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