golang 1.13 errors 包来了，不用写“err 气

引

这篇是对 errors 包 的姿势挖掘

气功波错误代码

从 http.Get()返回的错误 判断 syscall.ECONNREFUSED 错误.以前要对 go 标准库 error 结构有点熟悉，才能写出下面的代码

func CmdErr(err error) {
    if err == nil {
        return
    }   

    if uerr, ok := err.(*url.Error); ok {
        if noerr, ok := uerr.Err.(*net.OpError); ok {
            if scerr, ok := noerr.Err.(*os.SyscallError); ok {
                if scerr.Err == syscall.ECONNREFUSED {
                    fmt.Printf("gurl: (7) couldn't connect to host\n")
                    return
                }
            }
        }
    }   

    fmt.Printf("%s\n", err)
}

用 go1.13 errors 库重构气功波代码

现在只要知道，syscall.ECONNREFUSED 就行。errors.Is直接判断

func newCmdErr2(err error) {

    if errors.Is(err, syscall.ECONNREFUSED) {
        fmt.Printf("gurl: (7) couldn't connect to host\n")
        return
    }   
}

github

https://github.com/guonaihong/gout