Linux 程序后台运行的简单方法

int daemon()
{
    pid_t pid ;
    pid = fork () ;
    if (pid < 0) {
        printf ( "Cannot fork a new process to run in background\n") ; 
        return -2 ;
    }   
    if (pid > 0) {                       /* parent process */
        printf ( "NewMailNotify is now runing in background.\n" ) ; 
        exit (0) ;
    }   
    setsid () ;
    return 0 ; 
}

int main()
{
    daemon();
    ....
}