Skip to content

Kadai1 s-shiraki #76

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 10 commits into
base: master
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from 7 commits
Commits
File filter

Filter by extension

Filter by extension


Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions .gitignore
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
kadai1/image-convert
Binary file added kadai1/747.png
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
29 changes: 29 additions & 0 deletions kadai1/README.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,29 @@
# 課題 1:画像変換コマンドを作ろう

画像を指定の形式に変換する
変換後の画像ファイルは元の画像と同じディレクトリに配置される

## コマンドラインオプション

| オプション | 値の説明 | デフォルト値 |
| ---------- | -------------------------------------- | ------------ |
| -from | 変換前の画像形式(jpg,jpeg,pngから選択) | jpg |
| -to | 変換後の画像形式(jpg,jpeg,pngから選択) | png |
| -dir | ディレクトリの指定 | ./ |

## 使い方

- ビルド

```bash
go build -o image-convert
```

- ディレクトリを指定して実行

```bash
./image-convert [...options] [directory]
```
```example
./image-convert -from png -to jpg -dir d1
```
18 changes: 18 additions & 0 deletions kadai1/args/args.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
package args
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

ここは特に主要なロジックがあるわけではないので、別パッケージに分けずにmainパッケージに含めて良さそうです。


import "flag"

type CmdArgs struct {
From string
To string
Dir string
}

func ParseArgs() *CmdArgs {
var cmd CmdArgs
flag.StringVar(&cmd.From, "from", "jpg", "from")
flag.StringVar(&cmd.To, "to", "png", "to")
flag.StringVar(&cmd.Dir, "dir", "./", "directory")
flag.Parse()
return &cmd
}
64 changes: 64 additions & 0 deletions kadai1/convert/convert.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,64 @@
package convert

import (
"fmt"
"image"
"image/jpeg"
"image/png"
"log"
"os"
"path/filepath"
"strings"
)

func GetSelectedExtensionPath(fileType string, directory string) [][]string {
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

パスを返す関数なので[]stringで返した方が良さそうです。pathのみをappendしてその後の処理はパスを利用する関数で処理するのが良いかと思います。

var retval [][]string
err := filepath.Walk(directory, func(path string, info os.FileInfo, err error) error {
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

パスはディレクトリも含んでいるため、ディレクトリではないかのチェックが必要です。
例えばxxx.jpgという名前のディレクトリがあると誤動作します。

if err != nil {
return err
}
slice := strings.Split(path, ".")
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

拡張子を取るにはfilepath.Extというライブラリ及び関数があるのでそれを使った方が良さそうです。なお、このやり方だと.があるディレクトリ名と拡張子のないファイル名が組み合わさった時に誤動作するので好ましくないです。
https://play.golang.org/p/Jn50hY_Mt9B

if slice[len(slice)-1] == fileType {
retval = append(retval, slice)
}

return nil
})
if err != nil {
log.Fatal(err)
Copy link

@gosagawa gosagawa Sep 5, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

エラーはここで処理せずにmain関数にreturnしてmain関数で処理をした方が良く、そうするのがGoでは一般的です。理由としては呼び出し元でエラーをどう処理するかを委ねられること、エラーが発生しうる関数であることを明示できることなどがあります。具体的にはこのライブラリをcli以外で扱うことになったらここでlog.Fatalで落とすのが望ましくありません。

}
return retval
}

func ConvertImage(fileName string, from string, to string) {
f, err := os.Open(fileName + "." + from)
if err != nil {
fmt.Println("open:", err)
return
}
defer f.Close()

img, _, err := image.Decode(f)
if err != nil {
fmt.Println("decode:", err)
return
}

fso, err := os.Create(fileName + "." + to)
if err != nil {
fmt.Println("create:", err)
return
}
defer fso.Close()

switch {
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

以下のようにするのがシンプルかと思います。なお、元々の書き方だとtoと実際のエンコードの関数が逆になっているように思います。

switch to {
    case "jpg","jpeg":
         jpeg.Encode(fso, img, nil)
    case "png":
         png.Encode(fso, img)
    default:
        //エラー処理
}

case (from == "jpg" || from == "jpeg") && to == "png":
jpeg.Encode(fso, img, nil)
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

pngもそうですが、エンコード処理はエラーになりうるもので関数もエラーを返しているのでエラー処理が必要です。

case from == "png" && (to == "jpg" || to == "jpeg"):
png.Encode(fso, img)
}

if err := os.Remove(fileName + "." + from); err != nil {
fmt.Println(err)
}
}
Binary file added kadai1/d1/AE1.png
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Binary file added kadai1/d1/m1839.png
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
12 changes: 12 additions & 0 deletions kadai1/go.mod
Original file line number Diff line number Diff line change
@@ -0,0 +1,12 @@
module image-convert

go 1.17

require (
github.com/yuin/goldmark v1.3.5 // indirect
golang.org/x/mod v0.4.2 // indirect
golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect
golang.org/x/sys v0.0.0-20210510120138-977fb7262007 // indirect
golang.org/x/tools v0.1.5 // indirect
golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
)
28 changes: 28 additions & 0 deletions kadai1/go.sum
Original file line number Diff line number Diff line change
@@ -0,0 +1,28 @@
github.com/yuin/goldmark v1.3.5 h1:dPmz1Snjq0kmkz159iL7S6WzdahUTHnHB5M56WFVifs=
github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/mod v0.4.2 h1:Gz96sIWK3OalVv/I/qNygP42zyoKp3xptRVCWRFEBvo=
golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 h1:4nGaVu0QrbjT/AK2PRLuQfQuh6DJve+pELhqTdAj3x0=
golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
golang.org/x/tools v0.1.5 h1:ouewzE6p+/VEB31YYnTbEJdi8pFqKp4P4n85vwo3DHA=
golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
Binary file added kadai1/m1838.png
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
15 changes: 15 additions & 0 deletions kadai1/main.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
package main

import (
"image-convert/args"
"image-convert/convert"
"strings"
)

func main() {
var args = args.ParseArgs()
var convertList = convert.GetSelectedExtensionPath(args.From, args.Dir)
for _, v := range convertList {
convert.ConvertImage(strings.Join(v[:len(v)-1], "."), args.From, args.To)
}
}