Andrew's git / gitweb.git / help.c
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help.con commit help: reuse print_columns() for help -a (dbfae68)
   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
  10void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  11{
  12        struct cmdname *ent = xmalloc(sizeof(*ent) + len + 1);
  13
  14        ent->len = len;
  15        memcpy(ent->name, name, len);
  16        ent->name[len] = 0;
  17
  18        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  19        cmds->names[cmds->cnt++] = ent;
  20}
  21
  22static void clean_cmdnames(struct cmdnames *cmds)
  23{
  24        int i;
  25        for (i = 0; i < cmds->cnt; ++i)
  26                free(cmds->names[i]);
  27        free(cmds->names);
  28        cmds->cnt = 0;
  29        cmds->alloc = 0;
  30}
  31
  32static int cmdname_compare(const void *a_, const void *b_)
  33{
  34        struct cmdname *a = *(struct cmdname **)a_;
  35        struct cmdname *b = *(struct cmdname **)b_;
  36        return strcmp(a->name, b->name);
  37}
  38
  39static void uniq(struct cmdnames *cmds)
  40{
  41        int i, j;
  42
  43        if (!cmds->cnt)
  44                return;
  45
  46        for (i = j = 1; i < cmds->cnt; i++)
  47                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
  48                        cmds->names[j++] = cmds->names[i];
  49
  50        cmds->cnt = j;
  51}
  52
  53void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  54{
  55        int ci, cj, ei;
  56        int cmp;
  57
  58        ci = cj = ei = 0;
  59        while (ci < cmds->cnt && ei < excludes->cnt) {
  60                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  61                if (cmp < 0)
  62                        cmds->names[cj++] = cmds->names[ci++];
  63                else if (cmp == 0)
  64                        ci++, ei++;
  65                else if (cmp > 0)
  66                        ei++;
  67        }
  68
  69        while (ci < cmds->cnt)
  70                cmds->names[cj++] = cmds->names[ci++];
  71
  72        cmds->cnt = cj;
  73}
  74
  75static void pretty_print_string_list(struct cmdnames *cmds,
  76                                     unsigned int colopts)
  77{
  78        struct string_list list = STRING_LIST_INIT_NODUP;
  79        struct column_options copts;
  80        int i;
  81
  82        for (i = 0; i < cmds->cnt; i++)
  83                string_list_append(&list, cmds->names[i]->name);
  84        /*
  85         * always enable column display, we only consult column.*
  86         * about layout strategy and stuff
  87         */
  88        colopts = (colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
  89        memset(&copts, 0, sizeof(copts));
  90        copts.indent = "  ";
  91        copts.padding = 2;
  92        print_columns(&list, colopts, &copts);
  93        string_list_clear(&list, 0);
  94}
  95
  96static int is_executable(const char *name)
  97{
  98        struct stat st;
  99
 100        if (stat(name, &st) || /* stat, not lstat */
 101            !S_ISREG(st.st_mode))
 102                return 0;
 103
 104#if defined(WIN32) || defined(__CYGWIN__)
 105#if defined(__CYGWIN__)
 106if ((st.st_mode & S_IXUSR) == 0)
 107#endif
 108{       /* cannot trust the executable bit, peek into the file instead */
 109        char buf[3] = { 0 };
 110        int n;
 111        int fd = open(name, O_RDONLY);
 112        st.st_mode &= ~S_IXUSR;
 113        if (fd >= 0) {
 114                n = read(fd, buf, 2);
 115                if (n == 2)
 116                        /* DOS executables start with "MZ" */
 117                        if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
 118                                st.st_mode |= S_IXUSR;
 119                close(fd);
 120        }
 121}
 122#endif
 123        return st.st_mode & S_IXUSR;
 124}
 125
 126static void list_commands_in_dir(struct cmdnames *cmds,
 127                                         const char *path,
 128                                         const char *prefix)
 129{
 130        int prefix_len;
 131        DIR *dir = opendir(path);
 132        struct dirent *de;
 133        struct strbuf buf = STRBUF_INIT;
 134        int len;
 135
 136        if (!dir)
 137                return;
 138        if (!prefix)
 139                prefix = "git-";
 140        prefix_len = strlen(prefix);
 141
 142        strbuf_addf(&buf, "%s/", path);
 143        len = buf.len;
 144
 145        while ((de = readdir(dir)) != NULL) {
 146                int entlen;
 147
 148                if (prefixcmp(de->d_name, prefix))
 149                        continue;
 150
 151                strbuf_setlen(&buf, len);
 152                strbuf_addstr(&buf, de->d_name);
 153                if (!is_executable(buf.buf))
 154                        continue;
 155
 156                entlen = strlen(de->d_name) - prefix_len;
 157                if (has_extension(de->d_name, ".exe"))
 158                        entlen -= 4;
 159
 160                add_cmdname(cmds, de->d_name + prefix_len, 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(const char *title, 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("available %s in '%s'\n", title, exec_path);
 208                printf("----------------");
 209                mput_char('-', strlen(title) + strlen(exec_path));
 210                putchar('\n');
 211                pretty_print_string_list(main_cmds, colopts);
 212                putchar('\n');
 213        }
 214
 215        if (other_cmds->cnt) {
 216                printf("%s available from elsewhere on your $PATH\n", title);
 217                printf("---------------------------------------");
 218                mput_char('-', strlen(title));
 219                putchar('\n');
 220                pretty_print_string_list(other_cmds, colopts);
 221                putchar('\n');
 222        }
 223}
 224
 225int is_in_cmdlist(struct cmdnames *c, const char *s)
 226{
 227        int i;
 228        for (i = 0; i < c->cnt; i++)
 229                if (!strcmp(s, c->names[i]->name))
 230                        return 1;
 231        return 0;
 232}
 233
 234static int autocorrect;
 235static struct cmdnames aliases;
 236
 237static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 238{
 239        if (!strcmp(var, "help.autocorrect"))
 240                autocorrect = git_config_int(var,value);
 241        /* Also use aliases for command lookup */
 242        if (!prefixcmp(var, "alias."))
 243                add_cmdname(&aliases, var + 6, strlen(var + 6));
 244
 245        return git_default_config(var, value, cb);
 246}
 247
 248static int levenshtein_compare(const void *p1, const void *p2)
 249{
 250        const struct cmdname *const *c1 = p1, *const *c2 = p2;
 251        const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 252        int l1 = (*c1)->len;
 253        int l2 = (*c2)->len;
 254        return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 255}
 256
 257static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 258{
 259        int i;
 260        ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 261
 262        for (i = 0; i < old->cnt; i++)
 263                cmds->names[cmds->cnt++] = old->names[i];
 264        free(old->names);
 265        old->cnt = 0;
 266        old->names = NULL;
 267}
 268
 269/* An empirically derived magic number */
 270#define SIMILARITY_FLOOR 7
 271#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
 272
 273static const char bad_interpreter_advice[] =
 274        N_("'%s' appears to be a git command, but we were not\n"
 275        "able to execute it. Maybe git-%s is broken?");
 276
 277const char *help_unknown_cmd(const char *cmd)
 278{
 279        int i, n, best_similarity = 0;
 280        struct cmdnames main_cmds, other_cmds;
 281
 282        memset(&main_cmds, 0, sizeof(main_cmds));
 283        memset(&other_cmds, 0, sizeof(other_cmds));
 284        memset(&aliases, 0, sizeof(aliases));
 285
 286        git_config(git_unknown_cmd_config, NULL);
 287
 288        load_command_list("git-", &main_cmds, &other_cmds);
 289
 290        add_cmd_list(&main_cmds, &aliases);
 291        add_cmd_list(&main_cmds, &other_cmds);
 292        qsort(main_cmds.names, main_cmds.cnt,
 293              sizeof(main_cmds.names), cmdname_compare);
 294        uniq(&main_cmds);
 295
 296        /* This abuses cmdname->len for levenshtein distance */
 297        for (i = 0, n = 0; i < main_cmds.cnt; i++) {
 298                int cmp = 0; /* avoid compiler stupidity */
 299                const char *candidate = main_cmds.names[i]->name;
 300
 301                /*
 302                 * An exact match means we have the command, but
 303                 * for some reason exec'ing it gave us ENOENT; probably
 304                 * it's a bad interpreter in the #! line.
 305                 */
 306                if (!strcmp(candidate, cmd))
 307                        die(_(bad_interpreter_advice), cmd, cmd);
 308
 309                /* Does the candidate appear in common_cmds list? */
 310                while (n < ARRAY_SIZE(common_cmds) &&
 311                       (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
 312                        n++;
 313                if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
 314                        /* Yes, this is one of the common commands */
 315                        n++; /* use the entry from common_cmds[] */
 316                        if (!prefixcmp(candidate, cmd)) {
 317                                /* Give prefix match a very good score */
 318                                main_cmds.names[i]->len = 0;
 319                                continue;
 320                        }
 321                }
 322
 323                main_cmds.names[i]->len =
 324                        levenshtein(cmd, candidate, 0, 2, 1, 4) + 1;
 325        }
 326
 327        qsort(main_cmds.names, main_cmds.cnt,
 328              sizeof(*main_cmds.names), levenshtein_compare);
 329
 330        if (!main_cmds.cnt)
 331                die ("Uh oh. Your system reports no Git commands at all.");
 332
 333        /* skip and count prefix matches */
 334        for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
 335                ; /* still counting */
 336
 337        if (main_cmds.cnt <= n) {
 338                /* prefix matches with everything? that is too ambiguous */
 339                best_similarity = SIMILARITY_FLOOR + 1;
 340        } else {
 341                /* count all the most similar ones */
 342                for (best_similarity = main_cmds.names[n++]->len;
 343                     (n < main_cmds.cnt &&
 344                      best_similarity == main_cmds.names[n]->len);
 345                     n++)
 346                        ; /* still counting */
 347        }
 348        if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
 349                const char *assumed = main_cmds.names[0]->name;
 350                main_cmds.names[0] = NULL;
 351                clean_cmdnames(&main_cmds);
 352                fprintf(stderr, "WARNING: You called a Git command named '%s', "
 353                        "which does not exist.\n"
 354                        "Continuing under the assumption that you meant '%s'\n",
 355                        cmd, assumed);
 356                if (autocorrect > 0) {
 357                        fprintf(stderr, "in %0.1f seconds automatically...\n",
 358                                (float)autocorrect/10.0);
 359                        poll(NULL, 0, autocorrect * 100);
 360                }
 361                return assumed;
 362        }
 363
 364        fprintf(stderr, "git: '%s' is not a git command. See 'git --help'.\n", cmd);
 365
 366        if (SIMILAR_ENOUGH(best_similarity)) {
 367                fprintf(stderr, "\nDid you mean %s?\n",
 368                        n < 2 ? "this": "one of these");
 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}