Install watch with Homebrew, MacPorts, winget

Project links

• Homepage

Commands and aliases

• watch

Project history

The current procps-ng source keeps a compact lineage in the watch source header: it is based on Tony Rems's original 1991 watch, with later modifications by Francois Pinard; Mike Coleman, Albert Cahalan, Morty Abzug, Jarrod Lowe, Sami Kerola, Jim Warner, Craig Small, and Roman Zilka appear in the copyright and feature history. That lineage explains why a tiny command has accumulated practical terminal behavior over decades rather than becoming a new standalone project.

watch is maintained today as part of procps/procps-ng, the Linux /proc-oriented utility collection that also includes ps, top, free, vmstat, pgrep, pkill, uptime, w, and related tools. The procps-ng NEWS file records the 3.3.0 fork by Debian, Fedora, and openSUSE maintainers from procps, followed by steady watch-specific work such as Unicode and ANSI color handling, no-wrap mode, precise intervals, no-rerun-on-resize, equal-output exit behavior, 256-color support, and the more recent follow mode.

How it is used

The standard manual describes watch as running a command repeatedly, defaulting to a two-second interval, until interrupted. Its core options cover interval control, highlighting differences between refreshes, exiting when output changes or stabilizes, treating the command as exec rather than shell text, preserving or suppressing the title header, interpreting color, and reacting to non-zero command exits.

Typical package-nerd use is not limited to process monitoring. Users wrap arbitrary shell fragments: `watch -d ls -l`, `watch uname -r`, a pipeline over `/proc/cpuinfo`, a ping loop, a queue-depth check, or a package-build directory listing. Because the command is usually passed through `sh -c`, watch composes naturally with shell quoting, pipes, redirects, and text filters.

Why package nerds care

watch matters because it is the minimal repeat loop with terminal ergonomics. It occupies the space between a one-off command and writing a monitoring script: no daemon, no UI framework, no config, just a refresh interval, a screen, and a shell command. That makes it a fixture in build troubleshooting, service bring-up, kernel and container debugging, and package maintainer workflows where quick visual feedback beats a permanent monitoring stack.

Timeline

• 1991: Original watch by Tony Rems, later noted in the procps-ng source header.
• 1999-2009: Later source-header credits record Mike Coleman work, Morty Abzug's stderr/exec/beep additions, and Jarrod Lowe's Unicode support.
• 2011: procps-ng 3.3.0 is described in NEWS as the Debian, Fedora, and openSUSE fork of procps.
• 2014-2026: procps-ng NEWS shows continuing watch maintenance, including interval, Unicode, ANSI/color, resize, line wrapping, and output-change behavior.
• 2025: The man-pages copy of watch(1) documents modern options such as --follow, --equexit, --precise, --exec, and WATCH_INTERVAL.

Related projects

• watch is related to procps/procps-ng tools such as ps, top, vmstat, uptime, w, pgrep, and free; to shell loops such as `while true; do ...; sleep ...; done`; and to file/event-oriented rerun tools such as entr, watchexec, and Watchman, though watch itself is polling command output rather than subscribing to file changes.

Sources

• https://gitlab.com/procps-ng/procps/-/raw/master/NEWS
• https://gitlab.com/procps-ng/procps/-/raw/master/README.md
• https://gitlab.com/procps-ng/procps/-/raw/master/src/watch.c
• https://man7.org/linux/man-pages/man1/watch.1.html