Merge remote-tracking branch 'Kernel/master'

Kernel/include/cargs.h

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+/*
+MIT License
+
+Copyright (c) 2022 Leonard Iklé
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#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 <types.h>
+
+typedef unsigned int FILE; // TODO: Implement FILE
+
+#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