Existing Go (C Interface Binding) project with Apryse SDK PDF library integration

C interface binding example

This guide is a demo for using our C interface binding and is not a production version of the Go wrapper. Please visit our Apryse SDK for Go documentation for more information on using our production version of Go.

This guide will help you integrate a free trial of the Apryse SDK with Go using Apryse Headers on macOS, Linux or Windows in an existing Go app to create a new PDFDoc. (Or see instructions for creating a new Go app.)

Prerequisites

• Go 1.6+

macOS

Make sure Go is installed at /usr/local/go and /usr/local/go/bin.

• Apryse SDK for macOS

Linux

Make sure Go is installed at `/usr/local/go` and `/usr/local/go/bin`.

• Apryse SDK for Linux

Windows

Make sure Go is part of your path variable.

• Apryse SDK for Windows

• Get your Apryse trial key.

License Key Required

The trial of Apryse SDK requires a trial license key, which is provided in the box titled "License Key". A commercial license key is required for use in a production environment. Please contact sales to purchase a commercial key or if you need any other license key assistance.

Keep your license keys confidential.

License keys are uniquely generated. Please make sure that it is not publicly available (e.g. in your public GitHub).

Integrate Apryse SDK with Go

Start by adding these lines to the beginning of your .go file:

Go

// #cgo CFLAGS: -Ipath/to/your/download/PDFNetCMac/Headers
// #cgo LDFLAGS: -Lpath/to/your/download/PDFNetCMac/Lib -Wl,-rpath,PDFNetC64/Lib -lPDFNetC

Before calling other Apryse API, you must initialize PDFNet. The PDFNet initialize header is found in C/PDF/TRN_PDFNet.h and the PDFDoc header is found in C/PDF/TRN_PDFDoc.h. Include both at the beginning of your .go file:

Go

// #include "C/PDF/TRN_PDFNet.h"
// #include "C/PDF/TRN_PDFDoc.h"

Also import the unsafe library:

Go

import (
    "unsafe"
)

Then initialize PDFNet by calling these lines:

// Declare a license key and convert it to CString
ccp := C.CString("YOUR_LICENSE_KEY");
// Initialize PDFNet
C.TRN_PDFNetInitialize(ccp);
// Free the memory used for the license key
C.free(unsafe.Pointer(ccp));

To create a new PDFDoc in Go, you must allocate memory for it and handle freeing the memory associated with it.

You can follow these steps to instantiate a PDFDoc:

Go

// Declare a pointer for the PDFDoc.
var doc *C.TRN_PDFDoc;

// Get the size of the type using the pointer and allocate that amount of memory using malloc,
// then typecast void pointer returned by malloc to the required type explicitly.
doc = (*C.TRN_PDFDoc)(C.malloc(C.size_t(unsafe.Sizeof(*doc))));

// Call `TRN_PDFDocCreate` on the pointer to create the PDFDoc.
C.TRN_PDFDocCreate(doc);

To deallocate the memory used by the PDFDoc, you can use C.free:

Go

C.free(doc);

Next step

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