Get PDF Info

This guide will demonstrate how to get basic information of a PDF document.

Before you begin #

You should get your API key from your UniCloud account.

If this is your first time using UniPDF SDK, follow this guide to set up a local development environment.

Clone the project repository #

In your terminal, clone the examples repository. It contains the Go code we will be using for this guide.

git clone https://github.com/unidoc/unipdf-examples.git

Navigate to the analysis folder in the unipdf-examples directory.

cd unipdf-examples/analysis

How it works #

The import section is used to import necessary UniPDF packages and other Go libraries. The init section loads your license key prior to running the program.

The main function in lines 25-45, iterates through each input file in the command line arguments and gets the document information using getPdfProperties(inputPath).

The PdfProperties type which is used to hold PDF information is defined in lines 47-51.

Lines 53-93 define the getPdfProperties function. In this function in line 63, a new PdfReader is defined using pdfReader, err := model.NewPdfReader(f). Then the file is checked for encryption status using the IsEncrypted() method of model.PdfReader. If the document is encrypted the code in lines 77-84, tries to decrypt the document using an empty password as follows:

// Try decrypting with an empty one.
if isEncrypted {
auth, err := pdfReader.Decrypt([]byte(""))
if err != nil {
  return nil, err
}
ret.CanView = auth
return &ret, nil
}

Line 86, gets the number of pages using pdfReader.GetNumPages().

Run the code #

Run the code using the following command:

go run pdf_info.go input1.pdf [input2.pdf] ...

Sample output #

Input file: templates/documentation/unipdf-templates-documentation.pdf
Num Pages: 58
Is Encrypted: false
Is Viewable (without pass): true