parse-options.c

   1 #include "git-compat-util.h"
   2 #include "parse-options.h"
   3
   4 #define OPT_SHORT 1
   5 #define OPT_UNSET 2
   6
   7 struct optparse_t {
   8         const char **argv;
   9         int argc;
  10         const char *opt;
  11 };
  12
  13 static inline const char *get_arg(struct optparse_t *p)
  14 {
  15         if (p->opt) {
  16                 const char *res = p->opt;
  17                 p->opt = NULL;
  18                 return res;
  19         }
  20         p->argc--;
  21         return *++p->argv;
  22 }
  23
  24 static inline const char *skip_prefix(const char *str, const char *prefix)
  25 {
  26         size_t len = strlen(prefix);
  27         return strncmp(str, prefix, len) ? NULL : str + len;
  28 }
  29
  30 static int opterror(const struct option *opt, const char *reason, int flags)
  31 {
  32         if (flags & OPT_SHORT)
  33                 return error("switch `%c' %s", opt->short_name, reason);
  34         if (flags & OPT_UNSET)
  35                 return error("option `no-%s' %s", opt->long_name, reason);
  36         return error("option `%s' %s", opt->long_name, reason);
  37 }
  38
  39 static int get_value(struct optparse_t *p,
  40                      const struct option *opt, int flags)
  41 {
  42         const char *s, *arg;
  43         arg = p->opt ? p->opt : (p->argc > 1 ? p->argv[1] : NULL);
  44
  45         if (p->opt && (flags & OPT_UNSET))
  46                 return opterror(opt, "takes no value", flags);
  47
  48         switch (opt->type) {
  49         case OPTION_BOOLEAN:
  50                 if (!(flags & OPT_SHORT) && p->opt)
  51                         return opterror(opt, "takes no value", flags);
  52                 if (flags & OPT_UNSET)
  53                         *(int *)opt->value = 0;
  54                 else
  55                         (*(int *)opt->value)++;
  56                 return 0;
  57
  58         case OPTION_STRING:
  59                 if (flags & OPT_UNSET) {
  60                         *(const char **)opt->value = (const char *)NULL;
  61                         return 0;
  62                 }
  63                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-')) {
  64                         *(const char **)opt->value = (const char *)opt->defval;
  65                         return 0;
  66                 }
  67                 if (!arg)
  68                         return opterror(opt, "requires a value", flags);
  69                 *(const char **)opt->value = get_arg(p);
  70                 return 0;
  71
  72         case OPTION_CALLBACK:
  73                 if (flags & OPT_UNSET)
  74                         return (*opt->callback)(opt, NULL, 1);
  75                 if (opt->flags & PARSE_OPT_NOARG) {
  76                         if (p->opt && !(flags & OPT_SHORT))
  77                                 return opterror(opt, "takes no value", flags);
  78                         return (*opt->callback)(opt, NULL, 0);
  79                 }
  80                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || *arg == '-'))
  81                         return (*opt->callback)(opt, NULL, 0);
  82                 if (!arg)
  83                         return opterror(opt, "requires a value", flags);
  84                 return (*opt->callback)(opt, get_arg(p), 0);
  85
  86         case OPTION_INTEGER:
  87                 if (flags & OPT_UNSET) {
  88                         *(int *)opt->value = 0;
  89                         return 0;
  90                 }
  91                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || !isdigit(*arg))) {
  92                         *(int *)opt->value = opt->defval;
  93                         return 0;
  94                 }
  95                 if (!arg)
  96                         return opterror(opt, "requires a value", flags);
  97                 *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
  98                 if (*s)
  99                         return opterror(opt, "expects a numerical value", flags);
 100                 return 0;
 101
 102         default:
 103                 die("should not happen, someone must be hit on the forehead");
 104         }
 105 }
 106
 107 static int parse_short_opt(struct optparse_t *p, const struct option *options)
 108 {
 109         for (; options->type != OPTION_END; options++) {
 110                 if (options->short_name == *p->opt) {
 111                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
 112                         return get_value(p, options, OPT_SHORT);
 113                 }
 114         }
 115         return error("unknown switch `%c'", *p->opt);
 116 }
 117
 118 static int parse_long_opt(struct optparse_t *p, const char *arg,
 119                           const struct option *options)
 120 {
 121         const char *arg_end = strchr(arg, '=');
 122         const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
 123         int abbrev_flags = 0, ambiguous_flags = 0;
 124
 125         if (!arg_end)
 126                 arg_end = arg + strlen(arg);
 127
 128         for (; options->type != OPTION_END; options++) {
 129                 const char *rest;
 130                 int flags = 0;
 131
 132                 if (!options->long_name)
 133                         continue;
 134
 135                 rest = skip_prefix(arg, options->long_name);
 136                 if (!rest) {
 137                         /* abbreviated? */
 138                         if (!strncmp(options->long_name, arg, arg_end - arg)) {
 139 is_abbreviated:
 140                                 if (abbrev_option) {
 141                                         /*
 142                                          * If this is abbreviated, it is
 143                                          * ambiguous. So when there is no
 144                                          * exact match later, we need to
 145                                          * error out.
 146                                          */
 147                                         ambiguous_option = abbrev_option;
 148                                         ambiguous_flags = abbrev_flags;
 149                                 }
 150                                 if (!(flags & OPT_UNSET) && *arg_end)
 151                                         p->opt = arg_end + 1;
 152                                 abbrev_option = options;
 153                                 abbrev_flags = flags;
 154                                 continue;
 155                         }
 156                         /* negated and abbreviated very much? */
 157                         if (!prefixcmp("no-", arg)) {
 158                                 flags |= OPT_UNSET;
 159                                 goto is_abbreviated;
 160                         }
 161                         /* negated? */
 162                         if (strncmp(arg, "no-", 3))
 163                                 continue;
 164                         flags |= OPT_UNSET;
 165                         rest = skip_prefix(arg + 3, options->long_name);
 166                         /* abbreviated and negated? */
 167                         if (!rest && !prefixcmp(options->long_name, arg + 3))
 168                                 goto is_abbreviated;
 169                         if (!rest)
 170                                 continue;
 171                 }
 172                 if (*rest) {
 173                         if (*rest != '=')
 174                                 continue;
 175                         p->opt = rest + 1;
 176                 }
 177                 return get_value(p, options, flags);
 178         }
 179
 180         if (ambiguous_option)
 181                 return error("Ambiguous option: %s "
 182                         "(could be --%s%s or --%s%s)",
 183                         arg,
 184                         (ambiguous_flags & OPT_UNSET) ?  "no-" : "",
 185                         ambiguous_option->long_name,
 186                         (abbrev_flags & OPT_UNSET) ?  "no-" : "",
 187                         abbrev_option->long_name);
 188         if (abbrev_option)
 189                 return get_value(p, abbrev_option, abbrev_flags);
 190         return error("unknown option `%s'", arg);
 191 }
 192
 193 int parse_options(int argc, const char **argv, const struct option *options,
 194                   const char * const usagestr[], int flags)
 195 {
 196         struct optparse_t args = { argv + 1, argc - 1, NULL };
 197         int j = 0;
 198
 199         for (; args.argc; args.argc--, args.argv++) {
 200                 const char *arg = args.argv[0];
 201
 202                 if (*arg != '-' || !arg[1]) {
 203                         argv[j++] = args.argv[0];
 204                         continue;
 205                 }
 206
 207                 if (arg[1] != '-') {
 208                         args.opt = arg + 1;
 209                         do {
 210                                 if (*args.opt == 'h')
 211                                         usage_with_options(usagestr, options);
 212                                 if (parse_short_opt(&args, options) < 0)
 213                                         usage_with_options(usagestr, options);
 214                         } while (args.opt);
 215                         continue;
 216                 }
 217
 218                 if (!arg[2]) { /* "--" */
 219                         if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
 220                                 args.argc--;
 221                                 args.argv++;
 222                         }
 223                         break;
 224                 }
 225
 226                 if (!strcmp(arg + 2, "help"))
 227                         usage_with_options(usagestr, options);
 228                 if (parse_long_opt(&args, arg + 2, options))
 229                         usage_with_options(usagestr, options);
 230         }
 231
 232         memmove(argv + j, args.argv, args.argc * sizeof(*argv));
 233         argv[j + args.argc] = NULL;
 234         return j + args.argc;
 235 }
 236
 237 #define USAGE_OPTS_WIDTH 24
 238 #define USAGE_GAP         2
 239
 240 void usage_with_options(const char * const *usagestr,
 241                         const struct option *opts)
 242 {
 243         fprintf(stderr, "usage: %s\n", *usagestr++);
 244         while (*usagestr && **usagestr)
 245                 fprintf(stderr, "   or: %s\n", *usagestr++);
 246         while (*usagestr)
 247                 fprintf(stderr, "    %s\n", *usagestr++);
 248
 249         if (opts->type != OPTION_GROUP)
 250                 fputc('\n', stderr);
 251
 252         for (; opts->type != OPTION_END; opts++) {
 253                 size_t pos;
 254                 int pad;
 255
 256                 if (opts->type == OPTION_GROUP) {
 257                         fputc('\n', stderr);
 258                         if (*opts->help)
 259                                 fprintf(stderr, "%s\n", opts->help);
 260                         continue;
 261                 }
 262
 263                 pos = fprintf(stderr, "    ");
 264                 if (opts->short_name)
 265                         pos += fprintf(stderr, "-%c", opts->short_name);
 266                 if (opts->long_name && opts->short_name)
 267                         pos += fprintf(stderr, ", ");
 268                 if (opts->long_name)
 269                         pos += fprintf(stderr, "--%s", opts->long_name);
 270
 271                 switch (opts->type) {
 272                 case OPTION_INTEGER:
 273                         if (opts->flags & PARSE_OPT_OPTARG)
 274                                 pos += fprintf(stderr, " [<n>]");
 275                         else
 276                                 pos += fprintf(stderr, " <n>");
 277                         break;
 278                 case OPTION_CALLBACK:
 279                         if (opts->flags & PARSE_OPT_NOARG)
 280                                 break;
 281                         /* FALLTHROUGH */
 282                 case OPTION_STRING:
 283                         if (opts->argh) {
 284                                 if (opts->flags & PARSE_OPT_OPTARG)
 285                                         pos += fprintf(stderr, " [<%s>]", opts->argh);
 286                                 else
 287                                         pos += fprintf(stderr, " <%s>", opts->argh);
 288                         } else {
 289                                 if (opts->flags & PARSE_OPT_OPTARG)
 290                                         pos += fprintf(stderr, " [...]");
 291                                 else
 292                                         pos += fprintf(stderr, " ...");
 293                         }
 294                         break;
 295                 default:
 296                         break;
 297                 }
 298
 299                 if (pos <= USAGE_OPTS_WIDTH)
 300                         pad = USAGE_OPTS_WIDTH - pos;
 301                 else {
 302                         fputc('\n', stderr);
 303                         pad = USAGE_OPTS_WIDTH;
 304                 }
 305                 fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 306         }
 307         fputc('\n', stderr);
 308
 309         exit(129);
 310 }
 311
 312 /*----- some often used options -----*/
 313 #include "cache.h"
 314 int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
 315 {
 316         int v;
 317
 318         if (!arg) {
 319                 v = unset ? 0 : DEFAULT_ABBREV;
 320         } else {
 321                 v = strtol(arg, (char **)&arg, 10);
 322                 if (*arg)
 323                         return opterror(opt, "expects a numerical value", 0);
 324                 if (v && v < MINIMUM_ABBREV)
 325                         v = MINIMUM_ABBREV;
 326                 else if (v > 40)
 327                         v = 40;
 328         }
 329         *(int *)(opt->value) = v;
 330         return 0;
 331 }