Initial code to resize images

.gitignore

@@ -19,3 +19,6 @@
 
 # Go workspace file
 go.work
+
+# macOS
+.DS_Store

go.mod

@@ -0,0 +1,5 @@
+module resizer
+
+go 1.21.3
+
+require github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 // indirect

go.sum

@@ -0,0 +1,2 @@
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6Oo2LfFZAehjjQMERAvZLEDnQ=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=

main.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"fmt"
+	"image"
+	_ "image/png"
+	"image/jpeg"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/nfnt/resize"
+)
+
+func main() {
+	if len(os.Args) < 3 {
+		fmt.Println("Usage: resizer <image_path> <size> ...")
+		os.Exit(1)
+	}
+
+	imagePath := os.Args[1]
+	sizes := os.Args[2:]
+
+	// Open the file.
+	file, err := os.Open(imagePath)
+	if err != nil {
+		fmt.Println("Error opening file:", err)
+		os.Exit(1)
+	}
+	defer file.Close()
+
+	// Decode the image.
+	img, _, err := image.Decode(file)
+	if err != nil {
+		fmt.Println("Error decoding image:", err)
+		os.Exit(1)
+	}
+
+	for _, size := range sizes {
+		dimensions := strings.Split(size, "x")
+		var width, height uint
+		var err error
+
+		// Parse width and height.
+		width64, err := strconv.ParseUint(dimensions[0], 10, 64)
+		if err != nil {
+			fmt.Println("Invalid width:", err)
+			continue
+		}
+		width = uint(width64)
+
+		if len(dimensions) == 2 {
+			height64, err := strconv.ParseUint(dimensions[1], 10, 64)
+			if err != nil {
+				fmt.Println("Invalid height:", err)
+				continue
+			}
+			height = uint(height64)
+		} else {
+			height = width
+		}
+
+		// Resize the image.
+		m := resize.Resize(width, height, img, resize.Lanczos3)
+
+		// Create the output file.
+		out, err := os.Create(fmt.Sprintf("%s_%dx%d.jpg", strings.TrimSuffix(imagePath, ".png"), width, height))
+		if err != nil {
+			fmt.Println("Error creating file:", err)
+			continue
+		}
+		defer out.Close()
+
+		// Write the new image to file.
+		jpeg.Encode(out, m, nil)
+		fmt.Printf("Resized image to %dx%d and saved as %s_%dx%d.jpg\n", width, height, strings.TrimSuffix(imagePath, ".png"), width, height)
+	}
+}