Andrew's git / gitweb.git / parse-options.c
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parse-options.con commit parse-options: Allow abbreviated options when unambiguous (7f275b9)
   1#include "git-compat-util.h"
   2#include "parse-options.h"
   3
   4#define OPT_SHORT 1
   5#define OPT_UNSET 2
   6
   7struct optparse_t {
   8        const char **argv;
   9        int argc;
  10        const char *opt;
  11};
  12
  13static 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
  24static 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
  30static 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
  39static 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
 102static 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
 113static 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)) {
 134is_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
 179int 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
 226void 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"
 297int 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}