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_ARGUMENT,
   8         OPTION_GROUP,
   9         /* options with no arguments */
  10         OPTION_BIT,
  11         OPTION_BOOLEAN, /* _INCR would have been a better name */
  12         OPTION_SET_INT,
  13         OPTION_SET_PTR,
  14         /* options with arguments (usually) */
  15         OPTION_STRING,
  16         OPTION_INTEGER,
  17         OPTION_CALLBACK,
  18 };
  19
  20 enum parse_opt_flags {
  21         PARSE_OPT_KEEP_DASHDASH = 1,
  22         PARSE_OPT_STOP_AT_NON_OPTION = 2,
  23         PARSE_OPT_KEEP_ARGV0 = 4,
  24 };
  25
  26 enum parse_opt_option_flags {
  27         PARSE_OPT_OPTARG  = 1,
  28         PARSE_OPT_NOARG   = 2,
  29         PARSE_OPT_NONEG   = 4,
  30         PARSE_OPT_HIDDEN  = 8,
  31 };
  32
  33 struct option;
  34 typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
  35
  36 /*
  37  * `type`::
  38  *   holds the type of the option, you must have an OPTION_END last in your
  39  *   array.
  40  *
  41  * `short_name`::
  42  *   the character to use as a short option name, '\0' if none.
  43  *
  44  * `long_name`::
  45  *   the long option name, without the leading dashes, NULL if none.
  46  *
  47  * `value`::
  48  *   stores pointers to the values to be filled.
  49  *
  50  * `argh`::
  51  *   token to explain the kind of argument this option wants. Keep it
  52  *   homogenous across the repository.
  53  *
  54  * `help`::
  55  *   the short help associated to what the option does.
  56  *   Must never be NULL (except for OPTION_END).
  57  *   OPTION_GROUP uses this pointer to store the group header.
  58  *
  59  * `flags`::
  60  *   mask of parse_opt_option_flags.
  61  *   PARSE_OPT_OPTARG: says that the argument is optionnal (not for BOOLEANs)
  62  *   PARSE_OPT_NOARG: says that this option takes no argument, for CALLBACKs
  63  *   PARSE_OPT_NONEG: says that this option cannot be negated
  64  *   PARSE_OPT_HIDDEN this option is skipped in the default usage, showed in
  65  *                    the long one.
  66  *
  67  * `callback`::
  68  *   pointer to the callback to use for OPTION_CALLBACK.
  69  *
  70  * `defval`::
  71  *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
  72  *   OPTION_{BIT,SET_INT,SET_PTR} store the {mask,integer,pointer} to put in
  73  *   the value when met.
  74  *   CALLBACKS can use it like they want.
  75  */
  76 struct option {
  77         enum parse_opt_type type;
  78         int short_name;
  79         const char *long_name;
  80         void *value;
  81         const char *argh;
  82         const char *help;
  83
  84         int flags;
  85         parse_opt_cb *callback;
  86         intptr_t defval;
  87 };
  88
  89 #define OPT_END()                   { OPTION_END }
  90 #define OPT_ARGUMENT(l, h)          { OPTION_ARGUMENT, 0, (l), NULL, NULL, (h) }
  91 #define OPT_GROUP(h)                { OPTION_GROUP, 0, NULL, NULL, NULL, (h) }
  92 #define OPT_BIT(s, l, v, h, b)      { OPTION_BIT, (s), (l), (v), NULL, (h), 0, NULL, (b) }
  93 #define OPT_BOOLEAN(s, l, v, h)     { OPTION_BOOLEAN, (s), (l), (v), NULL, (h) }
  94 #define OPT_SET_INT(s, l, v, h, i)  { OPTION_SET_INT, (s), (l), (v), NULL, (h), 0, NULL, (i) }
  95 #define OPT_SET_PTR(s, l, v, h, p)  { OPTION_SET_PTR, (s), (l), (v), NULL, (h), 0, NULL, (p) }
  96 #define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), NULL, (h) }
  97 #define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
  98 #define OPT_DATE(s, l, v, h) \
  99         { OPTION_CALLBACK, (s), (l), (v), "time",(h), 0, \
 100           parse_opt_approxidate_cb }
 101 #define OPT_CALLBACK(s, l, v, a, h, f) \
 102         { OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }
 103
 104 /* parse_options() will filter out the processed options and leave the
 105  * non-option argments in argv[].
 106  * Returns the number of arguments left in argv[].
 107  */
 108 extern int parse_options(int argc, const char **argv,
 109                          const struct option *options,
 110                          const char * const usagestr[], int flags);
 111
 112 extern NORETURN void usage_with_options(const char * const *usagestr,
 113                                         const struct option *options);
 114
 115 /*----- incremantal advanced APIs -----*/
 116
 117 enum {
 118         PARSE_OPT_HELP = -1,
 119         PARSE_OPT_DONE,
 120         PARSE_OPT_UNKNOWN,
 121 };
 122
 123 /*
 124  * It's okay for the caller to consume argv/argc in the usual way.
 125  * Other fields of that structure are private to parse-options and should not
 126  * be modified in any way.
 127  */
 128 struct parse_opt_ctx_t {
 129         const char **argv;
 130         const char **out;
 131         int argc, cpidx;
 132         const char *opt;
 133         int flags;
 134 };
 135
 136 extern int parse_options_usage(const char * const *usagestr,
 137                                const struct option *opts);
 138
 139 extern void parse_options_start(struct parse_opt_ctx_t *ctx,
 140                                 int argc, const char **argv, int flags);
 141
 142 extern int parse_options_step(struct parse_opt_ctx_t *ctx,
 143                               const struct option *options,
 144                               const char * const usagestr[]);
 145
 146 extern int parse_options_end(struct parse_opt_ctx_t *ctx);
 147
 148
 149 /*----- some often used options -----*/
 150 extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
 151 extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
 152
 153 #define OPT__VERBOSE(var)  OPT_BOOLEAN('v', "verbose", (var), "be verbose")
 154 #define OPT__QUIET(var)    OPT_BOOLEAN('q', "quiet",   (var), "be quiet")
 155 #define OPT__DRY_RUN(var)  OPT_BOOLEAN('n', "dry-run", (var), "dry run")
 156 #define OPT__ABBREV(var)  \
 157         { OPTION_CALLBACK, 0, "abbrev", (var), "n", \
 158           "use <n> digits to display SHA-1s", \
 159           PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
 160
 161 #endif