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 {       /* cannot trust the executable bit, peek into the file instead */
 109         char buf[3] = { 0 };
 110         int n;
 111         int fd = open(name, O_RDONLY);
 112         st.st_mode &= ~S_IXUSR;
 113         if (fd >= 0) {
 114                 n = read(fd, buf, 2);
 115                 if (n == 2)
 116                         /* DOS executables start with "MZ" */
 117                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 118                                 st.st_mode |= S_IXUSR;
 119                 close(fd);
 120         }
 121 }
 122 #endif
 123         return st.st_mode & S_IXUSR;
 124 }
 125
 126 static void list_commands_in_dir(struct cmdnames *cmds,
 127                                          const char *path,
 128                                          const char *prefix)
 129 {
 130         DIR *dir = opendir(path);
 131         struct dirent *de;
 132         struct strbuf buf = STRBUF_INIT;
 133         int len;
 134
 135         if (!dir)
 136                 return;
 137         if (!prefix)
 138                 prefix = "git-";
 139
 140         strbuf_addf(&buf, "%s/", path);
 141         len = buf.len;
 142
 143         while ((de = readdir(dir)) != NULL) {
 144                 const char *ent;
 145                 size_t entlen;
 146
 147                 if (!skip_prefix(de->d_name, prefix, &ent))
 148                         continue;
 149
 150                 strbuf_setlen(&buf, len);
 151                 strbuf_addstr(&buf, de->d_name);
 152                 if (!is_executable(buf.buf))
 153                         continue;
 154
 155                 entlen = strlen(ent);
 156                 strip_suffix(ent, ".exe", &entlen);
 157
 158                 add_cmdname(cmds, ent, entlen);
 159         }
 160         closedir(dir);
 161         strbuf_release(&buf);
 162 }
 163
 164 void load_command_list(const char *prefix,
 165                 struct cmdnames *main_cmds,
 166                 struct cmdnames *other_cmds)
 167 {
 168         const char *env_path = getenv("PATH");
 169         const char *exec_path = git_exec_path();
 170
 171         if (exec_path) {
 172                 list_commands_in_dir(main_cmds, exec_path, prefix);
 173                 qsort(main_cmds->names, main_cmds->cnt,
 174                       sizeof(*main_cmds->names), cmdname_compare);
 175                 uniq(main_cmds);
 176         }
 177
 178         if (env_path) {
 179                 char *paths, *path, *colon;
 180                 path = paths = xstrdup(env_path);
 181                 while (1) {
 182                         if ((colon = strchr(path, PATH_SEP)))
 183                                 *colon = 0;
 184                         if (!exec_path || strcmp(path, exec_path))
 185                                 list_commands_in_dir(other_cmds, path, prefix);
 186
 187                         if (!colon)
 188                                 break;
 189                         path = colon + 1;
 190                 }
 191                 free(paths);
 192
 193                 qsort(other_cmds->names, other_cmds->cnt,
 194                       sizeof(*other_cmds->names), cmdname_compare);
 195                 uniq(other_cmds);
 196         }
 197         exclude_cmds(other_cmds, main_cmds);
 198 }
 199
 200 void list_commands(unsigned int colopts,
 201                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 202 {
 203         if (main_cmds->cnt) {
 204                 const char *exec_path = git_exec_path();
 205                 printf_ln(_("available git commands in '%s'"), exec_path);
 206                 putchar('\n');
 207                 pretty_print_cmdnames(main_cmds, colopts);
 208                 putchar('\n');
 209         }
 210
 211         if (other_cmds->cnt) {
 212                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 213                 putchar('\n');
 214                 pretty_print_cmdnames(other_cmds, colopts);
 215                 putchar('\n');
 216         }
 217 }
 218
 219 static int cmd_group_cmp(const void *elem1, const void *elem2)
 220 {
 221         const struct cmdname_help *e1 = elem1;
 222         const struct cmdname_help *e2 = elem2;
 223
 224         if (e1->group < e2->group)
 225                 return -1;
 226         if (e1->group > e2->group)
 227                 return 1;
 228         return strcmp(e1->name, e2->name);
 229 }
 230
 231 void list_common_cmds_help(void)
 232 {
 233         int i, longest = 0;
 234         int current_grp = -1;
 235
 236         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 237                 if (longest < strlen(common_cmds[i].name))
 238                         longest = strlen(common_cmds[i].name);
 239         }
 240
 241         qsort(common_cmds, ARRAY_SIZE(common_cmds),
 242                 sizeof(common_cmds[0]), cmd_group_cmp);
 243
 244         puts(_("These are common Git commands used in various situations:"));
 245
 246         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 247                 if (common_cmds[i].group != current_grp) {
 248                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
 249                         current_grp = common_cmds[i].group;
 250                 }
 251
 252                 printf("   %s   ", common_cmds[i].name);
 253                 mput_char(' ', longest - strlen(common_cmds[i].name));
 254                 puts(_(common_cmds[i].help));
 255         }
 256 }
 257
 258 int is_in_cmdlist(struct cmdnames *c, const char *s)
 259 {
 260         int i;
 261         for (i = 0; i < c->cnt; i++)
 262                 if (!strcmp(s, c->names[i]->name))
 263                         return 1;
 264         return 0;
 265 }
 266
 267 static int autocorrect;
 268 static struct cmdnames aliases;
 269
 270 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 271 {
 272         const char *p;
 273
 274         if (!strcmp(var, "help.autocorrect"))
 275                 autocorrect = git_config_int(var,value);
 276         /* Also use aliases for command lookup */
 277         if (skip_prefix(var, "alias.", &p))
 278                 add_cmdname(&aliases, p, strlen(p));
 279
 280         return git_default_config(var, value, cb);
 281 }
 282
 283 static int levenshtein_compare(const void *p1, const void *p2)
 284 {
 285         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 286         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 287         int l1 = (*c1)->len;
 288         int l2 = (*c2)->len;
 289         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 290 }
 291
 292 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 293 {
 294         int i;
 295         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 296
 297         for (i = 0; i < old->cnt; i++)
 298                 cmds->names[cmds->cnt++] = old->names[i];
 299         free(old->names);
 300         old->cnt = 0;
 301         old->names = NULL;
 302 }
 303
 304 /* An empirically derived magic number */
 305 #define SIMILARITY_FLOOR 7
 306 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 307
 308 static const char bad_interpreter_advice[] =
 309         N_("'%s' appears to be a git command, but we were not\n"
 310         "able to execute it. Maybe git-%s is broken?");
 311
 312 const char *help_unknown_cmd(const char *cmd)
 313 {
 314         int i, n, best_similarity = 0;
 315         struct cmdnames main_cmds, other_cmds;
 316
 317         memset(&main_cmds, 0, sizeof(main_cmds));
 318         memset(&other_cmds, 0, sizeof(other_cmds));
 319         memset(&aliases, 0, sizeof(aliases));
 320
 321         git_config(git_unknown_cmd_config, NULL);
 322
 323         load_command_list("git-", &main_cmds, &other_cmds);
 324
 325         add_cmd_list(&main_cmds, &aliases);
 326         add_cmd_list(&main_cmds, &other_cmds);
 327         qsort(main_cmds.names, main_cmds.cnt,
 328               sizeof(*main_cmds.names), cmdname_compare);
 329         uniq(&main_cmds);
 330
 331         /* This abuses cmdname->len for levenshtein distance */
 332         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 333                 int cmp = 0; /* avoid compiler stupidity */
 334                 const char *candidate = main_cmds.names[i]->name;
 335
 336                 /*
 337                  * An exact match means we have the command, but
 338                  * for some reason exec'ing it gave us ENOENT; probably
 339                  * it's a bad interpreter in the #! line.
 340                  */
 341                 if (!strcmp(candidate, cmd))
 342                         die(_(bad_interpreter_advice), cmd, cmd);
 343
 344                 /* Does the candidate appear in common_cmds list? */
 345                 while (n < ARRAY_SIZE(common_cmds) &&
 346                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 347                         n++;
 348                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 349                         /* Yes, this is one of the common commands */
 350                         n++; /* use the entry from common_cmds[] */
 351                         if (starts_with(candidate, cmd)) {
 352                                 /* Give prefix match a very good score */
 353                                 main_cmds.names[i]->len = 0;
 354                                 continue;
 355                         }
 356                 }
 357
 358                 main_cmds.names[i]->len =
 359                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 360         }
 361
 362         qsort(main_cmds.names, main_cmds.cnt,
 363               sizeof(*main_cmds.names), levenshtein_compare);
 364
 365         if (!main_cmds.cnt)
 366                 die(_("Uh oh. Your system reports no Git commands at all."));
 367
 368         /* skip and count prefix matches */
 369         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 370                 ; /* still counting */
 371
 372         if (main_cmds.cnt <= n) {
 373                 /* prefix matches with everything? that is too ambiguous */
 374                 best_similarity = SIMILARITY_FLOOR + 1;
 375         } else {
 376                 /* count all the most similar ones */
 377                 for (best_similarity = main_cmds.names[n++]->len;
 378                      (n < main_cmds.cnt &&
 379                       best_similarity == main_cmds.names[n]->len);
 380                      n++)
 381                         ; /* still counting */
 382         }
 383         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 384                 const char *assumed = main_cmds.names[0]->name;
 385                 main_cmds.names[0] = NULL;
 386                 clean_cmdnames(&main_cmds);
 387                 fprintf_ln(stderr,
 388                            _("WARNING: You called a Git command named '%s', "
 389                              "which does not exist.\n"
 390                              "Continuing under the assumption that you meant '%s'"),
 391                         cmd, assumed);
 392                 if (autocorrect > 0) {
 393                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 394                                 (float)autocorrect/10.0);
 395                         sleep_millisec(autocorrect * 100);
 396                 }
 397                 return assumed;
 398         }
 399
 400         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 401
 402         if (SIMILAR_ENOUGH(best_similarity)) {
 403                 fprintf_ln(stderr,
 404                            Q_("\nDid you mean this?",
 405                               "\nDid you mean one of these?",
 406                            n));
 407
 408                 for (i = 0; i < n; i++)
 409                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 410         }
 411
 412         exit(1);
 413 }
 414
 415 int cmd_version(int argc, const char **argv, const char *prefix)
 416 {
 417         /*
 418          * The format of this string should be kept stable for compatibility
 419          * with external projects that rely on the output of "git version".
 420          */
 421         printf("git version %s\n", git_version_string);
 422         return 0;
 423 }
 424
 425 struct similar_ref_cb {
 426         const char *base_ref;
 427         struct string_list *similar_refs;
 428 };
 429
 430 static int append_similar_ref(const char *refname, const struct object_id *oid,
 431                               int flags, void *cb_data)
 432 {
 433         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 434         char *branch = strrchr(refname, '/') + 1;
 435         const char *remote;
 436
 437         /* A remote branch of the same name is deemed similar */
 438         if (skip_prefix(refname, "refs/remotes/", &remote) &&
 439             !strcmp(branch, cb->base_ref))
 440                 string_list_append(cb->similar_refs, remote);
 441         return 0;
 442 }
 443
 444 static struct string_list guess_refs(const char *ref)
 445 {
 446         struct similar_ref_cb ref_cb;
 447         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 448
 449         ref_cb.base_ref = ref;
 450         ref_cb.similar_refs = &similar_refs;
 451         for_each_ref(append_similar_ref, &ref_cb);
 452         return similar_refs;
 453 }
 454
 455 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 456 {
 457         int i;
 458         struct string_list suggested_refs = guess_refs(ref);
 459
 460         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 461
 462         if (suggested_refs.nr > 0) {
 463                 fprintf_ln(stderr,
 464                            Q_("\nDid you mean this?",
 465                               "\nDid you mean one of these?",
 466                               suggested_refs.nr));
 467                 for (i = 0; i < suggested_refs.nr; i++)
 468                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 469         }
 470
 471         string_list_clear(&suggested_refs, 0);
 472         exit(1);
 473 }