messctrl.c

在进行linux服务器编程时经常要用到消息队列编程,但直接使用系统调用可能还不能实现需要.此例子演示了怎样在用内核调用操作消息队列,控制消息队列溢出,消除"死"消息的方法.

#include <stdio.h>
#include<stdlib.h>
#include<dirent.h>
#include<sys/msg.h>
#include<sys/ipc.h>
#include<sys/types.h>
#include <mysql/mysql.h>
#include <time.h>
#define QUEUE_SO 0x7333L
#define PERMS 0666

typedef struct
{
        long mtype;
        unsigned char mdata[8192];
} my_msg;

main()
{
	char str[128];
	int i,j,k;
	int pid;
	int proc[5000];
	int mm,qo,qo1,len;
	DIR *dirp;
	struct dirent *direntp;
	my_msg msg_buf;
	struct msqid_ds msqid_sys;
	write_log("Start Message Queue Control......");
	if ((qo = msgget (QUEUE_SO, PERMS | IPC_CREAT)) < 0)
      	 {
             	  write_log("get message queue error");
                exit(0);
        }
	if((pid=fork())==-1)
	{
		write_log("Fork child error!\n");
		exit(0);
	}
	if(pid)
		exit(0);	//parent exit
	while(1){
		dirp=opendir("/proc");
		j=0;
		k=0;
		while((direntp = readdir(dirp)) != NULL) //莉