int checkRunningPid(void)
{
pid_t pid;
pid = readPidFile();
if (pid < 2)
return 0;
if (kill(pid, 0) < 0)
return 0;
fprintf(stderr, "nginx_master is already running! process id %ld\n", (long int) pid);
return 1;
}
//SIGPIPE是正常的信号，对端断开后本端协议栈在向对端传送数据时，对端会返回TCP RST，导致本端抛出SIGPIPE信号
void init_daemon(char* cmd)
{
int pid;
char *buf = "This is a Daemon, wcdj\n";
char path[FILEPATH_MAX];
getRealPath(path);
strcat(path,"/");
strcat(path,"pushserver.lock");
pid = readPidFile(path);
if(pid != -1)
{
printf("The server is start ...\n");
}
if(strcmp(cmd,"stop") == 0 && pid != -1){
closeServer(pid,0);
int status;
int w;
do {
w = waitpid(pid, &status, WUNTRACED | WCONTINUED);
if (w == -1) { perror("waitpid"); exit(EXIT_FAILURE); }
if (WIFEXITED(status)) {
printf("exited, status=%d/n", WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
printf("killed by signal %d/n", WTERMSIG(status));
} else if (WIFSTOPPED(status)) {
printf("stopped by signal %d/n", WSTOPSIG(status));
} else if (WIFCONTINUED(status)) {
printf("continued/n");
}
} while (!WIFEXITED(status) && !WIFSIGNALED(status));
exit(0);
}
else if(strcmp(cmd,"restart") == 0 && pid != -1){
int status;
int w;
do {
w = waitpid(pid, &status, WUNTRACED | WCONTINUED);
if (w == -1) { perror("waitpid"); exit(EXIT_FAILURE); }
if (WIFEXITED(status)) {
printf("exited, status=%d/n", WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
printf("killed by signal %d/n", WTERMSIG(status));
} else if (WIFSTOPPED(status)) {
printf("stopped by signal %d/n", WSTOPSIG(status));
} else if (WIFCONTINUED(status)) {
printf("continued/n");
}
} while (!WIFEXITED(status) && !WIFSIGNALED(status));
}else if(pid != -1){
printf("The server is start ...\n");
exit(0);
}
/* 屏蔽一些有关控制终端操作的信号
* 防止在守护进程没有正常运转起来时，因控制终端受到干扰退出或挂起
*/
signal(SIGINT, SIG_IGN);// 终端中断
signal(SIGHUP, SIG_IGN);// 连接挂断
signal(SIGQUIT, SIG_IGN);// 终端退出
signal(SIGPIPE, SIG_IGN);// 向无读进程的管道写数据
signal(SIGTTOU, SIG_IGN);// 后台程序尝试写操作
signal(SIGTTIN, SIG_IGN);// 后台程序尝试读操作
signal(SIGTERM, SIG_IGN);// 终止
struct rlimit rl;
if (getrlimit(RLIMIT_NOFILE, &rl) < 0)
printf("%s: can't get file limit", "pushserver");
int i;
/*
pid=fork();
if(pid>0)
exit(0);//是父进程，结束父进程
else if(pid< 0)
exit(1);//fork失败，退出
//是第一子进程，后台继续执行
setsid();//第一子进程成为新的会话组长和进程组长
//并与控制终端分离
pid=fork();
if(pid>0)
exit(0);//是第一子进程，结束第一子进程
else if(pid< 0)
exit(1);//fork失败，退出
*/
if ((pid = fork()) < 0)
printf("%s: can't fork", cmd);
else if (pid != 0) /* parent */{
printf("tuichuzhu\n");
exit(0);
}
printf("jinlaile\n");
setsid();
//是第二子进程，继续
//第二子进程不再是会话组长
main_pid = getpid();
writePidFile(path);
for(i=3;i< NOFILE;++i)//关闭打开的文件描述符 MAXFILE 65536
close(i);
/*
// [3] set current path
char szPath[1024];
if(getcwd(szPath, sizeof(szPath)) == NULL)
{
perror("getcwd");
exit(1);
}
else
{
chdir(szPath);
printf("set current path succ [%s]\n", szPath);
}
*/
//chdir("/tmp");//改变工作目录到/tmp
umask(0);//重设文件创建掩模
// [6] set termianl signal
signal(SIGTERM, wait_close);
signal(SIGHUP, restart_server);
/*
* Close all open file descriptors.
*/
if (rl.rlim_max == RLIM_INFINITY)
rl.rlim_max = 1024;
for (i = 0; i < rl.rlim_max; i++)
close(i);
/*
* Attach file descriptors 0, 1, and 2 to /dev/null.
*/
int fd0 = open("/dev/null", O_RDWR);
int fd1 = dup(0);
int fd2 = dup(0);
/*
* Initialize the log file.
*/
openlog("pushserver", LOG_CONS, LOG_DAEMON);
if (fd0 != 0 || fd1 != 1 || fd2 != 2) {
syslog(LOG_ERR, "unexpected file descriptors %d %d %d",fd0, fd1, fd2);
exit(1);
}
syslog(LOG_DEBUG, "daem ok ");
return;
}