Well, heck. One of our Great and Holy Brethren, jdporter, took a shot at rewriting 'cut'... I can be brave too. :) Well, not all _that_ brave - I'm not rewriting "ls" from scratch, thankyouverymuch - but I've always wondered why it doesn't have an option for displaying permissions in octal. Well, now it does.

I've kept the formatting and all the other goodies of "ls" - you can still specify all the same options, etc. (not that I've done a huge amount of testing; I'm sure there are edge cases that would break it - I just haven't managed to come up with any.) I also suspect that there are better, smarter ways to do this, so comments would be very welcome.

Anyway, here it is. Enjoy. 

#!/usr/bin/perl -w
# Created by Ben Okopnik on Sat Mar 26 19:00:46 EDT 2011
use strict;

for my $ls (qx#/bin/ls -l @ARGV#){
    my ($t, $p, $r) = $ls =~ /^(.)([rwxsStT-]+)(\s+\d+\s+\w+.+)$/;
    print $ls and next unless $p;

    my $out = 0;
    my %d = map {split//} qw/sx S- r4 w2 x1 -0/;
    $out += 01000 if $p =~ y/tT/x-/;
    $out += 02000 if $p =~ s/(s)(?=.{3})$/$d{$1}/i;
    $out += 04000 if $p =~ s/(s)(?=.{6})$/$d{$1}/i;

    for ((100) x 3, (10) x 3, (1) x 3){
        $out += $d{$1} * oct($_) if $p =~ s/([rwx-])//;
    }

    printf "[%s] %04o  %s\n", $t, $out, $r;
}

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-- 
Education is not the filling of a pail, but the lighting of a fire.
 -- W. B. Yeats

In reply to 'ls' with octal permissions by oko1

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