Merge pull request #789 from AriehSchneier/rewrite-blame

plumbing: blame, Complete rewrite. Fixes #603

_examples/blame/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/go-git/go-git/v5"
+	. "github.com/go-git/go-git/v5/_examples"
+)
+
+// Basic example of how to blame a repository.
+func main() {
+	CheckArgs("<url>", "<file_to_blame>")
+	url := os.Args[1]
+	path := os.Args[2]
+
+	tmp, err := os.MkdirTemp("", "go-git-blame-*")
+	CheckIfError(err)
+
+	defer os.RemoveAll(tmp)
+
+	// Clone the given repository.
+	Info("git clone %s %s", url, tmp)
+	r, err := git.PlainClone(
+		tmp,
+		false,
+		&git.CloneOptions{
+			URL:  url,
+			Tags: git.NoTags,
+		},
+	)
+	CheckIfError(err)
+
+	// Retrieve the branch's HEAD, to then get the HEAD commit.
+	ref, err := r.Head()
+	CheckIfError(err)
+
+	c, err := r.CommitObject(ref.Hash())
+	CheckIfError(err)
+
+	Info("git blame %s", path)
+
+	// Blame the given file/path.
+	br, err := git.Blame(c, path)
+	CheckIfError(err)
+
+	fmt.Printf("%s", br.String())
+}