---
title: Reference
description: A complete reference of the cargs command line arguments parser library for C/C++.
---

## Basic

The basic functions available in cargs, which can be used to do basic command line argument parsing.

### Functions

- **[cag_option_init]({{ site.baseurl }}{% link reference/cag_option_init.md %})**
  Prepare argument options context for parsing.

- **[cag_option_fetch]({{ site.baseurl }}{% link reference/cag_option_fetch.md %})**
  Fetches an option from the argument list.

- **[cag_option_get_identifier]({{ site.baseurl }}{% link reference/cag_option_get_identifier.md %})**
  Gets the identifier of the option.

- **[cag_option_get_value]({{ site.baseurl }}{% link reference/cag_option_get_value.md %})**
  Gets the value from the option.

- **[cag_option_get_index]({{ site.baseurl }}{% link reference/cag_option_get_index.md %})**
  Gets the current index of the context.

- **[cag_option_get_error_index]({{ site.baseurl }}{% link reference/cag_option_get_error_index.md %})**
  Retrieves the index of an invalid option.

- **[cag_option_get_error_letter]({{ site.baseurl }}{% link reference/cag_option_get_error_letter.md %})**
  Retrieves the letter character of the invalid option.

## Output

This section describes functions which are used to output argument information.

### Functions

- **[cag_option_print_error]({{ site.baseurl }}{% link reference/cag_option_print_error.md %})**
  Prints the error associated with the invalid option to the specified destination.

- **[cag_option_print]({{ site.baseurl }}{% link reference/cag_option_print.md %})**
  Prints all options to the terminal.
