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         for (; options->type != OPTION_END; options++) {
 117                 const char *rest;
 118                 int flags = 0;
 119
 120                 if (!options->long_name)
 121                         continue;
 122
 123                 rest = skip_prefix(arg, options->long_name);
 124                 if (!rest) {
 125                         if (strncmp(arg, "no-", 3))
 126                                 continue;
 127                         flags |= OPT_UNSET;
 128                         rest = skip_prefix(arg + 3, options->long_name);
 129                         if (!rest)
 130                                 continue;
 131                 }
 132                 if (*rest) {
 133                         if (*rest != '=')
 134                                 continue;
 135                         p->opt = rest + 1;
 136                 }
 137                 return get_value(p, options, flags);
 138         }
 139         return error("unknown option `%s'", arg);
 140 }
 141
 142 int parse_options(int argc, const char **argv, const struct option *options,
 143                   const char * const usagestr[], int flags)
 144 {
 145         struct optparse_t args = { argv + 1, argc - 1, NULL };
 146         int j = 0;
 147
 148         for (; args.argc; args.argc--, args.argv++) {
 149                 const char *arg = args.argv[0];
 150
 151                 if (*arg != '-' || !arg[1]) {
 152                         argv[j++] = args.argv[0];
 153                         continue;
 154                 }
 155
 156                 if (arg[1] != '-') {
 157                         args.opt = arg + 1;
 158                         do {
 159                                 if (*args.opt == 'h')
 160                                         usage_with_options(usagestr, options);
 161                                 if (parse_short_opt(&args, options) < 0)
 162                                         usage_with_options(usagestr, options);
 163                         } while (args.opt);
 164                         continue;
 165                 }
 166
 167                 if (!arg[2]) { /* "--" */
 168                         if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
 169                                 args.argc--;
 170                                 args.argv++;
 171                         }
 172                         break;
 173                 }
 174
 175                 if (!strcmp(arg + 2, "help"))
 176                         usage_with_options(usagestr, options);
 177                 if (parse_long_opt(&args, arg + 2, options))
 178                         usage_with_options(usagestr, options);
 179         }
 180
 181         memmove(argv + j, args.argv, args.argc * sizeof(*argv));
 182         argv[j + args.argc] = NULL;
 183         return j + args.argc;
 184 }
 185
 186 #define USAGE_OPTS_WIDTH 24
 187 #define USAGE_GAP         2
 188
 189 void usage_with_options(const char * const *usagestr,
 190                         const struct option *opts)
 191 {
 192         fprintf(stderr, "usage: %s\n", *usagestr++);
 193         while (*usagestr && **usagestr)
 194                 fprintf(stderr, "   or: %s\n", *usagestr++);
 195         while (*usagestr)
 196                 fprintf(stderr, "    %s\n", *usagestr++);
 197
 198         if (opts->type != OPTION_GROUP)
 199                 fputc('\n', stderr);
 200
 201         for (; opts->type != OPTION_END; opts++) {
 202                 size_t pos;
 203                 int pad;
 204
 205                 if (opts->type == OPTION_GROUP) {
 206                         fputc('\n', stderr);
 207                         if (*opts->help)
 208                                 fprintf(stderr, "%s\n", opts->help);
 209                         continue;
 210                 }
 211
 212                 pos = fprintf(stderr, "    ");
 213                 if (opts->short_name)
 214                         pos += fprintf(stderr, "-%c", opts->short_name);
 215                 if (opts->long_name && opts->short_name)
 216                         pos += fprintf(stderr, ", ");
 217                 if (opts->long_name)
 218                         pos += fprintf(stderr, "--%s", opts->long_name);
 219
 220                 switch (opts->type) {
 221                 case OPTION_INTEGER:
 222                         if (opts->flags & PARSE_OPT_OPTARG)
 223                                 pos += fprintf(stderr, " [<n>]");
 224                         else
 225                                 pos += fprintf(stderr, " <n>");
 226                         break;
 227                 case OPTION_STRING:
 228                 case OPTION_CALLBACK:
 229                         if (opts->argh) {
 230                                 if (opts->flags & PARSE_OPT_OPTARG)
 231                                         pos += fprintf(stderr, " [<%s>]", opts->argh);
 232                                 else
 233                                         pos += fprintf(stderr, " <%s>", opts->argh);
 234                         } else {
 235                                 if (opts->flags & PARSE_OPT_OPTARG)
 236                                         pos += fprintf(stderr, " [...]");
 237                                 else
 238                                         pos += fprintf(stderr, " ...");
 239                         }
 240                         break;
 241                 default:
 242                         break;
 243                 }
 244
 245                 if (pos <= USAGE_OPTS_WIDTH)
 246                         pad = USAGE_OPTS_WIDTH - pos;
 247                 else {
 248                         fputc('\n', stderr);
 249                         pad = USAGE_OPTS_WIDTH;
 250                 }
 251                 fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 252         }
 253         fputc('\n', stderr);
 254
 255         exit(129);
 256 }