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