compare kernel config tool

#!/usr/bin/gorun
// @author dlin at gmail
// @license BSD 3-clause

// check is target kernel config fit with specific config
package main

import (
    "bufio"
    "fmt"
    "io"
    "log"
    "os"
    "strings"
)

func GetFileLines(fileName string) ([]string, error) {
    f, err := os.Open(fileName)
    if err != nil {
        log.Fatalln(err)
    }
    defer f.Close()
    r := bufio.NewReader(f)
    var lines []string
L_RD_LINE:
    for {
        line, isPrefix, err := r.ReadLine()
        if err == io.EOF {
            break
        }
        if err != nil {
            log.Fatalln(err)
        }
        for isPrefix {
            var ex_line []byte
            ex_line, isPrefix, err = r.ReadLine()
            if err == io.EOF {
                break L_RD_LINE
            }
            if err != nil {
                log.Fatalln(err)
            }
            line = append(line, ex_line...)
        }
        lines = append(lines, string(line))
    }
    return lines, nil
}

func getKeyFile(fileName string) map[string]string {
    lines, err := GetFileLines(fileName)
    if err != nil {
        log.Fatalln(err)
    }
    result := make(map[string]string)
    for _, line := range lines {
        line = strings.TrimSpace(line)
        if line != "" && !strings.HasPrefix(line, "#") {
            flds := strings.SplitN(line, "=", 2)
            key := strings.TrimSpace(flds[0])
            value := strings.TrimSpace(flds[1])
            result[key] = value
        }
    }
    return result
}

// compare key file, if fulfill all rules, return 0
func compareKeyFile(keyFileName, configFileName string) int {
    keys := getKeyFile(keyFileName)
    config := getKeyFile(configFileName)
    var errCnt int

    for k, v := range keys {
        if cv, ok := config[k]; ok {
            if v != cv {
                fmt.Print(k, "=", v, " # original ", cv, "\n")
                errCnt++
            }
        } else {
            fmt.Print(k, "=", v, "\n")
            errCnt++
        }
    }
    return errCnt
}

func main() {
    log.SetFlags(log.Lshortfile)
    if len(os.Args) != 3 {
        fmt.Println(`Usage: kernel_config_diff.go <require.config> <kernel.config>
  eg. kernel_config_diff.go req.config linux_pf.config`)
        os.Exit(1)
    }

    os.Exit(compareKeyFile(os.Args[1], os.Args[2]))
}