[SOLVED]How to get colorful output when pipe yaourt's STDIO to less?

Question

Hello, second post to NC.
My question is how to get a piped(e.g. pipe yaourt's STDOUT to less) program's colorful output on screen without such option like '--color=always'.
Before post this, I've configured less's default behaviour in "~/.zshrc" with following
less() {
env LESS=R less "$@"
And When I run:
$ dmesg --color=always | less
Everything works fine(I get good, colorful output), but when I run this:
$ yaourt -Qe --date | less
Seems that I can only get grey output on terminal emulator (without 'less' I get colorful output).
Does anyone has idea about getting yaourt's colorful output with 'less' ?
Last edited by izmntuk (2014-06-08 00:15:15)

Answer 1

Thanks for reply and after serveral mintues googling & getting some help from IRC:
It seems that there're some utilities that do not provide such a option like 'color=always', what we need to do is trick these utilities into thinking their's STDIO is to a tty, not a pipe.
1. stdoutisatty way (aur/stdoutisatty-git is needed) from [0]:
$ stdoutisatty yaourt -Qe --date | less
2. socat way (extra/socat is needed, sometimes doesn't work fine) from [1]:
$ socat EXEC:"yaourt -Qe --date",pty STDIO | less
3. script way (sometimes doesn't work fine) from [2]:
$ script -fqc 'yaourt -Qe --date' | less
4. unbuffer way (extra/expect is needed) from [3]:
$ unbuffer yaourt -Qe --date | less
5. zpty way (extra/zsh is needed) slightly modified from [4]:
zmodload zsh/zpty
autoload colors && colors
pty() {
local VERSION=0.2
if [[ -t 0 && $# -ne 0 && ${1} != '--help' ]];then
zpty pty-${UID} ${1+"$@"}
## when piping function pty to a pager, it may be a good idea to disable ^C *in this function*. assume that you're going to run this command: pty ls -alRi --color | less
## and now you enter a pager, and you press the End key by accident, and the pager seems stuck, and to get unstuck you pressed ^C, then the entire function interrupted. so to avoid the interrupt:
if [[ ! -t 1 ]];then
setopt local_traps
trap '' INT
zpty -r pty-${UID}
else
zpty -r pty-${UID}
fi
zpty -d pty-${UID}
elif [[ $# -eq 1 && ${1} == '--version' ]];then
print "pty v${VERSION}"
else
_-automatic-colored
print "${bldblu}Usage: ${bldgrn}pty${rst} ${bldcyn}command${rst} [${bldcyn}argv${rst}...]
wrapper function to run a program under pseudo-terminal
${bldcyn}--help${rst} print help message
${bldcyn}--version${rst} print version"
fi
ptypg() {
if [[ -t 0 && $# -ne 0 && ${1} != '--help' ]];then
pty $@ | pg
else
_-automatic-colored
print "${bldblu}Usage: ${bldgrn}ptypg${rst} ${bldcyn}command${rst} [${bldcyn}argv${rst}...]
wrapper function to run a program under pseudo-terminal and view its output in pg
${bldcyn}--help${rst} print help message"
fi
_-automatic-colored() {
if [[ "${1}" == unset || ! -t 1 ]];then
unset rst bld bldwht bldblk bldred bldgrn bldylw bldblu bldcyn blk red grn ylw blu cyn gry
return 0
elif [[ -t 1 ]];then
rst="${reset_color}"
bld="${fg_bold[default]}"
bldwht="${fg_bold[white]}"
bldblk="$fg_bold[black]"
bldred="$fg_bold[red]"
bldgrn="$fg_bold[green]"
bldylw="$fg_bold[yellow]"
bldblu="$fg_bold[blue]"
bldcyn="$fg_bold[cyan]"
gry="${fg[white]}"
blk="$fg[black]"
red="$fg[red]"
grn="$fg[green]"
ylw="$fg[yellow]"
blu="$fg[blue]"
cyn="$fg[cyan]"
return 0
fi
$ pty yaourt -Qe --date | less
$ ptypg yaourt -Qe --date
And if there are any better implementation please leave a comment add it to wiki .
Last edited by izmntuk (2014-08-19 14:18:45)