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, cmdname_compare);
 174                 uniq(main_cmds);
 175         }
 176
 177         if (env_path) {
 178                 char *paths, *path, *colon;
 179                 path = paths = xstrdup(env_path);
 180                 while (1) {
 181                         if ((colon = strchr(path, PATH_SEP)))
 182                                 *colon = 0;
 183                         if (!exec_path || strcmp(path, exec_path))
 184                                 list_commands_in_dir(other_cmds, path, prefix);
 185
 186                         if (!colon)
 187                                 break;
 188                         path = colon + 1;
 189                 }
 190                 free(paths);
 191
 192                 QSORT(other_cmds->names, other_cmds->cnt, cmdname_compare);
 193                 uniq(other_cmds);
 194         }
 195         exclude_cmds(other_cmds, main_cmds);
 196 }
 197
 198 void list_commands(unsigned int colopts,
 199                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 200 {
 201         if (main_cmds->cnt) {
 202                 const char *exec_path = git_exec_path();
 203                 printf_ln(_("available git commands in '%s'"), exec_path);
 204                 putchar('\n');
 205                 pretty_print_cmdnames(main_cmds, colopts);
 206                 putchar('\n');
 207         }
 208
 209         if (other_cmds->cnt) {
 210                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 211                 putchar('\n');
 212                 pretty_print_cmdnames(other_cmds, colopts);
 213                 putchar('\n');
 214         }
 215 }
 216
 217 static int cmd_group_cmp(const void *elem1, const void *elem2)
 218 {
 219         const struct cmdname_help *e1 = elem1;
 220         const struct cmdname_help *e2 = elem2;
 221
 222         if (e1->group < e2->group)
 223                 return -1;
 224         if (e1->group > e2->group)
 225                 return 1;
 226         return strcmp(e1->name, e2->name);
 227 }
 228
 229 void list_common_cmds_help(void)
 230 {
 231         int i, longest = 0;
 232         int current_grp = -1;
 233
 234         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 235                 if (longest < strlen(common_cmds[i].name))
 236                         longest = strlen(common_cmds[i].name);
 237         }
 238
 239         QSORT(common_cmds, ARRAY_SIZE(common_cmds), cmd_group_cmp);
 240
 241         puts(_("These are common Git commands used in various situations:"));
 242
 243         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 244                 if (common_cmds[i].group != current_grp) {
 245                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
 246                         current_grp = common_cmds[i].group;
 247                 }
 248
 249                 printf("   %s   ", common_cmds[i].name);
 250                 mput_char(' ', longest - strlen(common_cmds[i].name));
 251                 puts(_(common_cmds[i].help));
 252         }
 253 }
 254
 255 int is_in_cmdlist(struct cmdnames *c, const char *s)
 256 {
 257         int i;
 258         for (i = 0; i < c->cnt; i++)
 259                 if (!strcmp(s, c->names[i]->name))
 260                         return 1;
 261         return 0;
 262 }
 263
 264 static int autocorrect;
 265 static struct cmdnames aliases;
 266
 267 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 268 {
 269         const char *p;
 270
 271         if (!strcmp(var, "help.autocorrect"))
 272                 autocorrect = git_config_int(var,value);
 273         /* Also use aliases for command lookup */
 274         if (skip_prefix(var, "alias.", &p))
 275                 add_cmdname(&aliases, p, strlen(p));
 276
 277         return git_default_config(var, value, cb);
 278 }
 279
 280 static int levenshtein_compare(const void *p1, const void *p2)
 281 {
 282         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 283         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 284         int l1 = (*c1)->len;
 285         int l2 = (*c2)->len;
 286         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 287 }
 288
 289 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 290 {
 291         int i;
 292         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 293
 294         for (i = 0; i < old->cnt; i++)
 295                 cmds->names[cmds->cnt++] = old->names[i];
 296         free(old->names);
 297         old->cnt = 0;
 298         old->names = NULL;
 299 }
 300
 301 /* An empirically derived magic number */
 302 #define SIMILARITY_FLOOR 7
 303 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 304
 305 static const char bad_interpreter_advice[] =
 306         N_("'%s' appears to be a git command, but we were not\n"
 307         "able to execute it. Maybe git-%s is broken?");
 308
 309 const char *help_unknown_cmd(const char *cmd)
 310 {
 311         int i, n, best_similarity = 0;
 312         struct cmdnames main_cmds, other_cmds;
 313
 314         memset(&main_cmds, 0, sizeof(main_cmds));
 315         memset(&other_cmds, 0, sizeof(other_cmds));
 316         memset(&aliases, 0, sizeof(aliases));
 317
 318         git_config(git_unknown_cmd_config, NULL);
 319
 320         load_command_list("git-", &main_cmds, &other_cmds);
 321
 322         add_cmd_list(&main_cmds, &aliases);
 323         add_cmd_list(&main_cmds, &other_cmds);
 324         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 325         uniq(&main_cmds);
 326
 327         /* This abuses cmdname->len for levenshtein distance */
 328         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 329                 int cmp = 0; /* avoid compiler stupidity */
 330                 const char *candidate = main_cmds.names[i]->name;
 331
 332                 /*
 333                  * An exact match means we have the command, but
 334                  * for some reason exec'ing it gave us ENOENT; probably
 335                  * it's a bad interpreter in the #! line.
 336                  */
 337                 if (!strcmp(candidate, cmd))
 338                         die(_(bad_interpreter_advice), cmd, cmd);
 339
 340                 /* Does the candidate appear in common_cmds list? */
 341                 while (n < ARRAY_SIZE(common_cmds) &&
 342                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 343                         n++;
 344                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 345                         /* Yes, this is one of the common commands */
 346                         n++; /* use the entry from common_cmds[] */
 347                         if (starts_with(candidate, cmd)) {
 348                                 /* Give prefix match a very good score */
 349                                 main_cmds.names[i]->len = 0;
 350                                 continue;
 351                         }
 352                 }
 353
 354                 main_cmds.names[i]->len =
 355                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 356         }
 357
 358         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 359
 360         if (!main_cmds.cnt)
 361                 die(_("Uh oh. Your system reports no Git commands at all."));
 362
 363         /* skip and count prefix matches */
 364         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 365                 ; /* still counting */
 366
 367         if (main_cmds.cnt <= n) {
 368                 /* prefix matches with everything? that is too ambiguous */
 369                 best_similarity = SIMILARITY_FLOOR + 1;
 370         } else {
 371                 /* count all the most similar ones */
 372                 for (best_similarity = main_cmds.names[n++]->len;
 373                      (n < main_cmds.cnt &&
 374                       best_similarity == main_cmds.names[n]->len);
 375                      n++)
 376                         ; /* still counting */
 377         }
 378         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 379                 const char *assumed = main_cmds.names[0]->name;
 380                 main_cmds.names[0] = NULL;
 381                 clean_cmdnames(&main_cmds);
 382                 fprintf_ln(stderr,
 383                            _("WARNING: You called a Git command named '%s', "
 384                              "which does not exist.\n"
 385                              "Continuing under the assumption that you meant '%s'"),
 386                         cmd, assumed);
 387                 if (autocorrect > 0) {
 388                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 389                                 (float)autocorrect/10.0);
 390                         sleep_millisec(autocorrect * 100);
 391                 }
 392                 return assumed;
 393         }
 394
 395         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 396
 397         if (SIMILAR_ENOUGH(best_similarity)) {
 398                 fprintf_ln(stderr,
 399                            Q_("\nDid you mean this?",
 400                               "\nDid you mean one of these?",
 401                            n));
 402
 403                 for (i = 0; i < n; i++)
 404                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 405         }
 406
 407         exit(1);
 408 }
 409
 410 int cmd_version(int argc, const char **argv, const char *prefix)
 411 {
 412         /*
 413          * The format of this string should be kept stable for compatibility
 414          * with external projects that rely on the output of "git version".
 415          */
 416         printf("git version %s\n", git_version_string);
 417         while (*++argv) {
 418                 if (!strcmp(*argv, "--build-options")) {
 419                         printf("sizeof-long: %d\n", (int)sizeof(long));
 420                         /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 421                 }
 422         }
 423         return 0;
 424 }
 425
 426 struct similar_ref_cb {
 427         const char *base_ref;
 428         struct string_list *similar_refs;
 429 };
 430
 431 static int append_similar_ref(const char *refname, const struct object_id *oid,
 432                               int flags, void *cb_data)
 433 {
 434         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 435         char *branch = strrchr(refname, '/') + 1;
 436         const char *remote;
 437
 438         /* A remote branch of the same name is deemed similar */
 439         if (skip_prefix(refname, "refs/remotes/", &remote) &&
 440             !strcmp(branch, cb->base_ref))
 441                 string_list_append(cb->similar_refs, remote);
 442         return 0;
 443 }
 444
 445 static struct string_list guess_refs(const char *ref)
 446 {
 447         struct similar_ref_cb ref_cb;
 448         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 449
 450         ref_cb.base_ref = ref;
 451         ref_cb.similar_refs = &similar_refs;
 452         for_each_ref(append_similar_ref, &ref_cb);
 453         return similar_refs;
 454 }
 455
 456 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 457 {
 458         int i;
 459         struct string_list suggested_refs = guess_refs(ref);
 460
 461         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 462
 463         if (suggested_refs.nr > 0) {
 464                 fprintf_ln(stderr,
 465                            Q_("\nDid you mean this?",
 466                               "\nDid you mean one of these?",
 467                               suggested_refs.nr));
 468                 for (i = 0; i < suggested_refs.nr; i++)
 469                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 470         }
 471
 472         string_list_clear(&suggested_refs, 0);
 473         exit(1);
 474 }