parse-options.c

   1 #include "git-compat-util.h"
   2 #include "parse-options.h"
   3 #include "strbuf.h"
   4
   5 #define OPT_SHORT 1
   6 #define OPT_UNSET 2
   7
   8 struct optparse_t {
   9         const char **argv;
  10         int argc;
  11         const char *opt;
  12 };
  13
  14 static inline const char *get_arg(struct optparse_t *p)
  15 {
  16         if (p->opt) {
  17                 const char *res = p->opt;
  18                 p->opt = NULL;
  19                 return res;
  20         }
  21         p->argc--;
  22         return *++p->argv;
  23 }
  24
  25 static inline const char *skip_prefix(const char *str, const char *prefix)
  26 {
  27         size_t len = strlen(prefix);
  28         return strncmp(str, prefix, len) ? NULL : str + len;
  29 }
  30
  31 static int opterror(const struct option *opt, const char *reason, int flags)
  32 {
  33         if (flags & OPT_SHORT)
  34                 return error("switch `%c' %s", opt->short_name, reason);
  35         if (flags & OPT_UNSET)
  36                 return error("option `no-%s' %s", opt->long_name, reason);
  37         return error("option `%s' %s", opt->long_name, reason);
  38 }
  39
  40 static int get_value(struct optparse_t *p,
  41                      const struct option *opt, int flags)
  42 {
  43         const char *s;
  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 (!p->opt && p->argc <= 1)
  64                         return opterror(opt, "requires a value", flags);
  65                 *(const char **)opt->value = get_arg(p);
  66                 return 0;
  67
  68         case OPTION_INTEGER:
  69                 if (flags & OPT_UNSET) {
  70                         *(int *)opt->value = 0;
  71                         return 0;
  72                 }
  73                 if (!p->opt && p->argc <= 1)
  74                         return opterror(opt, "requires a value", flags);
  75                 *(int *)opt->value = strtol(get_arg(p), (char **)&s, 10);
  76                 if (*s)
  77                         return opterror(opt, "expects a numerical value", flags);
  78                 return 0;
  79
  80         default:
  81                 die("should not happen, someone must be hit on the forehead");
  82         }
  83 }
  84
  85 static int parse_short_opt(struct optparse_t *p, const struct option *options)
  86 {
  87         for (; options->type != OPTION_END; options++) {
  88                 if (options->short_name == *p->opt) {
  89                         p->opt = p->opt[1] ? p->opt + 1 : NULL;
  90                         return get_value(p, options, OPT_SHORT);
  91                 }
  92         }
  93         return error("unknown switch `%c'", *p->opt);
  94 }
  95
  96 static int parse_long_opt(struct optparse_t *p, const char *arg,
  97                           const struct option *options)
  98 {
  99         for (; options->type != OPTION_END; options++) {
 100                 const char *rest;
 101                 int flags = 0;
 102
 103                 if (!options->long_name)
 104                         continue;
 105
 106                 rest = skip_prefix(arg, options->long_name);
 107                 if (!rest) {
 108                         if (strncmp(arg, "no-", 3))
 109                                 continue;
 110                         flags |= OPT_UNSET;
 111                         rest = skip_prefix(arg + 3, options->long_name);
 112                         if (!rest)
 113                                 continue;
 114                 }
 115                 if (*rest) {
 116                         if (*rest != '=')
 117                                 continue;
 118                         p->opt = rest + 1;
 119                 }
 120                 return get_value(p, options, flags);
 121         }
 122         return error("unknown option `%s'", arg);
 123 }
 124
 125 int parse_options(int argc, const char **argv, const struct option *options,
 126                   const char * const usagestr[], int flags)
 127 {
 128         struct optparse_t args = { argv + 1, argc - 1, NULL };
 129         int j = 0;
 130
 131         for (; args.argc; args.argc--, args.argv++) {
 132                 const char *arg = args.argv[0];
 133
 134                 if (*arg != '-' || !arg[1]) {
 135                         argv[j++] = args.argv[0];
 136                         continue;
 137                 }
 138
 139                 if (arg[1] != '-') {
 140                         args.opt = arg + 1;
 141                         do {
 142                                 if (*args.opt == 'h')
 143                                         usage_with_options(usagestr, options);
 144                                 if (parse_short_opt(&args, options) < 0)
 145                                         usage_with_options(usagestr, options);
 146                         } while (args.opt);
 147                         continue;
 148                 }
 149
 150                 if (!arg[2]) { /* "--" */
 151                         if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
 152                                 args.argc--;
 153                                 args.argv++;
 154                         }
 155                         break;
 156                 }
 157
 158                 if (!strcmp(arg + 2, "help"))
 159                         usage_with_options(usagestr, options);
 160                 if (parse_long_opt(&args, arg + 2, options))
 161                         usage_with_options(usagestr, options);
 162         }
 163
 164         memmove(argv + j, args.argv, args.argc * sizeof(*argv));
 165         argv[j + args.argc] = NULL;
 166         return j + args.argc;
 167 }
 168
 169 #define USAGE_OPTS_WIDTH 24
 170 #define USAGE_GAP         2
 171
 172 void usage_with_options(const char * const *usagestr,
 173                         const struct option *opts)
 174 {
 175         struct strbuf sb;
 176
 177         strbuf_init(&sb, 4096);
 178         strbuf_addstr(&sb, *usagestr);
 179         strbuf_addch(&sb, '\n');
 180         while (*++usagestr)
 181                 strbuf_addf(&sb, "    %s\n", *usagestr);
 182
 183         if (opts->type != OPTION_GROUP)
 184                 strbuf_addch(&sb, '\n');
 185
 186         for (; opts->type != OPTION_END; opts++) {
 187                 size_t pos;
 188                 int pad;
 189
 190                 if (opts->type == OPTION_GROUP) {
 191                         strbuf_addch(&sb, '\n');
 192                         if (*opts->help)
 193                                 strbuf_addf(&sb, "%s\n", opts->help);
 194                         continue;
 195                 }
 196
 197                 pos = sb.len;
 198                 strbuf_addstr(&sb, "    ");
 199                 if (opts->short_name)
 200                         strbuf_addf(&sb, "-%c", opts->short_name);
 201                 if (opts->long_name && opts->short_name)
 202                         strbuf_addstr(&sb, ", ");
 203                 if (opts->long_name)
 204                         strbuf_addf(&sb, "--%s", opts->long_name);
 205
 206                 switch (opts->type) {
 207                 case OPTION_INTEGER:
 208                         strbuf_addstr(&sb, " <n>");
 209                         break;
 210                 case OPTION_STRING:
 211                         if (opts->argh)
 212                                 strbuf_addf(&sb, " <%s>", opts->argh);
 213                         else
 214                                 strbuf_addstr(&sb, " ...");
 215                         break;
 216                 default:
 217                         break;
 218                 }
 219
 220                 pad = sb.len - pos;
 221                 if (pad <= USAGE_OPTS_WIDTH)
 222                         pad = USAGE_OPTS_WIDTH - pad;
 223                 else {
 224                         strbuf_addch(&sb, '\n');
 225                         pad = USAGE_OPTS_WIDTH;
 226                 }
 227                 strbuf_addf(&sb, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 228         }
 229         usage(sb.buf);
 230 }