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_OPTARG && (!arg || *arg == '-'))
  76                         return (*opt->callback)(opt, NULL, 0);
  77                 if (!arg)
  78                         return opterror(opt, "requires a value", flags);
  79                 return (*opt->callback)(opt, get_arg(p), 0);
  80
  81         case OPTION_INTEGER:
  82                 if (flags & OPT_UNSET) {
  83                         *(int *)opt->value = 0;
  84                         return 0;
  85                 }
  86                 if (opt->flags & PARSE_OPT_OPTARG && (!arg || !isdigit(*arg))) {
  87                         *(int *)opt->value = opt->defval;
  88                         return 0;
  89                 }
  90                 if (!arg)
  91                         return opterror(opt, "requires a value", flags);
  92                 *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
  93                 if (*s)
  94                         return opterror(opt, "expects a numerical value", flags);
  95                 return 0;
  96
  97         default:
  98                 die("should not happen, someone must be hit on the forehead");
  99         }
 100 }
 101
 102 static int parse_short_opt(struct optparse_t *p, const struct option *options)
 103 {
 104         for (; options->type != OPTION_END; options++) {
 105                 if (options->short_name == *p->opt) {
 106                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
 107                         return get_value(p, options, OPT_SHORT);
 108                 }
 109         }
 110         return error("unknown switch `%c'", *p->opt);
 111 }
 112
 113 static int parse_long_opt(struct optparse_t *p, const char *arg,
 114                           const struct option *options)
 115 {
 116         const char *arg_end = strchr(arg, '=');
 117         const struct option *abbrev_option = NULL;
 118         int abbrev_flags = 0;
 119
 120         if (!arg_end)
 121                 arg_end = arg + strlen(arg);
 122
 123         for (; options->type != OPTION_END; options++) {
 124                 const char *rest;
 125                 int flags = 0;
 126
 127                 if (!options->long_name)
 128                         continue;
 129
 130                 rest = skip_prefix(arg, options->long_name);
 131                 if (!rest) {
 132                         /* abbreviated? */
 133                         if (!strncmp(options->long_name, arg, arg_end - arg)) {
 134 is_abbreviated:
 135                                 if (abbrev_option)
 136                                         return error("Ambiguous option: %s "
 137                                                 "(could be --%s%s or --%s%s)",
 138                                                 arg,
 139                                                 (flags & OPT_UNSET) ?
 140                                                         "no-" : "",
 141                                                 options->long_name,
 142                                                 (abbrev_flags & OPT_UNSET) ?
 143                                                         "no-" : "",
 144                                                 abbrev_option->long_name);
 145                                 if (!(flags & OPT_UNSET) && *arg_end)
 146                                         p->opt = arg_end + 1;
 147                                 abbrev_option = options;
 148                                 abbrev_flags = flags;
 149                                 continue;
 150                         }
 151                         /* negated and abbreviated very much? */
 152                         if (!prefixcmp("no-", arg)) {
 153                                 flags |= OPT_UNSET;
 154                                 goto is_abbreviated;
 155                         }
 156                         /* negated? */
 157                         if (strncmp(arg, "no-", 3))
 158                                 continue;
 159                         flags |= OPT_UNSET;
 160                         rest = skip_prefix(arg + 3, options->long_name);
 161                         /* abbreviated and negated? */
 162                         if (!rest && !prefixcmp(options->long_name, arg + 3))
 163                                 goto is_abbreviated;
 164                         if (!rest)
 165                                 continue;
 166                 }
 167                 if (*rest) {
 168                         if (*rest != '=')
 169                                 continue;
 170                         p->opt = rest + 1;
 171                 }
 172                 return get_value(p, options, flags);
 173         }
 174         if (abbrev_option)
 175                 return get_value(p, abbrev_option, abbrev_flags);
 176         return error("unknown option `%s'", arg);
 177 }
 178
 179 int parse_options(int argc, const char **argv, const struct option *options,
 180                   const char * const usagestr[], int flags)
 181 {
 182         struct optparse_t args = { argv + 1, argc - 1, NULL };
 183         int j = 0;
 184
 185         for (; args.argc; args.argc--, args.argv++) {
 186                 const char *arg = args.argv[0];
 187
 188                 if (*arg != '-' || !arg[1]) {
 189                         argv[j++] = args.argv[0];
 190                         continue;
 191                 }
 192
 193                 if (arg[1] != '-') {
 194                         args.opt = arg + 1;
 195                         do {
 196                                 if (*args.opt == 'h')
 197                                         usage_with_options(usagestr, options);
 198                                 if (parse_short_opt(&args, options) < 0)
 199                                         usage_with_options(usagestr, options);
 200                         } while (args.opt);
 201                         continue;
 202                 }
 203
 204                 if (!arg[2]) { /* "--" */
 205                         if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
 206                                 args.argc--;
 207                                 args.argv++;
 208                         }
 209                         break;
 210                 }
 211
 212                 if (!strcmp(arg + 2, "help"))
 213                         usage_with_options(usagestr, options);
 214                 if (parse_long_opt(&args, arg + 2, options))
 215                         usage_with_options(usagestr, options);
 216         }
 217
 218         memmove(argv + j, args.argv, args.argc * sizeof(*argv));
 219         argv[j + args.argc] = NULL;
 220         return j + args.argc;
 221 }
 222
 223 #define USAGE_OPTS_WIDTH 24
 224 #define USAGE_GAP         2
 225
 226 void usage_with_options(const char * const *usagestr,
 227                         const struct option *opts)
 228 {
 229         fprintf(stderr, "usage: %s\n", *usagestr++);
 230         while (*usagestr && **usagestr)
 231                 fprintf(stderr, "   or: %s\n", *usagestr++);
 232         while (*usagestr)
 233                 fprintf(stderr, "    %s\n", *usagestr++);
 234
 235         if (opts->type != OPTION_GROUP)
 236                 fputc('\n', stderr);
 237
 238         for (; opts->type != OPTION_END; opts++) {
 239                 size_t pos;
 240                 int pad;
 241
 242                 if (opts->type == OPTION_GROUP) {
 243                         fputc('\n', stderr);
 244                         if (*opts->help)
 245                                 fprintf(stderr, "%s\n", opts->help);
 246                         continue;
 247                 }
 248
 249                 pos = fprintf(stderr, "    ");
 250                 if (opts->short_name)
 251                         pos += fprintf(stderr, "-%c", opts->short_name);
 252                 if (opts->long_name && opts->short_name)
 253                         pos += fprintf(stderr, ", ");
 254                 if (opts->long_name)
 255                         pos += fprintf(stderr, "--%s", opts->long_name);
 256
 257                 switch (opts->type) {
 258                 case OPTION_INTEGER:
 259                         if (opts->flags & PARSE_OPT_OPTARG)
 260                                 pos += fprintf(stderr, " [<n>]");
 261                         else
 262                                 pos += fprintf(stderr, " <n>");
 263                         break;
 264                 case OPTION_STRING:
 265                 case OPTION_CALLBACK:
 266                         if (opts->argh) {
 267                                 if (opts->flags & PARSE_OPT_OPTARG)
 268                                         pos += fprintf(stderr, " [<%s>]", opts->argh);
 269                                 else
 270                                         pos += fprintf(stderr, " <%s>", opts->argh);
 271                         } else {
 272                                 if (opts->flags & PARSE_OPT_OPTARG)
 273                                         pos += fprintf(stderr, " [...]");
 274                                 else
 275                                         pos += fprintf(stderr, " ...");
 276                         }
 277                         break;
 278                 default:
 279                         break;
 280                 }
 281
 282                 if (pos <= USAGE_OPTS_WIDTH)
 283                         pad = USAGE_OPTS_WIDTH - pos;
 284                 else {
 285                         fputc('\n', stderr);
 286                         pad = USAGE_OPTS_WIDTH;
 287                 }
 288                 fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 289         }
 290         fputc('\n', stderr);
 291
 292         exit(129);
 293 }
 294
 295 /*----- some often used options -----*/
 296 #include "cache.h"
 297 int parse_opt_abbrev_cb(const struct option *opt, const char *arg, int unset)
 298 {
 299         int v;
 300
 301         if (!arg) {
 302                 v = unset ? 0 : DEFAULT_ABBREV;
 303         } else {
 304                 v = strtol(arg, (char **)&arg, 10);
 305                 if (*arg)
 306                         return opterror(opt, "expects a numerical value", 0);
 307                 if (v && v < MINIMUM_ABBREV)
 308                         v = MINIMUM_ABBREV;
 309                 else if (v > 40)
 310                         v = 40;
 311         }
 312         *(int *)(opt->value) = v;
 313         return 0;
 314 }