TexT::CSV and getline

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

This is very odd so I must be missing something really obvious. My test program:

#!/usr/bin/perl

use v5.10 ;
use strict;
use warnings ;
use Text::CSV ;
use FileHandle ;

my $csv = Text::CSV->new((binary => 1)) ;
my $fh = new FileHandle ;
open($fh, "<", $ARGV[0])
    or die "Can't open $ARGV[0]: $!\n" ;

say $fh ;

my $row = $csv->getline($fh) ;

exit
[download]

and when I run it, I get:

Desktop>csvtest.pl testcsv.csv
FileHandle=GLOB(0x1e9c20)
Can't call method "getline" on an undefined value at D:\Desktop\csvtes
+t.pl line 16.
[download]

I printed out $fh and it was clearly not undefined. The file is a vanilla windows-format file and neither my text editor nor excel nor word have a problem with it. ??? My little test file was pretty trivial:

Importance,Company,Department,"Job Title"
[download]

Comment on TexT::CSV and getline Select or Download Code

Replies are listed 'Best First'.
Re: TexT::CSV and getline by GrandFather (Saint) on Nov 04, 2020 at 20:16 UTC
The Text::CSV documentation says in part: new (Class method) Returns a new instance of class Text::CSV. The attributes are described by the (optional) hash ref \%attr So your $csv construction line should be: `my $csv = Text::CSV->new({binary => 1}) ;` [download] Note the currly braces `{}` instead of the parenthesis `()` as the argument to new. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply] [d/l] [select]
Re^2: TexT::CSV and getline by BernieC (Pilgrim) on Nov 05, 2020 at 15:22 UTC
Perfect --- in the docs {and with my bad eyes} I missed that a hashref was needed. THANKS!!	[reply]
Re: TexT::CSV and getline by swl (Parson) on Nov 04, 2020 at 21:03 UTC
GrandFather has answered the question, so this just another data point. Text::CSV returns undef when it is passed incorrect arguments. If you had added a print for the `$csv` as well as `$fh` then this would have come up as a warning about printing an undefined value. Or you could have added: `die "CSV object is undefined" if !defined $csv;` [download] This is one of those things that is much clearer in hindsight.	[reply] [d/l] [select]
Re: TexT::CSV and getline by BillKSmith (Monsignor) on Nov 04, 2020 at 21:43 UTC
Fix your constructor as GrandFather indicated, and your code 'works'. You probably did not intend to output a reference to a filehandle. I have made your test case the default input, and added one line to print $row. `BEGIN{ $ARGV[0] //= \qq(Importance,Company,Department,"Job Title"\n); } use v5.10 ; use strict; use warnings ; use Text::CSV ; use FileHandle ; my $csv = Text::CSV->new({binary => 1}) ; my $fh = new FileHandle ; open( $fh, "<", $ARGV[0]) or die "Can't open $ARGV[0]: $!\n" ; say $fh ; my $row = $csv->getline($fh) ; say do{ local $" = "\n"; "@$row" }; exit` [download] OUTPUT `FileHandle=GLOB(0x8bba28) Importance Company Department Job Title` [download] You do not need both FileHandle and open. Either one will do the job. Bill	[reply] [d/l] [select]
Re: TexT::CSV and getline by jszinger (Scribe) on Nov 04, 2020 at 20:02 UTC
`Can't call method "getline" on an undefined value at D:\Desktop\csvtes +t.pl line 16.` [download] says to me that $csv is undefined.	[reply] [d/l]
Re: Text::CSV and getline by davies (Prior) on Nov 04, 2020 at 20:07 UTC
I've never used the Filehandle module, so I'm guessing, but you don't appear to be using it as specified in the docs. The first thing I would try is to use a normal file handle without using the module, creating it in the "open" command, so: `open(my $fh, "<", $ARGV[0])` etc. Regards, John Davies	[reply] [d/l]


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