prg6_5.c

配套光盘网络编程进程间的通信,网络编程进程间的通信是一本很经典的好书

#include <sys/msg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>

int main(int argc, char **argv)
{
  int  msqid;
  struct  msqid_ds info;
  struct  msgbuf{
	long mtype;
	char mtext[1];
	};
  struct  msgbuf buf;
//  typedef unsigned long u_long; 

  ///创建一个新的消息队列
  msqid = msgget(IPC_PRIVATE,0660 | IPC_CREAT);
  
  buf.mtype = 1;
  buf.mtext[0] = 1;
  ///往一个消息队列上放置一个消息
  msgsnd(msqid,&buf,1,0);
  ///返回消息队列的当前msqid_ds结构
  msgctl(msqid,IPC_STAT,&info);
  printf("read-write:%03o,cbytes = %lu,qnum = %lu,qbytes = %lu\n",
  	info.msg_perm.mode & 0777,(u_long)info.msg_cbytes,
	(u_long)info.msg_qnum,(u_long)info.msg_qbytes);
  
  system("ipcs -q");
  msgctl(msqid,IPC_RMID,NULL);	///删除消息队列msqid
  exit(0);
}