Shell – Unix Shell and colours

The following script should filter out all ANSI/VT100/xterm control sequences for (based on ctlseqs). Minimally tested, please report any under- or over-match.

#!/usr/bin/env perl
## uncolor — remove terminal escape sequences such as color changes
while (<>) {
    s/ \e[ #%()*+\-.\/]. |
       \e\[ [ -?]* [@-~] | # CSI ... Cmd
       \e\] .*? (?:\e\\|[\a\x9c]) | # OSC ... (ST|BEL)
       \e[P^_] .*? (?:\e\\|\x9c) | # (DCS|PM|APC) ... ST
       \e. //xg;
    print;
}

Known issues:

• Doesn't complain about malformed sequences. That's not what this script is for.
• Multi-line string arguments to DCS/PM/APC/OSC are not supported.
• Bytes in the range 128–159 may be parsed as control characters, though this is rarely used. Here's a version which parses non-ASCII control characters (this will mangle non-ASCII text in some encodings including UTF-8).

#!/usr/bin/env perl
## uncolor — remove terminal escape sequences such as color changes
while (<>) {
    s/ \e[ #%()*+\-.\/]. |
       (?:\e\[|\x9b) [ -?]* [@-~] | # CSI ... Cmd
       (?:\e\]|\x9d) .*? (?:\e\\|[\a\x9c]) | # OSC ... (ST|BEL)
       (?:\e[P^_]|[\x90\x9e\x9f]) .*? (?:\e\\|\x9c) | # (DCS|PM|APC) ... ST
       \e.|[\x80-\x9f] //xg;
    print;
}

The same written for zsh in a much cleaner way:

#!/bin/zsh

typeset -A names
names[no]="global default"
names[fi]="normal file"
names[di]="directory"
names[ln]="symbolic link"
names[pi]="named pipe"
names[so]="socket"
names[do]="door"
names[bd]="block device"
names[cd]="character device"
names[or]="orphan symlink"
names[mi]="missing file"
names[su]="set uid"
names[sg]="set gid"
names[tw]="sticky other writable"
names[ow]="other writable"
names[st]="sticky"
names[ex]="executable"

for i in ${(s.:.)LS_COLORS}
do
    key=${i%\=*}
    color=${i#*\=}
    name=${names[(e)$key]-$key}
    printf '\e[%sm%s\e[m\n' $color $name
done