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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * getopt.h - a simple getopt(3) implementation.
- *
- * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
- * Copyright (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
- */
- #ifndef __GETOPT_H
- #define __GETOPT_H
- /**
- * struct getopt_state - Saved state across getopt() calls
- */
- struct getopt_state {
- /**
- * @index: Index of the next unparsed argument of @argv. If getopt() has
- * parsed all of @argv, then @index will equal @argc.
- */
- int index;
- /* private: */
- /** @arg_index: Index within the current argument */
- int arg_index;
- union {
- /* public: */
- /**
- * @opt: Option being parsed when an error occurs. @opt is only
- * valid when getopt() returns ``?`` or ``:``.
- */
- int opt;
- /**
- * @arg: The argument to an option, NULL if there is none. @arg
- * is only valid when getopt() returns an option character.
- */
- char *arg;
- /* private: */
- };
- };
- /**
- * getopt_init_state() - Initialize a &struct getopt_state
- * @gs: The state to initialize
- *
- * This must be called before using @gs with getopt().
- */
- void getopt_init_state(struct getopt_state *gs);
- int __getopt(struct getopt_state *gs, int argc, char *const argv[],
- const char *optstring, bool silent);
- /**
- * getopt() - Parse short command-line options
- * @gs: Internal state and out-of-band return arguments. This must be
- * initialized with getopt_init_context() beforehand.
- * @argc: Number of arguments, not including the %NULL terminator
- * @argv: Argument list, terminated by %NULL
- * @optstring: Option specification, as described below
- *
- * getopt() parses short options. Short options are single characters. They may
- * be followed by a required argument or an optional argument. Arguments to
- * options may occur in the same argument as an option (like ``-larg``), or
- * in the following argument (like ``-l arg``). An argument containing
- * options begins with a ``-``. If an option expects no arguments, then it may
- * be immediately followed by another option (like ``ls -alR``).
- *
- * @optstring is a list of accepted options. If an option is followed by ``:``
- * in @optstring, then it expects a mandatory argument. If an option is followed
- * by ``::`` in @optstring, it expects an optional argument. @gs.arg points
- * to the argument, if one is parsed.
- *
- * getopt() stops parsing options when it encounters the first non-option
- * argument, when it encounters the argument ``--``, or when it runs out of
- * arguments. For example, in ``ls -l foo -R``, option parsing will stop when
- * getopt() encounters ``foo``, if ``l`` does not expect an argument. However,
- * the whole list of arguments would be parsed if ``l`` expects an argument.
- *
- * An example invocation of getopt() might look like::
- *
- * char *argv[] = { "program", "-cbx", "-a", "foo", "bar", 0 };
- * int opt, argc = ARRAY_SIZE(argv) - 1;
- * struct getopt_state gs;
- *
- * getopt_init_state(&gs);
- * while ((opt = getopt(&gs, argc, argv, "a::b:c")) != -1)
- * printf("opt = %c, index = %d, arg = \"%s\"\n", opt, gs.index, gs.arg);
- * printf("%d argument(s) left\n", argc - gs.index);
- *
- * and would produce an output of::
- *
- * opt = c, index = 1, arg = "<NULL>"
- * opt = b, index = 2, arg = "x"
- * opt = a, index = 4, arg = "foo"
- * 1 argument(s) left
- *
- * For further information, refer to the getopt(3) man page.
- *
- * Return:
- * * An option character if an option is found. @gs.arg is set to the
- * argument if there is one, otherwise it is set to ``NULL``.
- * * ``-1`` if there are no more options, if a non-option argument is
- * encountered, or if an ``--`` argument is encountered.
- * * ``'?'`` if we encounter an option not in @optstring. @gs.opt is set to
- * the unknown option.
- * * ``':'`` if an argument is required, but no argument follows the
- * option. @gs.opt is set to the option missing its argument.
- *
- * @gs.index is always set to the index of the next unparsed argument in @argv.
- */
- static inline int getopt(struct getopt_state *gs, int argc,
- char *const argv[], const char *optstring)
- {
- return __getopt(gs, argc, argv, optstring, false);
- }
- /**
- * getopt_silent() - Parse short command-line options silently
- * @gs: State
- * @argc: Argument count
- * @argv: Argument list
- * @optstring: Option specification
- *
- * Same as getopt(), except no error messages are printed.
- */
- static inline int getopt_silent(struct getopt_state *gs, int argc,
- char *const argv[], const char *optstring)
- {
- return __getopt(gs, argc, argv, optstring, true);
- }
- #endif /* __GETOPT_H */
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