help.c

   1 #include "cache.h"
   2 #include "builtin.h"
   3 #include "exec_cmd.h"
   4 #include "run-command.h"
   5 #include "levenshtein.h"
   6 #include "help.h"
   7 #include "common-cmds.h"
   8 #include "string-list.h"
   9 #include "column.h"
  10 #include "version.h"
  11 #include "refs.h"
  12
  13 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  14 {
  15         struct cmdname *ent;
  16         FLEX_ALLOC_MEM(ent, name, name, len);
  17         ent->len = len;
  18
  19         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  20         cmds->names[cmds->cnt++] = ent;
  21 }
  22
  23 static void clean_cmdnames(struct cmdnames *cmds)
  24 {
  25         int i;
  26         for (i = 0; i < cmds->cnt; ++i)
  27                 free(cmds->names[i]);
  28         free(cmds->names);
  29         cmds->cnt = 0;
  30         cmds->alloc = 0;
  31 }
  32
  33 static int cmdname_compare(const void *a_, const void *b_)
  34 {
  35         struct cmdname *a = *(struct cmdname **)a_;
  36         struct cmdname *b = *(struct cmdname **)b_;
  37         return strcmp(a->name, b->name);
  38 }
  39
  40 static void uniq(struct cmdnames *cmds)
  41 {
  42         int i, j;
  43
  44         if (!cmds->cnt)
  45                 return;
  46
  47         for (i = j = 1; i < cmds->cnt; i++) {
  48                 if (!strcmp(cmds->names[i]->name, cmds->names[j-1]->name))
  49                         free(cmds->names[i]);
  50                 else
  51                         cmds->names[j++] = cmds->names[i];
  52         }
  53
  54         cmds->cnt = j;
  55 }
  56
  57 void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  58 {
  59         int ci, cj, ei;
  60         int cmp;
  61
  62         ci = cj = ei = 0;
  63         while (ci < cmds->cnt && ei < excludes->cnt) {
  64                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  65                 if (cmp < 0)
  66                         cmds->names[cj++] = cmds->names[ci++];
  67                 else if (cmp == 0) {
  68                         ei++;
  69                         free(cmds->names[ci++]);
  70                 } else if (cmp > 0)
  71                         ei++;
  72         }
  73
  74         while (ci < cmds->cnt)
  75                 cmds->names[cj++] = cmds->names[ci++];
  76
  77         cmds->cnt = cj;
  78 }
  79
  80 static void pretty_print_cmdnames(struct cmdnames *cmds, unsigned int colopts)
  81 {
  82         struct string_list list = STRING_LIST_INIT_NODUP;
  83         struct column_options copts;
  84         int i;
  85
  86         for (i = 0; i < cmds->cnt; i++)
  87                 string_list_append(&list, cmds->names[i]->name);
  88         /*
  89          * always enable column display, we only consult column.*
  90          * about layout strategy and stuff
  91          */
  92         colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
  93         memset(&copts, 0, sizeof(copts));
  94         copts.indent = "  ";
  95         copts.padding = 2;
  96         print_columns(&list, colopts, &copts);
  97         string_list_clear(&list, 0);
  98 }
  99
 100 static void list_commands_in_dir(struct cmdnames *cmds,
 101                                          const char *path,
 102                                          const char *prefix)
 103 {
 104         DIR *dir = opendir(path);
 105         struct dirent *de;
 106         struct strbuf buf = STRBUF_INIT;
 107         int len;
 108
 109         if (!dir)
 110                 return;
 111         if (!prefix)
 112                 prefix = "git-";
 113
 114         strbuf_addf(&buf, "%s/", path);
 115         len = buf.len;
 116
 117         while ((de = readdir(dir)) != NULL) {
 118                 const char *ent;
 119                 size_t entlen;
 120
 121                 if (!skip_prefix(de->d_name, prefix, &ent))
 122                         continue;
 123
 124                 strbuf_setlen(&buf, len);
 125                 strbuf_addstr(&buf, de->d_name);
 126                 if (!is_executable(buf.buf))
 127                         continue;
 128
 129                 entlen = strlen(ent);
 130                 strip_suffix(ent, ".exe", &entlen);
 131
 132                 add_cmdname(cmds, ent, entlen);
 133         }
 134         closedir(dir);
 135         strbuf_release(&buf);
 136 }
 137
 138 void load_command_list(const char *prefix,
 139                 struct cmdnames *main_cmds,
 140                 struct cmdnames *other_cmds)
 141 {
 142         const char *env_path = getenv("PATH");
 143         const char *exec_path = git_exec_path();
 144
 145         if (exec_path) {
 146                 list_commands_in_dir(main_cmds, exec_path, prefix);
 147                 QSORT(main_cmds->names, main_cmds->cnt, cmdname_compare);
 148                 uniq(main_cmds);
 149         }
 150
 151         if (env_path) {
 152                 char *paths, *path, *colon;
 153                 path = paths = xstrdup(env_path);
 154                 while (1) {
 155                         if ((colon = strchr(path, PATH_SEP)))
 156                                 *colon = 0;
 157                         if (!exec_path || strcmp(path, exec_path))
 158                                 list_commands_in_dir(other_cmds, path, prefix);
 159
 160                         if (!colon)
 161                                 break;
 162                         path = colon + 1;
 163                 }
 164                 free(paths);
 165
 166                 QSORT(other_cmds->names, other_cmds->cnt, cmdname_compare);
 167                 uniq(other_cmds);
 168         }
 169         exclude_cmds(other_cmds, main_cmds);
 170 }
 171
 172 void list_commands(unsigned int colopts,
 173                    struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 174 {
 175         if (main_cmds->cnt) {
 176                 const char *exec_path = git_exec_path();
 177                 printf_ln(_("available git commands in '%s'"), exec_path);
 178                 putchar('\n');
 179                 pretty_print_cmdnames(main_cmds, colopts);
 180                 putchar('\n');
 181         }
 182
 183         if (other_cmds->cnt) {
 184                 printf_ln(_("git commands available from elsewhere on your $PATH"));
 185                 putchar('\n');
 186                 pretty_print_cmdnames(other_cmds, colopts);
 187                 putchar('\n');
 188         }
 189 }
 190
 191 static int cmd_group_cmp(const void *elem1, const void *elem2)
 192 {
 193         const struct cmdname_help *e1 = elem1;
 194         const struct cmdname_help *e2 = elem2;
 195
 196         if (e1->group < e2->group)
 197                 return -1;
 198         if (e1->group > e2->group)
 199                 return 1;
 200         return strcmp(e1->name, e2->name);
 201 }
 202
 203 void list_common_cmds_help(void)
 204 {
 205         int i, longest = 0;
 206         int current_grp = -1;
 207
 208         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 209                 if (longest < strlen(common_cmds[i].name))
 210                         longest = strlen(common_cmds[i].name);
 211         }
 212
 213         QSORT(common_cmds, ARRAY_SIZE(common_cmds), cmd_group_cmp);
 214
 215         puts(_("These are common Git commands used in various situations:"));
 216
 217         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 218                 if (common_cmds[i].group != current_grp) {
 219                         printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
 220                         current_grp = common_cmds[i].group;
 221                 }
 222
 223                 printf("   %s   ", common_cmds[i].name);
 224                 mput_char(' ', longest - strlen(common_cmds[i].name));
 225                 puts(_(common_cmds[i].help));
 226         }
 227 }
 228
 229 int is_in_cmdlist(struct cmdnames *c, const char *s)
 230 {
 231         int i;
 232         for (i = 0; i < c->cnt; i++)
 233                 if (!strcmp(s, c->names[i]->name))
 234                         return 1;
 235         return 0;
 236 }
 237
 238 static int autocorrect;
 239 static struct cmdnames aliases;
 240
 241 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 242 {
 243         const char *p;
 244
 245         if (!strcmp(var, "help.autocorrect"))
 246                 autocorrect = git_config_int(var,value);
 247         /* Also use aliases for command lookup */
 248         if (skip_prefix(var, "alias.", &p))
 249                 add_cmdname(&aliases, p, strlen(p));
 250
 251         return git_default_config(var, value, cb);
 252 }
 253
 254 static int levenshtein_compare(const void *p1, const void *p2)
 255 {
 256         const struct cmdname *const *c1 = p1, *const *c2 = p2;
 257         const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 258         int l1 = (*c1)->len;
 259         int l2 = (*c2)->len;
 260         return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 261 }
 262
 263 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 264 {
 265         int i;
 266         ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 267
 268         for (i = 0; i < old->cnt; i++)
 269                 cmds->names[cmds->cnt++] = old->names[i];
 270         free(old->names);
 271         old->cnt = 0;
 272         old->names = NULL;
 273 }
 274
 275 /* An empirically derived magic number */
 276 #define SIMILARITY_FLOOR 7
 277 #define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 278
 279 static const char bad_interpreter_advice[] =
 280         N_("'%s' appears to be a git command, but we were not\n"
 281         "able to execute it. Maybe git-%s is broken?");
 282
 283 const char *help_unknown_cmd(const char *cmd)
 284 {
 285         int i, n, best_similarity = 0;
 286         struct cmdnames main_cmds, other_cmds;
 287
 288         memset(&main_cmds, 0, sizeof(main_cmds));
 289         memset(&other_cmds, 0, sizeof(other_cmds));
 290         memset(&aliases, 0, sizeof(aliases));
 291
 292         git_config(git_unknown_cmd_config, NULL);
 293
 294         load_command_list("git-", &main_cmds, &other_cmds);
 295
 296         add_cmd_list(&main_cmds, &aliases);
 297         add_cmd_list(&main_cmds, &other_cmds);
 298         QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
 299         uniq(&main_cmds);
 300
 301         /* This abuses cmdname->len for levenshtein distance */
 302         for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 303                 int cmp = 0; /* avoid compiler stupidity */
 304                 const char *candidate = main_cmds.names[i]->name;
 305
 306                 /*
 307                  * An exact match means we have the command, but
 308                  * for some reason exec'ing it gave us ENOENT; probably
 309                  * it's a bad interpreter in the #! line.
 310                  */
 311                 if (!strcmp(candidate, cmd))
 312                         die(_(bad_interpreter_advice), cmd, cmd);
 313
 314                 /* Does the candidate appear in common_cmds list? */
 315                 while (n < ARRAY_SIZE(common_cmds) &&
 316                        (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 317                         n++;
 318                 if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 319                         /* Yes, this is one of the common commands */
 320                         n++; /* use the entry from common_cmds[] */
 321                         if (starts_with(candidate, cmd)) {
 322                                 /* Give prefix match a very good score */
 323                                 main_cmds.names[i]->len = 0;
 324                                 continue;
 325                         }
 326                 }
 327
 328                 main_cmds.names[i]->len =
 329                         levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 330         }
 331
 332         QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
 333
 334         if (!main_cmds.cnt)
 335                 die(_("Uh oh. Your system reports no Git commands at all."));
 336
 337         /* skip and count prefix matches */
 338         for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 339                 ; /* still counting */
 340
 341         if (main_cmds.cnt <= n) {
 342                 /* prefix matches with everything? that is too ambiguous */
 343                 best_similarity = SIMILARITY_FLOOR + 1;
 344         } else {
 345                 /* count all the most similar ones */
 346                 for (best_similarity = main_cmds.names[n++]->len;
 347                      (n < main_cmds.cnt &&
 348                       best_similarity == main_cmds.names[n]->len);
 349                      n++)
 350                         ; /* still counting */
 351         }
 352         if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 353                 const char *assumed = main_cmds.names[0]->name;
 354                 main_cmds.names[0] = NULL;
 355                 clean_cmdnames(&main_cmds);
 356                 fprintf_ln(stderr,
 357                            _("WARNING: You called a Git command named '%s', "
 358                              "which does not exist.\n"
 359                              "Continuing under the assumption that you meant '%s'"),
 360                         cmd, assumed);
 361                 if (autocorrect > 0) {
 362                         fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 363                                 (float)autocorrect/10.0);
 364                         sleep_millisec(autocorrect * 100);
 365                 }
 366                 return assumed;
 367         }
 368
 369         fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 370
 371         if (SIMILAR_ENOUGH(best_similarity)) {
 372                 fprintf_ln(stderr,
 373                            Q_("\nThe most similar command is",
 374                               "\nThe most similar commands are",
 375                            n));
 376
 377                 for (i = 0; i < n; i++)
 378                         fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 379         }
 380
 381         exit(1);
 382 }
 383
 384 int cmd_version(int argc, const char **argv, const char *prefix)
 385 {
 386         /*
 387          * The format of this string should be kept stable for compatibility
 388          * with external projects that rely on the output of "git version".
 389          */
 390         printf("git version %s\n", git_version_string);
 391         while (*++argv) {
 392                 if (!strcmp(*argv, "--build-options")) {
 393                         printf("sizeof-long: %d\n", (int)sizeof(long));
 394                         /* NEEDSWORK: also save and output GIT-BUILD_OPTIONS? */
 395                 }
 396         }
 397         return 0;
 398 }
 399
 400 struct similar_ref_cb {
 401         const char *base_ref;
 402         struct string_list *similar_refs;
 403 };
 404
 405 static int append_similar_ref(const char *refname, const struct object_id *oid,
 406                               int flags, void *cb_data)
 407 {
 408         struct similar_ref_cb *cb = (struct similar_ref_cb *)(cb_data);
 409         char *branch = strrchr(refname, '/') + 1;
 410         const char *remote;
 411
 412         /* A remote branch of the same name is deemed similar */
 413         if (skip_prefix(refname, "refs/remotes/", &remote) &&
 414             !strcmp(branch, cb->base_ref))
 415                 string_list_append(cb->similar_refs, remote);
 416         return 0;
 417 }
 418
 419 static struct string_list guess_refs(const char *ref)
 420 {
 421         struct similar_ref_cb ref_cb;
 422         struct string_list similar_refs = STRING_LIST_INIT_NODUP;
 423
 424         ref_cb.base_ref = ref;
 425         ref_cb.similar_refs = &similar_refs;
 426         for_each_ref(append_similar_ref, &ref_cb);
 427         return similar_refs;
 428 }
 429
 430 void help_unknown_ref(const char *ref, const char *cmd, const char *error)
 431 {
 432         int i;
 433         struct string_list suggested_refs = guess_refs(ref);
 434
 435         fprintf_ln(stderr, _("%s: %s - %s"), cmd, ref, error);
 436
 437         if (suggested_refs.nr > 0) {
 438                 fprintf_ln(stderr,
 439                            Q_("\nDid you mean this?",
 440                               "\nDid you mean one of these?",
 441                               suggested_refs.nr));
 442                 for (i = 0; i < suggested_refs.nr; i++)
 443                         fprintf(stderr, "\t%s\n", suggested_refs.items[i].string);
 444         }
 445
 446         string_list_clear(&suggested_refs, 0);
 447         exit(1);
 448 }