use go-flags

Makefile

@@ -11,4 +11,4 @@ $(BINARY): $(SOURCES)
 all: $(BINARY) test
 
 test:
-	./$(BINARY) -url "https://images.pexels.com/photos/2558605/pexels-photo-2558605.jpeg?cs=srgb&dl=pexels-anel-rossouw-2558605.jpg&fm=jpg" -height 25
+	./$(BINARY) -u "https://images.pexels.com/photos/2558605/pexels-photo-2558605.jpeg?cs=srgb&dl=pexels-anel-rossouw-2558605.jpg&fm=jpg" -r 25

README.md

@@ -21,7 +21,7 @@ go build ./cmd/imgcat
 ## Usage
 
 ```
-./imgcat -url "https://images.pexels.com/photos/2558605/pexels-photo-2558605.jpeg?cs=srgb&dl=pexels-anel-rossouw-2558605.jpg&fm=jpg" -height 25
+./imgcat -u "https://images.pexels.com/photos/2558605/pexels-photo-2558605.jpeg?cs=srgb&dl=pexels-anel-rossouw-2558605.jpg&fm=jpg" -r 25
 ```
 
 <img width="1069" alt="Capture d’écran 2021-12-11 à 17 40 55" src="https://user-images.githubusercontent.com/65178/145684510-39617c22-5818-4573-896c-7e0e6915db91.png">
@@ -29,10 +29,13 @@ go build ./cmd/imgcat
 ## Help
 
 ```
-# imgcat -h
-Usage of imgcat:
-  -height int
-    	maximum height in lines
-  -url string
-    	url of the jpg
+Usage:
+  imgcat [OPTIONS]
+
+Application Options:
+  -u, --url=  url of the jpg
+  -r, --rows= maximum number of rows
+
+Help Options:
+  -h, --help  Show this help message
 ```

cmd/imgcat/main.go

@@ -2,18 +2,19 @@ package main
 
 import (
 	"encoding/base64"
-	"flag"
 	"fmt"
 	"io"
 	"log"
 	"net/http"
 	"os"
 	"strings"
+
+	"github.com/jessevdk/go-flags"
 )
 
 type Options struct {
-	url    string
-	height int
+	Url  string `short:"u" long:"url" description:"url of the jpg"`
+	Rows int    `short:"r" long:"rows" description:"maximum number of rows"`
 }
 
 func PrintHeader(size int64, height int) {
@@ -46,16 +47,16 @@ func PrintImg(img io.ReadCloser) {
 }
 
 func main() {
-	var opts = &Options{}
-	flag.StringVar(&opts.url, "url", "", "url of the jpg")
-	flag.IntVar(&opts.height, "height", 0, "maximum height in lines")
-	flag.Parse()
+	var options Options
+	if _, err := flags.Parse(&options); err != nil {
+		os.Exit(1)
+	}
 
-	if !(strings.HasPrefix(opts.url, "http://") || strings.HasPrefix(opts.url, "https://")) {
+	if !(strings.HasPrefix(options.Url, "http://") || strings.HasPrefix(options.Url, "https://")) {
 		log.Fatalln("url doesn't start with http")
 	}
 
-	resp, err := http.Get(opts.url)
+	resp, err := http.Get(options.Url)
 	if err != nil {
 		log.Fatalln(err)
 	}
@@ -64,7 +65,7 @@ func main() {
 		log.Fatalln(fmt.Sprintf("Issue to get img, status = %d", resp.StatusCode))
 	}
 
-	PrintHeader(resp.ContentLength, opts.height)
+	PrintHeader(resp.ContentLength, options.Rows)
 	PrintImg(resp.Body)
 
 	PrintFooter()

go.mod

@@ -1,3 +1,8 @@
 module github.com/celogeek/imgcat
 
 go 1.17
+
+require (
+	github.com/jessevdk/go-flags v1.5.0 // indirect
+	golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4 // indirect
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/jessevdk/go-flags v1.5.0 h1:1jKYvbxEjfUl0fmqTCOfonvskHHXMjBySTLW4y9LFvc=
+github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
+golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4 h1:EZ2mChiOa8udjfp6rRmswTbtZN/QzUQp4ptM4rnjHvc=
+golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=