in reply to Re: Redefining chomp()
in thread Redefining chomp()

As there is no quantifier on your character class, I have trouble understanding how this will remove multiple newlines as you say. Am I missing something?

Also, if the Windows newline is in fact "\r\n", this will not work, again because there is no quantifier.

It seems to me if you instead do

$count += $_ =~ s/\r?\n$//g;

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... then you alleviate the problem of killing all trailing newlines and, assuming "\r\n" is what all windows newlines are, you are matching both windows and unix newlines.

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Re: Re: Re: Redefining chomp()
by Limbic~Region (Chancellor) on Mar 24, 2004 at 18:42 UTC
    ryantate,
    My regex fu is non-existant as you can see. That does not really matter much as I said it would need to be fixed. I was on my way to a meeting so I didn't get to spend a lot of time on it. After thinking about it some more, I think the following would work a lot better. 
    package Chomp;
use Scalar::Readonly ':all';

BEGIN {
    *CORE::GLOBAL::chomp = sub {
        readonly_on( $/ );
        my ($count, $fix)  = (0, '');
        local $/  = "\r\n";
        for ( @_ ) {
            my ($first, $second) = (0, 0);
            eval { $first = chomp };
            if ( $@ ) {
                die $@ if $_ !~ /^\r?\n$/;
                $fix = $_;
                last;
            }
            if ( ! $first ) {
                local $/ = "\n";
                $second = chomp;
            }
            $count += $first + $second;
        }
        readonly_off( $/ );
        return $fix ? ($count , $fix) : $count;
    };
}
42;

# Then a script that uses it

#!/usr/bin/perl
use strict;
use warnings;
use Chomp;

my $foo = "foo\n\r\n";
my $bar = "bar\n\n\n";

print chomp $foo, $/;            # prints 2
print chomp $bar, "\n";          # prints 1
print chomp ($foo, $bar), "\n";  # prints 2

    [download]
    This does have the unfortunate side effect of not allowing someone to do: 
    chomp($/);  # $/ = undef;

    [download]
    I know this is ugly and there are probably a few more gotchas in there, but It was kind of fun to work on. Note: This can be done without a module, but it is much uglier. Anyone wanting to see that should say so.

    Cheers - L~R

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Re^3: Redefining chomp()
by Roy Johnson (Monsignor) on Mar 24, 2004 at 18:48 UTC
    I have trouble understanding how this will remove multiple newlines as you say. Am I missing something?
    If the trailing /g on an anchored s///g actually had some effect, maybe it would strip off all trailing newlines. But as it is, it doesn't.
    The PerlMonk tr/// Advocate
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