works. Thanks kenosis and others for taking the time.

#!/usr/bin/perl
use strict;
use warnings;

open FILE1,"input.txt";
open FILE2,">>output.txt";
foreach my $line ( <FILE1> )
{
$_= $line;
s/^HDR.{47}//;
s/\KFTR.{27}//;

print FILE2 $_;

}
close FILE1;
close FILE2;

this made the most clarity for me. I am assuming that the entire file doesnt gets stored in the $_ in this approach, correct me if i am wrong. and the file is only getting read one line at a time. This i want to make sure so that it performs well when i actually test with the huge file.

[Kenosis]

Consider the following instead:

use strict;
use warnings;
use autodie;

open my $FILE1, '<', 'input.txt';
open my $FILE2, '>', 'output.txt';

while (<$FILE1>) {
    s/^HDR.{47}|FTR.+//;
    print $FILE2 $_;
}

close $FILE1;
close $FILE2;

• autodie will trap the file i/o errors (you're not handling these, but you should)
• Use only lexical (my) file handles
• Use while to iterate through the file
• The two substitutions were combined into one

If FTR marks the footer to the end of the line, you can just use FTR.+ to remove it, since in your example there were only 30 characters left--including FTR. However, it's certainly OK to use FTR.{27}, if you prefer.

[gupr1980]

i tried testing this with the big file.

while ( <$FILE1> )
{

s/^HDR.{47}//;

is not stripping off the HDR and the following 47 characters.It looks like the 47th character is on a newline and hence not working? If i do a s/^HDR.{10}//; as a test it strips off the HDR fine. i also tried s/^HDR.{47}//g; doesnt make a difference. ***************** Never mind, found it. s/^HDR.{47}//s did it. Thanks.