search_between_files.go

package main

import (
	"io/ioutil"
	"os"
	"strings"
)

func stringInSlice(a string, list []string) bool {
	for _, b := range list {
		if b == a {
			return true
		}
	}
	return false
}

func main() {
	var mix_file, mix_err = ioutil.ReadFile("mixture")
	var fil_file, fil_err = ioutil.ReadFile("filter")
	var out_file, out_err = os.OpenFile("final_output", os.O_APPEND|os.O_WRONLY, 0600)

	if mix_err != nil {
		panic(mix_err)
	}
	if fil_err != nil {
		panic(fil_err)
	}
	if out_err != nil {
		panic(out_err)
	}

	defer out_file.Close()

	var mix_list = strings.Split(string(mix_file), "\n")
	var fil_list = strings.Split(string(fil_file), "\n")

	// An empty string at the last after the split
	var search_len = len(mix_list) - 1

	for i := 0; i < search_len; i++ {
		if stringInSlice(mix_list[i], fil_list) {
			if _, out_err = out_file.WriteString(mix_list[i] + "\n"); out_err != nil {
				panic(out_err)
			}
		}
	}

	out_file.Close()
}