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;
  15         FLEX_ALLOC_MEM(ent, name, name, len);
  16         ent->len = len;
  17
  18         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  19         cmds->names[cmds->cnt++] = ent;
  20 }
  21
  22 static void clean_cmdnames(struct cmdnames *cmds)
  23 {
  24         int i;
  25         for (i = 0; i < cmds->cnt; ++i)
  26                 free(cmds->names[i]);
  27         free(cmds->names);
  28         cmds->cnt = 0;
  29         cmds->alloc = 0;
  30 }
  31
  32 static int cmdname_compare(const void *a_, const void *b_)
  33 {
  34         struct cmdname *a = *(struct cmdname **)a_;
  35         struct cmdname *b = *(struct cmdname **)b_;
  36         return strcmp(a->name, b->name);
  37 }
  38
  39 static void uniq(struct cmdnames *cmds)
  40 {
  41         int i, j;
  42
  43         if (!cmds->cnt)
  44                 return;
  45
  46         for (i = j = 1; i < cmds->cnt; i++) {
  47                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
  48                         free(cmds->names[i]);
  49                 else
  50                         cmds->names[j++] = cmds->names[i];
  51         }
  52
  53         cmds->cnt = j;
  54 }
  55
  56 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  57 {
  58         int ci, cj, ei;
  59         int cmp;
  60
  61         ci = cj = ei = 0;
  62         while (ci < cmds->cnt && ei < excludes->cnt) {
  63                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  64                 if (cmp < 0)
  65                         cmds->names[cj++] = cmds->names[ci++];
  66                 else if (cmp == 0) {
  67                         ei++;
  68                         free(cmds->names[ci++]);
  69                 } else if (cmp > 0)
  70                         ei++;
  71         }
  72
  73         while (ci < cmds->cnt)
  74                 cmds->names[cj++] = cmds->names[ci++];
  75
  76         cmds->cnt = cj;
  77 }
  78
  79 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
  80 {
  81         struct string_list list = STRING_LIST_INIT_NODUP;
  82         struct column_options copts;
  83         int i;
  84
  85         for (i = 0; i < cmds->cnt; i++)
  86                 string_list_append(&list, cmds->names[i]->name);
  87         /*
  88          * always enable column display, we only consult column.*
  89          * about layout strategy and stuff
  90          */
  91         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
  92         memset(&copts, 0, sizeof(copts));
  93         copts.indent = "  ";
  94         copts.padding = 2;
  95         print_columns(&list, colopts, &copts);
  96         string_list_clear(&list, 0);
  97 }
  98
  99 static int is_executable(const char *name)
 100 {
 101         struct stat st;
 102
 103         if (stat(name, &st) || /* stat, not lstat */
 104             !S_ISREG(st.st_mode))
 105                 return 0;
 106
 107 #if defined(GIT_WINDOWS_NATIVE)
 108         /*
 109          * On Windows there is no executable bit. The file extension
 110          * indicates whether it can be run as an executable, and Git
 111          * has special-handling to detect scripts and launch them
 112          * through the indicated script interpreter. We test for the
 113          * file extension first because virus scanners may make
 114          * it quite expensive to open many files.
 115          */
 116         if (ends_with(name, ".exe"))
 117                 return S_IXUSR;
 118
 119 {
 120         /*
 121          * Now that we know it does not have an executable extension,
 122          * peek into the file instead.
 123          */
 124         char buf[3] = { 0 };
 125         int n;
 126         int fd = open(name, O_RDONLY);
 127         st.st_mode &= ~S_IXUSR;
 128         if (fd >= 0) {
 129                 n = read(fd, buf, 2);
 130                 if (n == 2)
 131                         /* look for a she-bang */
 132                         if (!strcmp(buf, "#!"))
 133                                 st.st_mode |= S_IXUSR;
 134                 close(fd);
 135         }
 136 }
 137 #endif
 138         return st.st_mode & S_IXUSR;
 139 }
 140
 141 static void list_commands_in_dir(struct cmdnames *cmds,
 142                                          const char *path,
 143                                          const char *prefix)
 144 {
 145         DIR *dir = opendir(path);
 146         struct dirent *de;
 147         struct strbuf buf = STRBUF_INIT;
 148         int len;
 149
 150         if (!dir)
 151                 return;
 152         if (!prefix)
 153                 prefix = "git-";
 154
 155         strbuf_addf(&buf, "%s/", path);
 156         len = buf.len;
 157
 158         while ((de = readdir(dir)) != NULL) {
 159                 const char *ent;
 160                 size_t entlen;
 161
 162                 if (!skip_prefix(de->d_name, prefix, &ent))
 163                         continue;
 164
 165                 strbuf_setlen(&buf, len);
 166                 strbuf_addstr(&buf, de->d_name);
 167                 if (!is_executable(buf.buf))
 168                         continue;
 169
 170                 entlen = strlen(ent);
 171                 strip_suffix(ent, ".exe", &entlen);
 172
 173                 add_cmdname(cmds, ent, entlen);
 174         }
 175         closedir(dir);
 176         strbuf_release(&buf);
 177 }
 178
 179 void load_command_list(const char *prefix,
 180                 struct cmdnames *main_cmds,
 181                 struct cmdnames *other_cmds)
 182 {
 183         const char *env_path = getenv("PATH");
 184         const char *exec_path = git_exec_path();
 185
 186         if (exec_path) {
 187                 list_commands_in_dir(main_cmds, exec_path, prefix);
 188                 QSORT(main_cmds->names, main_cmds->cnt, 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, cmdname_compare);
 208                 uniq(other_cmds);
 209         }
 210         exclude_cmds(other_cmds, main_cmds);
 211 }
 212
 213 void list_commands(unsigned int colopts,
 214                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 215 {
 216         if (main_cmds->cnt) {
 217                 const char *exec_path = git_exec_path();
 218                 printf_ln(_("available git commands in '%s'"), exec_path);
 219                 putchar('\n');
 220                 pretty_print_cmdnames(main_cmds, colopts);
 221                 putchar('\n');
 222         }
 223
 224         if (other_cmds->cnt) {
 225                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 226                 putchar('\n');
 227                 pretty_print_cmdnames(other_cmds, colopts);
 228                 putchar('\n');
 229         }
 230 }
 231
 232 static int cmd_group_cmp(const void *elem1, const void *elem2)
 233 {
 234         const struct cmdname_help *e1 = elem1;
 235         const struct cmdname_help *e2 = elem2;
 236
 237         if (e1->group < e2->group)
 238                 return -1;
 239         if (e1->group > e2->group)
 240                 return 1;
 241         return strcmp(e1->name, e2->name);
 242 }
 243
 244 void list_common_cmds_help(void)
 245 {
 246         int i, longest = 0;
 247         int current_grp = -1;
 248
 249         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 250                 if (longest < strlen(common_cmds[i].name))
 251                         longest = strlen(common_cmds[i].name);
 252         }
 253
 254         QSORT(common_cmds, ARRAY_SIZE(common_cmds), cmd_group_cmp);
 255
 256         puts(_("These are common Git commands used in various situations:"));
 257
 258         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 259                 if (common_cmds[i].group != current_grp) {
 260                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
 261                         current_grp = common_cmds[i].group;
 262                 }
 263
 264                 printf("   %s   ", common_cmds[i].name);
 265                 mput_char(' ', longest - strlen(common_cmds[i].name));
 266                 puts(_(common_cmds[i].help));
 267         }
 268 }
 269
 270 int is_in_cmdlist(struct cmdnames *c, const char *s)
 271 {
 272         int i;
 273         for (i = 0; i < c->cnt; i++)
 274                 if (!strcmp(s, c->names[i]->name))
 275                         return 1;
 276         return 0;
 277 }
 278
 279 static int autocorrect;
 280 static struct cmdnames aliases;
 281
 282 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 283 {
 284         const char *p;
 285
 286         if (!strcmp(var, "help.autocorrect"))
 287                 autocorrect = git_config_int(var,value);
 288         /* Also use aliases for command lookup */
 289         if (skip_prefix(var, "alias.", &p))
 290                 add_cmdname(&aliases, p, strlen(p));
 291
 292         return git_default_config(var, value, cb);
 293 }
 294
 295 static int levenshtein_compare(const void *p1, const void *p2)
 296 {
 297         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 298         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 299         int l1 = (*c1)->len;
 300         int l2 = (*c2)->len;
 301         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 302 }
 303
 304 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 305 {
 306         int i;
 307         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 308
 309         for (i = 0; i < old->cnt; i++)
 310                 cmds->names[cmds->cnt++] = old->names[i];
 311         free(old->names);
 312         old->cnt = 0;
 313         old->names = NULL;
 314 }
 315
 316 /* An empirically derived magic number */
 317 #define SIMILARITY_FLOOR 7
 318 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 319
 320 static const char bad_interpreter_advice[] =
 321         N_("'%s' appears to be a git command, but we were not\n"
 322         "able to execute it. Maybe git-%s is broken?");
 323
 324 const char *help_unknown_cmd(const char *cmd)
 325 {
 326         int i, n, best_similarity = 0;
 327         struct cmdnames main_cmds, other_cmds;
 328
 329         memset(&main_cmds, 0, sizeof(main_cmds));
 330         memset(&other_cmds, 0, sizeof(other_cmds));
 331         memset(&aliases, 0, sizeof(aliases));
 332
 333         git_config(git_unknown_cmd_config, NULL);
 334
 335         load_command_list("git-", &main_cmds, &other_cmds);
 336
 337         add_cmd_list(&main_cmds, &aliases);
 338         add_cmd_list(&main_cmds, &other_cmds);
 339         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 340         uniq(&main_cmds);
 341
 342         /* This abuses cmdname->len for levenshtein distance */
 343         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 344                 int cmp = 0; /* avoid compiler stupidity */
 345                 const char *candidate = main_cmds.names[i]->name;
 346
 347                 /*
 348                  * An exact match means we have the command, but
 349                  * for some reason exec'ing it gave us ENOENT; probably
 350                  * it's a bad interpreter in the #! line.
 351                  */
 352                 if (!strcmp(candidate, cmd))
 353                         die(_(bad_interpreter_advice), cmd, cmd);
 354
 355                 /* Does the candidate appear in common_cmds list? */
 356                 while (n < ARRAY_SIZE(common_cmds) &&
 357                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 358                         n++;
 359                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 360                         /* Yes, this is one of the common commands */
 361                         n++; /* use the entry from common_cmds[] */
 362                         if (starts_with(candidate, cmd)) {
 363                                 /* Give prefix match a very good score */
 364                                 main_cmds.names[i]->len = 0;
 365                                 continue;
 366                         }
 367                 }
 368
 369                 main_cmds.names[i]->len =
 370                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 371         }
 372
 373         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 374
 375         if (!main_cmds.cnt)
 376                 die(_("Uh oh. Your system reports no Git commands at all."));
 377
 378         /* skip and count prefix matches */
 379         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 380                 ; /* still counting */
 381
 382         if (main_cmds.cnt <= n) {
 383                 /* prefix matches with everything? that is too ambiguous */
 384                 best_similarity = SIMILARITY_FLOOR + 1;
 385         } else {
 386                 /* count all the most similar ones */
 387                 for (best_similarity = main_cmds.names[n++]->len;
 388                      (n < main_cmds.cnt &&
 389                       best_similarity == main_cmds.names[n]->len);
 390                      n++)
 391                         ; /* still counting */
 392         }
 393         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 394                 const char *assumed = main_cmds.names[0]->name;
 395                 main_cmds.names[0] = NULL;
 396                 clean_cmdnames(&main_cmds);
 397                 fprintf_ln(stderr,
 398                            _("WARNING: You called a Git command named '%s', "
 399                              "which does not exist.\n"
 400                              "Continuing under the assumption that you meant '%s'"),
 401                         cmd, assumed);
 402                 if (autocorrect > 0) {
 403                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 404                                 (float)autocorrect/10.0);
 405                         sleep_millisec(autocorrect * 100);
 406                 }
 407                 return assumed;
 408         }
 409
 410         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 411
 412         if (SIMILAR_ENOUGH(best_similarity)) {
 413                 fprintf_ln(stderr,
 414                            Q_("\nDid you mean this?",
 415                               "\nDid you mean one of these?",
 416                            n));
 417
 418                 for (i = 0; i < n; i++)
 419                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 420         }
 421
 422         exit(1);
 423 }
 424
 425 int cmd_version(int argc, const char **argv, const char *prefix)
 426 {
 427         /*
 428          * The format of this string should be kept stable for compatibility
 429          * with external projects that rely on the output of "git version".
 430          */
 431         printf("git version %s\n", git_version_string);
 432         while (*++argv) {
 433                 if (!strcmp(*argv, "--build-options")) {
 434                         printf("sizeof-long: %d\n", (int)sizeof(long));
 435                         /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 436                 }
 437         }
 438         return 0;
 439 }
 440
 441 struct similar_ref_cb {
 442         const char *base_ref;
 443         struct string_list *similar_refs;
 444 };
 445
 446 static int append_similar_ref(const char *refname, const struct object_id *oid,
 447                               int flags, void *cb_data)
 448 {
 449         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 450         char *branch = strrchr(refname, '/') + 1;
 451         const char *remote;
 452
 453         /* A remote branch of the same name is deemed similar */
 454         if (skip_prefix(refname, "refs/remotes/", &remote) &&
 455             !strcmp(branch, cb->base_ref))
 456                 string_list_append(cb->similar_refs, remote);
 457         return 0;
 458 }
 459
 460 static struct string_list guess_refs(const char *ref)
 461 {
 462         struct similar_ref_cb ref_cb;
 463         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 464
 465         ref_cb.base_ref = ref;
 466         ref_cb.similar_refs = &similar_refs;
 467         for_each_ref(append_similar_ref, &ref_cb);
 468         return similar_refs;
 469 }
 470
 471 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 472 {
 473         int i;
 474         struct string_list suggested_refs = guess_refs(ref);
 475
 476         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 477
 478         if (suggested_refs.nr > 0) {
 479                 fprintf_ln(stderr,
 480                            Q_("\nDid you mean this?",
 481                               "\nDid you mean one of these?",
 482                               suggested_refs.nr));
 483                 for (i = 0; i < suggested_refs.nr; i++)
 484                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 485         }
 486
 487         string_list_clear(&suggested_refs, 0);
 488         exit(1);
 489 }