C Programming Code Examples C > C on Unix Code Examples Program that shows how fork system call works 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); }
