2 * UCW Library -- Parsing of command line options
4 * (c) 2013 Jan Moskyto Matejka <mq@ucw.cz>
5 * (c) 2014 Martin Mares <mj@ucw.cz>
6 * (c) 2014 Pavel Charvat <pchar@ucw.cz>
8 * This software may be freely distributed and used according to the terms
9 * of the GNU Lesser General Public License.
21 #ifdef CONFIG_UCW_CLEAN_ABI
22 #define cf_def_file ucw_cf_def_file
23 #define cf_env_file ucw_cf_env_file
24 #define opt_conf_hook_internal ucw_opt_conf_hook_internal
25 #define opt_failure ucw_opt_failure
26 #define opt_handle_config ucw_opt_handle_config
27 #define opt_handle_dumpconfig ucw_opt_handle_dumpconfig
28 #define opt_handle_help ucw_opt_handle_help
29 #define opt_handle_set ucw_opt_handle_set
30 #define opt_help ucw_opt_help
31 #define opt_parse ucw_opt_parse
34 #define OPT_EXIT_BAD_ARGS 2
41 * Each option belongs to one of the following classes, which define
42 * the overall behavior of the option. In most cases, the classes
43 * are set automatically by <<macros,declaration macros>>.
45 * - `OPT_CL_END`: this is not a real option class, but a signal
46 * that the list of options ends.
47 * - `OPT_CL_BOOL`: a boolean option. If specified without an argument,
48 * it sets the corresponding variable to 1 (true). So does an argument of
49 * `1`, `y`, `yes`, or `true`. Conversely, an argument of `0`, `n`, `no`,
50 * or `false` sets the variable to 0 (false) and the same happens if
51 * the option is given as `--no-`'option' with no argument.
52 * - `OPT_CL_STATIC`: options of this class just take a value and store
54 * - `OPT_CL_MULTIPLE`: collect values from all occurrences of this
55 * option in a growing array (see `gary.h`).
56 * - `OPT_CL_SWITCH`: a multiple-choice switch, which sets the variable
57 * to a fixed value provided in option definition.
58 * - `OPT_CL_INC`: increments the variable (or decrements, if the
59 * `OPT_NEGATIVE` flag is set).
60 * - `OPT_CL_CALL`: instead of setting a variable, call a function
61 * and pass the value of the option to it.
62 * - `OPT_CL_SECTION`: not a real option, but an instruction to insert
63 * contents of another list of options.
64 * - `OPT_CL_HELP`: no option, just print a help text.
65 * - `OPT_CL_HOOK`: no option, but a definition of a <<hooks,hook>>.
66 * - `OPT_CL_BREAK`: when a given option occurs, stop parsing and keep
67 * the option in the argument list.
89 * The list of options is represented by `struct opt_section`, which points to
90 * a sequence of `struct opt_item`s.
92 * These structures are seldom used directly -- instead, they are produced
93 * by <<macros,declaration macros>>.
96 /** A section of option list. **/
98 const struct opt_item * opt;
101 /** A definition of a single option item. **/
103 const char * name; // long name (NULL if none)
104 int letter; // short name (0 if none)
105 void * ptr; // variable to store the value to
106 const char * help; // description in --help (NULL to omit the option from the help)
108 const struct opt_section * section; // subsection for OPT_CL_SECTION
109 int value; // value for OPT_CL_SWITCH
110 void (* call)(const struct opt_item * opt, const char * value, void * data); // function to call for OPT_CL_CALL
111 void (* hook)(const struct opt_item * opt, uint event, const char * value, void * data); // function to call for OPT_CL_HOOK
112 struct cf_user_type * utype; // specification of the user-defined type for CT_USER
114 u16 flags; // as defined below (for hooks, event mask is stored instead)
115 byte cls; // enum opt_class
116 byte type; // enum cf_type
124 * Each option can specify a combination of the following flags.
127 #define OPT_REQUIRED 0x1 /** The option must be always present. **/
128 #define OPT_REQUIRED_VALUE 0x2 /** The option must have a value. **/
129 #define OPT_NO_VALUE 0x4 /** The option must have no value. **/
130 #define OPT_MAYBE_VALUE 0x8 /** The option may have a value. **/
131 #define OPT_NEGATIVE 0x10 /** Reversing the effect of OPT_INC or saving @false into OPT_BOOL. **/
132 #define OPT_LAST_ARG 0x40 /** Stop processing arguments after this line. **/
133 #define OPT_SINGLE 0x100 /** The option must appear at most once. **/
134 #define OPT_MULTIPLE 0x200 /** The option may appear multiple times; will save all the values into a simple list. **/
135 #define OPT_SEEN_AS_LONG 0x400 // Used internally to signal that we currently process the long form of the option
136 #define OPT_BEFORE_CONFIG 0x800 /** The option may appear before a config file is loaded. **/
137 #define OPT_INTERNAL 0x4000 // Used internally to ask for passing of struct opt_context to OPT_CALL
140 * If none of these flags are specified, a default is chosen automatically
141 * according to option class:
143 * - `OPT_MAYBE_VALUE` for `OPT_CL_STATIC`
144 * - `OPT_REQUIRED_VALUE` for `OPT_CL_MULTIPLE`
145 * - `OPT_NO_VALUE` for `OPT_CL_BOOL`, `OPT_CL_SWITCH` and `OPT_CL_INC`
146 * - An error is reported in all other cases.
148 #define OPT_VALUE_FLAGS (OPT_REQUIRED_VALUE | OPT_NO_VALUE | OPT_MAYBE_VALUE)
152 * Macros for declaration of options
153 * ---------------------------------
155 * In most cases, option definitions are built using these macros.
158 /** Used inside `struct opt_section` to start a list of items. **/
159 #define OPT_ITEMS .opt = ( struct opt_item[] )
161 /** No option, just a piece of help text. **/
162 #define OPT_HELP(line) { .help = line, .cls = OPT_CL_HELP }
164 /** Standard `--help` option. **/
165 #define OPT_HELP_OPTION OPT_CALL(0, "help", opt_handle_help, NULL, OPT_BEFORE_CONFIG | OPT_INTERNAL | OPT_NO_VALUE, "\tShow this help")
167 /** Boolean option. @target should be a variable of type `int`. **/
168 #define OPT_BOOL(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, int *), .help = desc, .flags = fl, .cls = OPT_CL_BOOL, .type = CT_INT }
170 /** String option. @target should be a variable of type `char *`. **/
171 #define OPT_STRING(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, char **), .help = desc, .flags = fl, .cls = OPT_CL_STATIC, .type = CT_STRING }
173 /** Ordinary integer option. @target should be a variable of type `int`. **/
174 #define OPT_INT(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, int *), .help = desc, .flags = fl, .cls = OPT_CL_STATIC, .type = CT_INT }
176 /** Unsigned integer option. @target should be a variable of type `uint`. **/
177 #define OPT_UINT(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, uint *), .help = desc, .flags = fl, .cls = OPT_CL_STATIC, .type = CT_INT }
179 /** 64-bit integer option. @target should be a variable of type `u64`. **/
180 #define OPT_U64(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, u64 *), .help = desc, .flags = fl, .cls = OPT_CL_STATIC, .type = CT_U64 }
182 /** Floating-point option. @target should be a variable of type `double`. **/
183 #define OPT_DOUBLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, double *), .help = desc, .flags = fl, .cls = OPT_CL_STATIC, .type = CT_DOUBLE }
185 /** IP address option, currently IPv4 only. @target should be a variable of type `u32`. **/
186 #define OPT_IP(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, u32 *), .help = desc, .flags = fl, .cls = OPT_CL_STATIC, .type = CT_IP }
188 /** Multi-valued string option. @target should be a growing array of `char *`s. **/
189 #define OPT_STRING_MULTIPLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, char ***), .help = desc, .flags = fl, .cls = OPT_CL_MULTIPLE, .type = CT_STRING }
191 /** Multi-valued integer option. @target should be a growing array of `int`s. **/
192 #define OPT_INT_MULTIPLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, int **), .help = desc, .flags = fl, .cls = OPT_CL_MULTIPLE, .type = CT_INT }
194 /** Multi-valued unsigned integer option. @target should be a growing array of `uint`s. **/
195 #define OPT_UINT_MULTIPLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, uint **), .help = desc, .flags = fl, .cls = OPT_CL_MULTIPLE, .type = CT_INT }
197 /** Multi-valued 64-bit integer option. @target should be a growing array of `u64`s. **/
198 #define OPT_U64_MULTIPLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, u64 **), .help = desc, .flags = fl, .cls = OPT_CL_MULTIPLE, .type = CT_U64 }
200 /** Multi-valued floating-point option. @target should be a growing array of `double`s. **/
201 #define OPT_DOUBLE_MULTIPLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, double **), .help = desc, .flags = fl, .cls = OPT_CL_MULTIPLE, .type = CT_DOUBLE }
203 /** Multi-valued IPv4 address option. @target should be a growing array of `u32`s. **/
204 #define OPT_IP_MULTIPLE(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, u32 **), .help = desc, .flags = fl, .cls = OPT_CL_MULTIPLE, .type = CT_IP }
206 /** Switch option. @target should be a variable of type `int` and it will be set to the value @val. **/
207 #define OPT_SWITCH(shortopt, longopt, target, val, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, int *), .help = desc, .flags = fl, .cls = OPT_CL_SWITCH, .type = CT_LOOKUP, .u.value = val }
209 /** Incrementing option. @target should be a variable of type `int`. **/
210 #define OPT_INC(shortopt, longopt, target, fl, desc) { .letter = shortopt, .name = longopt, .ptr = CHECK_PTR_TYPE(&target, int *), .flags = fl, .help = desc, .cls = OPT_CL_INC, .type = CT_INT }
212 /** Breakpoint option. When this option occurs, parsing is terminated and the option is kept in the argument array. **/
213 #define OPT_BREAK(shortopt, longopt, fl) { .letter = shortopt, .name = longopt, .flags = fl, .cls = OPT_CL_BREAK }
215 /* FIXME: Backwards compatibility only, should not be used anymore. */
216 #define OPT_UNS OPT_UINT
217 #define OPT_UNS_MULTIPLE OPT_UINT_MULTIPLE
221 * When this option appears, call the function @fn with parameters @item, @value, @data,
222 * where @item points to the <<struct_opt_item,`struct opt_item`>> of this option,
223 * @value contains the current argument of the option (NULL if there is none),
224 * and @data is specified here.
226 #define OPT_CALL(shortopt, longopt, fn, data, fl, desc) { .letter = shortopt, .name = longopt, .ptr = data, .help = desc, .u.call = fn, .flags = fl, .cls = OPT_CL_CALL, .type = CT_USER }
229 * An option with user-defined syntax. @ttype is a <<conf:struct_cf_user_type,`cf_user_type`>>
230 * describing the syntax, @target is a variable of the corresponding type. If the @OPT_REQUIRED_VALUE
231 * flag is not set, the parser must be able to parse a NULL value.
233 #define OPT_USER(shortopt, longopt, target, ttype, fl, desc) { .letter = shortopt, .name = longopt, .ptr = &target, .u.utype = &ttype, .flags = fl, .help = desc, .cls = OPT_CL_STATIC, .type = CT_USER }
235 /** Multi-valued option of user-defined type. @target should be a growing array of the right kind of items. **/
236 #define OPT_USER_MULTIPLE(shortopt, longopt, target, ttype, fl, desc) { .letter = shortopt, .name = longopt, .ptr = &target, .u.utype = &ttype, .flags = fl, .help = desc, .cls = OPT_CL_MULTIPLE, .type = CT_USER }
238 /** A sub-section. **/
239 #define OPT_SECTION(sec) { .cls = OPT_CL_SECTION, .u.section = &sec }
241 /** Declares a <<hooks,hook>> to call upon any event from the specified set. **/
242 #define OPT_HOOK(fn, data, events) { .cls = OPT_CL_HOOK, .u.hook = fn, .flags = events, .ptr = data }
244 /** A terminator signalling the end of the option list. **/
245 #define OPT_END { .cls = OPT_CL_END }
249 * Positional arguments
250 * --------------------
252 * In addition to short and long options, the parser can also process 'positional
253 * arguments', which don't start with a dash and whose meaning depends solely on
256 * Positional arguments are declared as options with short name `OPT_POSITIONAL(n)`
257 * (where `n` is the position of the argument, starting with 1) and long name
258 * NULL. To accept an arbitrary number of positional arguments, use
259 * `OPT_POSITIONAL_TAIL` instead, which matches all arguments, for which no
260 * `OPT_POSITIONAL` is defined. (In the latter case, you probably want to define
261 * the argument as `OPT_MULTIPLE` or `OPT_CALL`, so that the values do not
262 * overwrite each other.)
264 * Options and positional arguments can be mixed arbitrarily. When a `--` appears
265 * as an argument, it is understood as a signal that all other arguments are
268 * `OPT_REQUIRED` can be used with positional arguments, but all required arguments
269 * must come before the non-required ones. When `OPT_POSITIONAL_TAIL` is declared
270 * required, it means that it must match at least once.
272 * Ordering of positional arguments within the list of options need not match
273 * their positions. Holes in position numbering are inadvisable.
276 #define OPT_POSITIONAL(n) (OPT_POSITIONAL_TAIL+(n))
277 #define OPT_POSITIONAL_TAIL 128
286 * Parse all arguments, given in a NULL-terminated array of strings.
288 * Typically, this is called from `main(argc, argv)` as `opt_parse(options, argv+1)`,
289 * skipping the 0th argument, which contains program name.
291 * Returns the number of arguments used (which need not be all of them
292 * if `OPT_LAST_ARG` was encountered).
294 * The argument array is left untouched.
295 * However, option values are not necessarily copied, the variables
296 * set by the parser may point to the argument array.
298 int opt_parse(const struct opt_section * options, char ** argv);
301 * Report parsing failure, suggest `--help`, and abort the program with
304 void opt_failure(const char * mesg, ...) FORMAT_CHECK(printf,1,2) NONRET;
306 void opt_help(const struct opt_section * sec);
307 void opt_handle_help(const struct opt_item * opt, const char * value, void * data);
311 * Cooperating with config file parser
312 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
314 * Parsing of command-line options and configuration files are usually
315 * intertwined in a somewhat tricky way. We want to provide command-line
316 * options that control the name of the configuration file, or possibly to
317 * override configuration settings from the command line. On the other hand,
318 * regular command-line options can refer to values loaded from the
319 * program's configuration.
321 * To achieve this goal, the option parser is able to cooperate with the
322 * config file parser. This is enabled by listing the `OPT_CONF_OPTIONS`
323 * macro in the list of command-line options.
325 * The following options are defined for you:
327 * - `-C` (`--config`) to load a specific configuration file. This option
328 * suppresses loading of the default configuration, but it can be given
329 * multiple times to merge settings from several files.
331 * - `-S` (`--set`) to include a part of configuration inline. For example,
332 * you can use `-Ssection.item=value` to change a single configuration item.
334 * - `--dumpconfig` to dump the configuration to standard output and exit.
335 * (This is available only if the program is compiled with `CONFIG_UCW_DEBUG`.)
337 * The default configuration file (as specified by <<var_cf_def_file,`cf_def_file`>>) is loaded
338 * as soon as the first option different from `-C` is encountered, unless
339 * a different file has been already loaded. For this reason, `-C` must be
340 * the very first argument given to the program.
342 * This interface supersedes <<conf:getopt_h,`cf_getopt()`>>.
345 #ifdef CONFIG_UCW_DEBUG
346 #define OPT_CONF_OPTIONS OPT_CONF_CONFIG, OPT_CONF_SET, OPT_CONF_DUMPCONFIG, OPT_CONF_HOOK
348 #define OPT_CONF_OPTIONS OPT_CONF_CONFIG, OPT_CONF_SET, OPT_CONF_HOOK
351 #define OPT_CONF_CONFIG OPT_CALL('C', "config", opt_handle_config, NULL, OPT_BEFORE_CONFIG | OPT_INTERNAL | OPT_REQUIRED_VALUE, "<file>\tOverride the default configuration file")
352 #define OPT_CONF_SET OPT_CALL('S', "set", opt_handle_set, NULL, OPT_BEFORE_CONFIG | OPT_INTERNAL | OPT_REQUIRED_VALUE, "<item>\tManual setting of a configuration item")
353 #define OPT_CONF_DUMPCONFIG OPT_CALL(0, "dumpconfig", opt_handle_dumpconfig, NULL, OPT_INTERNAL | OPT_NO_VALUE, "\tDump program configuration")
354 #define OPT_CONF_HOOK OPT_HOOK(opt_conf_hook_internal, NULL, OPT_HOOK_BEFORE_VALUE | OPT_HOOK_FINAL | OPT_HOOK_INTERNAL)
356 void opt_handle_config(const struct opt_item * opt, const char * value, void * data);
357 void opt_handle_set(const struct opt_item * opt, const char * value, void * data);
358 void opt_handle_dumpconfig(const struct opt_item * opt, const char * value, void * data);
359 void opt_conf_hook_internal(const struct opt_item * opt, uint event, const char * value, void * data);
361 // XXX: This is duplicated with <ucw/getopt.h>, but that one will hopefully go away one day.
363 * The name of the default configuration file (NULL if configuration has been
364 * already loaded). It is initialized to `CONFIG_UCW_DEFAULT_CONFIG`, but you
365 * usually want to replace it by your own config file.
367 extern char *cf_def_file;
369 * Name of environment variable that can override what configuration is loaded.
370 * Defaults to the value of the `CONFIG_UCW_ENV_VAR_CONFIG` compile-time option.
372 extern char *cf_env_file;
379 * You can supply hook functions, which will be called by the parser upon various
380 * events. Hooks are declared as option items of class `OPT_CL_HOOK`, whose @flags
381 * field specifies a mask of events the hook wants to receive.
383 * Please note that the hook interface is not considered stable yet,
384 * so it might change in future versions of libucw.
386 * The following events are defined:
389 #define OPT_HOOK_BEFORE_ARG 0x1 /** Call before option parsing **/
390 #define OPT_HOOK_BEFORE_VALUE 0x2 /** Call before value parsing **/
391 #define OPT_HOOK_AFTER_VALUE 0x4 /** Call after value parsing **/
392 #define OPT_HOOK_FINAL 0x8 /** Call just before @opt_parse() returns **/
393 #define OPT_HOOK_INTERNAL 0x4000 // Used internally to ask for passing of struct opt_context