getitimer - Linux

Overview

getitimer is a command used to fetch the current value of any timer under the POSIX.1b interval timer interface. This command enables the retrieval of timing information for various timers, allowing users to monitor and adjust their execution.

Syntax

getitimer <timer>

where <timer> is one of the following timer types:

• ITIMER_REAL: Real-time interval timer based on the system clock
• ITIMER_VIRTUAL: Virtual-time interval timer based on the process’s CPU time
• ITIMER_PROF: Profiling interval timer based on the process’s wall-clock time

Options/Flags

-n –null-data
Suppress the printing of any timing information, returning only the exit code.

Examples

Simple Example:

$ getitimer ITIMER_REAL
it_interval: {tv_sec: 1, tv_nsec: 0}
it_value:    {tv_sec: 10, tv_nsec: 0}

Complex Example:

# Monitor the real-time timer for 10 seconds
$ while true; do getitimer ITIMER_REAL --null-data && sleep 1; done

Common Issues

• Timer not found: If the specified timer type is not available, getitimer will return an error.
• Invalid timer value: If the specified timer value is incorrect, getitimer will return an error.

Integration

getitimer can be integrated with other commands to monitor system or process behavior. For example:

$ top -u $(whoami) | awk '{print $9}' | getitimer ITIMER_REAL --null-data

This command displays the CPU utilization of the current user and monitors the real-time timer.

Related Commands

• setitimer: Sets the value of an interval timer
• timer_gettime: Gets the current value of an interval timer
• timer_settime: Sets the value of an interval timer