help.c

   1 #include "cache.h"
   2 #include "builtin.h"
   3 #include "exec_cmd.h"
   4 #include "levenshtein.h"
   5 #include "help.h"
   6 #include "common-cmds.h"
   7 #include "string-list.h"
   8 #include "column.h"
   9 #include "version.h"
  10 #include "refs.h"
  11
  12 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  13 {
  14         struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
  15
  16         ent->len = len;
  17         memcpy(ent->name, name, len);
  18         ent->name[len] = 0;
  19
  20         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  21         cmds->names[cmds->cnt++] = ent;
  22 }
  23
  24 static void clean_cmdnames(struct cmdnames *cmds)
  25 {
  26         int i;
  27         for (i = 0; i < cmds->cnt; ++i)
  28                 free(cmds->names[i]);
  29         free(cmds->names);
  30         cmds->cnt = 0;
  31         cmds->alloc = 0;
  32 }
  33
  34 static int cmdname_compare(const void *a_, const void *b_)
  35 {
  36         struct cmdname *a = *(struct cmdname **)a_;
  37         struct cmdname *b = *(struct cmdname **)b_;
  38         return strcmp(a->name, b->name);
  39 }
  40
  41 static void uniq(struct cmdnames *cmds)
  42 {
  43         int i, j;
  44
  45         if (!cmds->cnt)
  46                 return;
  47
  48         for (i = j = 1; i < cmds->cnt; i++) {
  49                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
  50                         free(cmds->names[i]);
  51                 else
  52                         cmds->names[j++] = cmds->names[i];
  53         }
  54
  55         cmds->cnt = j;
  56 }
  57
  58 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  59 {
  60         int ci, cj, ei;
  61         int cmp;
  62
  63         ci = cj = ei = 0;
  64         while (ci < cmds->cnt && ei < excludes->cnt) {
  65                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  66                 if (cmp < 0)
  67                         cmds->names[cj++] = cmds->names[ci++];
  68                 else if (cmp == 0) {
  69                         ei++;
  70                         free(cmds->names[ci++]);
  71                 } else if (cmp > 0)
  72                         ei++;
  73         }
  74
  75         while (ci < cmds->cnt)
  76                 cmds->names[cj++] = cmds->names[ci++];
  77
  78         cmds->cnt = cj;
  79 }
  80
  81 static void pretty_print_string_list(struct cmdnames *cmds,
  82                                      unsigned int colopts)
  83 {
  84         struct string_list list = STRING_LIST_INIT_NODUP;
  85         struct column_options copts;
  86         int i;
  87
  88         for (i = 0; i < cmds->cnt; i++)
  89                 string_list_append(&list, cmds->names[i]->name);
  90         /*
  91          * always enable column display, we only consult column.*
  92          * about layout strategy and stuff
  93          */
  94         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
  95         memset(&copts, 0, sizeof(copts));
  96         copts.indent = "  ";
  97         copts.padding = 2;
  98         print_columns(&list, colopts, &copts);
  99         string_list_clear(&list, 0);
 100 }
 101
 102 static int is_executable(const char *name)
 103 {
 104         struct stat st;
 105
 106         if (stat(name, &st) || /* stat, not lstat */
 107             !S_ISREG(st.st_mode))
 108                 return 0;
 109
 110 #if defined(GIT_WINDOWS_NATIVE)
 111         /* On Windows we cannot use the executable bit. The executable
 112          * state is determined by extension only. We do this first
 113          * because with virus scanners opening an executeable for
 114          * reading is potentially expensive.
 115          */
 116         if (has_extension(name, ".exe"))
 117                 return S_IXUSR;
 118
 119 {       /* now that we know it does not have an executable extension,
 120            peek into the file instead */
 121         char buf[3] = { 0 };
 122         int n;
 123         int fd = open(name, O_RDONLY);
 124         st.st_mode &= ~S_IXUSR;
 125         if (fd >= 0) {
 126                 n = read(fd, buf, 2);
 127                 if (n == 2)
 128                         /* look for a she-bang */
 129                         if (!strcmp(buf, "#!"))
 130                                 st.st_mode |= S_IXUSR;
 131                 close(fd);
 132         }
 133 }
 134 #endif
 135         return st.st_mode & S_IXUSR;
 136 }
 137
 138 static void list_commands_in_dir(struct cmdnames *cmds,
 139                                          const char *path,
 140                                          const char *prefix)
 141 {
 142         int prefix_len;
 143         DIR *dir = opendir(path);
 144         struct dirent *de;
 145         struct strbuf buf = STRBUF_INIT;
 146         int len;
 147
 148         if (!dir)
 149                 return;
 150         if (!prefix)
 151                 prefix = "git-";
 152         prefix_len = strlen(prefix);
 153
 154         strbuf_addf(&buf, "%s/", path);
 155         len = buf.len;
 156
 157         while ((de = readdir(dir)) != NULL) {
 158                 int entlen;
 159
 160                 if (!starts_with(de->d_name, prefix))
 161                         continue;
 162
 163                 strbuf_setlen(&buf, len);
 164                 strbuf_addstr(&buf, de->d_name);
 165                 if (!is_executable(buf.buf))
 166                         continue;
 167
 168                 entlen = strlen(de->d_name) - prefix_len;
 169                 if (has_extension(de->d_name, ".exe"))
 170                         entlen -= 4;
 171
 172                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
 173         }
 174         closedir(dir);
 175         strbuf_release(&buf);
 176 }
 177
 178 void load_command_list(const char *prefix,
 179                 struct cmdnames *main_cmds,
 180                 struct cmdnames *other_cmds)
 181 {
 182         const char *env_path = getenv("PATH");
 183         const char *exec_path = git_exec_path();
 184
 185         if (exec_path) {
 186                 list_commands_in_dir(main_cmds, exec_path, prefix);
 187                 qsort(main_cmds->names, main_cmds->cnt,
 188                       sizeof(*main_cmds->names), cmdname_compare);
 189                 uniq(main_cmds);
 190         }
 191
 192         if (env_path) {
 193                 char *paths, *path, *colon;
 194                 path = paths = xstrdup(env_path);
 195                 while (1) {
 196                         if ((colon = strchr(path, PATH_SEP)))
 197                                 *colon = 0;
 198                         if (!exec_path || strcmp(path, exec_path))
 199                                 list_commands_in_dir(other_cmds, path, prefix);
 200
 201                         if (!colon)
 202                                 break;
 203                         path = colon + 1;
 204                 }
 205                 free(paths);
 206
 207                 qsort(other_cmds->names, other_cmds->cnt,
 208                       sizeof(*other_cmds->names), cmdname_compare);
 209                 uniq(other_cmds);
 210         }
 211         exclude_cmds(other_cmds, main_cmds);
 212 }
 213
 214 void list_commands(unsigned int colopts,
 215                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 216 {
 217         if (main_cmds->cnt) {
 218                 const char *exec_path = git_exec_path();
 219                 printf_ln(_("available git commands in '%s'"), exec_path);
 220                 putchar('\n');
 221                 pretty_print_string_list(main_cmds, colopts);
 222                 putchar('\n');
 223         }
 224
 225         if (other_cmds->cnt) {
 226                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 227                 putchar('\n');
 228                 pretty_print_string_list(other_cmds, colopts);
 229                 putchar('\n');
 230         }
 231 }
 232
 233 void list_common_cmds_help(void)
 234 {
 235         int i, longest = 0;
 236
 237         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 238                 if (longest < strlen(common_cmds[i].name))
 239                         longest = strlen(common_cmds[i].name);
 240         }
 241
 242         puts(_("The most commonly used git commands are:"));
 243         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 244                 printf("   %s   ", common_cmds[i].name);
 245                 mput_char(' ', longest - strlen(common_cmds[i].name));
 246                 puts(_(common_cmds[i].help));
 247         }
 248 }
 249
 250 int is_in_cmdlist(struct cmdnames *c, const char *s)
 251 {
 252         int i;
 253         for (i = 0; i < c->cnt; i++)
 254                 if (!strcmp(s, c->names[i]->name))
 255                         return 1;
 256         return 0;
 257 }
 258
 259 static int autocorrect;
 260 static struct cmdnames aliases;
 261
 262 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 263 {
 264         if (!strcmp(var, "help.autocorrect"))
 265                 autocorrect = git_config_int(var,value);
 266         /* Also use aliases for command lookup */
 267         if (starts_with(var, "alias."))
 268                 add_cmdname(&aliases, var + 6, strlen(var + 6));
 269
 270         return git_default_config(var, value, cb);
 271 }
 272
 273 static int levenshtein_compare(const void *p1, const void *p2)
 274 {
 275         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 276         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 277         int l1 = (*c1)->len;
 278         int l2 = (*c2)->len;
 279         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 280 }
 281
 282 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 283 {
 284         int i;
 285         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 286
 287         for (i = 0; i < old->cnt; i++)
 288                 cmds->names[cmds->cnt++] = old->names[i];
 289         free(old->names);
 290         old->cnt = 0;
 291         old->names = NULL;
 292 }
 293
 294 /* An empirically derived magic number */
 295 #define SIMILARITY_FLOOR 7
 296 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 297
 298 static const char bad_interpreter_advice[] =
 299         N_("'%s' appears to be a git command, but we were not\n"
 300         "able to execute it. Maybe git-%s is broken?");
 301
 302 const char *help_unknown_cmd(const char *cmd)
 303 {
 304         int i, n, best_similarity = 0;
 305         struct cmdnames main_cmds, other_cmds;
 306
 307         memset(&main_cmds, 0, sizeof(main_cmds));
 308         memset(&other_cmds, 0, sizeof(other_cmds));
 309         memset(&aliases, 0, sizeof(aliases));
 310
 311         git_config(git_unknown_cmd_config, NULL);
 312
 313         load_command_list("git-", &main_cmds, &other_cmds);
 314
 315         add_cmd_list(&main_cmds, &aliases);
 316         add_cmd_list(&main_cmds, &other_cmds);
 317         qsort(main_cmds.names, main_cmds.cnt,
 318               sizeof(main_cmds.names), cmdname_compare);
 319         uniq(&main_cmds);
 320
 321         /* This abuses cmdname->len for levenshtein distance */
 322         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 323                 int cmp = 0; /* avoid compiler stupidity */
 324                 const char *candidate = main_cmds.names[i]->name;
 325
 326                 /*
 327                  * An exact match means we have the command, but
 328                  * for some reason exec'ing it gave us ENOENT; probably
 329                  * it's a bad interpreter in the #! line.
 330                  */
 331                 if (!strcmp(candidate, cmd))
 332                         die(_(bad_interpreter_advice), cmd, cmd);
 333
 334                 /* Does the candidate appear in common_cmds list? */
 335                 while (n < ARRAY_SIZE(common_cmds) &&
 336                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 337                         n++;
 338                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 339                         /* Yes, this is one of the common commands */
 340                         n++; /* use the entry from common_cmds[] */
 341                         if (starts_with(candidate, cmd)) {
 342                                 /* Give prefix match a very good score */
 343                                 main_cmds.names[i]->len = 0;
 344                                 continue;
 345                         }
 346                 }
 347
 348                 main_cmds.names[i]->len =
 349                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 350         }
 351
 352         qsort(main_cmds.names, main_cmds.cnt,
 353               sizeof(*main_cmds.names), levenshtein_compare);
 354
 355         if (!main_cmds.cnt)
 356                 die(_("Uh oh. Your system reports no Git commands at all."));
 357
 358         /* skip and count prefix matches */
 359         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 360                 ; /* still counting */
 361
 362         if (main_cmds.cnt <= n) {
 363                 /* prefix matches with everything? that is too ambiguous */
 364                 best_similarity = SIMILARITY_FLOOR + 1;
 365         } else {
 366                 /* count all the most similar ones */
 367                 for (best_similarity = main_cmds.names[n++]->len;
 368                      (n < main_cmds.cnt &&
 369                       best_similarity == main_cmds.names[n]->len);
 370                      n++)
 371                         ; /* still counting */
 372         }
 373         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 374                 const char *assumed = main_cmds.names[0]->name;
 375                 main_cmds.names[0] = NULL;
 376                 clean_cmdnames(&main_cmds);
 377                 fprintf_ln(stderr,
 378                            _("WARNING: You called a Git command named '%s', "
 379                              "which does not exist.\n"
 380                              "Continuing under the assumption that you meant '%s'"),
 381                         cmd, assumed);
 382                 if (autocorrect > 0) {
 383                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 384                                 (float)autocorrect/10.0);
 385                         poll(NULL, 0, autocorrect * 100);
 386                 }
 387                 return assumed;
 388         }
 389
 390         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 391
 392         if (SIMILAR_ENOUGH(best_similarity)) {
 393                 fprintf_ln(stderr,
 394                            Q_("\nDid you mean this?",
 395                               "\nDid you mean one of these?",
 396                            n));
 397
 398                 for (i = 0; i < n; i++)
 399                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 400         }
 401
 402         exit(1);
 403 }
 404
 405 int cmd_version(int argc, const char **argv, const char *prefix)
 406 {
 407         /*
 408          * The format of this string should be kept stable for compatibility
 409          * with external projects that rely on the output of "git version".
 410          */
 411         printf("git version %s\n", git_version_string);
 412         return 0;
 413 }
 414
 415 struct similar_ref_cb {
 416         const char *base_ref;
 417         struct string_list *similar_refs;
 418 };
 419
 420 static int append_similar_ref(const char *refname, const unsigned char *sha1,
 421                               int flags, void *cb_data)
 422 {
 423         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 424         char *branch = strrchr(refname, '/') + 1;
 425         /* A remote branch of the same name is deemed similar */
 426         if (starts_with(refname, "refs/remotes/") &&
 427             !strcmp(branch, cb->base_ref))
 428                 string_list_append(cb->similar_refs,
 429                                    refname + strlen("refs/remotes/"));
 430         return 0;
 431 }
 432
 433 static struct string_list guess_refs(const char *ref)
 434 {
 435         struct similar_ref_cb ref_cb;
 436         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 437
 438         ref_cb.base_ref = ref;
 439         ref_cb.similar_refs = &similar_refs;
 440         for_each_ref(append_similar_ref, &ref_cb);
 441         return similar_refs;
 442 }
 443
 444 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 445 {
 446         int i;
 447         struct string_list suggested_refs = guess_refs(ref);
 448
 449         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 450
 451         if (suggested_refs.nr > 0) {
 452                 fprintf_ln(stderr,
 453                            Q_("\nDid you mean this?",
 454                               "\nDid you mean one of these?",
 455                               suggested_refs.nr));
 456                 for (i = 0; i < suggested_refs.nr; i++)
 457                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 458         }
 459
 460         string_list_clear(&suggested_refs, 0);
 461         exit(1);
 462 }