A function to retrieve caller information (function name, file containing it and a code line number wher it was called).

caller.go

package caller

// Info generates caller metadata:
// - func name (trimmed of leading path parts) - e.g. somepkg.(*SomeStruct).SomeMethod
// - file name - e.g. /go/src/github.com/someone/someproject/file.go
// - line - e.g. 23
func Info(depth, skip int) (string, string, int) {
	var (
		pcs      [depth]uintptr
		fn, file string
		line     int
		n        = runtime.Callers(skip, pcs[:])
		f, ok    = runtime.CallersFrames(pcs[:n]).Next()
	)
	if ok {
		fn, file, line = f.Function, f.File, f.Line
		if i := strings.LastIndexByte(fn, '/'); i != -1 {
			fn = fn[i+1:]
		}
	}
	return fn, file, line
}