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