logExample.go

logExample.go

package main

import (
    "errors"
    "log"
    "os"
)

func expectNil(err error) {
    if err != nil {
        log.Output(2, err.Error())
        os.Exit(1)
    }
}

func main() {
    log.SetFlags(log.LstdFlags | log.Lshortfile | log.LUTC)

    expectNil(errors.New("This is a test error.")) //  The log should show this line number.
}

/*
Expected Output:
    2023/05/22 15:02:33 logExample.go:19: This is a test error.
*/