国嵌必修实验代码2-4-1

#include <stdlib.h> #include <stdio.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/msg.h> struct my_msg_st { long int my_msg_type; char some_text[BUFSIZ]; }; int main(void) { int running=1; int msgid; struct my_msg_st some_data; long int msg_to_receive=0; /*创建消息队列*/ msgid=msgget((key_t)1234,0666 | IPC_CREAT); if(msgid==-1) { fprintf(stderr,"msgget failed with error: %d\n",errno); exit(EXIT_FAILURE); } /*循环从消息队列中接收消息*/ while(running) { /*读取消息*/ if(msgrcv(msgid,(void *)&some_data,BUFSIZ,msg_to_receive,0)==-1) { fprintf(stderr,"msgrcv failed with error: %d\n",errno); exit(EXIT_FAILURE); } printf("You wrote: %s",some_data.some_text); /*接收到的消息为“end”时结束循环*/ if(strncmp(some_data.some_text,"end",3)==0) { running=0; } } /*从系统内核中移走消息队列*/ if(msgctl(msgid,IPC_RMID,0)==-1) { fprintf(stderr,"msgctl(IPC_RMID) failed\n"); exit(EXIT_FAILURE); } exit(EXIT_SUCCESS); }