# xpipe<sup>[^1]</sup>

Use cross-platform IPC paths in Node.js.

## Background

In Node.js - instead of using TCP - you also can take IPC<sup>[^2]</sup> to communicate to services like

- web servers (NGINX, Caddy)
- databases (redis, PostgreSQL, MongoDB)
- etc.

or to interconnect Node.js apps, Electron frontends/backends and so on.

**This can lead to large speed gains.**

On unixoid operating systems - e.g. Linux and OS X - we use [Unix domain sockets](https://en.wikipedia.org/wiki/Unix_domain_socket)
that are referred by file descriptors.

Windows has [named pipes](https://en.wikipedia.org/wiki/Named_pipe) for it, living
in the root directory of the NPFS<sup>[^3]</sup>, mounted under the special path \\\\.\\pipe\\.

**To mitigate these differences and to to support writing portable code, xpipe was born...**

## Installation

    npm install xpipe

## Usage

```javascript
// CommonJS (CJS) require
const xpipe = require('xpipe');
```

```javascript
// ECMAScript Modules (ESM) import
import xpipe from 'xpipe';
```

### xpipe.prefix

```javascript
let prefix = xpipe.prefix;
console.log(`prefix:  ${prefix}`);

//   [empty string] on Linux and macOS
//   "//./pipe/" on Windows
```

### xpipe.eq

```javascript
let ipcPath = xpipe.eq('/tmp/my.sock');
console.log(`ipcPath: ${ipcPath}`);

//   Returns a cross-platform IPC path:
//   "/tmp/my.sock" on Linux and OS X
//   "//./pipe/tmp/my.sock" on Windows
```

## When did Windows start accepting forward slash as a path separator?

Every Windows API/kernel ever has accepted "/" as a path separator.
So has every version of MS-DOS beginning with DOS 2.0 (the first version
to support subdirectories).

It's only been in command lines that "/" was not allowed when it had
already been used as a switch delimiter in MS-DOS 1.0 (introduced by IBM).

This behaviour could be bypassed (at least on modern Windows systems) by including
the path in double quotation marks:

- **cd c:/Windows** and **cd /Windows** work<sup>[^4]</sup>
- **dir ./ /B** fails but **dir "./" /B** works

Further articles:

- https://en.m.wikipedia.org/wiki/Path_(computing)

<p>&nbsp;</p> 
  
[^1]: xpipe stands for **xp (cross-platform) IPC path equalizer**  
[^2]: inter-process communication, see [https://en.wikipedia.org/wiki/Inter-process_communication](https://en.wikipedia.org/wiki/Inter-process_communication)
[^3]: named pipe file system (in-memory)  
[^4]: on Windows "/" without a leading drive letter represents the root of the current drive