#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>

#define FTOK_PATH            "/dev/zero"
#define FTOK_PROJID          0x666

union semun 
{
    int val;
    struct semid_ds *buf;
    unsigned short *arry;
};

int main(int argc, char **argv)
{
    int            semid;

    if( (semid=init_set(1)) < 0)
    {
	
    }

}

int init_set(int nums)
{
    key_t          key;
    int            semid;
    union semun    sem_union;
		    
    if( (key=ftok(FTOK_PATH, FTOK_PROJID)) < 0 ) 
    {   
	printf("ftok() get IPC token failure: %s\n", strerror(errno)); 
	return -1;
    } 
    
    semid = semget(key, nums, IPC_CREAT|IPC_EXCL|0644);
    if( semid < 0)
    {
	printf("semget() get semid failure: %s\n", strerror(errno)); 
	return -2;
    }


    sem_union.val = 1;
    if( semctl(semid, 0, SETVAL, sem_union)<0 )
    {
	printf("semctl() set initial value failure: %s\n", strerror(errno)); 
	return -3;
    }

    return semid;
}