Andrew's git / gitweb.git / help.c
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help.con commit Merge branch 'ms/daemon-doc-typo' (9cbd27b)
   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[i-1]->name))
  49                        cmds->names[j++] = cmds->names[i];
  50
  51        cmds->cnt = j;
  52}
  53
  54void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  55{
  56        int ci, cj, ei;
  57        int cmp;
  58
  59        ci = cj = ei = 0;
  60        while (ci < cmds->cnt && ei < excludes->cnt) {
  61                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  62                if (cmp < 0)
  63                        cmds->names[cj++] = cmds->names[ci++];
  64                else if (cmp == 0)
  65                        ci++, ei++;
  66                else if (cmp > 0)
  67                        ei++;
  68        }
  69
  70        while (ci < cmds->cnt)
  71                cmds->names[cj++] = cmds->names[ci++];
  72
  73        cmds->cnt = cj;
  74}
  75
  76static void pretty_print_string_list(struct cmdnames *cmds,
  77                                     unsigned int colopts)
  78{
  79        struct string_list list = STRING_LIST_INIT_NODUP;
  80        struct column_options copts;
  81        int i;
  82
  83        for (i = 0; i < cmds->cnt; i++)
  84                string_list_append(&list, cmds->names[i]->name);
  85        /*
  86         * always enable column display, we only consult column.*
  87         * about layout strategy and stuff
  88         */
  89        colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
  90        memset(&copts, 0, sizeof(copts));
  91        copts.indent = "  ";
  92        copts.padding = 2;
  93        print_columns(&list, colopts, &copts);
  94        string_list_clear(&list, 0);
  95}
  96
  97static int is_executable(const char *name)
  98{
  99        struct stat st;
 100
 101        if (stat(name, &st) || /* stat, not lstat */
 102            !S_ISREG(st.st_mode))
 103                return 0;
 104
 105#if defined(WIN32) || defined(__CYGWIN__)
 106#if defined(__CYGWIN__)
 107if ((st.st_mode & S_IXUSR) == 0)
 108#endif
 109{       /* cannot trust the executable bit, peek into the file instead */
 110        char buf[3] = { 0 };
 111        int n;
 112        int fd = open(name, O_RDONLY);
 113        st.st_mode &= ~S_IXUSR;
 114        if (fd >= 0) {
 115                n = read(fd, buf, 2);
 116                if (n == 2)
 117                        /* DOS executables start with "MZ" */
 118                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 119                                st.st_mode |= S_IXUSR;
 120                close(fd);
 121        }
 122}
 123#endif
 124        return st.st_mode & S_IXUSR;
 125}
 126
 127static void list_commands_in_dir(struct cmdnames *cmds,
 128                                         const char *path,
 129                                         const char *prefix)
 130{
 131        int prefix_len;
 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        prefix_len = strlen(prefix);
 142
 143        strbuf_addf(&buf, "%s/", path);
 144        len = buf.len;
 145
 146        while ((de = readdir(dir)) != NULL) {
 147                int entlen;
 148
 149                if (prefixcmp(de->d_name, prefix))
 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(de->d_name) - prefix_len;
 158                if (has_extension(de->d_name, ".exe"))
 159                        entlen -= 4;
 160
 161                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 162        }
 163        closedir(dir);
 164        strbuf_release(&buf);
 165}
 166
 167void load_command_list(const char *prefix,
 168                struct cmdnames *main_cmds,
 169                struct cmdnames *other_cmds)
 170{
 171        const char *env_path = getenv("PATH");
 172        const char *exec_path = git_exec_path();
 173
 174        if (exec_path) {
 175                list_commands_in_dir(main_cmds, exec_path, prefix);
 176                qsort(main_cmds->names, main_cmds->cnt,
 177                      sizeof(*main_cmds->names), cmdname_compare);
 178                uniq(main_cmds);
 179        }
 180
 181        if (env_path) {
 182                char *paths, *path, *colon;
 183                path = paths = xstrdup(env_path);
 184                while (1) {
 185                        if ((colon = strchr(path, PATH_SEP)))
 186                                *colon = 0;
 187                        if (!exec_path || strcmp(path, exec_path))
 188                                list_commands_in_dir(other_cmds, path, prefix);
 189
 190                        if (!colon)
 191                                break;
 192                        path = colon + 1;
 193                }
 194                free(paths);
 195
 196                qsort(other_cmds->names, other_cmds->cnt,
 197                      sizeof(*other_cmds->names), cmdname_compare);
 198                uniq(other_cmds);
 199        }
 200        exclude_cmds(other_cmds, main_cmds);
 201}
 202
 203void list_commands(unsigned int colopts,
 204                   struct cmdnames *main_cmds, struct cmdnames *other_cmds)
 205{
 206        if (main_cmds->cnt) {
 207                const char *exec_path = git_exec_path();
 208                printf_ln(_("available git commands in '%s'"), exec_path);
 209                putchar('\n');
 210                pretty_print_string_list(main_cmds, colopts);
 211                putchar('\n');
 212        }
 213
 214        if (other_cmds->cnt) {
 215                printf_ln(_("git commands available from elsewhere on your $PATH"));
 216                putchar('\n');
 217                pretty_print_string_list(other_cmds, colopts);
 218                putchar('\n');
 219        }
 220}
 221
 222int is_in_cmdlist(struct cmdnames *c, const char *s)
 223{
 224        int i;
 225        for (i = 0; i < c->cnt; i++)
 226                if (!strcmp(s, c->names[i]->name))
 227                        return 1;
 228        return 0;
 229}
 230
 231static int autocorrect;
 232static struct cmdnames aliases;
 233
 234static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 235{
 236        if (!strcmp(var, "help.autocorrect"))
 237                autocorrect = git_config_int(var,value);
 238        /* Also use aliases for command lookup */
 239        if (!prefixcmp(var, "alias."))
 240                add_cmdname(&aliases, var + 6, strlen(var + 6));
 241
 242        return git_default_config(var, value, cb);
 243}
 244
 245static int levenshtein_compare(const void *p1, const void *p2)
 246{
 247        const struct cmdname *const *c1 = p1, *const *c2 = p2;
 248        const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 249        int l1 = (*c1)->len;
 250        int l2 = (*c2)->len;
 251        return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 252}
 253
 254static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 255{
 256        int i;
 257        ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 258
 259        for (i = 0; i < old->cnt; i++)
 260                cmds->names[cmds->cnt++] = old->names[i];
 261        free(old->names);
 262        old->cnt = 0;
 263        old->names = NULL;
 264}
 265
 266/* An empirically derived magic number */
 267#define SIMILARITY_FLOOR 7
 268#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 269
 270static const char bad_interpreter_advice[] =
 271        N_("'%s' appears to be a git command, but we were not\n"
 272        "able to execute it. Maybe git-%s is broken?");
 273
 274const char *help_unknown_cmd(const char *cmd)
 275{
 276        int i, n, best_similarity = 0;
 277        struct cmdnames main_cmds, other_cmds;
 278
 279        memset(&main_cmds, 0, sizeof(main_cmds));
 280        memset(&other_cmds, 0, sizeof(other_cmds));
 281        memset(&aliases, 0, sizeof(aliases));
 282
 283        git_config(git_unknown_cmd_config, NULL);
 284
 285        load_command_list("git-", &main_cmds, &other_cmds);
 286
 287        add_cmd_list(&main_cmds, &aliases);
 288        add_cmd_list(&main_cmds, &other_cmds);
 289        qsort(main_cmds.names, main_cmds.cnt,
 290              sizeof(main_cmds.names), cmdname_compare);
 291        uniq(&main_cmds);
 292
 293        /* This abuses cmdname->len for levenshtein distance */
 294        for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 295                int cmp = 0; /* avoid compiler stupidity */
 296                const char *candidate = main_cmds.names[i]->name;
 297
 298                /*
 299                 * An exact match means we have the command, but
 300                 * for some reason exec'ing it gave us ENOENT; probably
 301                 * it's a bad interpreter in the #! line.
 302                 */
 303                if (!strcmp(candidate, cmd))
 304                        die(_(bad_interpreter_advice), cmd, cmd);
 305
 306                /* Does the candidate appear in common_cmds list? */
 307                while (n < ARRAY_SIZE(common_cmds) &&
 308                       (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 309                        n++;
 310                if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 311                        /* Yes, this is one of the common commands */
 312                        n++; /* use the entry from common_cmds[] */
 313                        if (!prefixcmp(candidate, cmd)) {
 314                                /* Give prefix match a very good score */
 315                                main_cmds.names[i]->len = 0;
 316                                continue;
 317                        }
 318                }
 319
 320                main_cmds.names[i]->len =
 321                        levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
 322        }
 323
 324        qsort(main_cmds.names, main_cmds.cnt,
 325              sizeof(*main_cmds.names), levenshtein_compare);
 326
 327        if (!main_cmds.cnt)
 328                die(_("Uh oh. Your system reports no Git commands at all."));
 329
 330        /* skip and count prefix matches */
 331        for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 332                ; /* still counting */
 333
 334        if (main_cmds.cnt <= n) {
 335                /* prefix matches with everything? that is too ambiguous */
 336                best_similarity = SIMILARITY_FLOOR + 1;
 337        } else {
 338                /* count all the most similar ones */
 339                for (best_similarity = main_cmds.names[n++]->len;
 340                     (n < main_cmds.cnt &&
 341                      best_similarity == main_cmds.names[n]->len);
 342                     n++)
 343                        ; /* still counting */
 344        }
 345        if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 346                const char *assumed = main_cmds.names[0]->name;
 347                main_cmds.names[0] = NULL;
 348                clean_cmdnames(&main_cmds);
 349                fprintf_ln(stderr,
 350                           _("WARNING: You called a Git command named '%s', "
 351                             "which does not exist.\n"
 352                             "Continuing under the assumption that you meant '%s'"),
 353                        cmd, assumed);
 354                if (autocorrect > 0) {
 355                        fprintf_ln(stderr, _("in %0.1f seconds automatically..."),
 356                                (float)autocorrect/10.0);
 357                        poll(NULL, 0, autocorrect * 100);
 358                }
 359                return assumed;
 360        }
 361
 362        fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 363
 364        if (SIMILAR_ENOUGH(best_similarity)) {
 365                fprintf_ln(stderr,
 366                           Q_("\nDid you mean this?",
 367                              "\nDid you mean one of these?",
 368                           n));
 369
 370                for (i = 0; i < n; i++)
 371                        fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 372        }
 373
 374        exit(1);
 375}
 376
 377int cmd_version(int argc, const char **argv, const char *prefix)
 378{
 379        printf("git version %s\n", git_version_string);
 380        return 0;
 381}