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Version: Version 1.8

Get started with C

This guide walks you through the steps to use a sample project, and then explains how to integrate the Pdftools SDK into your application with the C programming language.

tip

Try the Pdftools SDK without a license key for free.

Getting started with a sample project

Learn how to use the Pdftools SDK using a C sample project and convert a PDF file to an image.

Prerequisites

This sample project uses GCC toolset 4.8+ and CMake version 3.16 or higher.

Compile and run the sample

  1. Download a sample project, and then unzip the file.

  2. In the command line, navigate to the root directory of the unzipped sample project and then run:

    cmake .
  3. Build the sample:

    cmake --build .
  4. The sample project contains a PDF file PdfPrimerWhitePaper.pdf. To render it in multi-page TIFF image format, run:

    ./pdftoolspdf2imgsimple PdfPrimerWhitePaper.pdf PdfPrimerWhitePaper.tiff

The code sample takes:

  • The input and output files are represented as a file name or a file path with the file name.
  • Both file paths (input and output) can be relative or absolute.

Review the following snippet with a placeholder and compare it to the last step of the previous procedure:

./pdftoolspdf2imgsimple INPUT_FILE OUTPUT_FILE
note

You can apply a similar procedure described in this tutorial for other code samples. For more information, see Code samples page.

Integrate the SDK into your application

Integrate and initialize the Pdftools SDK into your application by following the instructions in the following sections.

Add the SDK to your project

  1. Click the download link to get the latest version of the Pdftools SDK for C in a zip archive.

    Optional: For older Linux distributions running glibc 2.12+, download the SDK from a separate download.

  2. Unzip the file on your machine into a local directory recommended for your operating system. For example:

    C:\Program Files\PDF Tools AG\

    Included subdirectories are:

    SubdirectoryDescription
    ~Contains important information in the README.md file.
    libRuntime executable binaries and runtime import libraries:
    • win-x86\PdfToolsSdk.dll and win-x86\PdfToolsSdk.lib for 32-bit Windows.
    • win-x64\PdfToolsSdk.dll and win-x64\PdfToolsSdk.lib for 64-bit Windows.
    • win-arm64\PdfToolsSdk.dll and win-arm64\PdfToolsSdk.lib for 64-bit Windows ARM.
    includeHeader files to add to your C or C++ project. The main header PdfTools.h includes all the other headers.
  3. Optional: The native libraries must be available in your compiler's library path. This step is only required if your build process doesn't resolve it automatically:

    Add the lib\win-x64, lib\win-arm64 or lib\win-x86 subdirectory to the %PATH% environment variable.

Optional: Initialize the SDK

Learn how to remove watermarked output of the Pdftools SDK using a valid license key.

tip

You can try the Pdftools SDK without a license key for free. This section is optional if you want to evaluate this SDK. Initialization only lets you remove watermarks added to output files.

Getting a license key

Contact the Pdftools sales team through the Contact page to get a full license. For additional information, review Pdftools SDK license management.

To remove watermarks, follow these steps:

  1. Locate your license key. For more information, review Find the license key.

  2. Before you call any function of the Pdftools SDK, first call the PdfTools_Sdk_Initialize function.

    GOTO_CLEANUP_IF_FALSE_PRINT_ERROR(PdfTools_Sdk_Initialize(_T("insert-license-key-here"), NULL),
    _T("Failed to set the license key. %s (ErrorCode: 0x%08x).\n"), szErrorBuff,
    PdfTools_GetLastError());

    Replace the insert-license-key-here with the value of your license key. Include the less-than (<) and greater-than (>) signs.

To get a code sample with the PdfTools_Sdk_Initialize function that you can use as a reference for your code, follow these steps:

  1. On the Code samples page, download and unzip a C code sample. For example: Download Convert PDF to image sample.
  2. Unzip the file, and then find the PdfTools_Sdk_Initialize function in the main C file of the sample. For example: Convert PDF to image sample includes PdfTools_Sdk_Initialize function in the pdftoolspdf2imgsimple.c file.
  3. Uncomment the function and replace insert-license-key-here with your license key.

Uninitialize the SDK

After processing files with the Pdftools SDK, call the Uninitialize function to unload the library correctly:

// Uninitialize library
PdfTools_Uninitialize();

Implement your use case

  • Find more use cases and sample projects on the Code samples page.
  • For more technical information about the Pdftools SDK for C, consult the C technical notes.