In bash, watch (e.g. watch -n 5 ls -l) could be used to repeat the command at fixed intervals.
This command seem to be missing on zsh. Is there an equivalent?
3 Answers
watch is not an internal command:
$ type watch /usr/bin/watch so make sure it installed on the system where you are running zsh.
- 40That was it. I'm running Mac OSX, which didn't come with it. So installed via homebrew:
brew install watch. stackoverflow.com/a/23370705/1175956snowbound– snowbound2016-02-06 11:45:42 +00:00Commented Feb 6, 2016 at 11:45
I just improvised watch with: clear; while ls -lah; do sleep 2; clear; done
Interesting idea. I could write a function around that... Right, put this in your .zshrc
watch () { IN=2 case $1 in -n) IN=$2 shift 2 ;; esac printf '\033c' # clear CM="$*" LEFT="$(printf 'Every %.1f: %s' $IN $CM)" ((PAD = COLUMNS - ${#LEFT})) while : do DT=$(date) printf "$LEFT%${PAD}s\n" "$HOST $(date)" eval "$CM" sleep $IN printf '\033c' done } 
- 1Why reinvent the wheel? Also, how about the other options like
-d,-g, etc?GMaster– GMaster2020-05-16 15:45:39 +00:00Commented May 16, 2020 at 15:45 - 2Because not everybody uses Linux where it is installed by default. On OSX and the BSDs you'd have to install a package. Also, my aliases won't work in the normal watch. I don't care about the other features. If you do, feel free to add them. Also, you learn coding by doing it.Han– Han2020-05-16 15:49:43 +00:00Commented May 16, 2020 at 15:49
As pointed out by @Han, if you use that script that he made you will also be able to run commands using your local aliases, and also preserve terminal colors.
watchis not a builtin. It is an external command.