为什么0是真实的，但假的就是1中的壳呢？ [英] Why 0 is true but false is 1 in the shell?

问题描述

false; echo $?

以上将输出 1 ，这是矛盾与我知道了。

The above will output 1, which is contradictory with all other programming languages I know.

任何理由呢？

推荐答案

这是一个惯例，而是一个特别有用的之一，当你去想它。一般来说，如果一个程序成功，这就是你需要知道的。如果失败了，但是，您可能需要了解各种有关失败的信息 - 为什么会发生，如何解决它，等有均值为零成功和非零意味着失败让你可以检查pretty容易成功，并探讨更多细节的特定错误，如果你想。很多API和框架也有类似的约定 - 即成功返回0和功能的，失败给回一个错误code描述特定失败案例

It's a convention, but a particularly useful one when you think about it. In general, if a program succeeds that's all you need to know. If it fails, however, you might need to know all kinds of information about the failure - why it happened, how to fix it, etc. Having zero mean 'success' and non-zero mean failure lets you can check pretty easily for success, and investigate the particular error for more details if you want to. A lot of APIs and frameworks have a similar convention - functions that succeed return 0 and and those that fail give back an error code describing the particular failure case.

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