Get started with C

This guide walks you through the steps to use a code example, 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.

Getting started with a sample project

Learn how to use the Pdftools SDK using a C code example. The Pdf2ImgSimple example converts a PDF file to an image. Use similar steps to run any other code example from the sdk-examples-c repository.

Prerequisites

This code example uses GCC toolset 4.8+ and CMake version 3.16 or higher.

Compile and run the sample

1. Clone the sdk-examples-c repository:

   git clone https://github.com/pdf-tools/sdk-examples-c.git

2. Navigate to the Pdf2ImgSimple code example:

   cd sdk-examples-c/Pdf2ImgSimple

3. Configure and build:

   cmake .

4. Build the sample:

   cmake --build .

5. The code example contains a PDF file PdfPrimerWhitePaper.pdf. To render it in multi-page TIFF image format, run:

   ./pdftoolspdf2imgsimple PdfPrimerWhitePaper.pdf PdfPrimerWhitePaper.tiff

The code example takes:

• The input and output files 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 as described in this tutorial for other code examples. 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 next 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:

   Windows

   C:\Program Files\PDF Tools AG\

   Included subdirectories are:

   Subdirectory	Description
   ~	Contains important information in the README.md file.
   lib	Runtime 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
   include	Header files to add to your C or C++ project. The main header PdfTools.h includes all the other headers.

   Linux

   /opt/pdftools.com/

   Included subdirectories are:

   Subdirectory	Description
   ~	Contains important information in the README.md file.
   lib	Runtime executable binaries for all supported platforms: linux-x64/libPdfToolsSdk.so for 64-bit Linux
   include	Header files to add to your C or C++ project. The main header PdfTools.h includes all the other headers.

   macOS

   /opt/pdftools.com/

   Included subdirectories are:

   Subdirectory	Description
   ~	Contains important information in the README.md file.
   lib	Runtime executable binaries: osx-x64/libPdfToolsSdk.dylib for 64-bit (Intel) macOS osx-arm64/libPdfToolsSdk.dylib for ARM (Apple Silicon) macOS
   include	Header 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:

   Windows

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

   Linux

   Create a link to the shared library from one of the standard library directories, e.g:

   ln -s /opt/pdf-tools.com/lib/linux-x64/libPdfToolsSdk.so /usr/lib

   macOS

   Create a link to the shared library from one of the standard library directories. For example (for an Intel processor Mac):

   ln -s /opt/pdf-tools.com/lib/osx-x64/libPdfToolsSdk.dylib /usr/lib

Initialize the SDK

tip

Try the Pdftools SDK without a license key.

Without a license key, output files carry a watermark. To remove the watermark, follow these steps:

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

2. Find and uncomment the following function, and then replace the YOUR_LICENSE_KEY with the value of your license key:

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

   Use the license key in the same format you copied it. Include the less-than (<) and greater-than (>) signs.

Try it without license key

Without a license key, output files carry a watermark. For more information, review Pdftools SDK license management. Without a valid license key, the output files carry a watermark. Contact the Pdftools sales team through the Contact page to get a full license.

Uninitialize the SDK

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

// Uninitialize library
PdfTools_Uninitialize();

Implement your use case

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