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();    ....}