C Program to Remove (Delete) a Directory using LINUX System Calls

This is a C program to delete  or remove a directory using the system calls in Linux or Unix operating systems. The program make use of the remove() system call in Linux.

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



char fn[10];
printf("Enter source filename\n");
scanf("%s",fn);
if(remove(fn)==0)
printf("File removed\n");
else
printf("File cannot be removed\n");
}

C Program to open, read and write files and perform file copy operation usingSystem Calls in UNIX

Write a program to open, read and write files and perform file copy operation. This program show how to open, read, write and copy files using Linux or Unix system calls like open(), read() and write().

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


char buff[1000],fn1[10],fn2[10];
int fd1,fd2,n;
printf("Enter source filename\n");
scanf("%s",fn1);
printf("Enter destination file name\n");
scanf("%s",fn2);
fd1=open(fn1,O_RDONLY);
n=read(fd1,buff,1000);
fd2=open(fn2,O_CREAT|O_WRONLY);
n=write(fd2,buff,n);
close(fd1);
close(fd2);
}

How to use fork and exec System Call

Using fork and exec System calls in Linux (UNIX) operating systems. Fork system call is used to create a child process from a parent process.
#include<stdio.h>
main()
{

int pid;
pid=fork();
printf("%d\n",pid);
if(pid==0)
{
exec("/bin/date\n",NULL,NULL);
exit(0); }
else
{
printf("Parent process %d\n",pid); }}
if(sp)
while(dd=readdir(sp))
printf("--> %s\n",dd->d_name);
}
}