parse-options.hon commit archive: refactor file extension format-guessing (08716b3)
   1#ifndef PARSE_OPTIONS_H
   2#define PARSE_OPTIONS_H
   3
   4enum parse_opt_type {
   5        /* special types */
   6        OPTION_END,
   7        OPTION_ARGUMENT,
   8        OPTION_GROUP,
   9        OPTION_NUMBER,
  10        /* options with no arguments */
  11        OPTION_BIT,
  12        OPTION_NEGBIT,
  13        OPTION_BOOLEAN, /* _INCR would have been a better name */
  14        OPTION_SET_INT,
  15        OPTION_SET_PTR,
  16        /* options with arguments (usually) */
  17        OPTION_STRING,
  18        OPTION_INTEGER,
  19        OPTION_CALLBACK,
  20        OPTION_LOWLEVEL_CALLBACK,
  21        OPTION_FILENAME
  22};
  23
  24enum parse_opt_flags {
  25        PARSE_OPT_KEEP_DASHDASH = 1,
  26        PARSE_OPT_STOP_AT_NON_OPTION = 2,
  27        PARSE_OPT_KEEP_ARGV0 = 4,
  28        PARSE_OPT_KEEP_UNKNOWN = 8,
  29        PARSE_OPT_NO_INTERNAL_HELP = 16
  30};
  31
  32enum parse_opt_option_flags {
  33        PARSE_OPT_OPTARG  = 1,
  34        PARSE_OPT_NOARG   = 2,
  35        PARSE_OPT_NONEG   = 4,
  36        PARSE_OPT_HIDDEN  = 8,
  37        PARSE_OPT_LASTARG_DEFAULT = 16,
  38        PARSE_OPT_NODASH = 32,
  39        PARSE_OPT_LITERAL_ARGHELP = 64,
  40        PARSE_OPT_NEGHELP = 128,
  41        PARSE_OPT_SHELL_EVAL = 256
  42};
  43
  44struct option;
  45typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
  46
  47struct parse_opt_ctx_t;
  48typedef int parse_opt_ll_cb(struct parse_opt_ctx_t *ctx,
  49                                const struct option *opt, int unset);
  50
  51/*
  52 * `type`::
  53 *   holds the type of the option, you must have an OPTION_END last in your
  54 *   array.
  55 *
  56 * `short_name`::
  57 *   the character to use as a short option name, '\0' if none.
  58 *
  59 * `long_name`::
  60 *   the long option name, without the leading dashes, NULL if none.
  61 *
  62 * `value`::
  63 *   stores pointers to the values to be filled.
  64 *
  65 * `argh`::
  66 *   token to explain the kind of argument this option wants. Keep it
  67 *   homogeneous across the repository.
  68 *
  69 * `help`::
  70 *   the short help associated to what the option does.
  71 *   Must never be NULL (except for OPTION_END).
  72 *   OPTION_GROUP uses this pointer to store the group header.
  73 *
  74 * `flags`::
  75 *   mask of parse_opt_option_flags.
  76 *   PARSE_OPT_OPTARG: says that the argument is optional (not for BOOLEANs)
  77 *   PARSE_OPT_NOARG: says that this option does not take an argument
  78 *   PARSE_OPT_NONEG: says that this option cannot be negated
  79 *   PARSE_OPT_HIDDEN: this option is skipped in the default usage, and
  80 *                     shown only in the full usage.
  81 *   PARSE_OPT_LASTARG_DEFAULT: says that this option will take the default
  82 *                              value if no argument is given when the option
  83 *                              is last on the command line. If the option is
  84 *                              not last it will require an argument.
  85 *                              Should not be used with PARSE_OPT_OPTARG.
  86 *   PARSE_OPT_NODASH: this option doesn't start with a dash.
  87 *   PARSE_OPT_LITERAL_ARGHELP: says that argh shouldn't be enclosed in brackets
  88 *                              (i.e. '<argh>') in the help message.
  89 *                              Useful for options with multiple parameters.
  90 *   PARSE_OPT_NEGHELP: says that the long option should always be shown with
  91 *                              the --no prefix in the usage message. Sometimes
  92 *                              useful for users of OPTION_NEGBIT.
  93 *
  94 * `callback`::
  95 *   pointer to the callback to use for OPTION_CALLBACK or
  96 *   OPTION_LOWLEVEL_CALLBACK.
  97 *
  98 * `defval`::
  99 *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
 100 *   OPTION_{BIT,SET_INT,SET_PTR} store the {mask,integer,pointer} to put in
 101 *   the value when met.
 102 *   CALLBACKS can use it like they want.
 103 */
 104struct option {
 105        enum parse_opt_type type;
 106        int short_name;
 107        const char *long_name;
 108        void *value;
 109        const char *argh;
 110        const char *help;
 111
 112        int flags;
 113        parse_opt_cb *callback;
 114        intptr_t defval;
 115};
 116
 117#define OPT_END()                   { OPTION_END }
 118#define OPT_ARGUMENT(l, h)          { OPTION_ARGUMENT, 0, (l), NULL, NULL, \
 119                                      (h), PARSE_OPT_NOARG}
 120#define OPT_GROUP(h)                { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
 121#define OPT_BIT(s, l, v, h, b)      { OPTION_BIT, (s), (l), (v), NULL, (h), \
 122                                      PARSE_OPT_NOARG, NULL, (b) }
 123#define OPT_NEGBIT(s, l, v, h, b)   { OPTION_NEGBIT, (s), (l), (v), NULL, \
 124                                      (h), PARSE_OPT_NOARG, NULL, (b) }
 125#define OPT_BOOLEAN(s, l, v, h)     { OPTION_BOOLEAN, (s), (l), (v), NULL, \
 126                                      (h), PARSE_OPT_NOARG }
 127#define OPT_SET_INT(s, l, v, h, i)  { OPTION_SET_INT, (s), (l), (v), NULL, \
 128                                      (h), PARSE_OPT_NOARG, NULL, (i) }
 129#define OPT_SET_PTR(s, l, v, h, p)  { OPTION_SET_PTR, (s), (l), (v), NULL, \
 130                                      (h), PARSE_OPT_NOARG, NULL, (p) }
 131#define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), "n", (h) }
 132#define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
 133#define OPT_UYN(s, l, v, h)         { OPTION_CALLBACK, (s), (l), (v), NULL, \
 134                                      (h), PARSE_OPT_NOARG, &parse_opt_tertiary }
 135#define OPT_DATE(s, l, v, h) \
 136        { OPTION_CALLBACK, (s), (l), (v), "time",(h), 0, \
 137          parse_opt_approxidate_cb }
 138#define OPT_CALLBACK(s, l, v, a, h, f) \
 139        { OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }
 140#define OPT_NUMBER_CALLBACK(v, h, f) \
 141        { OPTION_NUMBER, 0, NULL, (v), NULL, (h), \
 142          PARSE_OPT_NOARG | PARSE_OPT_NONEG, (f) }
 143#define OPT_FILENAME(s, l, v, h)    { OPTION_FILENAME, (s), (l), (v), \
 144                                       "file", (h) }
 145#define OPT_COLOR_FLAG(s, l, v, h) \
 146        { OPTION_CALLBACK, (s), (l), (v), "when", (h), PARSE_OPT_OPTARG, \
 147                parse_opt_color_flag_cb, (intptr_t)"always" }
 148
 149
 150/* parse_options() will filter out the processed options and leave the
 151 * non-option arguments in argv[].
 152 * Returns the number of arguments left in argv[].
 153 */
 154extern int parse_options(int argc, const char **argv, const char *prefix,
 155                         const struct option *options,
 156                         const char * const usagestr[], int flags);
 157
 158extern NORETURN void usage_with_options(const char * const *usagestr,
 159                                        const struct option *options);
 160
 161extern NORETURN void usage_msg_opt(const char *msg,
 162                                   const char * const *usagestr,
 163                                   const struct option *options);
 164
 165/*----- incremental advanced APIs -----*/
 166
 167enum {
 168        PARSE_OPT_HELP = -1,
 169        PARSE_OPT_DONE,
 170        PARSE_OPT_NON_OPTION,
 171        PARSE_OPT_UNKNOWN
 172};
 173
 174/*
 175 * It's okay for the caller to consume argv/argc in the usual way.
 176 * Other fields of that structure are private to parse-options and should not
 177 * be modified in any way.
 178 */
 179struct parse_opt_ctx_t {
 180        const char **argv;
 181        const char **out;
 182        int argc, cpidx;
 183        const char *opt;
 184        int flags;
 185        const char *prefix;
 186};
 187
 188extern void parse_options_start(struct parse_opt_ctx_t *ctx,
 189                                int argc, const char **argv, const char *prefix,
 190                                const struct option *options, int flags);
 191
 192extern int parse_options_step(struct parse_opt_ctx_t *ctx,
 193                              const struct option *options,
 194                              const char * const usagestr[]);
 195
 196extern int parse_options_end(struct parse_opt_ctx_t *ctx);
 197
 198extern int parse_options_concat(struct option *dst, size_t, struct option *src);
 199
 200/*----- some often used options -----*/
 201extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
 202extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
 203extern int parse_opt_color_flag_cb(const struct option *, const char *, int);
 204extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
 205extern int parse_opt_with_commit(const struct option *, const char *, int);
 206extern int parse_opt_tertiary(const struct option *, const char *, int);
 207
 208#define OPT__VERBOSE(var, h)  OPT_BOOLEAN('v', "verbose", (var), (h))
 209#define OPT__QUIET(var, h)    OPT_BOOLEAN('q', "quiet",   (var), (h))
 210#define OPT__VERBOSITY(var) \
 211        { OPTION_CALLBACK, 'v', "verbose", (var), NULL, "be more verbose", \
 212          PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }, \
 213        { OPTION_CALLBACK, 'q', "quiet", (var), NULL, "be more quiet", \
 214          PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }
 215#define OPT__DRY_RUN(var, h)  OPT_BOOLEAN('n', "dry-run", (var), (h))
 216#define OPT__FORCE(var, h)    OPT_BOOLEAN('f', "force",   (var), (h))
 217#define OPT__ABBREV(var)  \
 218        { OPTION_CALLBACK, 0, "abbrev", (var), "n", \
 219          "use <n> digits to display SHA-1s", \
 220          PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
 221#define OPT__COLOR(var, h) \
 222        OPT_COLOR_FLAG(0, "color", (var), (h))
 223
 224#endif