How to Check Long Running Processes in Linux

It is important to keep track of long running processes on your system, whether you are a system administrator or not. Long running processes take up a lot of CPU processing and memory, and can slow down your system. Sometimes they may even stop working and slow down your system. In this article, we will check long running processes in Linux. Once you have determined the long running processes on your system, you can kill them if they have become non-responsive. You can use these steps on almost every Linux system.

How to Check Long Running Processes in Linux

We will mainly use ps command to identify long running processes in Linux. It stands for process status and displays the information about active/running processes. It provides useful details such as username, PID, cpu usage, memory usage, process start date & time, etc.

1. Shell Script to Check How Long High CPU Consumption Processes Run in Linux

Here is the command to find out list of users running processes and save the output to /tmp/long-running-processes.txt file.

ps -eo pid,user,ppid,%mem,%cpu,cmd --sort=-%cpu | head | tail -n +2 | awk '{print $1}' > /tmp/long-running-processes.txt

You can use this information to get process run time by user and commands.

Create an empty shell script.

$ sudo vi long-process-cpu-usage.sh

Add the following lines to it.

#!/bin/bash
ps -eo pid,user,ppid,%mem,%cpu,cmd --sort=-%cpu | head | tail -n +2 | awk '{print $1}' > /tmp/long-running-processes.txt
echo "--------------------------------------------------"
echo "UName     PID  CMD            Process_Running_Time"
echo "--------------------------------------------------"
for userid in `cat /tmp/long-running-processes.txt`
do
username=$(ps -u -p $userid | tail -1 | awk '{print $1}')
pruntime=$(ps -p $userid -o etime | tail -1)
ocmd=$(ps -p $userid | tail -1 | awk '{print $4}')
echo "$username $userid $ocmd $pruntime"
done | column -t
echo "--------------------------------------------------"

Save and close the file. Make it an executable with the following command.

$ sudo chmod +x long-process-cpu-usage.sh

When you run the above script, you will see the following output.

# sh /opt/scripts/long-running-cpu-proc.sh

----------------------------------------------------
UName     PID  CMD       Process_Running_Time
----------------------------------------------------
Ubuntu  3214  Web       01:18:48
Ubuntu  3748  Web       01:08:20
Ubuntu  1639  firefox   01:44:51
Ubuntu  3793  nautilus  24:14
Ubuntu  3301  Web       57:40
----------------------------------------------------

2. Shell Script to Check Top Memory Consuming Processes

Here is a shell script you can use to get top memory consuming processes on your system.

$ sudo vi long-running-memory-process.sh

Add the following lines to it.

#!/bin/bash
ps -eo pid,user,ppid,%mem,%cpu,cmd --sort=-%mem | head | tail -n +2 | awk '{print $1}' > /tmp/long-running-processes-1.txt
echo "--------------------------------------------------"
echo "UName     PID  CMD          Process_Running_Time"
echo "--------------------------------------------------"
for userid in `cat /tmp/long-running-processes-1.txt`
do
username=$(ps -u -p $userid | tail -1 | awk '{print $1}')
pruntime=$(ps -p $userid -o etime | tail -1)
ocmd=$(ps -p $userid | tail -1 | awk '{print $4}')
echo "$username $userid $ocmd $pruntime"
done | column -t
echo "--------------------------------------------------"

Save and close the file. Make the file executable.

$ chmod +x long-running-memory-process.sh

When you run the script you will see the following output.

# sh /opt/scripts/long-running-memory-process.sh

----------------------------------------------------
UName    PID   CMD       Process_Running_Time
----------------------------------------------------
ubuntu  3639  firefox   08:44:56
ubuntu  3997  Web       07:39:54
ubuntu  3269  Web       09:18:37
ubuntu  2712  Web       10:44:55
----------------------------------------------------

In this article, we have looked at two shell scripts to get memory consumption of long running processes.

How to Check Long Running Processes in Linux