#include
#include
#include
#include
int main(int argc, char** argv)
{
int pfd[2];
pid_t cpd;
char buf;
if(argc != 2)
{
fprintf(stderr, "need argv\n");
exit(EXIT_FAILURE);
}
if(pipe(pfd) == -1)
{
perror("pipe");
exit(EXIT_FAILURE);
}
cpd = fork();
if(cpd == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(cpd == 0)
{
close(pfd[1]);
while(read(pfd[0], &buf, 1) > 0)
write(STDOUT_FILENO, &buf, 1);
close(pfd[0]);
exit(EXIT_SUCCESS);
}
else
{
close(pfd[0]);
write(pfd[1], argv[1], strlen(argv[1]));
close(pfd[1]);
wait(NULL);
exit(EXIT_SUCCESS);
}
}
#include
#include
#include
#include
#include
int main(int argc, char** argv)
{
pid_t cpd;
if(argc != 2)
{
fprintf(stderr, "need argv\n");
exit(EXIT_FAILURE);
}
if(access("my_fifo", F_OK) == 0)
unlink("my_fifo");
if(mkfifo("my_fifo", 0777) == -1)
{
perror("mkfifo");
exit(EXIT_FAILURE);
}
cpd = fork();
if(cpd == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(cpd == 0)
{
int fd;
char buf;
fd = open("my_fifo", O_RDONLY);
while(read(fd, &buf, 1) > 0)
write(STDOUT_FILENO, &buf, 1);
close(fd);
exit(EXIT_SUCCESS);
}
else
{
int fd;
fd = open("my_fifo", O_WRONLY);
write(fd, argv[1], strlen(argv[1]));
close(fd);
wait(NULL);
exit(EXIT_SUCCESS);
}
}
#include
#include
#include
#include
void sig_act(int sig)
{
printf("thread%d got signal%d\n", pthread_self(), sig);
sleep(5);
printf("thread%d quit\n", pthread_self());
}
int main(int argc, char** argv)
{
struct sigaction act;
struct sigaction old_act;
act.sa_handler = sig_act;
sigaddset(&act.sa_mask, SIGQUIT);
act.sa_flags = SA_NODEFER | SA_RESETHAND;
sigaction(SIGINT, &act, &old_act);
printf("main thread%d\n", pthread_self());
for(;;) sleep(1);
return 0;
}
#include
#include
#include
#include
#include
#include
char *cache;
sem_t sem;
void *thread_function(void *arg)
{
sem_wait(&sem);
while(strncmp("#", cache, 1) != 0)
{
printf("%s from thread%d\n", cache, pthread_self());
sem_wait(&sem);
}
pthread_exit(NULL);
}
int main(int argc, char** argv)
{
pthread_t pth;
void *pthret;
cache = (char*)calloc(1, 1024);
if(sem_init(&sem, 0, 0) != 0)
{
perror("sem_init");
exit(EXIT_FAILURE);
}
if(pthread_create(&pth, NULL, thread_function, NULL) != 0)
{
perror("pthread_create");
exit(EXIT_FAILURE);
}
while(strncmp("#", cache, 1) != 0)
{
fgets(cache, 1024, stdin);
sem_post(&sem);
}
if(pthread_join(pth, &pthret) != 0)
{
perror("pthread_join");
exit(EXIT_FAILURE);
}
free(cache);
sem_destroy(&sem);
return 0;
}
#include
#include
#include
#include
#include
#include
#include
int main(int argc, char** argv)
{
pid_t cpd;
struct mq_attr attr;
mqd_t mqd;
char* messages[3];
attr.mq_maxmsg = 8;
attr.mq_msgsize = 1024;
messages[0] = "message1";
messages[1] = "message2";
messages[2] = "message3";
mqd = mq_open("/mymq",
O_RDWR | O_CREAT, 0777, &attr);
if(mqd == -1)
{
perror("mq_open");
exit(EXIT_FAILURE);
}
cpd = fork();
if(cpd == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(cpd == 0)
{
sleep(3);
char *msg;
size_t msg_len;
int pro;
struct timespec t;
t.tv_sec = 2;
t.tv_nsec = 0;
msg_len = attr.mq_msgsize;
msg = (char*)calloc(1, msg_len);
pro = 0;
while(mq_timedreceive(mqd, msg, msg_len, &pro, &t) > 0)
printf("message is %s, priority is %d\n", msg, pro);
printf("no more message\n");
free(msg);
mq_close(mqd);
exit(EXIT_SUCCESS);
}
else
{
mq_send(mqd, messages[0], strlen(messages[0]), 1);
mq_send(mqd, messages[1], strlen(messages[1]), 2);
mq_send(mqd, messages[2], strlen(messages[2]), 3);
mq_close(mqd);
wait(NULL);
mq_unlink("/mymq");
exit(EXIT_SUCCESS);
}
return 0;
}
#include
#include
#include
#include
#include
#include
int main(int argc, char** argv)
{
int shmid;
char* shmaddr;
pid_t pid;
shmid = shmget(IPC_PRIVATE, 1024, IPC_CREAT | 0600);
if(shmid < 0)
{
perror("shmget");
exit(EXIT_FAILURE);
}
pid = fork();
if(pid == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(pid == 0)
{
sleep(3);
struct shmid_ds buf;
if(shmctl(shmid, IPC_STAT, &buf) == -1)
{
perror("shmctl");
exit(EXIT_FAILURE);
}
printf("the creator is %d\n", buf.shm_cpid);
shmaddr = (char*)shmat(shmid, NULL, 0);
if((int)shmaddr == -1)
{
perror("shmat");
exit(EXIT_FAILURE);
}
printf("i am the child %d, i got message \"%s\" from %d\n",
getpid(), shmaddr, buf.shm_lpid);
shmdt(shmaddr);
return 0;
}
else
{
shmaddr = (char*)shmat(shmid, NULL, 0);
if((int)shmaddr == -1)
{
perror("shmat");
exit(EXIT_FAILURE);
}
strcpy(shmaddr, "i am the parent");
shmdt(shmaddr);
wait(NULL);
return 0;
}
}
#include
#include
#include
#include
#include
int main(int argc, char** argv)
{
char *addr;
int pid;
addr = mmap(0, 512, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
pid = fork();
if(pid == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(pid == 0)
{
sleep(3);
printf("i am the child %d, i got the message \"%s\"\n",
getpid(), addr);
return 0;
}
else
{
strcpy(addr, "i am the parent");
printf("i am the parent %d\n", getpid());
wait(NULL);
return 0;
}
}
#include
#include
#include
#include
#include
#include
int main(int argc, char** argv)
{
int socketfd[2];
pid_t pid;
char buf[64];
if(socketpair(AF_UNIX, SOCK_STREAM, 0, socketfd) == -1)
{
perror("socketpair");
exit(EXIT_FAILURE);
}
pid = fork();
if(pid == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
else if(pid == 0)
{
sleep(3);
char message[] = "child to parent";
close(socketfd[0]);
if(read(socketfd[1], buf, sizeof(buf)) < 0)
perror("read");
if(write(socketfd[1], message, sizeof(message)) < 0)
perror("write");
printf("child %d got message \"%s\"\n", getpid(), buf);
close(socketfd[1]);
return 0;
}
else
{
char message[] = "parent to child";
close(socketfd[1]);
if(write(socketfd[0], message, sizeof(message)) < 0)
perror("write");
if(read(socketfd[0], buf, sizeof(buf)) < 0)
perror("read");
printf("parent %d got message \"%s\"\n", getpid(), buf);
close(socketfd[0]);
wait(NULL);
return 0;
}
}
