use io.Reader when parsing urls

cmd/lnks/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"net/http"
 	"os"
 
 	"mcquay.me/spider"
@@ -14,7 +15,15 @@ func main() {
 		fmt.Fprintf(os.Stderr, "%s\n", usage)
 		os.Exit(1)
 	}
-	for _, l := range spider.URLs(os.Args[1]) {
+	resp, err := http.Get(os.Args[1])
+	if err != nil {
+		panic(err)
+	}
+	links, err := spider.URLs(resp.Body)
+	if err != nil {
+		panic(err)
+	}
+	for _, l := range links {
 		fmt.Println(l)
 	}
 }