Linux消息队列编程示例

key_t ftok(char *pathname, char proj)

int msgget(key_t key, int msgflg)

int msgsnd(int msqid, struct msgbuf *msgp, int msgsz, int msgflg)

struct msgbuf { long mtype; char mtext[100]; };

int msgrcv(int msqid, struct msgbuf *msgp, int msgsz, long msgtyp, int msgflg)

#include<stdio.h>#include<sys/msg.h>#include<fcntl.h>#include<stdlib.h>#include<string.h>#define max 100</p>
<p>struct haha{ long mtype; char data[max];};</p>
<p>int main(int argc,char *argv[]){ int pid; if(argc!=2){ printf(\”Usage: msg [Message]\\n\”); return -1; } key_t key; if((key=ftok(\”/tmp\”,\’g\’))<0){ //这里文件夹必须存在，有t属性并且上级目录也要有t属性 printf(\”Getting key error! \\n\”); return -1; } int mgsid; if((mgsid=msgget(key,IPC_CREAT|0666))==-1){ //key值随便写一个数也能用 printf(\”mgs queue create error\\n\”); return -1; } pid=fork(); if(pid <0){ printf(\”fork create error!\\n\”); _exit(1); } if(pid == 0){ printf(\”welcome in child process\\n Sending the message……\\n\”); sleep(1); struct haha hehe; hehe.mtype=getppid(); strcpy(hehe.data,argv[1]); if(msgsnd(mgsid,&hehe,sizeof(hehe.data),0)<0){ //此处注意长度 printf(\”Sending error!!!\\n\”); _exit(1); }else { printf(\”Sending complete!\\n\”); _exit(0); } }else{ wait(NULL); printf(\”welcome in parents process\\n Receiving the message……\\n\”); sleep(1); struct haha gaga; if(msgrcv(mgsid,&gaga,max,getpid(),0)<0){ printf(\”Receiving error!!!\\n\”); _exit(1); }else { printf(\”Receiving complete!\\n\”); printf(\”The message is %s \\n\”,gaga.data); } } return 0;}