From 2af6ad556631573b52286f8d6779bd282ed7601c Mon Sep 17 00:00:00 2001
From: Ralph Slooten <axllent@gmail.com>
Date: Sat, 3 Aug 2019 00:37:51 +1200
Subject: [PATCH] Update flags

---
 goptimize.go | 12 ++++++------
 main.go      | 27 ++++++++++++++-------------
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/goptimize.go b/goptimize.go
index 9648830..17ee5bf 100644
--- a/goptimize.go
+++ b/goptimize.go
@@ -154,7 +154,7 @@ func Goptimize(file string) {
 	// calculate saved percent
 	savedPercent := 100 - math.Round(float64(dstSize)/float64(srcSize)*100)
 
-	if dstSize < srcSize {
+	if savedPercent > 0 {
 		// (over)write the file - not all filesystems support
 		// cross-filesystem moving so we overwrite the original
 		out, err := os.Create(dstFile)
@@ -170,14 +170,14 @@ func Goptimize(file string) {
 			return
 		}
 
-		if !skipPreserveModTimes {
+		if preserveModificationTimes {
 			// transfer original modification times
 			if err := os.Chtimes(dstFile, atime, mtime); err != nil {
 				fmt.Printf("Error setting file timestamp: %v\n", err)
 			}
 		}
 
-		fmt.Printf("Goptimized %s (%dx%d %s->%s %v%%)\n", dstFile, resultW, resultH, ByteCountSI(srcSize), ByteCountSI(dstSize), savedPercent)
+		fmt.Printf("Goptimized %s (%dx%d %s > %s %v%%)\n", dstFile, resultW, resultH, ByteCountSI(srcSize), ByteCountSI(dstSize), savedPercent)
 	} else {
 		// If the output directory is not the same,
 		// then write a copy of the original file
@@ -199,17 +199,17 @@ func Goptimize(file string) {
 				return
 			}
 
-			if !skipPreserveModTimes {
+			if preserveModificationTimes {
 				// transfer original modification times
 				if err := os.Chtimes(dstFile, atime, mtime); err != nil {
 					fmt.Printf("Error setting file timestamp: %v\n", err)
 				}
 			}
 
-			fmt.Printf("Copied %s (%dx%d %s->%s %v%%)\n", dstFile, srcW, srcH, ByteCountSI(srcSize), ByteCountSI(srcSize), 0)
+			fmt.Printf("Copied %s (%dx%d %s %v%%)\n", dstFile, srcW, srcH, ByteCountSI(srcSize), 0)
 		} else {
 			// we didn't actually change anything
-			fmt.Printf("Skipped %s (%dx%d %s->%s %v%%)\n", dstFile, srcW, srcH, ByteCountSI(srcSize), ByteCountSI(srcSize), 0)
+			fmt.Printf("Skipped %s (%dx%d %s %v%%)\n", dstFile, srcW, srcH, ByteCountSI(srcSize), 0)
 		}
 	}
 
diff --git a/main.go b/main.go
index d45c565..0a202f7 100644
--- a/main.go
+++ b/main.go
@@ -10,26 +10,27 @@ import (
 )
 
 var (
-	quality              int
-	maxWidth             int
-	maxHeight            int
-	outputDir            string
-	skipPreserveModTimes bool
-	jpegoptim            string
-	jpegtran             string
-	optipng              string
-	pngquant             string
-	gifsicle             string
+	quality                   int
+	maxWidth                  int
+	maxHeight                 int
+	outputDir                 string
+	preserveModificationTimes bool
+	jpegoptim                 string
+	jpegtran                  string
+	optipng                   string
+	pngquant                  string
+	gifsicle                  string
 )
 
 func main() {
 	// set the default help
 	flag.Usage = func() {
-		fmt.Println("Goptimize - Resample optimized images")
+		fmt.Println("Goptimize - downscales and optimizes existing images")
 		fmt.Printf("\nUsage: %s [options] <images>\n", os.Args[0])
 		fmt.Println("\nOptions:")
 		flag.PrintDefaults()
 		fmt.Println("\nExamples:")
+		fmt.Printf("  %s image.png\n", os.Args[0])
 		fmt.Printf("  %s -m 800x800 *.jpg\n", os.Args[0])
 		fmt.Printf("  %s -o out/ -q 90 -m 1600x1600 *.jpg\n", os.Args[0])
 
@@ -46,8 +47,8 @@ func main() {
 
 	flag.IntVar(&quality, "q", 75, "Quality - JPEG only")
 	flag.StringVar(&outputDir, "o", "", "Output directory (default overwrites original)")
-	flag.BoolVar(&skipPreserveModTimes, "n", false, "Do not preserve file modification times")
-	flag.StringVar(&maxSizes, "m", "", "Scale down to a maximum width & height. Format must be <width>x<height>.")
+	flag.BoolVar(&preserveModificationTimes, "p", true, "Preserve file modification times")
+	flag.StringVar(&maxSizes, "m", "", "Downscale to a maximum width & height in pixels (<width>x<height>)")
 
 	// third-party optimizers
 	flag.StringVar(&gifsicle, "gifsicle", "gifsicle", "gifsicle binary")