initial commit

Author: Tim0401

.vscode/launch.json

@@ -0,0 +1,18 @@
+{
+    // IntelliSense を使用して利用可能な属性を学べます。
+    // 既存の属性の説明をホバーして表示します。
+    // 詳細情報は次を確認してください: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch",
+            "type": "go",
+            "request": "launch",
+            "mode": "debug",
+            "program": "${workspaceFolder}/cmd/ulid-cli/",
+            "cwd": "${workspaceFolder}",
+            "env": {},
+            "args": []
+        }
+    ]
+}

README.md

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+# ulid-cli
+
+## Motivation
+
+Interconversion between ULID strings and [16]bytes.  
+
+## Install
+
+```
+go install https://github.com/Tim0401/ulid-cli/cmd/ulid-cli@{version}
+```
+
+## Usage
+
+string->byte
+ex) 01FM73V2R6A8G3T20KQ9SQDM6D
+```
+ulid-cli -sb ${ULID}
+```
+
+byte->string  
+ex) 0x17d0e3d8b0652203d0813ba7376d0cd
+```
+ulid-cli -bs ${ULID}
+```
+
+## TODO
+
+- テストを書く
+- ロジックのmain.goからの分離

cmd/ulid-cli/main.go

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+package main
+
+import (
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"log"
+	"strings"
+
+	"github.com/oklog/ulid/v2"
+)
+
+func main() {
+	var (
+		sb = flag.Bool("sb", false, "string->byte")
+		bs = flag.Bool("bs", false, "byte->string")
+	)
+	flag.Parse()
+	if !(*sb || *bs) || (*sb && *bs) {
+		log.Fatal("Specify either -sb or -bs")
+	}
+	arg := flag.Arg(0)
+
+	// string->byte
+	if *sb {
+		id, err := ulid.ParseStrict(arg)
+		if err != nil {
+			log.Fatal("Input error")
+		}
+		fmt.Println(hex.EncodeToString(id[:]))
+		return
+	}
+
+	// byte->string
+	if *bs {
+		arg = strings.TrimPrefix(arg, "0x")
+		slice, err := hex.DecodeString(arg)
+		if err != nil || len(slice) != 16 {
+			log.Fatal("Input error")
+		}
+		array := [16]byte{}
+		copy(array[:], slice)
+		str := ulid.ULID(array).String()
+		fmt.Println(str)
+		return
+	}
+}

go.mod

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+module github.com/Tim0401/ulid-cli
+
+go 1.17
+
+require github.com/oklog/ulid/v2 v2.0.2

go.sum

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+github.com/oklog/ulid/v2 v2.0.2 h1:r4fFzBm+bv0wNKNh5eXTwU7i85y5x+uwkxCUTNVQqLc=
+github.com/oklog/ulid/v2 v2.0.2/go.mod h1:mtBL0Qe/0HAx6/a4Z30qxVIAL1eQDweXq5lxOEiwQ68=
+github.com/pborman/getopt v0.0.0-20170112200414-7148bc3a4c30/go.mod h1:85jBQOZwpVEaDAr341tbn15RS4fCAsIst0qp7i8ex1o=