remove json fields

main.go

package main

import (
    "os"
    "encoding/json"
    "io/ioutil"
    "fmt"
    "strings"
)

var (
    filename string
    rm_fields []string
)

func parseArg() {
    if len(os.Args) != 3 {
        fmt.Println("Usage ./a.out $filename $rmFields")
        panic(0)
    }
    filename = os.Args[1]
    rm_fields = strings.Split(os.Args[2], ",")
}

func main() {
    parseArg()

    data, e := ioutil.ReadFile(filename)
    if e != nil {
        panic(e)
    }

    var tmp map[string]interface{}
    e = json.Unmarshal(data, &tmp)
    if e != nil {
        panic(e)
    }

    for _, field := range rm_fields {
        delete(tmp, field)
    }

    out, e := json.Marshal(tmp)
    if e != nil {
        panic(e)
    }
    fmt.Println(string(out))
}