Upload files to "/"

main.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"net/http"
+	"net/url"
+)
+
+func main() {
+	m := map[string]string{}
+	s := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/" && r.Method == "GET" {
+			fmt.Fprintln(w, "<h1>shortener</h1>")
+			fmt.Fprintln(w, "<form method='POST'>")
+			fmt.Fprintln(w, "<input name='url' placeholder='https://example.com'>")
+			fmt.Fprintln(w, "<button>ok</button>")
+			fmt.Fprintln(w, "</form>")
+			return
+		}
+
+		if r.URL.Path == "/" && r.Method == "POST" {
+			a := r.FormValue("url")
+
+			if a == "" {
+				fmt.Fprintln(w, "empty")
+				return
+			}
+
+			u, err := url.Parse(a)
+			if err != nil || u.Scheme == "" || u.Host == "" {
+				fmt.Fprintln(w, "bad url")
+				return
+			}
+
+			b := ""
+			for j := 0; j < 6; j++ {
+				b = b + string(s[rand.Intn(len(s))])
+			}
+
+			for m[b] != "" {
+				b = ""
+				for j := 0; j < 6; j++ {
+					b = b + string(s[rand.Intn(len(s))])
+				}
+			}
+
+			m[b] = a
+			fmt.Fprintln(w, "short url: http://localhost:8080/"+b)
+			return
+		}
+
+		x := r.URL.Path[1:]
+		y := m[x]
+
+		if y == "" {
+			fmt.Fprintln(w, "not found")
+			return
+		}
+
+		http.Redirect(w, r, y, 302)
+	})
+
+	fmt.Println("start http://localhost:8080")
+	http.ListenAndServe(":8080", nil)
+}