---
title: "proc_exit()"
description: "Terminate the process normally. An exit code of 0 indicates successful termination of the program. The meanings of other values are dependent on the environment."
url: "https://wasix.org/docs/api-reference/wasi/proc_exit/"
markdown: "https://wasix.org/docs/api-reference/wasi/proc_exit.md"
---

# `proc_exit()`

Terminate the process normally. An exit code of 0 indicates successful termination of the program. The meanings of other values are dependent on the environment.

## Description

The `proc_exit()` function is similar to the `exit()` function in POSIX systems. It allows the program to gracefully terminate with an exit code. The provided exit code is returned to the operating system.

## Syntax

```ebnf
  ;;; the environment.
  ;;; termination of the program. The meanings of other values is dependent on
  ;;; Terminate the process normally. An exit code of 0 indicates successful
  (@interface func (export "proc_exit")
    ;;; The exit code returned by the process.
    (param $rval $exitcode)
    (@witx noreturn)
  )
```

## Parameters

- `ctx`: A mutable reference to the function environment.
- `code`: The exit code to return to the operating system.

## Return Value

This function returns `Result<(), WasiError>`. If the termination is successful, it returns `Ok(())`. Otherwise, it returns an appropriate `WasiError` indicating the cause of the failure.

## Logging

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

- `code`: The exit code provided as input.

## Notes

- The behavior of `proc_exit()` is similar to the POSIX `exit()` function, which terminates the calling process.
- The `exit()` function in POSIX does not have a return value, as the termination of the process is immediate.
- It is important to note that `proc_exit()` is specific to the WASIX system call toolchain for WebAssembly and may have slight differences from the POSIX `exit()` function.
- In POSIX systems, the `exit()` function is usually called at the end of the program or when an error occurs that requires immediate termination.
- The exit code returned by `proc_exit()` can be used by the parent process or by the operating system to determine the status of the terminated process.
- The meanings of exit codes other than 0 depend on the specific environment or application. In POSIX systems, non-zero exit codes are often used to indicate different types of errors or exceptional conditions.
- When writing portable code, it is important to consider the exit code meanings in the target environment and ensure proper handling of different exit codes.

---

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