--- /dev/null
+#ifndef CCAN_OPT_H
+#define CCAN_OPT_H
+#include <ccan/typesafe_cb/typesafe_cb.h>
+#include <stdbool.h>
+
+/* You can use this directly to build tables, but the macros will ensure
+ * consistency and type safety. */
+enum opt_flags {
+ OPT_NOARG = 1, /* -f/--foo */
+ OPT_HASARG = 2, /* -f arg/--foo=arg/--foo arg */
+ OPT_SUBTABLE = 4, /* Actually, longopt points to a subtable... */
+ OPT_END = 8, /* End of the table. */
+};
+
+struct opt_table {
+ const char *longopt; /* --longopt, or NULL */
+ char shortopt; /* -s, or 0 */
+ enum opt_flags flags;
+ char *(*cb)(void *arg); /* OPT_NOARG */
+ char *(*cb_arg)(const char *optarg, void *arg); /* OPT_HASARG */
+ void *arg;
+ const char *desc;
+};
+
+/**
+ * OPT_WITHOUT_ARG() - macro for initializing an opt_table entry (without arg)
+ * @longopt: the name of the argument (eg. "foo" for "--foo"), or NULL.
+ * @shortopt: the character of the argument (eg. 'f' for "-f"), or 0.
+ * @cb: the callback when the option is found.
+ * @arg: the argument to hand to @cb.
+ *
+ * This is a typesafe wrapper for intializing a struct opt_table. The callback
+ * of type "char *cb(type *)", "char *cb(const type *)" or "char *cb(void *)",
+ * where "type" is the type of the @arg argument.
+ *
+ * At least one of @longopt and @shortopt must be non-zero. If the
+ * @cb returns non-NULL, opt_parse() will stop parsing, use the returned
+ * string to form an error message, free() the string and return false.
+ *
+ * See Also:
+ * OPT_WITH_ARG()
+ */
+#define OPT_WITHOUT_ARG(longopt, shortopt, cb, arg) \
+ (longopt), (shortopt), OPT_CB_NOARG((cb), (arg))
+
+/**
+ * OPT_WITH_ARG() - macro for initializing long and short option (with arg)
+ * @longopt: the name of the argument (eg. "foo" for "--foo <arg>"), or NULL.
+ * @shortopt: the character of the argument (eg. 'f' for "-f <arg>"), or 0.
+ * @cb: the callback when the option is found (along with <arg>).
+ * @arg: the argument to hand to @cb.
+ *
+ * This is a typesafe wrapper for intializing a struct opt_table. The callback
+ * is of type "bool cb(const char *, type *)",
+ * "bool cb(const char *, const type *)" or "bool cb(const char *, void *)",
+ * where "type" is the type of the @arg argument. The first argument to the
+ * @cb is the argument found on the commandline.
+ *
+ * At least one of @longopt and @shortopt must be non-zero. If the
+ * @cb returns false, opt_parse() will stop parsing and return false.
+ *
+ * See Also:
+ * OPT_WITH_ARG()
+ */
+#define OPT_WITH_ARG(longopt, shortopt, cb, arg) \
+ (longopt), (shortopt), OPT_CB_ARG((cb), (arg))
+
+/**
+ * OPT_SUBTABLE() - macro for including another table inside a table.
+ * @table: the table to include in this table.
+ * @desc: description of this subtable (for opt_usage()) or NULL.
+ *
+ * The @desc field can be opt_table_hidden to hide the options from opt_usage().
+ */
+#define OPT_SUBTABLE(table, desc) \
+ { (const char *)(table), sizeof(_check_is_entry(table)), \
+ OPT_SUBTABLE, NULL, NULL, NULL, (desc) }
+
+/**
+ * opt_table_hidden - string for undocumented option tables.
+ *
+ * This can be used as the desc option to OPT_SUBTABLE or passed to
+ * opt_register_table() if you want the options not to be shown by
+ * opt_usage().
+ */
+extern const char opt_table_hidden[];
+
+/**
+ * OPT_ENDTABLE - macro to create final entry in table.
+ *
+ * This must be the final element in the opt_table array.
+ */
+#define OPT_ENDTABLE { NULL, 0, OPT_END }
+
+/**
+ * opt_register_table - register a table of options
+ * @table: the table of options
+ * @desc: description of this subtable (for opt_usage()) or NULL.
+ *
+ * The table must be terminated by OPT_ENDTABLE.
+ *
+ * Example:
+ * static struct opt_table opts[] = {
+ * { OPT_WITHOUT_ARG("verbose", 'v', opt_inc_intval, &verbose),
+ * "Verbose mode (can be specified more than once)" },
+ * { OPT_WITHOUT_ARG("usage", 0, opt_usage_and_exit,
+ * "args...\nA silly test program."),
+ * "Print this message." },
+ * OPT_ENDTABLE
+ * };
+ *
+ * ...
+ * opt_register_table(opts, NULL);
+ */
+void opt_register_table(const struct opt_table table[], const char *desc);
+
+/**
+ * opt_register_noarg - register an option with no arguments
+ * @longopt: the name of the argument (eg. "foo" for "--foo"), or NULL.
+ * @shortopt: the character of the argument (eg. 'f' for "-f"), or 0.
+ * @cb: the callback when the option is found.
+ * @arg: the argument to hand to @cb.
+ * @desc: the verbose desction of the option (for opt_usage()), or NULL.
+ *
+ * This is used for registering a single commandline option which takes
+ * no argument.
+ *
+ * The callback is of type "bool cb(type *)", "bool cb(const type *)"
+ * or "bool cb(void *)", where "type" is the type of the @arg
+ * argument.
+ *
+ * At least one of @longopt and @shortopt must be non-zero. If the
+ * @cb returns false, opt_parse() will stop parsing and return false.
+ */
+#define opt_register_noarg(longopt, shortopt, cb, arg, desc) \
+ _opt_register((longopt), (shortopt), OPT_CB_NOARG((cb), (arg)), (desc))
+
+/**
+ * opt_register_arg - register an option with an arguments
+ * @longopt: the name of the argument (eg. "foo" for "--foo"), or NULL.
+ * @shortopt: the character of the argument (eg. 'f' for "-f"), or 0.
+ * @cb: the callback when the option is found.
+ * @arg: the argument to hand to @cb.
+ * @desc: the verbose desction of the option (for opt_usage()), or NULL.
+ *
+ * This is used for registering a single commandline option which takes
+ * an argument.
+ *
+ * The callback is of type "bool cb(const char *, type *)",
+ * "bool cb(const char *, const type *)" or "bool cb(const char *, void *)",
+ * where "type" is the type of the @arg argument. The first argument to the
+ * @cb is the argument found on the commandline.
+ *
+ * At least one of @longopt and @shortopt must be non-zero. If the
+ * @cb returns false, opt_parse() will stop parsing and return false.
+ *
+ * Example:
+ * opt_register_arg("explode", 'e', explode_cb, NULL,
+ * "Make the machine explode (developers only)");
+ */
+#define opt_register_arg(longopt, shortopt, cb, arg, desc) \
+ _opt_register((longopt), (shortopt), OPT_CB_ARG((cb), (arg)), (desc))
+
+/**
+ * opt_parse - parse arguments.
+ * @argc: pointer to argc
+ * @argv: argv array.
+ * @errlog: the function to print errors (usually opt_log_stderr).
+ *
+ * This iterates through the command line and calls callbacks registered with
+ * opt_register_table()/opt_register_arg()/opt_register_noarg(). If there
+ * are unknown options, missing arguments or a callback returns false, then
+ * an error message is printed and false is returned.
+ *
+ * On success, argc and argv are adjusted so only the non-option elements
+ * remain, and true is returned.
+ *
+ * Example:
+ * if (!opt_parse(argc, argv, opt_log_stderr)) {
+ * printf("%s", opt_usage(argv[0], "<args>..."));
+ * exit(1);
+ * }
+ */
+bool opt_parse(int *argc, char *argv[], void (*errlog)(const char *fmt, ...));
+
+/**
+ * opt_log_stderr - print message to stderr.
+ * @fmt: printf-style format.
+ *
+ * This is the standard helper for opt_parse, to print errors.
+ */
+void opt_log_stderr(const char *fmt, ...);
+
+/**
+ * opt_invalid_argument - helper to allocate an "Invalid argument '%s'" string
+ * @arg: the argument which was invalid.
+ *
+ * This is a helper for callbacks to return a simple error string.
+ */
+char *opt_invalid_argument(const char *arg);
+
+/**
+ * opt_usage - create usage message
+ * @argv0: the program name
+ * @extra: extra details to print after the initial command, or NULL.
+ *
+ * Creates a usage message, with the program name, arguments, some extra details
+ * and a table of all the options with their descriptions.
+ *
+ * The result should be passed to free().
+ */
+char *opt_usage(const char *argv0, const char *extra);
+
+/* Standard helpers. You can write your own: */
+/* Sets the @b to true. */
+char *opt_set_bool(bool *b);
+/* Sets @b based on arg: (yes/no/true/false). */
+char *opt_set_bool_arg(const char *arg, bool *b);
+/* The inverse */
+char *opt_set_invbool(bool *b);
+char *opt_set_invbool_arg(const char *arg, bool *b);
+
+/* Set a char *. */
+char *opt_set_charp(const char *arg, char **p);
+
+/* Set an integer value, various forms. Sets to 1 on arg == NULL. */
+char *opt_set_intval(const char *arg, int *i);
+char *opt_set_uintval(const char *arg, unsigned int *ui);
+char *opt_set_longval(const char *arg, long *l);
+char *opt_set_ulongval(const char *arg, unsigned long *ul);
+
+/* Increment. */
+char *opt_inc_intval(int *i);
+
+/* Display version string to stdout, exit(0). */
+char *opt_show_version_and_exit(const char *version);
+
+/* Display usage string to stdout, exit(0). */
+char *opt_usage_and_exit(const char *extra);
+
+/* Below here are private declarations. */
+/* Resolves to the four parameters for non-arg callbacks. */
+#define OPT_CB_NOARG(cb, arg) \
+ OPT_NOARG, \
+ cast_if_any(char *(*)(void *), (cb), &*(cb), \
+ char *(*)(typeof(*(arg))*), \
+ char *(*)(const typeof(*(arg))*), \
+ char *(*)(const typeof(*(arg))*)), \
+ NULL, (arg)
+
+/* Resolves to the four parameters for arg callbacks. */
+#define OPT_CB_ARG(cb, arg) \
+ OPT_HASARG, NULL, \
+ cast_if_any(char *(*)(const char *,void *), (cb), &*(cb), \
+ char *(*)(const char *, typeof(*(arg))*), \
+ char *(*)(const char *, const typeof(*(arg))*), \
+ char *(*)(const char *, const typeof(*(arg))*)), \
+ (arg)
+
+/* Non-typesafe register function. */
+void _opt_register(const char *longopt, char shortopt, enum opt_flags flags,
+ char *(*cb)(void *arg),
+ char *(*cb_arg)(const char *optarg, void *arg),
+ void *arg, const char *desc);
+
+/* We use this to get typechecking for OPT_SUBTABLE */
+static inline int _check_is_entry(struct opt_table *e) { return 0; }
+
+#endif /* CCAN_OPT_H */