Merge pull request #4 from adrg/master

Add README.md

README.md

@@ -1 +1,299 @@
 # unicli
+
+[![GoDoc](https://godoc.org/github.com/unidoc/unicli?status.svg)](https://godoc.org/github.com/unidoc/unicli)
+[![Go Report Card](https://goreportcard.com/badge/github.com/unidoc/unicli)](https://goreportcard.com/report/github.com/unidoc/unicli)
+
+unicli is a CLI tool which makes working with PDF files very easy. It supports
+the most common PDF operations. The application is written in Golang and is
+powered by the [UniDoc](https://github.com/unidoc/unidoc) PDF library.
+
+## Features
+
+- [Merge PDF files](#merge)
+- [Split PDF files](#split)
+- [Encrypt PDF files](#encrypt)
+- [Decrypt PDF files](#decrypt)
+- [Change user/owner password](#passwd)
+- [Optimize PDF files](#optimize)
+- [Add watermark images to PDF files](#watermark)
+- [Convert PDF files to grayscale](#grayscale)
+- [Validate and print PDF file information](#info)
+- [Extract text from PDF files](#extract)
+- [Extract images from PDF files](#extract)
+- [Search text in PDF files](#search)
+
+## Short demo
+
+[![asciicast](https://i.imgur.com/nQZq6T7.png)](https://asciinema.org/a/220314)
+
+## Installation
+
+```
+go get github.com/unidoc/unicli
+```
+
+## Showcase
+
+#### Grayscale conversion
+
+![encrypt example](https://i.imgur.com/9QgXWUc.png)
+
+#### Add watermark
+
+![watermark example](https://i.imgur.com/GIRsTnT.png)
+
+## Usage
+
+#### Merge
+
+Merge multiple PDF files into a single output file.
+
+```
+unicli merge OUTPUT_FILE INPUT_FILE...
+
+Examples:
+unicli merge output_file.pdf input_file1.pdf input_file2.pdf
+```
+
+#### Split
+
+Extract one or more page ranges from PDF file and save the result as a
+single output file.
+
+```
+unicli split [FLAG]... INPUT_FILE OUTPUT_FILE [PAGES]
+
+Flags:
+-p, --password string   PDF file password
+
+Examples:
+unicli split input_file.pdf output_file.pdf 1-2
+unicli split -p pass input_file.pd output_file.pdf 1-2,4
+
+PAGES parameter example: 1-3,4,6-7
+Only pages 1,2,3 (1-3), 4 and 6,7 (6-7) will be present in the output file,
+while page number 5 is skipped.
+```
+
+#### Encrypt
+
+Add password protection to PDF files. Owner and user passwords can be
+specified, along with a set of user permissions. The encryption algorithm
+used for protecting the file is configurable.
+
+```
+unicli encrypt [FLAG]... INPUT_FILE OWNER_PASSWORD [USER_PASSWORD]
+
+Flags:
+-m, --mode string         Algorithm to use for encrypting the file (default "rc4")
+-o, --output-file string  Output file
+-P, --perms string        User permissions (default "all")
+
+Examples:
+unicli encrypt input_file.pdf owner_pass
+unicli encrypt input_file.pdf owner_pass user_pass
+unicli encrypt -o output_file.pdf -m aes256 input_file.pdf owner_pass user_pass
+unicli encrypt -o output_file.pdf -P none -m aes256 input_file.pdf owner_pass user_pass
+unicli encrypt -o output_file.pdf -P modify,annotate -m aes256 input_file.pdf owner_pass user
+
+Supported encryption algorithms:
+- rc4 (default)
+- aes128
+- aes256
+
+Supported user permissions:
+- all (default)
+- none
+- print-low-res
+- print-high-res
+- modify
+- extract
+- extract-graphics
+- annotate
+- fill-forms
+- rotate
+```
+
+#### Decrypt
+
+Remove password protection from PDF files.
+
+```
+unicli decrypt [FLAG]... INPUT_FILE
+
+Flags:
+-o, --output-file string   Output file
+-p, --password string      PDF file password
+
+Examples:
+unicli decrypt -p pass input_file.pdf
+unicli decrypt -p pass -o output_file.pdf input_file.pdf
+```
+
+#### Passwd
+
+Change protected PDF user/owner password.
+
+```
+unicli passwd [FLAG]... INPUT_FILE NEW_OWNER_PASSWORD [NEW_USER_PASSWORD]
+
+Flags:
+-o, --output-file string   Output file
+-p, --password string      PDF file password
+
+Examples:
+unicli passwd -p pass input_file.pdf new_owner_pass
+unicli passwd -p pass -o output_file.pdf input_file.pdf new_owner_pass
+unicli passwd -p pass -o output_file.pdf input_file.pdf new_owner_pass new_user_pass
+```
+
+#### Optimize
+
+Optimize PDF files by removing redundant objects. The quality of the
+contained images can also be configured.
+
+```
+unicli optimize [FLAG]... INPUT_FILE
+
+Flags:
+-q, --image-quality int    Optimized image quality (default 100)
+-o, --output-file string   Output file
+-p, --password string      File password
+
+Examples:
+unicli optimize input_file.pdf
+unicli optimize -o output_file input_file.pdf
+unicli optimize -o output_file -i 75 input_file.pdf
+unicli optimize -o output_file -i 75 -p pass input_file.pdf
+```
+
+#### Watermark
+
+Add watermark images to PDF files.
+
+```
+unicli watermark [FLAG]... INPUT_FILE WATERMARK_IMAGE
+
+Flags:
+-o, --output-file string   Output file
+-P, --pages string         Pages on which to add watermark
+-p, --password string      PDF file password
+
+Examples:
+unicli watermark input_file.pdf watermark.png
+unicli watermark -o output file.png input_file.pdf watermark.png
+unicli watermark -o output file.png -P 1-3 input_file.pdf watermark.png
+unicli watermark -o output file.png -P 1-3 -p pass input_file.pdf watermark.png
+
+Pages parameter example: 1-3,4,6-7
+Only pages 1,2,3 (1-3), 4 and 6,7 (6-7) will be present in the output file,
+while page number 5 is skipped.
+```
+
+#### Grayscale
+
+Convert PDF files to grayscale.
+
+```
+unicli grayscale [FLAG]... INPUT_FILE
+
+Flags:
+-o, --output-file string   Output file
+-P, --pages string         Pages to convert to grayscale
+-p, --password string      PDF file password
+
+Examples:
+unicli grayscale input_file.pdf
+unicli grayscale -o output_file input_file.pdf
+unicli grayscale -o output_file -P 1-3 input_file.pdf
+unicli grayscale -o output_file -P 1-3 -p pass input_file.pdf
+
+Pages parameter example: 1-3,4,6-7
+Only pages 1,2,3 (1-3), 4 and 6,7 (6-7) will be present in the output file,
+while page number 5 is skipped.
+```
+
+#### Info
+
+Outputs file information. Also does some basic validation.
+
+```
+unicli info [FLAG]... INPUT_FILE
+
+Flags:
+-p, --password string   PDF file password
+
+Examples:
+unicli info input_file.pdf
+unicli info -p pass input_file.pdf
+```
+
+#### Extract
+
+Extract resources (text, images) from PDF files.
+
+```
+unicli extract [FLAG]... INPUT_FILE
+
+Flags:
+-o, --output-file string     Output file
+-P, --pages string           Pages to extract resources from
+-r, --resource string        Resource to extract
+-p, --user-password string   Input file password
+
+Examples:
+unicli extract -r text input_file.pdf
+unicli extract -r text -P 1-3 input_file.pdf
+unicli extract -r text -P 1-3 -p pass input_file.pdf
+unicli extract -r images input_file.pdf
+unicli extract -r images -o images.zip input_file.pdf
+unicli extract -r images -P 1-3 -p pass -o images.zip input_file.pdf
+
+Pages parameter example: 1-3,4,6-7
+Only pages 1,2,3 (1-3), 4 and 6,7 (6-7) will be present in the output file,
+while page number 5 is skipped.
+
+Supported resources:
+- text
+- images
+```
+
+#### Search
+
+Search text in PDF files.
+
+```
+unicli search [FLAG]... INPUT_FILE TEXT
+
+Flags:
+-p, --password string   PDF file password
+
+Examples:
+unicli search input_file.pdf text_to_search
+unicli search -p pass input_file.pdf text_to_search
+```
+
+## License
+
+The application is licensed under the same conditions as the
+[UniDoc](https://github.com/unidoc/unidoc) library.
+Is has a dual license, a commercial one suitable for closed source projects
+and an AGPL license that can be used in open source software.
+
+Depending on your needs, you can choose one of them and follow its policies.
+A detail of the policies and agreements for each license type are available in
+the [LICENSE.COMMERCIAL](LICENSE.COMMERCIAL) and [LICENSE.AGPL](LICENSE.AGPL)
+files.
+
+Please see [pricing](http://unidoc.io/pricing) to purchase a commercial
+[UniDoc](https://github.com/unidoc/unidoc) license or contact sales at
+sales@unidoc.io for more info.
+
+If you have a license for [UniDoc](https://github.com/unidoc/unidoc), you can
+set it through the UNIDOC_LICENSE_FILE and UNIDOC_LICENSE_CUSTOMER environment
+variables.
+
+```
+export UNIDOC_LICENSE_FILE="PATH_TO_LICENSE_FILE"
+export UNIDOC_LICENSE_CUSTOMER="CUSTOMER_NAME"
+```

cmd/optimize.go

@@ -59,7 +59,7 @@ var optimizeCmd = &cobra.Command{
 			printErr("Could not optimize input file: %s\n", err)
 		}
 
-		fmt.Printf("Input file %s sucessfully optimized\n", inputPath)
+		fmt.Printf("Input file %s successfully optimized\n", inputPath)
 		fmt.Printf("Output file saved to %s\n", outputPath)
 	},
 	Args: func(cmd *cobra.Command, args []string) error {

cmd/search.go

@@ -45,7 +45,7 @@ var searchCmd = &cobra.Command{
 		totalOccurrences := 0
 		for _, result := range results {
 			totalOccurrences += result.Occurrences
-			fmt.Printf("Page %d: %d occurences\n", result.Page, result.Occurrences)
+			fmt.Printf("Page %d: %d occurrences\n", result.Page, result.Occurrences)
 		}
 
 		fmt.Printf("Total occurrences: %d\n", totalOccurrences)

cmd/watermark.go

@@ -63,7 +63,7 @@ var watermarkCmd = &cobra.Command{
 			printErr("Could not apply watermark to the input file: %s\n", err)
 		}
 
-		fmt.Printf("Watermark sucessfully applied to %s\n", inputPath)
+		fmt.Printf("Watermark successfully applied to %s\n", inputPath)
 		fmt.Printf("Output file saved to %s\n", outputPath)
 	},
 	Args: func(cmd *cobra.Command, args []string) error {

pdf/grayscale.go

@@ -703,8 +703,8 @@ func convertShadingToGray(shading *unipdf.PdfShading) (*unipdf.PdfShading, error
 		shading.ColorSpace = transformcs
 
 		return shading, nil
-	} else {
-		unicommon.Log.Debug("Cannot convert to shading pattern grayscale, color space N = %d", cs.GetNumComponents())
-		return nil, errors.New("unsupported pattern colorspace for grayscale conversion")
 	}
+
+	unicommon.Log.Debug("Cannot convert to shading pattern grayscale, color space N = %d", cs.GetNumComponents())
+	return nil, errors.New("unsupported pattern colorspace for grayscale conversion")
 }

pdf/utils.go

@@ -90,10 +90,8 @@ func writePDF(filename string, w *unipdf.PdfWriter, safe bool) error {
 				if err = os.Rename(tempPath, filename); err != nil {
 					return err
 				}
-				if err = os.Remove(tempPath); err != nil {
-					return err
-				}
-				return nil
+
+				return os.Remove(tempPath)
 			}()
 		}
 	}
@@ -131,10 +129,8 @@ func writeCreatorPDF(filename string, c *unicreator.Creator, safe bool) error {
 				if err = os.Rename(tempPath, filename); err != nil {
 					return err
 				}
-				if err = os.Remove(tempPath); err != nil {
-					return err
-				}
-				return nil
+
+				return os.Remove(tempPath)
 			}()
 		}
 	}
@@ -147,11 +143,7 @@ func writeCreatorPDF(filename string, c *unicreator.Creator, safe bool) error {
 	defer of.Close()
 
 	// Write output file.
-	if err = c.Write(of); err != nil {
-		return err
-	}
-
-	return nil
+	return c.Write(of)
 }
 
 func readerToWriter(r *unipdf.PdfReader, w *unipdf.PdfWriter, pages []int) error {