/* Execute the given command in the array. Supports arguments */
void execute(char *input){
pid_t pid;
char command[BUF_SIZE];
trim(input, command);
if(strcmp("exit", command) == 0){
printf("exiting...\n");
exit(0);
}
else if(strcmp("", command) != 0){
pid = fork();
if(pid < 0){
perror("fork");
exit(-1);
}
else if(pid == 0){ /*child*/
child_code(command);
}
else{ /* parent */
parent_code();
}
}
}
main(int ac, char *av[])
{
void child_code(int), parent_code(int);
pid_t pid;
int i,n;
int delay;
/*
* setup
*/
if ( ac == 1 ){
fprintf(stderr,"usage: sol08.8b numberofchildren\n");
exit(1);
}
n = atoi(av[1]);
srand(getpid());
printf("before: mypid is %d\n", getpid());
/*
* main loop
*/
for(i=0; i<n ; i++){
delay = 1 + (rand() % MAXDELAY);
pid = fork();
if ( pid == -1 )
oops("fork", 2);
if ( pid == 0 )
child_code(delay);
}
parent_code(n);
return 0;
}
void *entry (void *arg)
{
Shared *shared = (Shared *) arg;
child_code (shared);
printf ("Child done.\n");
pthread_exit (NULL);
}
int main(int argc, char const *argv[])
{
/* basically the same key used
for the semaphore programs */
key_t key;
pid_t childPid;
int msqid;
/* create a token */
if((key = ftok("/tmp", SECRET_KEY)) == -1) {
printf("[-] Error on ftok\n");
return 1;
}
/* create a set of msg */
if((msqid = msgget(key, 0666|IPC_CREAT|IPC_EXCL)) == -1) {
printf("[-] Error on msgid\n");
return 1;
}
/* now use the fork */
switch (childPid = fork()){
case -1: //fork fallita
return 1;
break;
case 0: // eseguo il codice del figlio
child_code(msqid);
break;
default: // eseguo il codice del padre
parent_code(msqid);
break;
}
return 0;
}
// main takes two parameters: argc is the number of command-line
// arguments; argv is an array of strings containing the command
// line arguments
int main (int argc, char *argv[])
{
int status;
pid_t pid;
double start, stop;
int i, num_children;
// the first command-line argument is the name of the executable.
// if there is a second, it is the number of children to create.
if (argc == 2) {
num_children = atoi (argv[1]);
} else {
num_children = 1;
}
// get the start time
start = get_seconds ();
for (i=0; i<num_children; i++) {
// create a child process
printf ("Creating child %d.\n", i);
pid = fork ();
/* check for an error */
if (pid == -1) {
fprintf (stderr, "fork failed: %s\n", strerror(errno));
perror (argv[0]);
exit (1);
}
/* see if we're the parent or the child */
if (pid == 0) {
child_code(i);
}
}
/* parent continues */
printf ("Hello from the parent.\n");
for (i=0; i<num_children; i++) {
pid = wait (&status);
if (pid == -1) {
fprintf (stderr, "wait failed: %s\n", strerror(errno));
perror (argv[0]);
exit (1);
}
// check the exit status of the child
status = WEXITSTATUS (status);
printf ("Child %d exited with error code %d.\n", pid, status);
}
// compute the elapsed time
stop = get_seconds ();
printf ("Elapsed time = %f seconds.\n", stop - start);
exit (0);
}
int main(void) {
int newpid;
printf("Before: my pid is %d\n", getpid());
if ((newpid = fork()) == -1)
perror("fork");
else if (newpid == 0)
child_code(DELAY);
else
parent_code(newpid);
return EXIT_SUCCESS;
}
int main()
{
int newpid;
void child_code(), parent_code();
printf("before: my pid is %d \n", getpid());
if ((newpid = fork()) == -1)
perror("fork");
else if (newpid == 0)
child_code(DELAY);
else
parent_code(newpid);
}
int main(int argc, char *argv[]) {
process_num = atoi(argv[1]);
int parent_pid = getpid();
printf("Before: my pid is %d\n", parent_pid);
for (int i = 0; i < process_num; ++i)
child_code(parent_pid, DELAY);
signal(SIGCHLD, parent_code);
while (true) {
printf("waiting...\n");
sleep(1);
}
return EXIT_SUCCESS;
}
int main(void)
{
int newpid;
void child_code(), parent_code();
printf("before: my pid is %d\n", getpid());
if ((newpid = fork()) == -1) {
perror("fork");
} else if (newpid == 0) {
child_code(DELAY);
} else {
parent_code(newpid);
}
return 0;
}
int main(int argc, char **argv)
{
int newpid;
int i;
void child_code(int);
void parent_code(int);
if(argc != 2){
printf("Usage: waitdemo_l number_of_fork\n");
exit(0);
}
for(i = 0; i < atoi(argv[1]); i++){
if((newpid = fork()) == -1){
perror("fork");
exit(0);
}else if(newpid == 0)
child_code(DELAY);
else
parent_code(newpid);
}
return 0;
}
int main(int argc, char *argv[])
{
int i;
int n_children;
int father_pid;
int sec;
/*int pid[MAX];*/
// Print all argument (debug purpose)
printf("Arguments:\n");
for (i = 0; i < argc; i++)
printf("[%d]:%s\n", i,argv[i]);
//Check number of arguments
if(argc != 4){
printf("Illegal number of parameters\n");
exit(1);
}
//Check argument is digit
if(!isdigit(argv[1][0])){
printf("%d must be digit\n",argv[1][0]);
exit(1);
}
//Check argument is positive
if (argv[1][0]<=0)
{
printf("%d must be >0\n",argv[1][0]);
exit(1);
}
//Check files exist and executable
for (i = 2; i < argc-1; ++i)
{
if (access(argv[i],F_OK)!= -1 && access (argv[i],X_OK)!=-1)
{
printf("file: %s exist and executable\n", argv[i]);
}
else {
printf("file: %s incorrect\n", argv[i]);
}
}
sec = atoi(argv[1]);
n_children = 2;
printf("n_children = %d\n", n_children);
signal(SIGUSR1,&signal_handler);
signal(SIGTERM,&signal_handler);
printf("----- start program -----\n");
//Pid of the father
father_pid = getpid();
for (i = 0; i < n_children; ++i)
{
//printf("about to create child [%d]\n", i);
pid[i] = fork();
if (pid[i] == 0) //child
{
printf("child:pid - [%d][%d]\n",i,getpid());
child_code(argv[i+2],i,sec);
}
else if (pid[i] > 0)//father
{}
else //Errors
{
perror("Unable to fork()");
exit(2);
}
}
//father code
for (i = 0; i < n_children; ++i)
{
wait_child();
}
return 0;
}
