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#pragma once
/**
* This is a simple alternative cross-platform implementation of getopt, which
* is used to parse argument strings submitted to the executable (argc and argv
* which are received in the main function).
*/
#ifndef CAG_LIBRARY_H
#define CAG_LIBRARY_H
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#if defined(_WIN32) || defined(__CYGWIN__)
#define CAG_EXPORT __declspec(dllexport)
#define CAG_IMPORT __declspec(dllimport)
#elif __GNUC__ >= 4
#define CAG_EXPORT __attribute__((visibility("default")))
#define CAG_IMPORT __attribute__((visibility("default")))
#else
#define CAG_EXPORT
#define CAG_IMPORT
#endif
#if defined(CAG_SHARED)
#if defined(CAG_EXPORTS)
#define CAG_PUBLIC CAG_EXPORT
#else
#define CAG_PUBLIC CAG_IMPORT
#endif
#else
#define CAG_PUBLIC
#endif
#ifdef __cplusplus
extern "C" {
#endif
/**
* An option is used to describe a flag/argument option submitted when the
* program is run.
*/
typedef struct cag_option
{
const char identifier;
const char *access_letters;
const char *access_name;
const char *value_name;
const char *description;
} cag_option;
/**
* A context is used to iterate over all options provided. It stores the parsing
* state.
*/
typedef struct cag_option_context
{
const struct cag_option *options;
size_t option_count;
int argc;
char **argv;
int index;
int inner_index;
bool forced_end;
char identifier;
char *value;
} cag_option_context;
/**
* This is just a small macro which calculates the size of an array.
*/
#define CAG_ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
/**
* @brief Prints all options to the terminal.
*
* This function prints all options to the terminal. This can be used to
* generate the output for a "--help" option.
*
* @param options The options which will be printed.
* @param option_count The option count which will be printed.
* @param destination The destination where the output will be printed.
*/
CAG_PUBLIC void cag_option_print(const cag_option *options, size_t option_count,
FILE *destination);
/**
* @brief Prepare argument options context for parsing.
*
* This function prepares the context for iteration and initializes the context
* with the supplied options and arguments. After the context has been prepared,
* it can be used to fetch arguments from it.
*
* @param context The context which will be initialized.
* @param options The registered options which are available for the program.
* @param option_count The amount of options which are available for the
* program.
* @param argc The amount of arguments the user supplied in the main function.
* @param argv A pointer to the arguments of the main function.
*/
CAG_PUBLIC void cag_option_prepare(cag_option_context *context,
const cag_option *options, size_t option_count, int argc, char **argv);
/**
* @brief Fetches an option from the argument list.
*
* This function fetches a single option from the argument list. The context
* will be moved to that item. Information can be extracted from the context
* after the item has been fetched.
* The arguments will be re-ordered, which means that non-option arguments will
* be moved to the end of the argument list. After all options have been
* fetched, all non-option arguments will be positioned after the index of
* the context.
*
* @param context The context from which we will fetch the option.
* @return Returns true if there was another option or false if the end is
* reached.
*/
CAG_PUBLIC bool cag_option_fetch(cag_option_context *context);
/**
* @brief Gets the identifier of the option.
*
* This function gets the identifier of the option, which should be unique to
* this option and can be used to determine what kind of option this is.
*
* @param context The context from which the option was fetched.
* @return Returns the identifier of the option.
*/
CAG_PUBLIC char cag_option_get(const cag_option_context *context);
/**
* @brief Gets the value from the option.
*
* This function gets the value from the option, if any. If the option does not
* contain a value, this function will return NULL.
*
* @param context The context from which the option was fetched.
* @return Returns a pointer to the value or NULL if there is no value.
*/
CAG_PUBLIC const char *cag_option_get_value(const cag_option_context *context);
/**
* @brief Gets the current index of the context.
*
* This function gets the index within the argv arguments of the context. The
* context always points to the next item which it will inspect. This is
* particularly useful to inspect the original argument array, or to get
* non-option arguments after option fetching has finished.
*
* @param context The context from which the option was fetched.
* @return Returns the current index of the context.
*/
CAG_PUBLIC int cag_option_get_index(const cag_option_context *context);
#ifdef __cplusplus
} // extern "C"
#endif
#endif
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