help.con commit Merge branch 'master' of git://ozlabs.org/~paulus/gitk (92e625d)
   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
  12void 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
  24static 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
  34static 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
  41static 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
  58void 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
  81static 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
 101static 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
 128static 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
 166void 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
 202void 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
 221void 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
 238int 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
 247static int autocorrect;
 248static struct cmdnames aliases;
 249
 250static 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
 263static 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
 272static 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
 288static 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
 292const 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
 395int 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
 405struct similar_ref_cb {
 406        const char *base_ref;
 407        struct string_list *similar_refs;
 408};
 409
 410static 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
 424static 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
 435void 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}