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ebusd/src/lib/utils/arg.h
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/*
* ebusd - daemon for communication with eBUS heating systems.
* Copyright (C) 2023 John Baier <ebusd@ebusd.eu>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LIB_UTILS_ARG_H_
#define LIB_UTILS_ARG_H_
namespace ebusd {
/** \file lib/utils/args.h */
/** the available arg flags. */
enum ArgFlag {
af_optional = 1<<0, //!< optional argument value
af_multiple = 1<<1, //!< may appear multiple times (only allowed for last positional)
af_noHelp = 1<<2, //!< do not include -?/--help option
af_noVersion = 1<<3, //!< do not include -V/--version option
};
/** Definition of a single argument. */
typedef struct argDef {
const char* name; //!< the (long) name of the argument, or nullptr for a group header or positional
int key; //!< the argument key, also used as short name if alphabetic or the question mark
const char* valueName; //!< the optional argument value name, or nullptr for group header or argument without value name
int flags; //!< flags for the argument, bit combination of @a ArgFlag
const char* help; //!< help text (mandatory)
} argDef;
struct argParseOpt;
/**
* Function to be called for each argument.
* @param key the argument key as defined. for positional arguments with multiple flag this will be increased with each call.
* @param arg the argument value, or nullptr.
* @param parseOpt pointer to the @a argParseOpt structure.
* @param userArg pointer to user argument.
* @return 0 on success, non-zero otherwise.
*/
typedef int (*parse_function_t)(int key, char *arg, const struct argParseOpt *parseOpt, void *userArg);
/** Options for child definitions. */
typedef struct argParseChildOpt {
const argDef *argDefs; //!< pointer to the argument defintions (last one needs to have nullptr help as end sign)
parse_function_t parser; //!< parse function to use
} argParseChildOpt;
/** Options to pass to @a argParse(). */
typedef struct argParseOpt {
const argDef *argDefs; //!< pointer to the argument defintions (last one needs to have nullptr help as end sign)
parse_function_t parser; //!< parse function to use
int flags; //!< flags for the parser, bit combination of @a ArgFlag
const char* help; //!< help text for the program (second line of help output)
const char* suffix; //!< optional help suffix text
const argParseChildOpt *childOpts; //!< optional child definitions
} argParseOpt;
/**
* Parse the arguments given in @a argv.
* @param parseOpt pointer to the @a argParseOpt structure.
* @param argc the argument count (including the full program name in index 0).
* @param argv the argument values (including the full program name in index 0).
* @param userArg pointer to user argument to pass to parser.
* @return 0 on success, '!' for an invalid argument value, ':' for a missing argument value,
* '?' when "-?" was given, or the result of the parse function if non-zero.
*/
int argParse(const argParseOpt *parseOpt, int argc, char **argv, void *userArg);
/**
* Print the help text.
* @param name the name of the program.
* @param parseOpt pointer to the @a argParseOpt structure.
*/
void argHelp(const char* name, const argParseOpt *parseOpt);
/**
* Convenience macro to print an error message to stderr.
*/
#define argParseError(argParseOpt, message) fprintf(stderr, "%s\n", message);
} // namespace ebusd
#endif // LIB_UTILS_ARG_H_