System monitoring from the command line
Command Line – watch and fswatch
© Lead Image © Shao-Chun Wang, 123RF.com
Two monitoring tools, watch and fswatch, let you gather system information from the command line.
Most users familiar with Linux have probably used cron or at to schedule the running of commands. Both can be useful in their place: cron for repeated scheduling of events and at for scheduling an event once. However, what both lack is the ability to gather system information and respond to it unless you write a specific script. Usually, it is much easier to use watch [1] and fswatch [2] to do both these things. While watch and fswatch can be used simply to gather information or to check for possible security incursions, both can be tweaked to act like a scheduler with little effort and minimal script-writing ability.
watch
The purpose of watch is to follow how a command's output changes over time (Figure 1). This information can be used for troubleshooting, as well as for keeping a root or regular user informed about system changes as new packages are installed or updated. In limited circumstances, it could also be used as a simpler replacement for at or cron. Several other common uses are shown in Table 1. By default, watch runs every two seconds until closed or interrupted. The basic command structure is:
watch OPTIONS COMMAND
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
USB4 Maintainer Leaves Intel
Michael Jamet, one of the primary maintainers of USB4 and Thunderbolt drivers, has left Intel, leaving a gaping hole for the Linux community to deal with.
-
Budgie 10.9.3 Now Available
The latest version of this elegant and configurable Linux desktop aligns with changes in Gnome 49.
-
KDE Linux Alpha Available for Daring Users
It's official, KDE Linux has arrived, but it's not quite ready for prime time.
-
AMD Initiates Graphics Driver Updates for Linux Kernel 6.18
This new AMD update focuses on power management, display handling, and hardware support for Radeon GPUs.
-
AerynOS Alpha Release Available
With a choice of several desktop environments, AerynOS 2025.08 is almost ready to be your next operating system.
-
AUR Repository Still Under DDoS Attack
Arch User Repository continues to be under a DDoS attack that has been going on for more than two weeks.
-
RingReaper Malware Poses Danger to Linux Systems
A new kind of malware exploits modern Linux kernels for I/O operations.
-
Happy Birthday, Linux
On August 25, Linux officially turns 34.
-
VirtualBox 7.2 Has Arrived
With early support for Linux kernel 6.17 and other new additions, VirtualBox 7.2 is a must-update for users.
-
Linux Mint 22.2 Beta Available for Testing
Some interesting new additions and improvements are coming to Linux Mint. Check out the Linux Mint 22.2 Beta to give it a test run.