NAME

watch — periodically execute a command and display its output

SYNOPSIS

watch [-celwx] [-s seconds] command [arg ...]

The watch utility periodically executes and displays the output of command. Differences between successive runs can be highlighted.

The options are as follows:

-c: Highlight changed characters.
-e: Pause updating if command exits with a non-zero exit code.
-l: Highlight changed lines.
-s seconds: Set the interval between updates to seconds. The default is 1 second.
-w: Highlight changed words.
-x: Pass command to execl(3) instead of sh -c, for different quoting and shell escaping behaviour.

Certain characters cause immediate action by watch. These are:

⟨Space⟩: Run command again.
⟨Page Down⟩: Scroll down a screenful.
⟨Page Up⟩: Scroll up a screenful.
[ | ⟨left arrow⟩: Scroll left by one column.
] | ⟨right arrow⟩: Scroll right by one column.
c: Highlight changed characters.
e: Pause command executions if the command exits with a non-zero exit code.
g: Scroll to top.
H: Scroll left half a screen.
h | ?: Display a summary of the commands (help screen).
J: Scroll down half a screen.
j | ⟨down arrow⟩: Scroll down one line.
K: Scroll up half a screen.
k | ⟨up arrow⟩: Scroll up one line.
L: Scroll right half a screen.
l: Highlight changed lines.
r: Display information about resource utilization.
s: Change the update interval.
p: Pause or resume command executions. ⟨Space⟩ can be used while paused.
w: Highlight changed words.
q: Quit watch.

watch was first published in 1991 and has been available since OpenBSD 7.8.

Takuya Sato, Kazumasa Utashiro, YASUOKA Masahiko <yasuoka@openbsd.org>, and Job Snijders <job@openbsd.org>.