CODEWITHSUNDEEP
perl
user1336997
user1336997

Reputation: 105

Appending an array at the end of a line in perl

I have more code before this which populates the array @a_nam. Now I want to append the elements in the array @a_nam at the end of the line shown below in abc.txt. I tried something but its not working. please give your inputs. edited: i tried "+>>" which didnt work.

## NAME_id , course, Fall 10 ,spring 11, ........

open my $file, '+>>', 'abc.txt' or die "failed : $!";
while (<$file>) {
    chomp;
    if (/^## NAME(.*)/) {
       print  $file join ",", @a_nam;
    }   
}
close($file);

Upvotes: 2

Views: 204

Answers (2)

chrsblck
chrsblck

Reputation: 4088

Simple example using Tie::File

I'm not going to repeat @choroba, as he's already explained why your example doesn't work.

UPDATED. It will now append the array to the end of the line, instead of removing it. 

use warnings;
use strict;
use Tie::File;
my @a_nam = qw(append some stuff);
my $match = "## NAME";

tie my @lines, 'Tie::File', "abc.txt" or die "failed: $!";

for my $line (@lines){
    if( $line =~ /^($match.*)/ ) {
        $line = $1 . ", " . join ', ', @a_nam;
    }
}
untie @lines;

File before:

1 blah blah
2 ## NAME, foo, bar, baz
3 whatever lines here

File after:

1 blah blah
2 ## NAME, foo, bar, baz, append, some, stuff
3 whatever lines here

Upvotes: 3

choroba
choroba

Reputation: 241758

You open the file for appending

open my $file, '>>'

but then you try to read from the file

while (<$file>)

This is not possible. Open the file for reading and write to another file. At the end, rename the old file to a backup and the new file to the original.

Upvotes: 4

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