snap.go

package main

import (
	"fmt"
	"io"
	"log"
	"net"
	"net/http"
	"os"
	"os/exec"
	"syscall"
)

func init() {
	Path = "raspistill"
}

var Path string

func cameraStill(w io.Writer, flip string) {
	args := []string{"-o", "-"}

	if flip != "" {
		if flip == "vf" || flip == "hf" {
			args = append([]string{"-" + flip}, args...)
		} else {
			args = nil
			fmt.Fprintf(w, "Error: Invalid parameters")
		}
	}

	cmd := exec.Command(Path, args...)
	out, err := cmd.StdoutPipe()
	if err != nil {
		log.Println(err)
	}
	err = cmd.Start()
	if err != nil {
		log.Println(err)
	}
	_, err = io.Copy(w, out)
	if err != nil {
		log.Println(err)
	}
	cmd.Wait()
}

func main() {
	// Listen on Unix Socket.
	go func() {
		addr := "/tmp/unixdomain"
		if err := syscall.Unlink(addr); err != nil && !os.IsNotExist(err) {
			panic(err)
		}
		ln, err := net.ListenUnix("unix", &net.UnixAddr{addr, "unix"})
		if err != nil {
			fmt.Println(err)
		}
		defer os.Remove(addr)
		for {
			conn, err := ln.AcceptUnix()
			if err != nil {
				fmt.Println(err)
				continue
			}
			go cameraStill(conn, "")
		}
	}()

	// Listen on HTTP.
	http.HandleFunc("/snap", func(w http.ResponseWriter, r *http.Request) {
		f := r.URL.Query().Get("flip")
		w.WriteHeader(http.StatusOK)
		cameraStill(w, f)
	})
	http.ListenAndServe(":3000", nil)
}