---
title: "proc_id()"
description: "Returns the handle of the current process."
url: "https://wasix.org/docs/api-reference/wasix/proc_id/"
markdown: "https://wasix.org/docs/api-reference/wasix/proc_id.md"
---

# `proc_id()`

Returns the handle of the current process.

## Description

The `proc_id()` function is used to retrieve the handle of the current process. It returns the process identifier (PID) of the calling process.

In POSIX systems, a process ID is a unique identifier assigned to each running process. The PID is used by the operating system to track and manage processes.

## Syntax

```ebnf
  ;;; Returns the handle of the current process
  (@interface func (export "proc_id")
    (result $error (expected $pid (error $errno)))
  )
```

## Parameters

- `ctx`: The function environment.
- `ret_pid`: Pointer to store the returned process ID.

## Return Value

The function returns an `Errno` value indicating the result of the operation. If the operation is successful, it returns `Errno::Success`.

## Logging

This function is instrumented with `debug` level logging. It includes the following field for debugging purposes:

- `pid`: The process ID of the current process.

## Note

- The `proc_id()` function is used to retrieve the handle of the current process.
- It accesses the process identifier (PID) of the calling process using the `pid()` method of the current process.
- The function stores the process ID in the specified `ret_pid` pointer.
- The process ID is a unique identifier assigned to each running process.
- The function does not raise any errors and always returns `Errno::Success`.

---

[Documentation index](https://wasix.org/llms.txt) · [HTML version](https://wasix.org/docs/api-reference/wasix/proc_id/)