Program that shows how fork system call works

#include "stdio.h"
#include "stdlib.h"
#include "unistd.h"
#include "sys/types.h"

int main(void)
{
pid_t pid;
char cwdir_cld[100];
char cwdir_prt[100];

if ((pid = fork()) < 0)
{
perror("fork error");
exit(1);
}

if (pid == 0)
{
/*
* Now we are in the childs thread
* let us issue a chdir syscall :)
*/
if(chdir("/tmp") < 0) {
perror("chdir error");
}

/*
* Let us now print the current working directory of the child
*/
if (getcwd(cwdir_cld, 100) != NULL)
{
printf("Current working directory of the child is : %s", cwdir_cld);
}
else
{

perror("getcwd error");
}

/* end of the child */
} else
{
/*
* Now we are in the parent thread
* Let is check the current working directory
*/
if (getcwd(cwdir_prt, 100) != NULL)
{
printf("Current working directory of the parent is : %s", cwdir_prt);
} else
{
perror("getcwd error");
}
}

printf(" ");
return(0);
}