parse-options.h

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