ls --color support for systems that don't have it, like AIX, and when you don't want to install gnu

aix-ls

#!/usr/bin/perl

use strict;
use Getopt::Long qw(:config pass_through no_ignore_case bundling);

my $do_color;

GetOptions("colors"=>\$do_color);

my @buf;
my $do_cols;
my $cur_col;
my $max_len;
my $num_cols;
my $screen_width;
my $cur_len;
if (!$do_color) {
    exec("/usr/bin/ls", @ARGV);
} else {
    my ($do_long);
    my ($sr_dir);

    GetOptions("l"=>\$do_long);

    if ($do_long) {
        unshift @ARGV, "-l";
    } elsif (-t STDOUT) {
        $do_cols=1;
        $screen_width=`tput cols`; chomp $screen_width;
    }

    for (@ARGV) {
        s/\"/\\\"/g;
        $sr_dir=$_;
        $_="\"$_\"";
    }
    open(I,"/usr/bin/ls @ARGV|");
    while(<I>) {
        chomp;

        my $type;
        if (!$do_long) {
            $type = 'x' if -x "$sr_dir$_";
            $type = 'd' if -d "$sr_dir$_";
            $type = 'l' if -l "$sr_dir$_";
            $type = 's' if -k "$sr_dir$_";
        } else {
            $type = $1 if /^(.)/;
            $type = 'x' if $type eq '-' && (/^...x/ || /^......x/ || /^.........x/);
        }
        if ($do_cols>0) {
            if ($do_cols==2) {
                print_col();
            } else {
                push @buf, [$type, $_];
                if (length($_) > $max_len) {
                    $max_len = length($_);
                }
                if (@buf > 1000) {
                    print_buf();
                }
            }
        } else {
            print colorize($type, $_), "\n";
        }
    }
    if ($screen_width > 0) {
        print_buf();
        if ($cur_col) {
            print "\n";
        }
    }
}

sub print_col {
    my ($type, $str) = @_;
    my $padding = " " x ((($max_len+1)*$cur_col) - $cur_len);
    print $padding;
    $cur_len+=(length($str)+length($padding));
    print colorize($type, $str);
    if ($cur_col==($num_cols-1)) {
        print "\n";
        $cur_col=0;
        $cur_len=0;
    } else {
        ++$cur_col;
    }
}


sub print_buf {
    $num_cols = int($screen_width/($max_len+2));
    for (@buf) {
        print_col(@$_);
    }
    $do_cols=2;
    @buf=();
}

sub colorize {
    my ($type, $str) = @_;
    ($type eq 'd') and ($str="\033[1;34m$str\033[0m");
    ($type eq 'l') and ($str="\033[1;36m$str\033[0m");
    ($type eq 's') and ($str="\033[1;31m$str\033[0m");
    ($type eq 'x') and ($str="\033[1;32m$str\033[0m");
    $str="\033[0m$str";
    return $str;
}