Implement general utility binaries go-bsdiff and go-bspatch.

cmd/bsdiff/main.go

@@ -1,31 +0,0 @@
-package main
-
-import (
-	"log"
-	"os"
-
-	"github.com/icedream/go-bsdiff"
-)
-
-func must(err error) {
-	if err == nil {
-		return
-	}
-
-	log.Fatal(err)
-}
-
-func main() {
-	oldFile, err := os.Open("test.txt")
-	must(err)
-
-	newFile, err := os.Open("test_new.txt")
-	must(err)
-
-	patchFile, err := os.Create("test.patch")
-	must(err)
-
-	must(bsdiff.Diff(oldFile, newFile, patchFile))
-
-	log.Println("Done.")
-}

cmd/go-bsdiff/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/icedream/go-bsdiff/patch"
+	"gopkg.in/alecthomas/kingpin.v2"
+)
+
+var (
+	cli = kingpin.New("go-bspatch", "Applies binary patches generated using the bsdiff algorithm.")
+
+	argOld   = cli.Arg("old", "The old file.").Required().ExistingFile()
+	argNew   = cli.Arg("new", "Where the new file will be written to.").Required().File()
+	argPatch = cli.Arg("patch", "The patch file.").Required().ExistingFile()
+)
+
+func must(err error) {
+	if err == nil {
+		return
+	}
+
+	log.Fatal(err)
+}
+
+func main() {
+	kingpin.MustParse(cli.Parse(os.Args[1:]))
+
+	newFile := *argNew
+	defer newFile.Close()
+
+	oldFile, err := os.Open(*argOld)
+	must(err)
+	defer oldFile.Close()
+
+	patchFile, err := os.Open(*argPatch)
+	must(err)
+	defer patchFile.Close()
+
+	must(patch.Patch(oldFile, newFile, patchFile))
+}

cmd/go-bspatch/main.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/icedream/go-bsdiff/diff"
+	"gopkg.in/alecthomas/kingpin.v2"
+)
+
+var (
+	cli = kingpin.New("go-bsdiff", "Generates binary patches.")
+
+	argOld   = cli.Arg("old", "The old file.").Required().ExistingFile()
+	argNew   = cli.Arg("new", "The new file.").Required().ExistingFile()
+	argPatch = cli.Arg("patch", "Where to output the patch file.").Required().File()
+)
+
+func must(err error) {
+	if err == nil {
+		return
+	}
+
+	log.Fatal(err)
+}
+
+func main() {
+	kingpin.MustParse(cli.Parse(os.Args[1:]))
+
+	patchFile := *argPatch
+	defer patchFile.Close()
+
+	oldFile, err := os.Open(*argOld)
+	must(err)
+	defer oldFile.Close()
+
+	newFile, err := os.Open(*argNew)
+	must(err)
+	defer newFile.Close()
+
+	must(diff.Diff(oldFile, newFile, patchFile))
+}