help.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "builtin.h"
   4 #include "exec_cmd.h"
   5 #include "levenshtein.h"
   6 #include "help.h"
   7 #include "common-cmds.h"
   8 #include "string-list.h"
   9 #include "column.h"
  10 #include "version.h"
  11 #include "refs.h"
  12
  13 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  14 {
  15         struct cmdname *ent;
  16         FLEX_ALLOC_MEM(ent, name, name, len);
  17         ent->len = len;
  18
  19         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  20         cmds->names[cmds->cnt++] = ent;
  21 }
  22
  23 static void clean_cmdnames(struct cmdnames *cmds)
  24 {
  25         int i;
  26         for (i = 0; i < cmds->cnt; ++i)
  27                 free(cmds->names[i]);
  28         free(cmds->names);
  29         cmds->cnt = 0;
  30         cmds->alloc = 0;
  31 }
  32
  33 static int cmdname_compare(const void *a_, const void *b_)
  34 {
  35         struct cmdname *a = *(struct cmdname **)a_;
  36         struct cmdname *b = *(struct cmdname **)b_;
  37         return strcmp(a->name, b->name);
  38 }
  39
  40 static void uniq(struct cmdnames *cmds)
  41 {
  42         int i, j;
  43
  44         if (!cmds->cnt)
  45                 return;
  46
  47         for (i = j = 1; i < cmds->cnt; i++) {
  48                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
  49                         free(cmds->names[i]);
  50                 else
  51                         cmds->names[j++] = cmds->names[i];
  52         }
  53
  54         cmds->cnt = j;
  55 }
  56
  57 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  58 {
  59         int ci, cj, ei;
  60         int cmp;
  61
  62         ci = cj = ei = 0;
  63         while (ci < cmds->cnt && ei < excludes->cnt) {
  64                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  65                 if (cmp < 0)
  66                         cmds->names[cj++] = cmds->names[ci++];
  67                 else if (cmp == 0) {
  68                         ei++;
  69                         free(cmds->names[ci++]);
  70                 } else if (cmp > 0)
  71                         ei++;
  72         }
  73
  74         while (ci < cmds->cnt)
  75                 cmds->names[cj++] = cmds->names[ci++];
  76
  77         cmds->cnt = cj;
  78 }
  79
  80 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
  81 {
  82         struct string_list list = STRING_LIST_INIT_NODUP;
  83         struct column_options copts;
  84         int i;
  85
  86         for (i = 0; i < cmds->cnt; i++)
  87                 string_list_append(&list, cmds->names[i]->name);
  88         /*
  89          * always enable column display, we only consult column.*
  90          * about layout strategy and stuff
  91          */
  92         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
  93         memset(&copts, 0, sizeof(copts));
  94         copts.indent = "  ";
  95         copts.padding = 2;
  96         print_columns(&list, colopts, &copts);
  97         string_list_clear(&list, 0);
  98 }
  99
 100 static int is_executable(const char *name)
 101 {
 102         struct stat st;
 103
 104         if (stat(name, &st) || /* stat, not lstat */
 105             !S_ISREG(st.st_mode))
 106                 return 0;
 107
 108 #if defined(GIT_WINDOWS_NATIVE)
 109         /*
 110          * On Windows there is no executable bit. The file extension
 111          * indicates whether it can be run as an executable, and Git
 112          * has special-handling to detect scripts and launch them
 113          * through the indicated script interpreter. We test for the
 114          * file extension first because virus scanners may make
 115          * it quite expensive to open many files.
 116          */
 117         if (ends_with(name, ".exe"))
 118                 return S_IXUSR;
 119
 120 {
 121         /*
 122          * Now that we know it does not have an executable extension,
 123          * peek into the file instead.
 124          */
 125         char buf[3] = { 0 };
 126         int n;
 127         int fd = open(name, O_RDONLY);
 128         st.st_mode &= ~S_IXUSR;
 129         if (fd >= 0) {
 130                 n = read(fd, buf, 2);
 131                 if (n == 2)
 132                         /* look for a she-bang */
 133                         if (!strcmp(buf, "#!"))
 134                                 st.st_mode |= S_IXUSR;
 135                 close(fd);
 136         }
 137 }
 138 #endif
 139         return st.st_mode & S_IXUSR;
 140 }
 141
 142 static void list_commands_in_dir(struct cmdnames *cmds,
 143                                          const char *path,
 144                                          const char *prefix)
 145 {
 146         DIR *dir = opendir(path);
 147         struct dirent *de;
 148         struct strbuf buf = STRBUF_INIT;
 149         int len;
 150
 151         if (!dir)
 152                 return;
 153         if (!prefix)
 154                 prefix = "git-";
 155
 156         strbuf_addf(&buf, "%s/", path);
 157         len = buf.len;
 158
 159         while ((de = readdir(dir)) != NULL) {
 160                 const char *ent;
 161                 size_t entlen;
 162
 163                 if (!skip_prefix(de->d_name, prefix, &ent))
 164                         continue;
 165
 166                 strbuf_setlen(&buf, len);
 167                 strbuf_addstr(&buf, de->d_name);
 168                 if (!is_executable(buf.buf))
 169                         continue;
 170
 171                 entlen = strlen(ent);
 172                 strip_suffix(ent, ".exe", &entlen);
 173
 174                 add_cmdname(cmds, ent, entlen);
 175         }
 176         closedir(dir);
 177         strbuf_release(&buf);
 178 }
 179
 180 void load_command_list(const char *prefix,
 181                 struct cmdnames *main_cmds,
 182                 struct cmdnames *other_cmds)
 183 {
 184         const char *env_path = getenv("PATH");
 185         const char *exec_path = git_exec_path();
 186
 187         if (exec_path) {
 188                 list_commands_in_dir(main_cmds, exec_path, prefix);
 189                 QSORT(main_cmds->names, main_cmds->cnt, cmdname_compare);
 190                 uniq(main_cmds);
 191         }
 192
 193         if (env_path) {
 194                 char *paths, *path, *colon;
 195                 path = paths = xstrdup(env_path);
 196                 while (1) {
 197                         if ((colon = strchr(path, PATH_SEP)))
 198                                 *colon = 0;
 199                         if (!exec_path || strcmp(path, exec_path))
 200                                 list_commands_in_dir(other_cmds, path, prefix);
 201
 202                         if (!colon)
 203                                 break;
 204                         path = colon + 1;
 205                 }
 206                 free(paths);
 207
 208                 QSORT(other_cmds->names, other_cmds->cnt, 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_cmdnames(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_cmdnames(other_cmds, colopts);
 229                 putchar('\n');
 230         }
 231 }
 232
 233 static int cmd_group_cmp(const void *elem1, const void *elem2)
 234 {
 235         const struct cmdname_help *e1 = elem1;
 236         const struct cmdname_help *e2 = elem2;
 237
 238         if (e1->group < e2->group)
 239                 return -1;
 240         if (e1->group > e2->group)
 241                 return 1;
 242         return strcmp(e1->name, e2->name);
 243 }
 244
 245 void list_common_cmds_help(void)
 246 {
 247         int i, longest = 0;
 248         int current_grp = -1;
 249
 250         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 251                 if (longest < strlen(common_cmds[i].name))
 252                         longest = strlen(common_cmds[i].name);
 253         }
 254
 255         QSORT(common_cmds, ARRAY_SIZE(common_cmds), cmd_group_cmp);
 256
 257         puts(_("These are common Git commands used in various situations:"));
 258
 259         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 260                 if (common_cmds[i].group != current_grp) {
 261                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
 262                         current_grp = common_cmds[i].group;
 263                 }
 264
 265                 printf("   %s   ", common_cmds[i].name);
 266                 mput_char(' ', longest - strlen(common_cmds[i].name));
 267                 puts(_(common_cmds[i].help));
 268         }
 269 }
 270
 271 int is_in_cmdlist(struct cmdnames *c, const char *s)
 272 {
 273         int i;
 274         for (i = 0; i < c->cnt; i++)
 275                 if (!strcmp(s, c->names[i]->name))
 276                         return 1;
 277         return 0;
 278 }
 279
 280 static int autocorrect;
 281 static struct cmdnames aliases;
 282
 283 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 284 {
 285         const char *p;
 286
 287         if (!strcmp(var, "help.autocorrect"))
 288                 autocorrect = git_config_int(var,value);
 289         /* Also use aliases for command lookup */
 290         if (skip_prefix(var, "alias.", &p))
 291                 add_cmdname(&aliases, p, strlen(p));
 292
 293         return git_default_config(var, value, cb);
 294 }
 295
 296 static int levenshtein_compare(const void *p1, const void *p2)
 297 {
 298         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 299         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 300         int l1 = (*c1)->len;
 301         int l2 = (*c2)->len;
 302         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 303 }
 304
 305 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 306 {
 307         int i;
 308         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 309
 310         for (i = 0; i < old->cnt; i++)
 311                 cmds->names[cmds->cnt++] = old->names[i];
 312         free(old->names);
 313         old->cnt = 0;
 314         old->names = NULL;
 315 }
 316
 317 /* An empirically derived magic number */
 318 #define SIMILARITY_FLOOR 7
 319 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 320
 321 static const char bad_interpreter_advice[] =
 322         N_("'%s' appears to be a git command, but we were not\n"
 323         "able to execute it. Maybe git-%s is broken?");
 324
 325 const char *help_unknown_cmd(const char *cmd)
 326 {
 327         int i, n, best_similarity = 0;
 328         struct cmdnames main_cmds, other_cmds;
 329
 330         memset(&main_cmds, 0, sizeof(main_cmds));
 331         memset(&other_cmds, 0, sizeof(other_cmds));
 332         memset(&aliases, 0, sizeof(aliases));
 333
 334         read_early_config(git_unknown_cmd_config, NULL);
 335
 336         load_command_list("git-", &main_cmds, &other_cmds);
 337
 338         add_cmd_list(&main_cmds, &aliases);
 339         add_cmd_list(&main_cmds, &other_cmds);
 340         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 341         uniq(&main_cmds);
 342
 343         /* This abuses cmdname->len for levenshtein distance */
 344         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 345                 int cmp = 0; /* avoid compiler stupidity */
 346                 const char *candidate = main_cmds.names[i]->name;
 347
 348                 /*
 349                  * An exact match means we have the command, but
 350                  * for some reason exec'ing it gave us ENOENT; probably
 351                  * it's a bad interpreter in the #! line.
 352                  */
 353                 if (!strcmp(candidate, cmd))
 354                         die(_(bad_interpreter_advice), cmd, cmd);
 355
 356                 /* Does the candidate appear in common_cmds list? */
 357                 while (n < ARRAY_SIZE(common_cmds) &&
 358                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 359                         n++;
 360                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 361                         /* Yes, this is one of the common commands */
 362                         n++; /* use the entry from common_cmds[] */
 363                         if (starts_with(candidate, cmd)) {
 364                                 /* Give prefix match a very good score */
 365                                 main_cmds.names[i]->len = 0;
 366                                 continue;
 367                         }
 368                 }
 369
 370                 main_cmds.names[i]->len =
 371                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 372         }
 373
 374         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 375
 376         if (!main_cmds.cnt)
 377                 die(_("Uh oh. Your system reports no Git commands at all."));
 378
 379         /* skip and count prefix matches */
 380         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 381                 ; /* still counting */
 382
 383         if (main_cmds.cnt <= n) {
 384                 /* prefix matches with everything? that is too ambiguous */
 385                 best_similarity = SIMILARITY_FLOOR + 1;
 386         } else {
 387                 /* count all the most similar ones */
 388                 for (best_similarity = main_cmds.names[n++]->len;
 389                      (n < main_cmds.cnt &&
 390                       best_similarity == main_cmds.names[n]->len);
 391                      n++)
 392                         ; /* still counting */
 393         }
 394         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 395                 const char *assumed = main_cmds.names[0]->name;
 396                 main_cmds.names[0] = NULL;
 397                 clean_cmdnames(&main_cmds);
 398                 fprintf_ln(stderr,
 399                            _("WARNING: You called a Git command named '%s', "
 400                              "which does not exist.\n"
 401                              "Continuing under the assumption that you meant '%s'"),
 402                         cmd, assumed);
 403                 if (autocorrect > 0) {
 404                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 405                                 (float)autocorrect/10.0);
 406                         sleep_millisec(autocorrect * 100);
 407                 }
 408                 return assumed;
 409         }
 410
 411         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 412
 413         if (SIMILAR_ENOUGH(best_similarity)) {
 414                 fprintf_ln(stderr,
 415                            Q_("\nDid you mean this?",
 416                               "\nDid you mean one of these?",
 417                            n));
 418
 419                 for (i = 0; i < n; i++)
 420                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 421         }
 422
 423         exit(1);
 424 }
 425
 426 int cmd_version(int argc, const char **argv, const char *prefix)
 427 {
 428         /*
 429          * The format of this string should be kept stable for compatibility
 430          * with external projects that rely on the output of "git version".
 431          */
 432         printf("git version %s\n", git_version_string);
 433         while (*++argv) {
 434                 if (!strcmp(*argv, "--build-options")) {
 435                         printf("sizeof-long: %d\n", (int)sizeof(long));
 436                         /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 437                 }
 438         }
 439         return 0;
 440 }
 441
 442 struct similar_ref_cb {
 443         const char *base_ref;
 444         struct string_list *similar_refs;
 445 };
 446
 447 static int append_similar_ref(const char *refname, const struct object_id *oid,
 448                               int flags, void *cb_data)
 449 {
 450         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 451         char *branch = strrchr(refname, '/') + 1;
 452         const char *remote;
 453
 454         /* A remote branch of the same name is deemed similar */
 455         if (skip_prefix(refname, "refs/remotes/", &remote) &&
 456             !strcmp(branch, cb->base_ref))
 457                 string_list_append(cb->similar_refs, remote);
 458         return 0;
 459 }
 460
 461 static struct string_list guess_refs(const char *ref)
 462 {
 463         struct similar_ref_cb ref_cb;
 464         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 465
 466         ref_cb.base_ref = ref;
 467         ref_cb.similar_refs = &similar_refs;
 468         for_each_ref(append_similar_ref, &ref_cb);
 469         return similar_refs;
 470 }
 471
 472 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 473 {
 474         int i;
 475         struct string_list suggested_refs = guess_refs(ref);
 476
 477         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 478
 479         if (suggested_refs.nr > 0) {
 480                 fprintf_ln(stderr,
 481                            Q_("\nDid you mean this?",
 482                               "\nDid you mean one of these?",
 483                               suggested_refs.nr));
 484                 for (i = 0; i < suggested_refs.nr; i++)
 485                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 486         }
 487
 488         string_list_clear(&suggested_refs, 0);
 489         exit(1);
 490 }