c语言如何 调用外部程序答:用 法: int execl(char *pathname, char *arg0, arg1, ..., argn, NULL);int execle(char *pathname, char *arg0, arg1, ..., argn, NULL,char *envp[]);int execlp(char *pathname, char *arg0, arg1, .., NULL);int execple(char *pathname, char *arg0, arg1, ..., NULL,...