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) || defined(__CYGWIN__)
 111 #if defined(__CYGWIN__)
 112 if ((st.st_mode & S_IXUSR) == 0)
 113 #endif
 114 {       /* cannot trust the executable bit, peek into the file instead */
 115         char buf[3] = { 0 };
 116         int n;
 117         int fd = open(name, O_RDONLY);
 118         st.st_mode &= ~S_IXUSR;
 119         if (fd >= 0) {
 120                 n = read(fd, buf, 2);
 121                 if (n == 2)
 122                         /* DOS executables start with "MZ" */
 123                         if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 124                                 st.st_mode |= S_IXUSR;
 125                 close(fd);
 126         }
 127 }
 128 #endif
 129         return st.st_mode & S_IXUSR;
 130 }
 131
 132 static void list_commands_in_dir(struct cmdnames *cmds,
 133                                          const char *path,
 134                                          const char *prefix)
 135 {
 136         int prefix_len;
 137         DIR *dir = opendir(path);
 138         struct dirent *de;
 139         struct strbuf buf = STRBUF_INIT;
 140         int len;
 141
 142         if (!dir)
 143                 return;
 144         if (!prefix)
 145                 prefix = "git-";
 146         prefix_len = strlen(prefix);
 147
 148         strbuf_addf(&buf, "%s/", path);
 149         len = buf.len;
 150
 151         while ((de = readdir(dir)) != NULL) {
 152                 int entlen;
 153
 154                 if (prefixcmp(de->d_name, prefix))
 155                         continue;
 156
 157                 strbuf_setlen(&buf, len);
 158                 strbuf_addstr(&buf, de->d_name);
 159                 if (!is_executable(buf.buf))
 160                         continue;
 161
 162                 entlen = strlen(de->d_name) - prefix_len;
 163                 if (has_extension(de->d_name, ".exe"))
 164                         entlen -= 4;
 165
 166                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
 167         }
 168         closedir(dir);
 169         strbuf_release(&buf);
 170 }
 171
 172 void load_command_list(const char *prefix,
 173                 struct cmdnames *main_cmds,
 174                 struct cmdnames *other_cmds)
 175 {
 176         const char *env_path = getenv("PATH");
 177         const char *exec_path = git_exec_path();
 178
 179         if (exec_path) {
 180                 list_commands_in_dir(main_cmds, exec_path, prefix);
 181                 qsort(main_cmds->names, main_cmds->cnt,
 182                       sizeof(*main_cmds->names), cmdname_compare);
 183                 uniq(main_cmds);
 184         }
 185
 186         if (env_path) {
 187                 char *paths, *path, *colon;
 188                 path = paths = xstrdup(env_path);
 189                 while (1) {
 190                         if ((colon = strchr(path, PATH_SEP)))
 191                                 *colon = 0;
 192                         if (!exec_path || strcmp(path, exec_path))
 193                                 list_commands_in_dir(other_cmds, path, prefix);
 194
 195                         if (!colon)
 196                                 break;
 197                         path = colon + 1;
 198                 }
 199                 free(paths);
 200
 201                 qsort(other_cmds->names, other_cmds->cnt,
 202                       sizeof(*other_cmds->names), cmdname_compare);
 203                 uniq(other_cmds);
 204         }
 205         exclude_cmds(other_cmds, main_cmds);
 206 }
 207
 208 void list_commands(unsigned int colopts,
 209                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 210 {
 211         if (main_cmds->cnt) {
 212                 const char *exec_path = git_exec_path();
 213                 printf_ln(_("available git commands in '%s'"), exec_path);
 214                 putchar('\n');
 215                 pretty_print_string_list(main_cmds, colopts);
 216                 putchar('\n');
 217         }
 218
 219         if (other_cmds->cnt) {
 220                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 221                 putchar('\n');
 222                 pretty_print_string_list(other_cmds, colopts);
 223                 putchar('\n');
 224         }
 225 }
 226
 227 void list_common_cmds_help(void)
 228 {
 229         int i, longest = 0;
 230
 231         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 232                 if (longest < strlen(common_cmds[i].name))
 233                         longest = strlen(common_cmds[i].name);
 234         }
 235
 236         puts(_("The most commonly used git commands are:"));
 237         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 238                 printf("   %s   ", common_cmds[i].name);
 239                 mput_char(' ', longest - strlen(common_cmds[i].name));
 240                 puts(_(common_cmds[i].help));
 241         }
 242 }
 243
 244 int is_in_cmdlist(struct cmdnames *c, const char *s)
 245 {
 246         int i;
 247         for (i = 0; i < c->cnt; i++)
 248                 if (!strcmp(s, c->names[i]->name))
 249                         return 1;
 250         return 0;
 251 }
 252
 253 static int autocorrect;
 254 static struct cmdnames aliases;
 255
 256 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 257 {
 258         if (!strcmp(var, "help.autocorrect"))
 259                 autocorrect = git_config_int(var,value);
 260         /* Also use aliases for command lookup */
 261         if (!prefixcmp(var, "alias."))
 262                 add_cmdname(&aliases, var + 6, strlen(var + 6));
 263
 264         return git_default_config(var, value, cb);
 265 }
 266
 267 static int levenshtein_compare(const void *p1, const void *p2)
 268 {
 269         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 270         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 271         int l1 = (*c1)->len;
 272         int l2 = (*c2)->len;
 273         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 274 }
 275
 276 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 277 {
 278         int i;
 279         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 280
 281         for (i = 0; i < old->cnt; i++)
 282                 cmds->names[cmds->cnt++] = old->names[i];
 283         free(old->names);
 284         old->cnt = 0;
 285         old->names = NULL;
 286 }
 287
 288 /* An empirically derived magic number */
 289 #define SIMILARITY_FLOOR 7
 290 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 291
 292 static const char bad_interpreter_advice[] =
 293         N_("'%s' appears to be a git command, but we were not\n"
 294         "able to execute it. Maybe git-%s is broken?");
 295
 296 const char *help_unknown_cmd(const char *cmd)
 297 {
 298         int i, n, best_similarity = 0;
 299         struct cmdnames main_cmds, other_cmds;
 300
 301         memset(&main_cmds, 0, sizeof(main_cmds));
 302         memset(&other_cmds, 0, sizeof(other_cmds));
 303         memset(&aliases, 0, sizeof(aliases));
 304
 305         git_config(git_unknown_cmd_config, NULL);
 306
 307         load_command_list("git-", &main_cmds, &other_cmds);
 308
 309         add_cmd_list(&main_cmds, &aliases);
 310         add_cmd_list(&main_cmds, &other_cmds);
 311         qsort(main_cmds.names, main_cmds.cnt,
 312               sizeof(main_cmds.names), cmdname_compare);
 313         uniq(&main_cmds);
 314
 315         /* This abuses cmdname->len for levenshtein distance */
 316         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 317                 int cmp = 0; /* avoid compiler stupidity */
 318                 const char *candidate = main_cmds.names[i]->name;
 319
 320                 /*
 321                  * An exact match means we have the command, but
 322                  * for some reason exec'ing it gave us ENOENT; probably
 323                  * it's a bad interpreter in the #! line.
 324                  */
 325                 if (!strcmp(candidate, cmd))
 326                         die(_(bad_interpreter_advice), cmd, cmd);
 327
 328                 /* Does the candidate appear in common_cmds list? */
 329                 while (n < ARRAY_SIZE(common_cmds) &&
 330                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 331                         n++;
 332                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 333                         /* Yes, this is one of the common commands */
 334                         n++; /* use the entry from common_cmds[] */
 335                         if (!prefixcmp(candidate, cmd)) {
 336                                 /* Give prefix match a very good score */
 337                                 main_cmds.names[i]->len = 0;
 338                                 continue;
 339                         }
 340                 }
 341
 342                 main_cmds.names[i]->len =
 343                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 344         }
 345
 346         qsort(main_cmds.names, main_cmds.cnt,
 347               sizeof(*main_cmds.names), levenshtein_compare);
 348
 349         if (!main_cmds.cnt)
 350                 die(_("Uh oh. Your system reports no Git commands at all."));
 351
 352         /* skip and count prefix matches */
 353         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 354                 ; /* still counting */
 355
 356         if (main_cmds.cnt <= n) {
 357                 /* prefix matches with everything? that is too ambiguous */
 358                 best_similarity = SIMILARITY_FLOOR + 1;
 359         } else {
 360                 /* count all the most similar ones */
 361                 for (best_similarity = main_cmds.names[n++]->len;
 362                      (n < main_cmds.cnt &&
 363                       best_similarity == main_cmds.names[n]->len);
 364                      n++)
 365                         ; /* still counting */
 366         }
 367         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 368                 const char *assumed = main_cmds.names[0]->name;
 369                 main_cmds.names[0] = NULL;
 370                 clean_cmdnames(&main_cmds);
 371                 fprintf_ln(stderr,
 372                            _("WARNING: You called a Git command named '%s', "
 373                              "which does not exist.\n"
 374                              "Continuing under the assumption that you meant '%s'"),
 375                         cmd, assumed);
 376                 if (autocorrect > 0) {
 377                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 378                                 (float)autocorrect/10.0);
 379                         poll(NULL, 0, autocorrect * 100);
 380                 }
 381                 return assumed;
 382         }
 383
 384         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 385
 386         if (SIMILAR_ENOUGH(best_similarity)) {
 387                 fprintf_ln(stderr,
 388                            Q_("\nDid you mean this?",
 389                               "\nDid you mean one of these?",
 390                            n));
 391
 392                 for (i = 0; i < n; i++)
 393                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 394         }
 395
 396         exit(1);
 397 }
 398
 399 int cmd_version(int argc, const char **argv, const char *prefix)
 400 {
 401         /*
 402          * The format of this string should be kept stable for compatibility
 403          * with external projects that rely on the output of "git version".
 404          */
 405         printf("git version %s\n", git_version_string);
 406         return 0;
 407 }
 408
 409 struct similar_ref_cb {
 410         const char *base_ref;
 411         struct string_list *similar_refs;
 412 };
 413
 414 static int append_similar_ref(const char *refname, const unsigned char *sha1,
 415                               int flags, void *cb_data)
 416 {
 417         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 418         char *branch = strrchr(refname, '/') + 1;
 419         /* A remote branch of the same name is deemed similar */
 420         if (!prefixcmp(refname, "refs/remotes/") &&
 421             !strcmp(branch, cb->base_ref))
 422                 string_list_append(cb->similar_refs,
 423                                    refname + strlen("refs/remotes/"));
 424         return 0;
 425 }
 426
 427 static struct string_list guess_refs(const char *ref)
 428 {
 429         struct similar_ref_cb ref_cb;
 430         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 431
 432         ref_cb.base_ref = ref;
 433         ref_cb.similar_refs = &similar_refs;
 434         for_each_ref(append_similar_ref, &ref_cb);
 435         return similar_refs;
 436 }
 437
 438 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 439 {
 440         int i;
 441         struct string_list suggested_refs = guess_refs(ref);
 442
 443         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 444
 445         if (suggested_refs.nr > 0) {
 446                 fprintf_ln(stderr,
 447                            Q_("\nDid you mean this?",
 448                               "\nDid you mean one of these?",
 449                               suggested_refs.nr));
 450                 for (i = 0; i < suggested_refs.nr; i++)
 451                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 452         }
 453
 454         string_list_clear(&suggested_refs, 0);
 455         exit(1);
 456 }