Linux_C下的错误捕获.经常在调用linux 系统api 的时候会出现一些错误，比方说使用open() write() creat()之类的函数有些时候会返回-1，也就是调用失败，这个时候往往需要知道失败的原因。这个时候使用errno这个全局变量就相当有用了。-Linux_C the error trapping. Often called api linux system when there will be some errors, for example using the open () write () creat () function like sometimes returns-1, which is the call fails, this time is often need to know the reason for the failure. This time using the global variable errno is quite useful.