Add a --write and --diff flag; require --write to be set before making any changes, for safety

tesseract/genconf/nginx.go

@@ -76,7 +76,7 @@ type NginxTemplateData struct {
 	ListenPort     string
 }
 
-func generateNginx(yamlFile string) {
+func generateNginx(yamlFile string, wantDiff bool, allowWrite bool, useColor bool) {
 	config := loadConfig(yamlFile)
 
 	// Extract port from first listen address
@@ -123,7 +123,7 @@ func generateNginx(yamlFile string) {
 		}
 
 		// Write file with status
-		err = writeFileWithStatus(outputPath, buf.Bytes())
+		err = writeFileWithStatus(outputPath, buf.Bytes(), wantDiff, allowWrite, useColor)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Failed to write nginx config file %s: %v\n", outputPath, err)
 			continue