---
title: "args_sizes_get()"
description: "The args_sizes_get() function is used to retrieve the sizes of the command-line argument data provided to the WebAssembly module. The sizes are written to the specified output pointers."
url: "https://wasix.org/docs/api-reference/wasi/args_sizes_get/"
markdown: "https://wasix.org/docs/api-reference/wasi/args_sizes_get.md"
---

# `args_sizes_get()`

Return command-line argument data sizes.

## Description

The `args_sizes_get()` function is used to retrieve the sizes of the command-line argument data provided to the WebAssembly module. The sizes are written to the specified output pointers.

## Syntax

```ebnf
  ;;; Return command-line argument data sizes.
  (@interface func (export "args_sizes_get")
    (param $argc (@witx pointer (@witx pointer u32)))
    (param $argv_buf_size (@witx pointer (@witx pointer u32)))
    ;;; Returns the number of arguments and the size of the argument string
    ;;; data, or an error.
    (result $error (expected (tuple $size $size) (error $errno)))
  )
```

## Parameters

- `ctx`: A mutable reference to the function environment.
- `argc`: A WebAssembly pointer to a memory location where the number of arguments will be written.
- `argv_buf_size`: A WebAssembly pointer to a memory location where the size of the argument string data will be written.

## Return Value

The function returns an `Errno` value indicating the success or failure of the operation.

## Logging

This function has been instrumented with debug-level logging. It will log the following information:

- `argc`: The number of arguments.
- `argv_buf_size`: The size of the argument string data.

Please make sure the logging configuration is properly set up to capture the desired logs.

## Note

The `args_sizes_get()` function returns the sizes of the command-line argument data provided to the WebAssembly module. The number of arguments and the size of the argument string data are written to the specified memory locations.

---

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