Have you ever been in a situation where you wanted to know how long a process has been running on your Linux box? No? No problem! This brief guide helps you to find out the uptime of an active process in Linux.
You don't need any monitoring applications. In Linux and other Unix-like operating systems, there is a command called
ps, which is used to display the information about the active processes. Using
ps command, we can easily find out how long a process is running in Linux.
Find out how long a process has been running in Linux
ps command has different format specifiers (keywords) that can be used to control the output format. We are going to use the following two keywords to find the uptime of an active process.
etime- elapsed time since the process was started, in the form of
etimes- elapsed time since the process was started, in seconds.
First, you need to find out the
PID of a process. The following command displays the
$ pidof dhcpcd 8299
As you see in the above output,
8299 is the
Now, we can find how long this process has been running using command:
$ ps -p 8299 -o etime ELAPSED 04:05:37
You can also view the elapsed time in seconds using etimes keyword.
$ ps -p 8299 -o etimes ELAPSED 14749
Not only a single process, we can also display the uptime of all processes like below.
$ ps -eo pid,comm,lstart,etime,time,args
$ ps -eo pid,comm,lstart,etimes,time,args
The first command displays the uptime of all Linux processes, in
[[DD-]hh:]mm:ss format, and the latter displays the uptime in seconds.
Here is the sample output of second command.
As you see in the above output, we have the uptime of all processes with six columns format.
PID- The Process ID.
COMMAND(second column) - The command name without options and/or arguments.
STARTED- The absolute starting time of the process.
ELAPSED- The elapsed time since the process was started, in the form of [[dd-]hh:]mm:ss.
TIME- Cumulative CPU time, "[dd-]hh:mm:ss" format.
COMMAND(last column) - Command name with all its provided options and arguments.
For more details about
ps command, check the man pages.
$ man ps