What's the best way to open and read a file in Perl?

Question

Please note - I am not looking for the \"right\" way to open/read a file, or the way I should open/read a file every single time. I am just interested to find out what way m

Answer 1

It's true that there are as many best ways to open a file in Perl as there are

$files_in_the_known_universe * $perl_programmers

...but it's still interesting to see who usually does it which way. My preferred form of slurping (reading the whole file at once) is:

use strict;
use warnings;

use IO::File;

my $file = shift @ARGV or die "what file?";

my $fh = IO::File->new( $file, '<' ) or die "$file: $!";
my $data = do { local $/; <$fh> };
$fh->close();

# If you didn't just run out of memory, you have:
printf "%d characters (possibly bytes)\n", length($data);

And when going line-by-line:

my $fh = IO::File->new( $file, '<' ) or die "$file: $!";
while ( my $line = <$fh> ) {
    print "Better than cat: $line";
}
$fh->close();

Caveat lector of course: these are just the approaches I've committed to muscle memory for everyday work, and they may be radically unsuited to the problem you're trying to solve.