server.go

package main

import (
    "fmt"
    "os"
    "net"
    "bufio"
    "encoding/json"
    bcap "github.com/fromYukki/browscap_go"
)

const bcapFile = "browscap.ini"
const socket = "server.sock"
var errorJson []byte = []byte("{\"error\":\"Something went wrong\"}")

func handleConnection(conn net.Conn, requestNumber int64) {
    var err error
    var res []byte

    line, err := bufio.NewReader(conn).ReadString('\n')
    if err != nil {
        panic(err)
    }

    browser, ok := bcap.GetBrowser(line)
    if !ok || browser == nil {
        res = errorJson
    } else {
        res, err = json.Marshal(browser)
        if err != nil {
            panic(err)
        }
    }

    conn.Write(res)
    conn.Close()

    fmt.Printf("\nRequest #%d: %s", requestNumber, line)
    fmt.Println("Response: ", string(res))
}

func exists() bool {
    if _, err := os.Stat(bcapFile); err == nil {
        return true
    }
    return false
}

func main() {
    if !exists() {
        fmt.Println("Downloading ", bcapFile)
        err := bcap.DownloadFile(bcapFile)
        if err != nil {
            panic(err)
        }
    }

    fmt.Println("Initialising")
    if err := bcap.InitBrowsCap(bcapFile, false); err != nil {
        panic(err)
    }

    os.Remove(socket)
    ln, err := net.Listen("unix", socket)
    if err != nil {
        panic(err)
    }
    defer ln.Close()
    fmt.Println("Listening for connections")
    
    var requests int64 = 0;
    for {
        conn, err := ln.Accept()
        if err != nil {
            panic(err)
	}
        requests ++
	go handleConnection(conn, requests)
    }
}