ゴルーチンを使ってwindows用のtouchコマンドを作ってみた

概要

windowsでtouchが使えないので、以下の機能を持つtouchコマンド作ってみた。

1. 複数ファイルを一度に作る (例) touch file1 file2 file3
2. 既存ファイルは上書きしない

githubレポジトリ

mainコード

mainコード

main.go

package main

import (
    "errors"
    "flag"
    "os"
    "sync"
)

func main() {
    flag.Parse()
    execute(flag.Args())
}

func execute(fileNames []string) {
    wg := sync.WaitGroup{}
    for _, name := range fileNames {
        wg.Add(1)
        go touch(name, &wg)
    }
    wg.Wait()
}

func touch(fileName string, wg *sync.WaitGroup) {
    defer wg.Done()

    if fileExists(fileName) {
        return
    }

    createFile(fileName)
}

func fileExists(name string) bool {
    if _, err := os.Stat(name); err != nil {
        return false
    }
    return true
}

func createFile(fileName string) error {
    if file, err := os.Create(fileName); err == nil {
        file.Close()
        return nil
    }
    return errors.New("")
}

testコード

testコード

main_test.go

package main

import (
    "os"
    "sync"
    "testing"
)

func TestFileExists(t *testing.T) {
    const fileName = "file"

    if exist := fileExists(fileName); exist != false {
        t.Fatalf("it should return false because %s doesn't exist", fileName)
    }

    // setup for test
    file, err := os.Create(fileName)
    if err != nil {
        t.Fatalf("test setup failed")
    }
    defer os.Remove(fileName)
    defer file.Close()

    if exist := fileExists(fileName); exist != true {
        t.Fatalf("it should return true because %s exists", fileName)
    }
}

func TestCreateFile(t *testing.T) {
    const fileName = "file"
    err := createFile(fileName)
    defer os.Remove(fileName)

    if _, e := os.Stat(fileName); e != nil {
        t.Fatalf("it should create %s", fileName)
    }
    if err != nil {
        t.Fatalf("it should return nil becuase file is created now")
    }
}

func TestTouch(t *testing.T) {
    const fileName = "file"
    wg := sync.WaitGroup{}

    wg.Add(1)
    go touch(fileName, &wg)
    defer os.Remove(fileName)
    wg.Wait()
    if !fileExists(fileName) {
        t.Fatalf("it should create %s", fileName)
    }

    wg.Add(1)
    go touch(fileName, &wg)
    wg.Wait()
    if !fileExists(fileName) {
        t.Fatalf("it should remain %s", fileName)
    }
}

func TestExecute(t *testing.T) {
    fileNames := []string{"file1", "file2", "file3"}

    execute(fileNames)
    defer func() {
        for _, name := range fileNames {
            os.Remove(name)
        }
    }()
    for _, name := range fileNames {
        if exist := fileExists(name); exist != true {
            t.Fatalf("it should create %s", name)
        }
    }
}