Question

I’m trying to use getpos in Perl. I am using a FileHandle object in the code below, and it doesn’t seem to be working. Can anyone tell me what I’m doing wrong?

use strict;
use warnings;
use FileHandle;

my $fh = new FileHandle;
$fh->open("<test.txt") or die "$!";
my $pos = $fh->getpos;
print "pos: \"$pos\"\n";

The output is:

pos: ""

I would expect “0” to be output…

Answer 1

Note the caveat (emphasis added) in the documentation:

If the C functions fgetpos and fsetpos are available, then FileHandle::getpos returns an opaque value that represents the current position of the FileHandle, and FileHandle::setpos uses that value to return to a previously visited position.

Opaque means you shouldn’t pay attention the value: use it only as a parameter in future requests from the module.

Why not use Perl’s tell and seek operators?

#! /usr/bin/perl

use warnings;
use strict;

open my $fh, "<", $0 or die "$0: open: $!";
print tell($fh), "\n";

The output of the above program is 0, as you expect.