removing lines from a file

[Anonymous Monk]

Hi monks. I have a file cut_out

cut_out
8
2

i need to copy the first 8 lines of ORIGINAL to a new file 1.out.test. then print the next 2 lines to 2.out.test

ORIGINAL
1
2
3
4
TO 10

open (true, "<ORIGINAL");
open (edit, "<cut_out2");
open (rest, ">REST");
while (<edit>) {
chomp;

 $j = $_;
print $j;
open (out, ">$.out.test");
    while (<true>){
        if (1..$.==$j) {print out}

else {print rest};

print "\nCUT";
rename (REST, COMPARE);
                }

}
~

works for the first copy but not the second? thanks

[Random_Walk]

Please use strict and warnings. Please do not use a filehandle called true, then have a while (<true>) that will go false. That hurt my head ;)

It is good practice to test the result of attempts to open a file, and polite to close them when you have finished reading from them.

perltidy is your friend

The three argument form of open is safer

update

Added a check that there is something remaining in the original file while editing

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

# true was a confusing name
open ORIG, "<", "ORIGINAL" or die "probs: ORIGINAL : $!\n";
open EDIT, "<", "cut_out"  or die "probs: cut_out2 : $!\n";
open REST, ">", "REST"     or die "probs: REST     : $!\n";

while (<EDIT>) {
    chomp;
    my $j = $_;
    print "grabbing $j lines to $.out.test\n";
    open OUT, ">", "$.out.test" or die "can not open $.out.test : $!\n
+";
    while ($j--){
        if (my $line = <ORIG>) {
            print OUT $line;
        } else {
            die "Ran out of input file before editing complete !\n";
        }
    }
    close OUT;
}
close EDIT;
while (<ORIG>) {
    print REST;
}
close ORIG;
close REST;

# rename ("REST", "COMPARE");

Cheers,
R.

[Anonymous Monk]

thanks for that, works exactly the way i wanted cheers

[gopalr]

Hi,

Your whole coding is not good.

Try the below:

open (true, "< DATA.txt");
open (first, "> 1.out.text");
open (rest, "> 2.out.text");

$. <= 8 ? print first $_ : print rest $_ while(<true>);

DATA.txt

1
2
3
4
5
6
7
8
9
10

Update: true is included

[CountZero]

But it doen't take into account the data in the cut_out file.

[Anonymous Monk]

the output files are empty? when u use the above

[gopalr]

Here it's working fine. I don't know what u do.

Just copy the coding and run it.

Still if u face the problem again, let me know.

[Anonymous Monk]

oooppps <DATA> shoule be <true> so how can i next remove the following two lines, bearing in mind that i may have 30 or so continous deletions to perform?

[Anonymous Monk]

when i try to print out COMPARE after renaming its denied?

[Miguel]

Another alternative:

Updated: to include the cut_out.txt file.

#!/usr/bin/perl -w
use strict;
use IO::All;

my @cut_out = io("cut_out.txt")->slurp;
my @lines = io('original.txt')->slurp;

my $total_lines = 0;
$total_lines += $_ foreach @cut_out;

for (my $i = 0; $i <= ($total_lines - 1); $i++ ) {
    $i <= $cut_out[0] - 1 ? 
    io("1.out.test.txt")->append($lines[$i]) :
    io("2.out.test.txt")->append($lines[$i])
}