Printing debug info only if -v mentioned

img.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"strconv"
 	"strings"
@@ -14,6 +15,7 @@ var sizeHasSet, merginHasSet = false, false
 
 // func addImageToPdf(inputPath string, outputPath string, imagePath string, pageNum int, xPos float64, yPos float64, iwidth float64) error {
 func addImage(filePath string, c *creator.Creator) error {
+	debugInfo(fmt.Sprintf("Adding image: %s", filePath))
 
 	img, err := creator.NewImageFromFile(filePath)
 	if err != nil {

main.go

@@ -13,21 +13,20 @@ import (
 )
 
 var size, margin string
-var scaleH, scaleW bool
+var scaleH, scaleW, verbose bool
 
 const (
 	DefaultSize   = "IMG-SIZE"
 	DefaultMargin = "1,1,1,1"
 )
 
 func init() {
-	// Debug log level.
-	unicommon.SetLogger(unicommon.NewConsoleLogger(unicommon.LogLevelDebug))
 
 	flag.StringVarP(&size, "size", "s", DefaultSize, "Resize image pages to print size. One of A4, A3, Legal or Letter.")
 	flag.StringVarP(&margin, "margin", "m", DefaultMargin, "Comma separated numbers for left, right, top, bottm side margin in inch.")
 	flag.BoolVarP(&scaleW, "scale-width", "w", false, "Scale Image to page width. Only if --size specified.")
 	flag.BoolVarP(&scaleH, "scale-height", "h", false, "Scale Image to page height. Only if --size specified.")
+	flag.BoolVarP(&verbose, "verbose", "v", false, "Display debug info.")
 
 	flag.Usage = func() {
 		fmt.Println("Requires at least 3 arguments: output_path and 2 input paths (and optional page numbers)")
@@ -44,6 +43,10 @@ func main() {
 		os.Exit(0)
 	}
 
+	if verbose {
+		unicommon.SetLogger(unicommon.NewConsoleLogger(unicommon.LogLevelDebug))
+	}
+
 	outputPath := args[0]
 	inputPaths := []string{}
 	inputPages := [][]int{}
@@ -79,7 +82,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	fmt.Printf("Complete, see output file: %s\n", outputPath)
+	debugInfo(fmt.Sprintf("Complete, see output file: %s", outputPath))
 }
 
 func mergePdf(inputPaths []string, inputPages [][]int, outputPath string) error {
@@ -105,10 +108,6 @@ func mergePdf(inputPaths []string, inputPages [][]int, outputPath string) error
 			err = addPdfPages(f, inputPages[i], c)
 		} else if fileType[:6] == "image/" {
 			err = addImage(inputPath, c)
-
-			fmt.Println("%+v", pageMargin)
-			fmt.Println("%+v", pageSize)
-
 		} else {
 			err = errors.New("Unsupported type:" + inputPath)
 		}

pdf.go

@@ -2,7 +2,9 @@ package main
 
 import (
 	"errors"
+	"fmt"
 	"io"
+	"os"
 
 	"github.com/unidoc/unidoc/pdf/creator"
 	pdf "github.com/unidoc/unidoc/pdf/model"
@@ -33,13 +35,14 @@ func getReader(rs io.ReadSeeker) (*pdf.PdfReader, error) {
 	return pdfReader, nil
 }
 
-func addPdfPages(file io.ReadSeeker, pages []int, c *creator.Creator) error {
+func addPdfPages(file *os.File, pages []int, c *creator.Creator) error {
 	pdfReader, err := getReader(file)
 	if err != nil {
 		return err
 	}
 
 	if len(pages) > 0 {
+		debugInfo(fmt.Sprintf("Adding all pages of PDF: %s", file.Name()))
 		for _, pageNo := range pages {
 			if page, pageErr := pdfReader.GetPage(pageNo); pageErr != nil {
 				return pageErr
@@ -60,6 +63,7 @@ func addPdfPages(file io.ReadSeeker, pages []int, c *creator.Creator) error {
 				return err
 			}
 
+			debugInfo(fmt.Sprintf("Adding page %d of PDF: %s", pageNum, file.Name()))
 			if err = c.AddPage(page); err != nil {
 				return err
 			}

util.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"log"
 	"net/http"
 	"os"
 	"reflect"
@@ -43,3 +44,9 @@ func getFileType(file *os.File) (string, error) {
 		return http.DetectContentType(buffer), nil
 	}
 }
+
+func debugInfo(message string) {
+	if verbose {
+		log.Println(message)
+	}
+}