/* * UCW Library -- Parsing of command line options * * (c) 2013 Maria Matejka * (c) 2014 Martin Mares * (c) 2014 Pavel Charvat * * This software may be freely distributed and used according to the terms * of the GNU Lesser General Public License. */ #ifndef _UCW_OPT_H #define _UCW_OPT_H #include #include #include #include #include #ifdef CONFIG_UCW_CLEAN_ABI #define cf_def_file ucw_cf_def_file #define cf_env_file ucw_cf_env_file #define opt_conf_hook_internal ucw_opt_conf_hook_internal #define opt_failure ucw_opt_failure #define opt_handle_config ucw_opt_handle_config #define opt_handle_dumpconfig ucw_opt_handle_dumpconfig #define opt_handle_help ucw_opt_handle_help #define opt_handle_set ucw_opt_handle_set #define opt_help ucw_opt_help #define opt_parse ucw_opt_parse #endif #define OPT_EXIT_BAD_ARGS 2 /*** * [[classes]] * Option classes * -------------- * * Each option belongs to one of the following classes, which define * the overall behavior of the option. In most cases, the classes * are set automatically by <>. * * - `OPT_CL_END`: this is not a real option class, but a signal * that the list of options ends. * - `OPT_CL_BOOL`: a boolean option. If specified without an argument, * it sets the corresponding variable to 1 (true). So does an argument of * `1`, `y`, `yes`, or `true`. Conversely, an argument of `0`, `n`, `no`, * or `false` sets the variable to 0 (false) and the same happens if * the option is given as `--no-`'option' with no argument. * - `OPT_CL_STATIC`: options of this class just take a value and store * it in the variable. * - `OPT_CL_MULTIPLE`: collect values from all occurrences of this * option in a growing array (see `gary.h`). * - `OPT_CL_SWITCH`: a multiple-choice switch, which sets the variable * to a fixed value provided in option definition. * - `OPT_CL_INC`: increments the variable (or decrements, if the * `OPT_NEGATIVE` flag is set). * - `OPT_CL_CALL`: instead of setting a variable, call a function * and pass the value of the option to it. * - `OPT_CL_SECTION`: not a real option, but an instruction to insert * contents of another list of options. * - `OPT_CL_HELP`: no option, just print a help text. * - `OPT_CL_HOOK`: no option, but a definition of a <>. * - `OPT_CL_BREAK`: when a given option occurs, stop parsing and keep * the option in the argument list. ***/ enum opt_class { OPT_CL_END, OPT_CL_BOOL, OPT_CL_STATIC, OPT_CL_MULTIPLE, OPT_CL_SWITCH, OPT_CL_INC, OPT_CL_CALL, OPT_CL_SECTION, OPT_CL_HELP, OPT_CL_HOOK, OPT_CL_BREAK, }; /*** * [[opt_item]] * Option definitions * ------------------ * * The list of options is represented by `struct opt_section`, which points to * a sequence of `struct opt_item`s. * * These structures are seldom used directly -- instead, they are produced * by <>. ***/ /** A section of option list. **/ struct opt_section { const struct opt_item * opt; }; /** A definition of a single option item. **/ struct opt_item { const char * name; // long name (NULL if none) int letter; // short name (0 if none) void * ptr; // variable to store the value to const char * help; // description in --help (NULL to omit the option from the help) union opt_union { const struct opt_section * section; // subsection for OPT_CL_SECTION int value; // value for OPT_CL_SWITCH void (* call)(const struct opt_item * opt, const char * value, void * data); // function to call for OPT_CL_CALL void (* hook)(const struct opt_item * opt, uint event, const char * value, void * data); // function to call for OPT_CL_HOOK struct cf_user_type * utype; // specification of the user-defined type for CT_USER const struct xtype * xtype; // specification of the extended type for CT_XTYPE } u; u16 flags; // as defined below (for hooks, event mask is stored instead) byte cls; // enum opt_class byte type; // enum cf_type }; /*** * [[flags]] * Option flags * ------------ * * Each option can specify a combination of the following flags. ***/ #define OPT_REQUIRED 0x1 /** The option must be always present. **/ #define OPT_REQUIRED_VALUE 0x2 /** The option must have a value. **/ #define OPT_NO_VALUE 0x4 /** The option must have no value. **/ #define OPT_MAYBE_VALUE 0x8 /** The option may have a value. **/ #define OPT_NEGATIVE 0x10 /** Reversing the effect of OPT_INC or saving @false into OPT_BOOL. **/ #define OPT_LAST_ARG 0x40 /** Stop processing arguments after this line. **/ #define OPT_SINGLE 0x100 /** The option must appear at most once. **/ #define OPT_MULTIPLE 0x200 /** The option may appear multiple times; will save all the values into a simple list. **/ #define OPT_SEEN_AS_LONG 0x400 // Used internally to signal that we currently process the long form of the option #define OPT_BEFORE_CONFIG 0x800 /** The option may appear before a config file is loaded. **/ #define OPT_HELP_COL 0x1000 /** Used for OPT_CL_HELP to signal that tabs switch columns. **/ #define OPT_INTERNAL 0x4000 // Used internally to ask for passing of struct opt_context to OPT_CALL /** * If none of these flags are specified, a default is chosen automatically * according to option class: * * - `OPT_MAYBE_VALUE` for `OPT_CL_STATIC` * - `OPT_REQUIRED_VALUE` for `OPT_CL_MULTIPLE` * - `OPT_NO_VALUE` for `OPT_CL_BOOL`, `OPT_CL_SWITCH` and `OPT_CL_INC` * - An error is reported in all other cases. **/ #define OPT_VALUE_FLAGS (OPT_REQUIRED_VALUE | OPT_NO_VALUE | OPT_MAYBE_VALUE) /*** * [[macros]] * Macros for declaration of options * --------------------------------- * * In most cases, option definitions are built using these macros. ***/ /** Used inside `struct opt_section` to start a list of items. **/ #define OPT_ITEMS .opt = ( struct opt_item[] ) /** No option, just a piece of help text. **/ #define OPT_HELP(line) { .help = line, .cls = OPT_CL_HELP } /** Like OPT_HELP, but the help text uses tab characters to switch columns like help text for ordinary options does. **/ #define OPT_HELP_COLUMNS(line) { .help = line, .flags = OPT_HELP_COL, .cls = OPT_CL_HELP } /** Standard `--help` option. **/ #define OPT_HELP_OPTION OPT_CALL(0, "help", opt_handle_help, NULL, OPT_BEFORE_CONFIG | OPT_INTERNAL | OPT_NO_VALUE, "\tShow this help") /** Boolean option. @target should be a variable of type `int`. **/ #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 } /** String option. @target should be a variable of type `char *`. **/ #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 } /** Ordinary integer option. @target should be a variable of type `int`. **/ #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 } /** Unsigned integer option. @target should be a variable of type `uint`. **/ #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 } /** 64-bit integer option. @target should be a variable of type `u64`. **/ #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 } /** Floating-point option. @target should be a variable of type `double`. **/ #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 } /** IP address option, currently IPv4 only. @target should be a variable of type `u32`. **/ #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 } /** Multi-valued string option. @target should be a growing array of `char *`s. **/ #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 } /** Multi-valued integer option. @target should be a growing array of `int`s. **/ #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 } /** Multi-valued unsigned integer option. @target should be a growing array of `uint`s. **/ #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 } /** Multi-valued 64-bit integer option. @target should be a growing array of `u64`s. **/ #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 } /** Multi-valued floating-point option. @target should be a growing array of `double`s. **/ #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 } /** Multi-valued IPv4 address option. @target should be a growing array of `u32`s. **/ #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 } /** Switch option. @target should be a variable of type `int` and it will be set to the value @val. **/ #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 } /** Incrementing option. @target should be a variable of type `int`. **/ #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 } /** Breakpoint option. When this option occurs, parsing is terminated and the option is kept in the argument array. **/ #define OPT_BREAK(shortopt, longopt, fl) { .letter = shortopt, .name = longopt, .flags = fl, .cls = OPT_CL_BREAK } /* FIXME: Backwards compatibility only, should not be used anymore. */ #define OPT_UNS OPT_UINT #define OPT_UNS_MULTIPLE OPT_UINT_MULTIPLE /** * When this option appears, call the function @fn with parameters @item, @value, @data, * where @item points to the <> of this option, * @value contains the current argument of the option (NULL if there is none), * and @data is specified here. **/ #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 } /** * An option with user-defined syntax. @ttype is a <> * describing the syntax, @target is a variable of the corresponding type. If the @OPT_REQUIRED_VALUE * flag is not set, the parser must be able to parse a NULL value. **/ #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 } /** Multi-valued option of user-defined type. @target should be a growing array of the right kind of items. **/ #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 } /** * An option with user-defined syntax. @xtype is a <> * describing the syntax, @target is a variable of the corresponding type. If the @OPT_REQUIRED_VALUE * flag is not set, the parser must be able to parse a NULL value. **/ #define OPT_XTYPE(shortopt, longopt, target, ttype, fl, desc) { .letter = shortopt, .name = longopt, .ptr = &target, .u.xtype = &ttype, .flags = fl, .help = desc, .cls = OPT_CL_STATIC, .type = CT_XTYPE } /** Multi-valued option of extended type. @target should be a growing array of the right kind of items. **/ #define OPT_XTYPE_MULTIPLE(shortopt, longopt, target, ttype, fl, desc) { .letter = shortopt, .name = longopt, .ptr = &target, .u.xtype = &ttype, .flags = fl, .help = desc, .cls = OPT_CL_MULTIPLE, .type = CT_XTYPE } /** A sub-section. **/ #define OPT_SECTION(sec) { .cls = OPT_CL_SECTION, .u.section = &sec } /** Declares a <> to call upon any event from the specified set. **/ #define OPT_HOOK(fn, data, events) { .cls = OPT_CL_HOOK, .u.hook = fn, .flags = events, .ptr = data } /** A terminator signalling the end of the option list. **/ #define OPT_END { .cls = OPT_CL_END } /*** * [[positional]] * Positional arguments * -------------------- * * In addition to short and long options, the parser can also process 'positional * arguments', which don't start with a dash and whose meaning depends solely on * their position. * * Positional arguments are declared as options with short name `OPT_POSITIONAL(n)` * (where `n` is the position of the argument, starting with 1) and long name * NULL. To accept an arbitrary number of positional arguments, use * `OPT_POSITIONAL_TAIL` instead, which matches all arguments, for which no * `OPT_POSITIONAL` is defined. (In the latter case, you probably want to define * the argument as `OPT_MULTIPLE` or `OPT_CALL`, so that the values do not * overwrite each other.) * * Options and positional arguments can be mixed arbitrarily. When a `--` appears * as an argument, it is understood as a signal that all other arguments are * positional. * * `OPT_REQUIRED` can be used with positional arguments, but all required arguments * must come before the non-required ones. When `OPT_POSITIONAL_TAIL` is declared * required, it means that it must match at least once. * * Ordering of positional arguments within the list of options need not match * their positions. Holes in position numbering are inadvisable. ***/ #define OPT_POSITIONAL(n) (OPT_POSITIONAL_TAIL+(n)) #define OPT_POSITIONAL_TAIL 128 /*** * [[func]] * Functions * --------- ***/ /** * Parse all arguments, given in a NULL-terminated array of strings. * * Typically, this is called from `main(argc, argv)` as `opt_parse(options, argv+1)`, * skipping the 0th argument, which contains program name. * * Returns the number of arguments used (which need not be all of them * if `OPT_LAST_ARG` was encountered). * * The argument array is left untouched. * However, option values are not necessarily copied, the variables * set by the parser may point to the argument array. **/ int opt_parse(const struct opt_section * options, char ** argv); /** * Report parsing failure, suggest `--help`, and abort the program with * exit code 2. **/ void opt_failure(const char * mesg, ...) FORMAT_CHECK(printf,1,2) NONRET; void opt_help(const struct opt_section * sec); void opt_handle_help(const struct opt_item * opt, const char * value, void * data); /*** * [[conf]] * Cooperating with config file parser * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * Parsing of command-line options and configuration files are usually * intertwined in a somewhat tricky way. We want to provide command-line * options that control the name of the configuration file, or possibly to * override configuration settings from the command line. On the other hand, * regular command-line options can refer to values loaded from the * program's configuration. * * To achieve this goal, the option parser is able to cooperate with the * config file parser. This is enabled by listing the `OPT_CONF_OPTIONS` * macro in the list of command-line options. * * The following options are defined for you: * * - `-C` (`--config`) to load a specific configuration file. This option * suppresses loading of the default configuration, but it can be given * multiple times to merge settings from several files. * * - `-S` (`--set`) to include a part of configuration inline. For example, * you can use `-Ssection.item=value` to change a single configuration item. * * - `--dumpconfig` to dump the configuration to standard output and exit. * (This is available only if the program is compiled with `CONFIG_UCW_DEBUG`.) * * The default configuration file (as specified by <>) is loaded * as soon as the first option different from `-C` is encountered, unless * a different file has been already loaded. For this reason, `-C` must be * the very first argument given to the program. * * This interface supersedes <>. ***/ #ifdef CONFIG_UCW_DEBUG #define OPT_CONF_OPTIONS OPT_CONF_CONFIG, OPT_CONF_SET, OPT_CONF_DUMPCONFIG, OPT_CONF_HOOK #else #define OPT_CONF_OPTIONS OPT_CONF_CONFIG, OPT_CONF_SET, OPT_CONF_HOOK #endif #define OPT_CONF_CONFIG OPT_CALL('C', "config", opt_handle_config, NULL, OPT_BEFORE_CONFIG | OPT_INTERNAL | OPT_REQUIRED_VALUE, "\tOverride the default configuration file") #define OPT_CONF_SET OPT_CALL('S', "set", opt_handle_set, NULL, OPT_BEFORE_CONFIG | OPT_INTERNAL | OPT_REQUIRED_VALUE, "\tManual setting of a configuration item") #define OPT_CONF_DUMPCONFIG OPT_CALL(0, "dumpconfig", opt_handle_dumpconfig, NULL, OPT_INTERNAL | OPT_NO_VALUE, "\tDump program configuration") #define OPT_CONF_HOOK OPT_HOOK(opt_conf_hook_internal, NULL, OPT_HOOK_BEFORE_VALUE | OPT_HOOK_FINAL | OPT_HOOK_INTERNAL) void opt_handle_config(const struct opt_item * opt, const char * value, void * data); void opt_handle_set(const struct opt_item * opt, const char * value, void * data); void opt_handle_dumpconfig(const struct opt_item * opt, const char * value, void * data); void opt_conf_hook_internal(const struct opt_item * opt, uint event, const char * value, void * data); // XXX: This is duplicated with , but that one will hopefully go away one day. /** * The name of the default configuration file (NULL if configuration has been * already loaded). It is initialized to `CONFIG_UCW_DEFAULT_CONFIG`, but you * usually want to replace it by your own config file. */ extern char *cf_def_file; /** * Name of environment variable that can override what configuration is loaded. * Defaults to the value of the `CONFIG_UCW_ENV_VAR_CONFIG` compile-time option. **/ extern char *cf_env_file; /*** * [[hooks]] * Hooks * ----- * * You can supply hook functions, which will be called by the parser upon various * events. Hooks are declared as option items of class `OPT_CL_HOOK`, whose @flags * field specifies a mask of events the hook wants to receive. * * Please note that the hook interface is not considered stable yet, * so it might change in future versions of libucw. * * The following events are defined: ***/ #define OPT_HOOK_BEFORE_ARG 0x1 /** Call before option parsing **/ #define OPT_HOOK_BEFORE_VALUE 0x2 /** Call before value parsing **/ #define OPT_HOOK_AFTER_VALUE 0x4 /** Call after value parsing **/ #define OPT_HOOK_FINAL 0x8 /** Call just before @opt_parse() returns **/ #define OPT_HOOK_INTERNAL 0x4000 // Used internally to ask for passing of struct opt_context #endif