#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include "sem.h"
typedef struct
{
char buf[1024];
}memory;
int main(int argc, const char *argv[])
{
key_t key;
memory *p = NULL;
int shmid;
int create_flag = 0;
int sem_id;
if ((key = ftok(".", 'a')) < 0) {
perror("failed to get key");
exit(-1);
}
if ((sem_id = semget(key, 1, 0666 | IPC_CREAT | IPC_EXCL)) < 0) {
if (errno == EEXIST) {
if ((sem_id = semget(key, 1, 0666)) < 0) {
perror("failed to semget");
exit(-1);
}
}
}
init_sem(sem_id, 0);
if ((shmid = shmget(key, sizeof(memory), 0666 | IPC_CREAT | IPC_EXCL)) < 0) {
if (errno == EEXIST) {
if ((shmid = shmget(key, sizeof(memory), 0666)) < 0) {
perror("failed to shmget memory");
exit(-1);
}
}
else {
perror("failed to shmget");
exit(-1);
}
}
else {
create_flag = 1;
}
if ((p = shmat(shmid, NULL, 0)) == (void *)(-1)) {
perror("failed to shmat memory");
exit(-1);
}
while(1) {
printf(">");
fgets(p->buf, sizeof(p->buf), stdin);
p->buf[strlen(p->buf) - 1] = 0;
sem_v(sem_id);
if (strncmp(p->buf, "quit", 4) == 0)
break;
}
if (create_flag == 1) {
if (shmdt(p) < 0) {
perror("failed to shmdt memory");
exit(-1);
}
if (shmctl(shmid, IPC_RMID, NULL) == -1) {
perror("failed to delete share memory");
exit(-1);
}
delete_sem(sem_id);
}
return 0;
}
