Why 1? It's arbitrary, but it's anything other than zero so I just exit because something went wrong and this program is just going to bail.

为什么是1？这是任意的，但它是非零的,因为出错了，我退出程序,然后这个程序就释放了。

哈佛公开课 - 计算机科学课程节选

And most of these commands you don't actually need but this little caret symbol means control, so every keyboard these days has a control key so you hold that and hit X for instance to exit the program.

这里大多数命令你们都用不着,这个小插入符意味着控制，每个键盘都有一个控制键,譬如，当你敲入X时，就退出这个程序。

哈佛公开课 - 计算机科学课程节选