watch

Linux · Processes · reference only

What it does

Runs a command repeatedly every few seconds and shows its output full screen, so you can watch it change.

Syntax

watch [opciones] comando

Options and parameters

• -n segundos

  Interval between runs; 2 seconds by default.

• -d

  Highlights the differences between one run and the next.

• -t

  Hides the header with the interval and time.

• -e

  Stops if the command returns an error.

• -g

  Exits when the command's output changes.

• -c

  Interprets ANSI colors in the output.

• -b

  Beeps if the command exits with an error.

Usage examples

• watch -n 2 date

  Shows the time, updated every 2 seconds.

• watch -d ls -l

  Highlights changes in a directory while you work.

• watch -n 1 'df -h /'

  Watches the root disk usage change every second.

• watch -g 'ls | wc -l'

  Waits until the number of files in the directory changes.

Notes and common mistakes

• Press Ctrl+C to exit.
• If the command has pipes or several words, put it in quotes.

Related commands

• at
• bg
• crontab
• fg
• jobs
• kill