如何准确标记错误以符合golang

Question

I have seem this answer and use @OneOfOne answers. How do you get a Golang program to print the line number of the error it just called?

But there is some questions.

func FancyHandleError(err error) (b bool) {
    if err != nil {
        pc, fn, line, _ := runtime.Caller(1)
        log.Printf("[error] in %s[%s:%d] %v", runtime.FuncForPC(pc).Name(), fn, line, err)
        b = true
    }
    return
}

func main(){
    FancyHandleError（funcA())
}

func funcA()error{
    err := funcB()
    return err
}

func funcB()error{
    err := funcC()
    return err
}

func funcC()error{
    err := errors.New("deep errors!!") //I want to get the location in here!!!!!!!!!!!!!!!!!!!!!!
    return err
}

It will print "[error] in main.main[/root/temp/error.go:23]" That is in function main's line number.

But how to locate the error's line number in function C()?

Answer 1

See runtime.Caller which will give you all the details you need.

Your custom NewError function may look like this:

func NewError(message string) error {
    _, file, line, _ := runtime.Caller(1)
    return fmt.Errorf("[%s][%d] : %s" , file, line, message)
}

Here is play link for a sample play