From 2cb3c3df4099297b0a0554bb482e2de04fe86b5c Mon Sep 17 00:00:00 2001 From: sanine Date: Wed, 24 Aug 2022 00:02:17 -0500 Subject: add command-line arguments --- libs/cargs/include/cargs.h | 162 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 libs/cargs/include/cargs.h (limited to 'libs/cargs/include') diff --git a/libs/cargs/include/cargs.h b/libs/cargs/include/cargs.h new file mode 100644 index 0000000..17cba0a --- /dev/null +++ b/libs/cargs/include/cargs.h @@ -0,0 +1,162 @@ +#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 +#include +#include + +#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 -- cgit v1.2.1