parse-options.h

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