In this article we will create, monitor different types of linux processes and illustrate IPC process communication applications using practical examples, code snippets.

Online courses related to this article

Course description

Learn to develop embedded systems, interfacing electronic peripherals through real time projects and get required practical skills for software jobs

Course description

Learn to develop software solutions for linux environment, implement requirements through real time projects and get required practical skills for software jobs

Updated: Mar 23, 2020

Related online test

Process in Linux

Code:AL000015

By: admin

Article contents

• What is a process in linux?
• Creating a Linux process
• States of process, Zombie process
• Creating a process using fork
• Getting process ID(PID) and group

Learn linux process, creating a process, states of linux process, zombie process, creating process using fork system call, getting process ID(PID) and group info using system calls.

What is a linux process?

A process is an active program i.e. a program that is under execution.

Creating a Linux process

Let's write the following small program square.c and create an executable SQUARE for it.

#include "stdio.h"
void main()
{
        int num;
        start:
        printf("Enter a number\n");
        scanf("%d",&num);
        while(num < 10)
        {
                printf("Square of your number:%d\n",num * num);
                goto start;
        }
}

$ gcc square.c -o SQUARE
$ ./SQUARE
Enter a number
3
Square of your number:9
Enter a number
5
Square of your number:25
Enter a number

Let's open another console and execute ps -aux command to observe the process we have created.

$ ps -aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.6  26936  5940 ?        Ss   01:46   0:02 /sbin/init splash
pi        2063  0.0  0.0   1812   328 pts/0    S+   05:09   0:00 ./SQUARE
pi        2115  0.0  0.3   7736  2868 pts/1    R+   05:13   0:00 ps -aux
$ 

When we executed the ps -aux command we got all processes information detail. I have intentionally removed the other processes and kept few lines for your observation

States of process, Zombie process