C-node is a module that allows invoking C code from your nodeJs application.
The module uses the TCC compiler. It does not use node-gyp. It does not use Python.

# Installation

```shell
npm install @thimpat/c-node
```

<br/>

---

# Usage

CJS
```javascript
const cNode = require("@thimpat/c-node");
```

<br/>

ESM

```javascript
import cNode from "@thimpat/c-node";
```

<br/>

----

### From a shell

```shell
// C-node uses the TCC compiler under the hood.
$> c-node [options] 
```

---

# Quick start 

<br/>

#### Invoking a function from a .dll in Node


###### dll.c ↴
```c
#include <windows.h>

// Export function "hello_func" to .dll
__declspec(dllexport) char* hello_func (char* name)
{
    char str[100];
    sprintf(str, "From DLL: %d - %s", 10000, name);
    MessageBox (0, "Hi world!", str, MB_ICONINFORMATION);
    return "All okay";
}
```

> dll.c will be compiled automatically when loadFunctions is invoked

<br/>

###### index.js ↴
```javascript
const {loadFunctions} = require("@thimpat/c-node");

// Import c function "hello_func()" from c library
const {hello_func} = loadFunctions("dll.c", {
    hello_func: {
        // hello_func prototype from dll.c without names (only types)
        prototype: "char* hello_func (char*)",
    }
});

// Invoke dll function
const result = hello_func("My name is awesome");

console.log(result);           // All okay
```

<br/>

```shell
node index.js
```

💻  ↴

![Execute a c function from Node](https://raw.githubusercontent.com/thimpat/demos/main/c-node/images/execute-c-function-from-node.png)

<br/>

💻  ↴

![Output result](https://raw.githubusercontent.com/thimpat/demos/main/c-node/images/output-c-function-result.png)


<br/>

---

# Examples

All examples are part of the TCC library.

### Compilation

<br/>

#### Example 1 - Compile a C program to an executable

```javascript
const {compileSource} = require("@thimpat/c-node");
const {success, status} = compileSource("examples/hello_win.c");
if (!success)
{
    console.error(`Compilation failed. Status: ${status}`)
}
```

<br/>

---
#### Example 2 - Compile a C source to a shared library (dll)

```javascript
const {compileLibrary} = require("@thimpat/c-node");
const {success, status} = compileLibrary("examples/dll.c")
```

<br/>

---

### Execution

<br/>

#### Example 3 - Compile if target nonexistent, then run source

###### example.js ↴
```javascript
const {runFile} = require("@thimpat/c-node");
runFile("examples/hello_win.c");
```

💻  ↴

![Message Box Hello World](https://raw.githubusercontent.com/thimpat/demos/main/c-node/images/message-box-hello-world.png)

<br/>

---

### Run source using JIT (Just in time compilation)

###### example.js ↴
```javascript
const {runLive} = require("@thimpat/c-node");

// Runs from source code
runLive("examples/hello_win.c");
```

<br/>

---

# API

<br/>

## runFile

> Compile then run a source code

<br/>

#### Usage

```javascript
runFile(sourcePath, options);
```

<br/>

#### Options

| Properties | Description                             | Type   | Default                               |     |
|------------|-----------------------------------------|--------|---------------------------------------|-----|
| outputDir  | Directory path for generated the binary | string | ""                                    |     |
| output     | File path for generated binary          | string | current location + target binary name |     |
|            |                                         |        |                                       |     |

<br/>

#### Examples

###### example.js ↴
```javascript
const {runFile} = require("@thimpat/c-node");

// Generate ./demo/ex1.exe
runFile("examples/ex1.c", {outputDir: "demo/"});
```

<br/>

---

## loadBinaryFunctions

Load functions from a .dll

<br/>

#### Usage

```javascript
loadBinaryFunctions("<your-lib>.dll", {
    [funcName]: {
        prototype: "...",
    },
})
```

<br/>

#### Examples

###### example.js ↴
```javascript
const {hello_func} = loadBinaryFunctions("dll.dll", {
    hello_func: {
        prototype: "char* hello_func (char*)",
    }
});

const res = hello_func("My name is awesome");
console.log({lid: "NC6452"}, res);
```

<br/>

---

## invokeFunction

Call a function from a c source code

<br/>

#### Usage

```javascript
invokeFunction(functionCallString, filePath, {outputDir});
```

<br/>

#### Options

| Properties | Description                             | Type   | Default                               |     |
|------------|-----------------------------------------|--------|---------------------------------------|-----|
| outputDir  | Directory path for generated the binary | string | ""                                    |     |

<br/>

#### Examples

###### example.js ↴
```javascript
const {invokeFunction} = require("@thimpat/c-node");

const result = invokeFunction("hello_func()", "examples/dll.c", {outputDir: "demo/"});
console.log(result);
```

<br/>

---

## invokeBinaryFunction

Call a function from a .dll

<br/>

#### Examples

###### example.js ↴
```javascript
const {invokeFunction} = require("@thimpat/c-node");

const result = invokeBinaryFunction("hello_func()", "examples/dll.dll", {outputDir: "demo/"});
console.log(result);
```