C Program to Open, Read and Write a file using System Calls

This is a C program to open , read and write files using system calls in Linux (UNIX) operating systems. The system calls open(), read() and write() are used in the C program to open, read and write files in Unix/Linux operating systems.

#include<stdio.h>
#include<fcntl.h>
main()
{

Using System calls in C Program to rename a Directory in Linux

C Program to rename a directory in Unix or Linux operating systems using system call rename().

#include<stdio.h>
main()
{

How to Create process and display Process ID (pid) of Both Parent and Child

This program shows how to create process and display Process ID (pid) of Both Parent and Child processes. The process is created using the fork system call in UNIX (Linux) operating systems.

#include<stdio.h>
#include<dirent.h>
main(int argc,char **argv)
{

How to use exit() System call

C program to show how to use exit system call. The function exit() is used to exit from a process (or to terminate a process). This works both in Linux or UNIX and Windows operating systems.

#include<stdio.h>
main()
{

Creating A Process in Linux (UNIX) - fork() Example Program

The system call fork() is used to  create a new process in UNIX based operating systems and Linux systems. The fork() system call creates a child process when called from a parent process. Unix will make an exact copy of the parent's address space and give it to the child. Therefore, the parent and child processes have separate address spaces. Here is a C program which uses the fork() system call to create a process during execution. The program is commented well for better understanding.

Program

/*The program (parent process) reads an array from the user.
It sorts it in descending order.