Rename variables as same as GoReleaser default

CONTRIBUTING.md

@@ -11,7 +11,7 @@
 (prepared bash)
 
 > task
-task: [build] go build -ldflags "-X main.revision=$(git rev-parse --short HEAD)"
+task: [build] go build ..."
 task: [test] go test
 task: [lint] dprint check
 task: [lint] go vet

README.md

@@ -12,7 +12,7 @@ When I want to bump it, I always visit the nixpkgs repository and copy and paste
 ## Usage
 
 ```console
-> go install -ldflags "-X main.revision=$(git rev-parse --short HEAD)"
+> go install -ldflags "-X main.commit=$(git rev-parse --short HEAD) -X main.date=$(date --iso-8601)"
 > cd repository-that-using-nix
 > ${GOPATH:-"$HOME/go"}/bin/nix-headbump && git commit -m 'Bump nixpkgs to latest' *.nix
 [main 213d1bf] Bump nixpkgs to latest

Taskfile.yml

@@ -10,10 +10,10 @@ tasks:
       - task: build
   install:
     cmds:
-      - go install -ldflags "-X main.revision=$(git rev-parse --short HEAD)"
+      - go install -ldflags "-X main.commit=$(git rev-parse HEAD) -X main.date=$(date --iso-8601)"
   build:
     cmds:
-      - go build -ldflags "-X main.revision=$(git rev-parse --short HEAD)"
+      - go build -ldflags "-X main.commit=$(git rev-parse HEAD) -X main.date=$(date --iso-8601)"
   test:
     cmds:
       - go test

nix-headbump.go

@@ -12,11 +12,13 @@ import (
 	"regexp"
 )
 
-const version string = "0.1.0"
+var (
+	version = "dev"
+	commit  = "none"
+	date    = "unknown"
 
-var re = regexp.MustCompile(`(?s)(import\s+\(fetchTarball\s+"https://github.com/NixOS/nixpkgs/archive/)([^"]+?)(\.tar\.gz"\))`)
-
-var revision string
+	re = regexp.MustCompile(`(?s)(import\s+\(fetchTarball\s+"https://github.com/NixOS/nixpkgs/archive/)([^"]+?)(\.tar\.gz"\))`)
+)
 
 func main() {
 	versionFlag := flag.Bool("version", false, "print the version of this program")
@@ -25,7 +27,8 @@ func main() {
 	flag.Parse()
 
 	if *versionFlag {
-		fmt.Printf("%s\n", version+"("+revision+")")
+		revision := commit[:7]
+		fmt.Printf("%s\n", "nix-headbump"+" "+version+" "+"("+revision+") # "+date)
 		return
 	}