add versioning (#2)

.goreleaser.yml

@@ -13,6 +13,8 @@ builds:
       - linux
       - windows
       - darwin
+    ldflags:
+      - -s -w -X github.com/agrimrules/hashmatch/cmd.version=v{{.Version}}
 archives:
   - replacements:
       darwin: Darwin

cmd/root.go

@@ -27,6 +27,8 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var version = "dev"
+
 var rootCmd = &cobra.Command{
 	Use:   "hashmatch",
 	Short: "print hashes of files in tabular form",

cmd/version.go

@@ -0,0 +1,36 @@
+/*
+Copyright © 2021 NAME HERE <EMAIL ADDRESS>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+// versionCmd represents the version command
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Current version",
+	Long:  `Prints the version of the tool currently installed`,
+	Run: func(cmd *cobra.Command, args []string) {
+		fmt.Println("version " + version)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(versionCmd)
+}