Andrew's git / gitweb.git / help.c
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help.con commit Merge branch 'jc/merge-blobs' (9591fcc)
   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
  11void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  12{
  13        struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
  14
  15        ent->len = len;
  16        memcpy(ent->name, name, len);
  17        ent->name[len] = 0;
  18
  19        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  20        cmds->names[cmds->cnt++] = ent;
  21}
  22
  23static 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
  33static 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
  40static 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
  57void 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
  80static void pretty_print_string_list(struct cmdnames *cmds,
  81                                     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(WIN32) || defined(__CYGWIN__)
 110#if defined(__CYGWIN__)
 111if ((st.st_mode & S_IXUSR) == 0)
 112#endif
 113{       /* cannot trust the executable bit, peek into the file instead */
 114        char buf[3] = { 0 };
 115        int n;
 116        int fd = open(name, O_RDONLY);
 117        st.st_mode &= ~S_IXUSR;
 118        if (fd >= 0) {
 119                n = read(fd, buf, 2);
 120                if (n == 2)
 121                        /* DOS executables start with "MZ" */
 122                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 123                                st.st_mode |= S_IXUSR;
 124                close(fd);
 125        }
 126}
 127#endif
 128        return st.st_mode & S_IXUSR;
 129}
 130
 131static void list_commands_in_dir(struct cmdnames *cmds,
 132                                         const char *path,
 133                                         const char *prefix)
 134{
 135        int prefix_len;
 136        DIR *dir = opendir(path);
 137        struct dirent *de;
 138        struct strbuf buf = STRBUF_INIT;
 139        int len;
 140
 141        if (!dir)
 142                return;
 143        if (!prefix)
 144                prefix = "git-";
 145        prefix_len = strlen(prefix);
 146
 147        strbuf_addf(&buf, "%s/", path);
 148        len = buf.len;
 149
 150        while ((de = readdir(dir)) != NULL) {
 151                int entlen;
 152
 153                if (prefixcmp(de->d_name, prefix))
 154                        continue;
 155
 156                strbuf_setlen(&buf, len);
 157                strbuf_addstr(&buf, de->d_name);
 158                if (!is_executable(buf.buf))
 159                        continue;
 160
 161                entlen = strlen(de->d_name) - prefix_len;
 162                if (has_extension(de->d_name, ".exe"))
 163                        entlen -= 4;
 164
 165                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 166        }
 167        closedir(dir);
 168        strbuf_release(&buf);
 169}
 170
 171void load_command_list(const char *prefix,
 172                struct cmdnames *main_cmds,
 173                struct cmdnames *other_cmds)
 174{
 175        const char *env_path = getenv("PATH");
 176        const char *exec_path = git_exec_path();
 177
 178        if (exec_path) {
 179                list_commands_in_dir(main_cmds, exec_path, prefix);
 180                qsort(main_cmds->names, main_cmds->cnt,
 181                      sizeof(*main_cmds->names), cmdname_compare);
 182                uniq(main_cmds);
 183        }
 184
 185        if (env_path) {
 186                char *paths, *path, *colon;
 187                path = paths = xstrdup(env_path);
 188                while (1) {
 189                        if ((colon = strchr(path, PATH_SEP)))
 190                                *colon = 0;
 191                        if (!exec_path || strcmp(path, exec_path))
 192                                list_commands_in_dir(other_cmds, path, prefix);
 193
 194                        if (!colon)
 195                                break;
 196                        path = colon + 1;
 197                }
 198                free(paths);
 199
 200                qsort(other_cmds->names, other_cmds->cnt,
 201                      sizeof(*other_cmds->names), cmdname_compare);
 202                uniq(other_cmds);
 203        }
 204        exclude_cmds(other_cmds, main_cmds);
 205}
 206
 207void list_commands(unsigned int colopts,
 208                   struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 209{
 210        if (main_cmds->cnt) {
 211                const char *exec_path = git_exec_path();
 212                printf_ln(_("available git commands in '%s'"), exec_path);
 213                putchar('\n');
 214                pretty_print_string_list(main_cmds, colopts);
 215                putchar('\n');
 216        }
 217
 218        if (other_cmds->cnt) {
 219                printf_ln(_("git commands available from elsewhere on your $PATH"));
 220                putchar('\n');
 221                pretty_print_string_list(other_cmds, colopts);
 222                putchar('\n');
 223        }
 224}
 225
 226int is_in_cmdlist(struct cmdnames *c, const char *s)
 227{
 228        int i;
 229        for (i = 0; i < c->cnt; i++)
 230                if (!strcmp(s, c->names[i]->name))
 231                        return 1;
 232        return 0;
 233}
 234
 235static int autocorrect;
 236static struct cmdnames aliases;
 237
 238static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 239{
 240        if (!strcmp(var, "help.autocorrect"))
 241                autocorrect = git_config_int(var,value);
 242        /* Also use aliases for command lookup */
 243        if (!prefixcmp(var, "alias."))
 244                add_cmdname(&aliases, var + 6, strlen(var + 6));
 245
 246        return git_default_config(var, value, cb);
 247}
 248
 249static int levenshtein_compare(const void *p1, const void *p2)
 250{
 251        const struct cmdname *const *c1 = p1, *const *c2 = p2;
 252        const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 253        int l1 = (*c1)->len;
 254        int l2 = (*c2)->len;
 255        return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 256}
 257
 258static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 259{
 260        int i;
 261        ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 262
 263        for (i = 0; i < old->cnt; i++)
 264                cmds->names[cmds->cnt++] = old->names[i];
 265        free(old->names);
 266        old->cnt = 0;
 267        old->names = NULL;
 268}
 269
 270/* An empirically derived magic number */
 271#define SIMILARITY_FLOOR 7
 272#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 273
 274static const char bad_interpreter_advice[] =
 275        N_("'%s' appears to be a git command, but we were not\n"
 276        "able to execute it. Maybe git-%s is broken?");
 277
 278const char *help_unknown_cmd(const char *cmd)
 279{
 280        int i, n, best_similarity = 0;
 281        struct cmdnames main_cmds, other_cmds;
 282
 283        memset(&main_cmds, 0, sizeof(main_cmds));
 284        memset(&other_cmds, 0, sizeof(other_cmds));
 285        memset(&aliases, 0, sizeof(aliases));
 286
 287        git_config(git_unknown_cmd_config, NULL);
 288
 289        load_command_list("git-", &main_cmds, &other_cmds);
 290
 291        add_cmd_list(&main_cmds, &aliases);
 292        add_cmd_list(&main_cmds, &other_cmds);
 293        qsort(main_cmds.names, main_cmds.cnt,
 294              sizeof(main_cmds.names), cmdname_compare);
 295        uniq(&main_cmds);
 296
 297        /* This abuses cmdname->len for levenshtein distance */
 298        for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 299                int cmp = 0; /* avoid compiler stupidity */
 300                const char *candidate = main_cmds.names[i]->name;
 301
 302                /*
 303                 * An exact match means we have the command, but
 304                 * for some reason exec'ing it gave us ENOENT; probably
 305                 * it's a bad interpreter in the #! line.
 306                 */
 307                if (!strcmp(candidate, cmd))
 308                        die(_(bad_interpreter_advice), cmd, cmd);
 309
 310                /* Does the candidate appear in common_cmds list? */
 311                while (n < ARRAY_SIZE(common_cmds) &&
 312                       (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 313                        n++;
 314                if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 315                        /* Yes, this is one of the common commands */
 316                        n++; /* use the entry from common_cmds[] */
 317                        if (!prefixcmp(candidate, cmd)) {
 318                                /* Give prefix match a very good score */
 319                                main_cmds.names[i]->len = 0;
 320                                continue;
 321                        }
 322                }
 323
 324                main_cmds.names[i]->len =
 325                        levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 326        }
 327
 328        qsort(main_cmds.names, main_cmds.cnt,
 329              sizeof(*main_cmds.names), levenshtein_compare);
 330
 331        if (!main_cmds.cnt)
 332                die(_("Uh oh. Your system reports no Git commands at all."));
 333
 334        /* skip and count prefix matches */
 335        for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 336                ; /* still counting */
 337
 338        if (main_cmds.cnt <= n) {
 339                /* prefix matches with everything? that is too ambiguous */
 340                best_similarity = SIMILARITY_FLOOR + 1;
 341        } else {
 342                /* count all the most similar ones */
 343                for (best_similarity = main_cmds.names[n++]->len;
 344                     (n < main_cmds.cnt &&
 345                      best_similarity == main_cmds.names[n]->len);
 346                     n++)
 347                        ; /* still counting */
 348        }
 349        if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 350                const char *assumed = main_cmds.names[0]->name;
 351                main_cmds.names[0] = NULL;
 352                clean_cmdnames(&main_cmds);
 353                fprintf_ln(stderr,
 354                           _("WARNING: You called a Git command named '%s', "
 355                             "which does not exist.\n"
 356                             "Continuing under the assumption that you meant '%s'"),
 357                        cmd, assumed);
 358                if (autocorrect > 0) {
 359                        fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 360                                (float)autocorrect/10.0);
 361                        poll(NULL, 0, autocorrect * 100);
 362                }
 363                return assumed;
 364        }
 365
 366        fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 367
 368        if (SIMILAR_ENOUGH(best_similarity)) {
 369                fprintf_ln(stderr,
 370                           Q_("\nDid you mean this?",
 371                              "\nDid you mean one of these?",
 372                           n));
 373
 374                for (i = 0; i < n; i++)
 375                        fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 376        }
 377
 378        exit(1);
 379}
 380
 381int cmd_version(int argc, const char **argv, const char *prefix)
 382{
 383        printf("git version %s\n", git_version_string);
 384        return 0;
 385}