Concerning Text::CSV_XS getline in while loop

freddo411 has asked for the wisdom of the Perl Monks concerning the following question:

Esteemed Monks,

Consider the following code, input file, and output:

#!/usr/local/bin/perl

use strict;
use Text::CSV_XS;
use FileHandle;

my $infile = "foo.csv";
my $IN = new FileHandle;
open ( $IN, "<$infile") or die "can't read $infile: $!";

my $c = 0;
my $csv = Text::CSV_XS->new( {'binary'      => 1});

while (  my $cols_aref = $csv->getline( $IN )  ) {
   my @a = @{$cols_aref};

   print "$a[0],$a[1],$a[2]\n";

   $c++;     # Alternative way to assure exiting loop
   exit if ( $c > 5  );
}
exit;

## My foo.csv
Fred,foo,3
Tom,bar,4

## Output:
Fred,foo,3
Tom,bar,4
,,
,,
,,
,,
[download]

I don't understand what's happening in the while condition that prevents it from ending when it reaches EOF. Can anyone educate me?

-------------------------------------
Nothing is too wonderful to be true
-- Michael Faraday

Comment on Concerning Text::CSV_XS getline in while loop Download Code

Replies are listed 'Best First'.
Re: Concerning Text::CSV_XS getline in while loop by jZed (Prior) on Dec 21, 2004 at 21:53 UTC
This is one of the reasons I am proposing the new interface :-). Until then, put this at the top of the loop: last unless @$cols_aref; getline() returns an empty arrayref when it runs out of lines in the file so you need to check for an arrayref with no elements.	[reply]
Re^2: Concerning Text::CSV_XS getline in while loop by freddo411 (Chaplain) on Dec 21, 2004 at 22:45 UTC
getline() returns an empty arrayref when it runs out of lines in the file so you need to check for an arrayref with no elements. Makes sense. Oh, and thanks for the pointing getline() out to me. ------------------------------------- Nothing is too wonderful to be true -- Michael Faraday	[reply] [d/l]
Re^2: Concerning Text::CSV_XS getline in while loop by Anonymous Monk on Feb 27, 2010 at 16:38 UTC
Hi, I am having a simular problem, but the EOF is found if a non-ASCII character is found in the input string, like a German U or character of the same kind. Depending on the file it happens at the offending line. The input file has been produced by EXCEL and making a CSV-file from it on a Windows computer, while the PERL-script is running on a Linux machine. Kind regards, Bert Mengerink SPOORHOBBY	[reply]
Re^3: Concerning Text::CSV_XS getline in while loop by Tux (Canon) on Feb 28, 2010 at 10:12 UTC
My bet would be you forgot to read the documentation, and did not pass `binary => 1` in the constructor: `my $csv = Text::CSV_XS->new ({ binary => 1, auto_diag => 1 });` Enjoy, Have FUN! H.Merijn	[reply] [d/l] [select]