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Help solving an error" readline() on closed filehandle"

maneshmotts
Novice

Sep 26, 2012, 11:50 PM

Post #1 of 4 (1261 views)

Help solving an error" readline() on closed filehandle"	Can't Post

HI ,

I using a file handler to copy it into an array, but I am getting an
error.readline() on closed filehandle FILE

Code

#!usr/bin/perl 
 
use strict; 
use warnings; 
 
open(FILE,"<input.txt"); 
my @number; 
 
while(<FILE>){ 
@number = <FILE>; 
} 
print @number; 
 
close(FILE);

Quote

FishMonger
Veteran / Moderator

Sep 27, 2012, 6:15 AM

Post #2 of 4 (1238 views)

Re: [maneshmotts] Help solving an error" readline() on closed filehandle" [In reply to]	Can't Post

You're receiving that error because the open call failed.

You need to add error handling on the open call to verify that it was successful. I would also suggest that you use a lexical var for the filehandle and the 3 arg form of open.

Code

my $file = 'input.txt'; 
open my $fh, '<', $file or die "failed to open '$file' <$!>";

maneshmotts
Novice

Oct 15, 2012, 12:14 AM

Post #3 of 4 (888 views)

Re: [FishMonger] Help solving an error" readline() on closed filehandle" [In reply to]	Can't Post

HI thanks for the reply could you please explain me about the three variable form .

The $fh variable you have use here is consider as an file handler ?

Then can I use the as "my @array = <fh>;" will this work please let me know

Thanks

Laurent_R
Veteran / Moderator

Oct 15, 2012, 4:36 AM

Post #4 of 4 (884 views)

Re: [maneshmotts] Help solving an error" readline() on closed filehandle" [In reply to]	Can't Post

Hi

the three arguments form of the open command:
- First arg: file handle
- second arg: open mode
- third arg: file name.

Yes, $fh is a file handle and you can use it as follows:

while (my $line = <$fh>) { # ...
or
my @lines = <$fh>;
#...

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