watch

Additional Notes

watch is a process-management command used to run a command repeatedly and display the output. It runs a command repeatedly and displays its output, highlighting differences between runs.

Use -n to set the interval in seconds and -d to highlight what changed between updates. Commands with pipes or redirects should be quoted.

Syntax

watch [options] command

Parameters

• options: Flags that change how watch behaves.
• command: Command to rerun repeatedly.

Common Options

• -n N: Run every N seconds.
• -d: Highlight differences between updates.
• -t: Hide the header.

Examples

watch df -h
watch -n 1 "ss -tuln"
watch -d "ls -l"

Practical Notes

Quote commands that contain pipes, redirects, or multiple arguments.