我应该设置errno吗？(Should I set errno?)

我正在写一个模块，导出类似于send和recv的接口。

由于这些函数应该分别返回发送和接收的字节数，所以我不能像通常那样进行适当的错误管理（即使用枚举和返回助记符值）。

在这样的情况下，我应该设置errno作为标准库吗？ 如果是这样，由于errno是线程特定的，有没有特别的写法，或者我可以简单地给它赋值？

编辑：试验它我注意到，通过赋值设置errno正在工作。 仍然：这是安全和便携的任何系统？

I'm writing a module which exports an interface similar to send and recv.

Since those functions are supposed to return respectively the number of sent and received bytes, I cannot do proper error management as I would do normally (i.e. using enumeratives and returning mnemonic values).

In a situation like this should I set errno as the standard library does? If so, since errno is thread specific, is there a particular way of writing on it, or can I simply assign a value to it?

Edit: experimenting it I noticed that setting errno by assignment is working. Still: is this safe and portable for any system?

最满意答案

这有点旧 ，但errno - 手册第3节说，你可以直接分配给它，即使它是一个宏，它将是线程本地

This is a bit old, but errno - manual section 3 says that you can directly assign to it, even though it is a macro, and it will be thread local

我应该设置errno吗？(Should I set errno?)

我正在写一个模块，导出类似于send和recv的接口。

由于这些函数应该分别返回发送和接收的字节数，所以我不能像通常那样进行适当的错误管理（即使用枚举和返回助记符值）。

在这样的情况下，我应该设置errno作为标准库吗？ 如果是这样，由于errno是线程特定的，有没有特别的写法，或者我可以简单地给它赋值？

编辑：试验它我注意到，通过赋值设置errno正在工作。 仍然：这是安全和便携的任何系统？

I'm writing a module which exports an interface similar to send and recv.

Since those functions are supposed to return respectively the number of sent and received bytes, I cannot do proper error management as I would do normally (i.e. using enumeratives and returning mnemonic values).

In a situation like this should I set errno as the standard library does? If so, since errno is thread specific, is there a particular way of writing on it, or can I simply assign a value to it?

Edit: experimenting it I noticed that setting errno by assignment is working. Still: is this safe and portable for any system?

最满意答案

这有点旧 ，但errno - 手册第3节说，你可以直接分配给它，即使它是一个宏，它将是线程本地

This is a bit old, but errno - manual section 3 says that you can directly assign to it, even though it is a macro, and it will be thread local