help.con commit Merge branch 'jk/git-connection-deadlock-fix' into maint (5590fe7)
   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
   8/* most GUI terminals set COLUMNS (although some don't export it) */
   9static int term_columns(void)
  10{
  11        char *col_string = getenv("COLUMNS");
  12        int n_cols;
  13
  14        if (col_string && (n_cols = atoi(col_string)) > 0)
  15                return n_cols;
  16
  17#ifdef TIOCGWINSZ
  18        {
  19                struct winsize ws;
  20                if (!ioctl(1, TIOCGWINSZ, &ws)) {
  21                        if (ws.ws_col)
  22                                return ws.ws_col;
  23                }
  24        }
  25#endif
  26
  27        return 80;
  28}
  29
  30void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  31{
  32        struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
  33
  34        ent->len = len;
  35        memcpy(ent->name, name, len);
  36        ent->name[len] = 0;
  37
  38        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  39        cmds->names[cmds->cnt++] = ent;
  40}
  41
  42static void clean_cmdnames(struct cmdnames *cmds)
  43{
  44        int i;
  45        for (i = 0; i < cmds->cnt; ++i)
  46                free(cmds->names[i]);
  47        free(cmds->names);
  48        cmds->cnt = 0;
  49        cmds->alloc = 0;
  50}
  51
  52static int cmdname_compare(const void *a_, const void *b_)
  53{
  54        struct cmdname *a = *(struct cmdname **)a_;
  55        struct cmdname *b = *(struct cmdname **)b_;
  56        return strcmp(a->name, b->name);
  57}
  58
  59static void uniq(struct cmdnames *cmds)
  60{
  61        int i, j;
  62
  63        if (!cmds->cnt)
  64                return;
  65
  66        for (i = j = 1; i < cmds->cnt; i++)
  67                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
  68                        cmds->names[j++] = cmds->names[i];
  69
  70        cmds->cnt = j;
  71}
  72
  73void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  74{
  75        int ci, cj, ei;
  76        int cmp;
  77
  78        ci = cj = ei = 0;
  79        while (ci < cmds->cnt && ei < excludes->cnt) {
  80                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  81                if (cmp < 0)
  82                        cmds->names[cj++] = cmds->names[ci++];
  83                else if (cmp == 0)
  84                        ci++, ei++;
  85                else if (cmp > 0)
  86                        ei++;
  87        }
  88
  89        while (ci < cmds->cnt)
  90                cmds->names[cj++] = cmds->names[ci++];
  91
  92        cmds->cnt = cj;
  93}
  94
  95static void pretty_print_string_list(struct cmdnames *cmds, int longest)
  96{
  97        int cols = 1, rows;
  98        int space = longest + 1; /* min 1 SP between words */
  99        int max_cols = term_columns() - 1; /* don't print *on* the edge */
 100        int i, j;
 101
 102        if (space < max_cols)
 103                cols = max_cols / space;
 104        rows = DIV_ROUND_UP(cmds->cnt, cols);
 105
 106        for (i = 0; i < rows; i++) {
 107                printf("  ");
 108
 109                for (j = 0; j < cols; j++) {
 110                        int n = j * rows + i;
 111                        int size = space;
 112                        if (n >= cmds->cnt)
 113                                break;
 114                        if (j == cols-1 || n + rows >= cmds->cnt)
 115                                size = 1;
 116                        printf("%-*s", size, cmds->names[n]->name);
 117                }
 118                putchar('\n');
 119        }
 120}
 121
 122static int is_executable(const char *name)
 123{
 124        struct stat st;
 125
 126        if (stat(name, &st) || /* stat, not lstat */
 127            !S_ISREG(st.st_mode))
 128                return 0;
 129
 130#ifdef WIN32
 131{       /* cannot trust the executable bit, peek into the file instead */
 132        char buf[3] = { 0 };
 133        int n;
 134        int fd = open(name, O_RDONLY);
 135        st.st_mode &= ~S_IXUSR;
 136        if (fd >= 0) {
 137                n = read(fd, buf, 2);
 138                if (n == 2)
 139                        /* DOS executables start with "MZ" */
 140                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 141                                st.st_mode |= S_IXUSR;
 142                close(fd);
 143        }
 144}
 145#endif
 146        return st.st_mode & S_IXUSR;
 147}
 148
 149static void list_commands_in_dir(struct cmdnames *cmds,
 150                                         const char *path,
 151                                         const char *prefix)
 152{
 153        int prefix_len;
 154        DIR *dir = opendir(path);
 155        struct dirent *de;
 156        struct strbuf buf = STRBUF_INIT;
 157        int len;
 158
 159        if (!dir)
 160                return;
 161        if (!prefix)
 162                prefix = "git-";
 163        prefix_len = strlen(prefix);
 164
 165        strbuf_addf(&buf, "%s/", path);
 166        len = buf.len;
 167
 168        while ((de = readdir(dir)) != NULL) {
 169                int entlen;
 170
 171                if (prefixcmp(de->d_name, prefix))
 172                        continue;
 173
 174                strbuf_setlen(&buf, len);
 175                strbuf_addstr(&buf, de->d_name);
 176                if (!is_executable(buf.buf))
 177                        continue;
 178
 179                entlen = strlen(de->d_name) - prefix_len;
 180                if (has_extension(de->d_name, ".exe"))
 181                        entlen -= 4;
 182
 183                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 184        }
 185        closedir(dir);
 186        strbuf_release(&buf);
 187}
 188
 189void load_command_list(const char *prefix,
 190                struct cmdnames *main_cmds,
 191                struct cmdnames *other_cmds)
 192{
 193        const char *env_path = getenv("PATH");
 194        const char *exec_path = git_exec_path();
 195
 196        if (exec_path) {
 197                list_commands_in_dir(main_cmds, exec_path, prefix);
 198                qsort(main_cmds->names, main_cmds->cnt,
 199                      sizeof(*main_cmds->names), cmdname_compare);
 200                uniq(main_cmds);
 201        }
 202
 203        if (env_path) {
 204                char *paths, *path, *colon;
 205                path = paths = xstrdup(env_path);
 206                while (1) {
 207                        if ((colon = strchr(path, PATH_SEP)))
 208                                *colon = 0;
 209                        if (!exec_path || strcmp(path, exec_path))
 210                                list_commands_in_dir(other_cmds, path, prefix);
 211
 212                        if (!colon)
 213                                break;
 214                        path = colon + 1;
 215                }
 216                free(paths);
 217
 218                qsort(other_cmds->names, other_cmds->cnt,
 219                      sizeof(*other_cmds->names), cmdname_compare);
 220                uniq(other_cmds);
 221        }
 222        exclude_cmds(other_cmds, main_cmds);
 223}
 224
 225void list_commands(const char *title, struct cmdnames *main_cmds,
 226                   struct cmdnames *other_cmds)
 227{
 228        int i, longest = 0;
 229
 230        for (i = 0; i < main_cmds->cnt; i++)
 231                if (longest < main_cmds->names[i]->len)
 232                        longest = main_cmds->names[i]->len;
 233        for (i = 0; i < other_cmds->cnt; i++)
 234                if (longest < other_cmds->names[i]->len)
 235                        longest = other_cmds->names[i]->len;
 236
 237        if (main_cmds->cnt) {
 238                const char *exec_path = git_exec_path();
 239                printf("available %s in '%s'\n", title, exec_path);
 240                printf("----------------");
 241                mput_char('-', strlen(title) + strlen(exec_path));
 242                putchar('\n');
 243                pretty_print_string_list(main_cmds, longest);
 244                putchar('\n');
 245        }
 246
 247        if (other_cmds->cnt) {
 248                printf("%s available from elsewhere on your $PATH\n", title);
 249                printf("---------------------------------------");
 250                mput_char('-', strlen(title));
 251                putchar('\n');
 252                pretty_print_string_list(other_cmds, longest);
 253                putchar('\n');
 254        }
 255}
 256
 257int is_in_cmdlist(struct cmdnames *c, const char *s)
 258{
 259        int i;
 260        for (i = 0; i < c->cnt; i++)
 261                if (!strcmp(s, c->names[i]->name))
 262                        return 1;
 263        return 0;
 264}
 265
 266static int autocorrect;
 267static struct cmdnames aliases;
 268
 269static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 270{
 271        if (!strcmp(var, "help.autocorrect"))
 272                autocorrect = git_config_int(var,value);
 273        /* Also use aliases for command lookup */
 274        if (!prefixcmp(var, "alias."))
 275                add_cmdname(&aliases, var + 6, strlen(var + 6));
 276
 277        return git_default_config(var, value, cb);
 278}
 279
 280static 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
 289static 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
 305const char *help_unknown_cmd(const char *cmd)
 306{
 307        int i, n, best_similarity = 0;
 308        struct cmdnames main_cmds, other_cmds;
 309
 310        memset(&main_cmds, 0, sizeof(main_cmds));
 311        memset(&other_cmds, 0, sizeof(other_cmds));
 312        memset(&aliases, 0, sizeof(aliases));
 313
 314        git_config(git_unknown_cmd_config, NULL);
 315
 316        load_command_list("git-", &main_cmds, &other_cmds);
 317
 318        add_cmd_list(&main_cmds, &aliases);
 319        add_cmd_list(&main_cmds, &other_cmds);
 320        qsort(main_cmds.names, main_cmds.cnt,
 321              sizeof(main_cmds.names), cmdname_compare);
 322        uniq(&main_cmds);
 323
 324        /* This abuses cmdname->len for levenshtein distance */
 325        for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 326                int cmp = 0; /* avoid compiler stupidity */
 327                const char *candidate = main_cmds.names[i]->name;
 328
 329                /* Does the candidate appear in common_cmds list? */
 330                while (n < ARRAY_SIZE(common_cmds) &&
 331                       (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 332                        n++;
 333                if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 334                        /* Yes, this is one of the common commands */
 335                        n++; /* use the entry from common_cmds[] */
 336                        if (!prefixcmp(candidate, cmd)) {
 337                                /* Give prefix match a very good score */
 338                                main_cmds.names[i]->len = 0;
 339                                continue;
 340                        }
 341                }
 342
 343                main_cmds.names[i]->len =
 344                        levenshtein(cmd, candidate, 0, 2, 1, 4) + 1;
 345        }
 346
 347        qsort(main_cmds.names, main_cmds.cnt,
 348              sizeof(*main_cmds.names), levenshtein_compare);
 349
 350        if (!main_cmds.cnt)
 351                die ("Uh oh. Your system reports no Git commands at all.");
 352
 353        /* skip and count prefix matches */
 354        for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 355                ; /* still counting */
 356
 357        if (main_cmds.cnt <= n) {
 358                /* prefix matches with everything? that is too ambiguous */
 359                best_similarity = SIMILARITY_FLOOR + 1;
 360        } else {
 361                /* count all the most similar ones */
 362                for (best_similarity = main_cmds.names[n++]->len;
 363                     (n < main_cmds.cnt &&
 364                      best_similarity == main_cmds.names[n]->len);
 365                     n++)
 366                        ; /* still counting */
 367        }
 368        if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 369                const char *assumed = main_cmds.names[0]->name;
 370                main_cmds.names[0] = NULL;
 371                clean_cmdnames(&main_cmds);
 372                fprintf(stderr, "WARNING: You called a Git command named '%s', "
 373                        "which does not exist.\n"
 374                        "Continuing under the assumption that you meant '%s'\n",
 375                        cmd, assumed);
 376                if (autocorrect > 0) {
 377                        fprintf(stderr, "in %0.1f seconds automatically...\n",
 378                                (float)autocorrect/10.0);
 379                        poll(NULL, 0, autocorrect * 100);
 380                }
 381                return assumed;
 382        }
 383
 384        fprintf(stderr, "git: '%s' is not a git command. See 'git --help'.\n", cmd);
 385
 386        if (SIMILAR_ENOUGH(best_similarity)) {
 387                fprintf(stderr, "\nDid you mean %s?\n",
 388                        n < 2 ? "this": "one of these");
 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
 397int cmd_version(int argc, const char **argv, const char *prefix)
 398{
 399        printf("git version %s\n", git_version_string);
 400        return 0;
 401}