parse-options.hon commit git-mergetool documentaiton: show toolnames in typewriter font (bbdfbc4)
   1#ifndef PARSE_OPTIONS_H
   2#define PARSE_OPTIONS_H
   3
   4enum parse_opt_type {
   5        /* special types */
   6        OPTION_END,
   7        OPTION_GROUP,
   8        /* options with no arguments */
   9        OPTION_BIT,
  10        OPTION_BOOLEAN, /* _INCR would have been a better name */
  11        OPTION_SET_INT,
  12        OPTION_SET_PTR,
  13        /* options with arguments (usually) */
  14        OPTION_STRING,
  15        OPTION_INTEGER,
  16        OPTION_CALLBACK,
  17};
  18
  19enum parse_opt_flags {
  20        PARSE_OPT_KEEP_DASHDASH = 1,
  21};
  22
  23enum parse_opt_option_flags {
  24        PARSE_OPT_OPTARG  = 1,
  25        PARSE_OPT_NOARG   = 2,
  26        PARSE_OPT_NONEG   = 4,
  27        PARSE_OPT_HIDDEN  = 8,
  28};
  29
  30struct option;
  31typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
  32
  33/*
  34 * `type`::
  35 *   holds the type of the option, you must have an OPTION_END last in your
  36 *   array.
  37 *
  38 * `short_name`::
  39 *   the character to use as a short option name, '\0' if none.
  40 *
  41 * `long_name`::
  42 *   the long option name, without the leading dashes, NULL if none.
  43 *
  44 * `value`::
  45 *   stores pointers to the values to be filled.
  46 *
  47 * `argh`::
  48 *   token to explain the kind of argument this option wants. Keep it
  49 *   homogenous across the repository.
  50 *
  51 * `help`::
  52 *   the short help associated to what the option does.
  53 *   Must never be NULL (except for OPTION_END).
  54 *   OPTION_GROUP uses this pointer to store the group header.
  55 *
  56 * `flags`::
  57 *   mask of parse_opt_option_flags.
  58 *   PARSE_OPT_OPTARG: says that the argument is optionnal (not for BOOLEANs)
  59 *   PARSE_OPT_NOARG: says that this option takes no argument, for CALLBACKs
  60 *   PARSE_OPT_NONEG: says that this option cannot be negated
  61 *   PARSE_OPT_HIDDEN this option is skipped in the default usage, showed in
  62 *                    the long one.
  63 *
  64 * `callback`::
  65 *   pointer to the callback to use for OPTION_CALLBACK.
  66 *
  67 * `defval`::
  68 *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
  69 *   OPTION_{BIT,SET_INT,SET_PTR} store the {mask,integer,pointer} to put in
  70 *   the value when met.
  71 *   CALLBACKS can use it like they want.
  72 */
  73struct option {
  74        enum parse_opt_type type;
  75        int short_name;
  76        const char *long_name;
  77        void *value;
  78        const char *argh;
  79        const char *help;
  80
  81        int flags;
  82        parse_opt_cb *callback;
  83        intptr_t defval;
  84};
  85
  86#define OPT_END()                   { OPTION_END }
  87#define OPT_GROUP(h)                { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
  88#define OPT_BIT(s, l, v, h, b)      { OPTION_BIT, (s), (l), (v), NULL, (h), 0, NULL, (b) }
  89#define OPT_BOOLEAN(s, l, v, h)     { OPTION_BOOLEAN, (s), (l), (v), NULL, (h) }
  90#define OPT_SET_INT(s, l, v, h, i)  { OPTION_SET_INT, (s), (l), (v), NULL, (h), 0, NULL, (i) }
  91#define OPT_SET_PTR(s, l, v, h, p)  { OPTION_SET_PTR, (s), (l), (v), NULL, (h), 0, NULL, (p) }
  92#define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), NULL, (h) }
  93#define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
  94#define OPT_CALLBACK(s, l, v, a, h, f) \
  95        { OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }
  96
  97/* parse_options() will filter out the processed options and leave the
  98 * non-option argments in argv[].
  99 * Returns the number of arguments left in argv[].
 100 */
 101extern int parse_options(int argc, const char **argv,
 102                         const struct option *options,
 103                         const char * const usagestr[], int flags);
 104
 105extern NORETURN void usage_with_options(const char * const *usagestr,
 106                                        const struct option *options);
 107
 108/*----- some often used options -----*/
 109extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
 110
 111#define OPT__VERBOSE(var)  OPT_BOOLEAN('v', "verbose", (var), "be verbose")
 112#define OPT__QUIET(var)    OPT_BOOLEAN('q', "quiet",   (var), "be quiet")
 113#define OPT__DRY_RUN(var)  OPT_BOOLEAN('n', "dry-run", (var), "dry run")
 114#define OPT__ABBREV(var)  \
 115        { OPTION_CALLBACK, 0, "abbrev", (var), "n", \
 116          "use <n> digits to display SHA-1s", \
 117          PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
 118
 119#endif