Andrew's git / gitweb.git / config.c
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config.con commit compat/snprintf.c: handle snprintf's that always return the # chars transmitted (a81892d)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 * Copyright (C) Johannes Schindelin, 2005
   6 *
   7 */
   8#include "cache.h"
   9#include "exec_cmd.h"
  10
  11#define MAXNAME (256)
  12
  13static FILE *config_file;
  14static const char *config_file_name;
  15static int config_linenr;
  16static int config_file_eof;
  17static int zlib_compression_seen;
  18
  19const char *config_exclusive_filename = NULL;
  20
  21static int get_next_char(void)
  22{
  23        int c;
  24        FILE *f;
  25
  26        c = '\n';
  27        if ((f = config_file) != NULL) {
  28                c = fgetc(f);
  29                if (c == '\r') {
  30                        /* DOS like systems */
  31                        c = fgetc(f);
  32                        if (c != '\n') {
  33                                ungetc(c, f);
  34                                c = '\r';
  35                        }
  36                }
  37                if (c == '\n')
  38                        config_linenr++;
  39                if (c == EOF) {
  40                        config_file_eof = 1;
  41                        c = '\n';
  42                }
  43        }
  44        return c;
  45}
  46
  47static char *parse_value(void)
  48{
  49        static char value[1024];
  50        int quote = 0, comment = 0, len = 0, space = 0;
  51
  52        for (;;) {
  53                int c = get_next_char();
  54                if (len >= sizeof(value))
  55                        return NULL;
  56                if (c == '\n') {
  57                        if (quote)
  58                                return NULL;
  59                        value[len] = 0;
  60                        return value;
  61                }
  62                if (comment)
  63                        continue;
  64                if (isspace(c) && !quote) {
  65                        space = 1;
  66                        continue;
  67                }
  68                if (!quote) {
  69                        if (c == ';' || c == '#') {
  70                                comment = 1;
  71                                continue;
  72                        }
  73                }
  74                if (space) {
  75                        if (len)
  76                                value[len++] = ' ';
  77                        space = 0;
  78                }
  79                if (c == '\\') {
  80                        c = get_next_char();
  81                        switch (c) {
  82                        case '\n':
  83                                continue;
  84                        case 't':
  85                                c = '\t';
  86                                break;
  87                        case 'b':
  88                                c = '\b';
  89                                break;
  90                        case 'n':
  91                                c = '\n';
  92                                break;
  93                        /* Some characters escape as themselves */
  94                        case '\\': case '"':
  95                                break;
  96                        /* Reject unknown escape sequences */
  97                        default:
  98                                return NULL;
  99                        }
 100                        value[len++] = c;
 101                        continue;
 102                }
 103                if (c == '"') {
 104                        quote = 1-quote;
 105                        continue;
 106                }
 107                value[len++] = c;
 108        }
 109}
 110
 111static inline int iskeychar(int c)
 112{
 113        return isalnum(c) || c == '-';
 114}
 115
 116static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 117{
 118        int c;
 119        char *value;
 120
 121        /* Get the full name */
 122        for (;;) {
 123                c = get_next_char();
 124                if (config_file_eof)
 125                        break;
 126                if (!iskeychar(c))
 127                        break;
 128                name[len++] = tolower(c);
 129                if (len >= MAXNAME)
 130                        return -1;
 131        }
 132        name[len] = 0;
 133        while (c == ' ' || c == '\t')
 134                c = get_next_char();
 135
 136        value = NULL;
 137        if (c != '\n') {
 138                if (c != '=')
 139                        return -1;
 140                value = parse_value();
 141                if (!value)
 142                        return -1;
 143        }
 144        return fn(name, value, data);
 145}
 146
 147static int get_extended_base_var(char *name, int baselen, int c)
 148{
 149        do {
 150                if (c == '\n')
 151                        return -1;
 152                c = get_next_char();
 153        } while (isspace(c));
 154
 155        /* We require the format to be '[base "extension"]' */
 156        if (c != '"')
 157                return -1;
 158        name[baselen++] = '.';
 159
 160        for (;;) {
 161                int c = get_next_char();
 162                if (c == '\n')
 163                        return -1;
 164                if (c == '"')
 165                        break;
 166                if (c == '\\') {
 167                        c = get_next_char();
 168                        if (c == '\n')
 169                                return -1;
 170                }
 171                name[baselen++] = c;
 172                if (baselen > MAXNAME / 2)
 173                        return -1;
 174        }
 175
 176        /* Final ']' */
 177        if (get_next_char() != ']')
 178                return -1;
 179        return baselen;
 180}
 181
 182static int get_base_var(char *name)
 183{
 184        int baselen = 0;
 185
 186        for (;;) {
 187                int c = get_next_char();
 188                if (config_file_eof)
 189                        return -1;
 190                if (c == ']')
 191                        return baselen;
 192                if (isspace(c))
 193                        return get_extended_base_var(name, baselen, c);
 194                if (!iskeychar(c) && c != '.')
 195                        return -1;
 196                if (baselen > MAXNAME / 2)
 197                        return -1;
 198                name[baselen++] = tolower(c);
 199        }
 200}
 201
 202static int git_parse_file(config_fn_t fn, void *data)
 203{
 204        int comment = 0;
 205        int baselen = 0;
 206        static char var[MAXNAME];
 207
 208        for (;;) {
 209                int c = get_next_char();
 210                if (c == '\n') {
 211                        if (config_file_eof)
 212                                return 0;
 213                        comment = 0;
 214                        continue;
 215                }
 216                if (comment || isspace(c))
 217                        continue;
 218                if (c == '#' || c == ';') {
 219                        comment = 1;
 220                        continue;
 221                }
 222                if (c == '[') {
 223                        baselen = get_base_var(var);
 224                        if (baselen <= 0)
 225                                break;
 226                        var[baselen++] = '.';
 227                        var[baselen] = 0;
 228                        continue;
 229                }
 230                if (!isalpha(c))
 231                        break;
 232                var[baselen] = tolower(c);
 233                if (get_value(fn, data, var, baselen+1) < 0)
 234                        break;
 235        }
 236        die("bad config file line %d in %s", config_linenr, config_file_name);
 237}
 238
 239static int parse_unit_factor(const char *end, unsigned long *val)
 240{
 241        if (!*end)
 242                return 1;
 243        else if (!strcasecmp(end, "k")) {
 244                *val *= 1024;
 245                return 1;
 246        }
 247        else if (!strcasecmp(end, "m")) {
 248                *val *= 1024 * 1024;
 249                return 1;
 250        }
 251        else if (!strcasecmp(end, "g")) {
 252                *val *= 1024 * 1024 * 1024;
 253                return 1;
 254        }
 255        return 0;
 256}
 257
 258int git_parse_long(const char *value, long *ret)
 259{
 260        if (value && *value) {
 261                char *end;
 262                long val = strtol(value, &end, 0);
 263                unsigned long factor = 1;
 264                if (!parse_unit_factor(end, &factor))
 265                        return 0;
 266                *ret = val * factor;
 267                return 1;
 268        }
 269        return 0;
 270}
 271
 272int git_parse_ulong(const char *value, unsigned long *ret)
 273{
 274        if (value && *value) {
 275                char *end;
 276                unsigned long val = strtoul(value, &end, 0);
 277                if (!parse_unit_factor(end, &val))
 278                        return 0;
 279                *ret = val;
 280                return 1;
 281        }
 282        return 0;
 283}
 284
 285static void die_bad_config(const char *name)
 286{
 287        if (config_file_name)
 288                die("bad config value for '%s' in %s", name, config_file_name);
 289        die("bad config value for '%s'", name);
 290}
 291
 292int git_config_int(const char *name, const char *value)
 293{
 294        long ret;
 295        if (!git_parse_long(value, &ret))
 296                die_bad_config(name);
 297        return ret;
 298}
 299
 300unsigned long git_config_ulong(const char *name, const char *value)
 301{
 302        unsigned long ret;
 303        if (!git_parse_ulong(value, &ret))
 304                die_bad_config(name);
 305        return ret;
 306}
 307
 308int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 309{
 310        *is_bool = 1;
 311        if (!value)
 312                return 1;
 313        if (!*value)
 314                return 0;
 315        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 316                return 1;
 317        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 318                return 0;
 319        *is_bool = 0;
 320        return git_config_int(name, value);
 321}
 322
 323int git_config_bool(const char *name, const char *value)
 324{
 325        int discard;
 326        return !!git_config_bool_or_int(name, value, &discard);
 327}
 328
 329int git_config_string(const char **dest, const char *var, const char *value)
 330{
 331        if (!value)
 332                return config_error_nonbool(var);
 333        *dest = xstrdup(value);
 334        return 0;
 335}
 336
 337static int git_default_core_config(const char *var, const char *value)
 338{
 339        /* This needs a better name */
 340        if (!strcmp(var, "core.filemode")) {
 341                trust_executable_bit = git_config_bool(var, value);
 342                return 0;
 343        }
 344        if (!strcmp(var, "core.trustctime")) {
 345                trust_ctime = git_config_bool(var, value);
 346                return 0;
 347        }
 348
 349        if (!strcmp(var, "core.quotepath")) {
 350                quote_path_fully = git_config_bool(var, value);
 351                return 0;
 352        }
 353
 354        if (!strcmp(var, "core.symlinks")) {
 355                has_symlinks = git_config_bool(var, value);
 356                return 0;
 357        }
 358
 359        if (!strcmp(var, "core.ignorecase")) {
 360                ignore_case = git_config_bool(var, value);
 361                return 0;
 362        }
 363
 364        if (!strcmp(var, "core.bare")) {
 365                is_bare_repository_cfg = git_config_bool(var, value);
 366                return 0;
 367        }
 368
 369        if (!strcmp(var, "core.ignorestat")) {
 370                assume_unchanged = git_config_bool(var, value);
 371                return 0;
 372        }
 373
 374        if (!strcmp(var, "core.prefersymlinkrefs")) {
 375                prefer_symlink_refs = git_config_bool(var, value);
 376                return 0;
 377        }
 378
 379        if (!strcmp(var, "core.logallrefupdates")) {
 380                log_all_ref_updates = git_config_bool(var, value);
 381                return 0;
 382        }
 383
 384        if (!strcmp(var, "core.warnambiguousrefs")) {
 385                warn_ambiguous_refs = git_config_bool(var, value);
 386                return 0;
 387        }
 388
 389        if (!strcmp(var, "core.loosecompression")) {
 390                int level = git_config_int(var, value);
 391                if (level == -1)
 392                        level = Z_DEFAULT_COMPRESSION;
 393                else if (level < 0 || level > Z_BEST_COMPRESSION)
 394                        die("bad zlib compression level %d", level);
 395                zlib_compression_level = level;
 396                zlib_compression_seen = 1;
 397                return 0;
 398        }
 399
 400        if (!strcmp(var, "core.compression")) {
 401                int level = git_config_int(var, value);
 402                if (level == -1)
 403                        level = Z_DEFAULT_COMPRESSION;
 404                else if (level < 0 || level > Z_BEST_COMPRESSION)
 405                        die("bad zlib compression level %d", level);
 406                core_compression_level = level;
 407                core_compression_seen = 1;
 408                if (!zlib_compression_seen)
 409                        zlib_compression_level = level;
 410                return 0;
 411        }
 412
 413        if (!strcmp(var, "core.packedgitwindowsize")) {
 414                int pgsz_x2 = getpagesize() * 2;
 415                packed_git_window_size = git_config_int(var, value);
 416
 417                /* This value must be multiple of (pagesize * 2) */
 418                packed_git_window_size /= pgsz_x2;
 419                if (packed_git_window_size < 1)
 420                        packed_git_window_size = 1;
 421                packed_git_window_size *= pgsz_x2;
 422                return 0;
 423        }
 424
 425        if (!strcmp(var, "core.packedgitlimit")) {
 426                packed_git_limit = git_config_int(var, value);
 427                return 0;
 428        }
 429
 430        if (!strcmp(var, "core.deltabasecachelimit")) {
 431                delta_base_cache_limit = git_config_int(var, value);
 432                return 0;
 433        }
 434
 435        if (!strcmp(var, "core.autocrlf")) {
 436                if (value && !strcasecmp(value, "input")) {
 437                        auto_crlf = -1;
 438                        return 0;
 439                }
 440                auto_crlf = git_config_bool(var, value);
 441                return 0;
 442        }
 443
 444        if (!strcmp(var, "core.safecrlf")) {
 445                if (value && !strcasecmp(value, "warn")) {
 446                        safe_crlf = SAFE_CRLF_WARN;
 447                        return 0;
 448                }
 449                safe_crlf = git_config_bool(var, value);
 450                return 0;
 451        }
 452
 453        if (!strcmp(var, "core.pager"))
 454                return git_config_string(&pager_program, var, value);
 455
 456        if (!strcmp(var, "core.editor"))
 457                return git_config_string(&editor_program, var, value);
 458
 459        if (!strcmp(var, "core.excludesfile"))
 460                return git_config_string(&excludes_file, var, value);
 461
 462        if (!strcmp(var, "core.whitespace")) {
 463                if (!value)
 464                        return config_error_nonbool(var);
 465                whitespace_rule_cfg = parse_whitespace_rule(value);
 466                return 0;
 467        }
 468
 469        if (!strcmp(var, "core.fsyncobjectfiles")) {
 470                fsync_object_files = git_config_bool(var, value);
 471                return 0;
 472        }
 473
 474        /* Add other config variables here and to Documentation/config.txt. */
 475        return 0;
 476}
 477
 478static int git_default_user_config(const char *var, const char *value)
 479{
 480        if (!strcmp(var, "user.name")) {
 481                if (!value)
 482                        return config_error_nonbool(var);
 483                strlcpy(git_default_name, value, sizeof(git_default_name));
 484                if (git_default_email[0])
 485                        user_ident_explicitly_given = 1;
 486                return 0;
 487        }
 488
 489        if (!strcmp(var, "user.email")) {
 490                if (!value)
 491                        return config_error_nonbool(var);
 492                strlcpy(git_default_email, value, sizeof(git_default_email));
 493                if (git_default_name[0])
 494                        user_ident_explicitly_given = 1;
 495                return 0;
 496        }
 497
 498        /* Add other config variables here and to Documentation/config.txt. */
 499        return 0;
 500}
 501
 502static int git_default_i18n_config(const char *var, const char *value)
 503{
 504        if (!strcmp(var, "i18n.commitencoding"))
 505                return git_config_string(&git_commit_encoding, var, value);
 506
 507        if (!strcmp(var, "i18n.logoutputencoding"))
 508                return git_config_string(&git_log_output_encoding, var, value);
 509
 510        /* Add other config variables here and to Documentation/config.txt. */
 511        return 0;
 512}
 513
 514static int git_default_branch_config(const char *var, const char *value)
 515{
 516        if (!strcmp(var, "branch.autosetupmerge")) {
 517                if (value && !strcasecmp(value, "always")) {
 518                        git_branch_track = BRANCH_TRACK_ALWAYS;
 519                        return 0;
 520                }
 521                git_branch_track = git_config_bool(var, value);
 522                return 0;
 523        }
 524        if (!strcmp(var, "branch.autosetuprebase")) {
 525                if (!value)
 526                        return config_error_nonbool(var);
 527                else if (!strcmp(value, "never"))
 528                        autorebase = AUTOREBASE_NEVER;
 529                else if (!strcmp(value, "local"))
 530                        autorebase = AUTOREBASE_LOCAL;
 531                else if (!strcmp(value, "remote"))
 532                        autorebase = AUTOREBASE_REMOTE;
 533                else if (!strcmp(value, "always"))
 534                        autorebase = AUTOREBASE_ALWAYS;
 535                else
 536                        return error("Malformed value for %s", var);
 537                return 0;
 538        }
 539
 540        /* Add other config variables here and to Documentation/config.txt. */
 541        return 0;
 542}
 543
 544int git_default_config(const char *var, const char *value, void *dummy)
 545{
 546        if (!prefixcmp(var, "core."))
 547                return git_default_core_config(var, value);
 548
 549        if (!prefixcmp(var, "user."))
 550                return git_default_user_config(var, value);
 551
 552        if (!prefixcmp(var, "i18n."))
 553                return git_default_i18n_config(var, value);
 554
 555        if (!prefixcmp(var, "branch."))
 556                return git_default_branch_config(var, value);
 557
 558        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 559                pager_use_color = git_config_bool(var,value);
 560                return 0;
 561        }
 562
 563        /* Add other config variables here and to Documentation/config.txt. */
 564        return 0;
 565}
 566
 567int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 568{
 569        int ret;
 570        FILE *f = fopen(filename, "r");
 571
 572        ret = -1;
 573        if (f) {
 574                config_file = f;
 575                config_file_name = filename;
 576                config_linenr = 1;
 577                config_file_eof = 0;
 578                ret = git_parse_file(fn, data);
 579                fclose(f);
 580                config_file_name = NULL;
 581        }
 582        return ret;
 583}
 584
 585const char *git_etc_gitconfig(void)
 586{
 587        static const char *system_wide;
 588        if (!system_wide)
 589                system_wide = system_path(ETC_GITCONFIG);
 590        return system_wide;
 591}
 592
 593static int git_env_bool(const char *k, int def)
 594{
 595        const char *v = getenv(k);
 596        return v ? git_config_bool(k, v) : def;
 597}
 598
 599int git_config_system(void)
 600{
 601        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 602}
 603
 604int git_config_global(void)
 605{
 606        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 607}
 608
 609int git_config(config_fn_t fn, void *data)
 610{
 611        int ret = 0;
 612        char *repo_config = NULL;
 613        const char *home = NULL;
 614
 615        /* $GIT_CONFIG makes git read _only_ the given config file,
 616         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 617         * global config file, the same way it would the per-repository
 618         * config file otherwise. */
 619        if (config_exclusive_filename)
 620                return git_config_from_file(fn, config_exclusive_filename, data);
 621        if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 622                ret += git_config_from_file(fn, git_etc_gitconfig(),
 623                                            data);
 624
 625        home = getenv("HOME");
 626        if (git_config_global() && home) {
 627                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 628                if (!access(user_config, R_OK))
 629                        ret += git_config_from_file(fn, user_config, data);
 630                free(user_config);
 631        }
 632
 633        repo_config = xstrdup(git_path("config"));
 634        ret += git_config_from_file(fn, repo_config, data);
 635        free(repo_config);
 636        return ret;
 637}
 638
 639/*
 640 * Find all the stuff for git_config_set() below.
 641 */
 642
 643#define MAX_MATCHES 512
 644
 645static struct {
 646        int baselen;
 647        char* key;
 648        int do_not_match;
 649        regex_t* value_regex;
 650        int multi_replace;
 651        size_t offset[MAX_MATCHES];
 652        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 653        int seen;
 654} store;
 655
 656static int matches(const char* key, const char* value)
 657{
 658        return !strcmp(key, store.key) &&
 659                (store.value_regex == NULL ||
 660                 (store.do_not_match ^
 661                  !regexec(store.value_regex, value, 0, NULL, 0)));
 662}
 663
 664static int store_aux(const char* key, const char* value, void *cb)
 665{
 666        const char *ep;
 667        size_t section_len;
 668
 669        switch (store.state) {
 670        case KEY_SEEN:
 671                if (matches(key, value)) {
 672                        if (store.seen == 1 && store.multi_replace == 0) {
 673                                warning("%s has multiple values", key);
 674                        } else if (store.seen >= MAX_MATCHES) {
 675                                error("too many matches for %s", key);
 676                                return 1;
 677                        }
 678
 679                        store.offset[store.seen] = ftell(config_file);
 680                        store.seen++;
 681                }
 682                break;
 683        case SECTION_SEEN:
 684                /*
 685                 * What we are looking for is in store.key (both
 686                 * section and var), and its section part is baselen
 687                 * long.  We found key (again, both section and var).
 688                 * We would want to know if this key is in the same
 689                 * section as what we are looking for.  We already
 690                 * know we are in the same section as what should
 691                 * hold store.key.
 692                 */
 693                ep = strrchr(key, '.');
 694                section_len = ep - key;
 695
 696                if ((section_len != store.baselen) ||
 697                    memcmp(key, store.key, section_len+1)) {
 698                        store.state = SECTION_END_SEEN;
 699                        break;
 700                }
 701
 702                /*
 703                 * Do not increment matches: this is no match, but we
 704                 * just made sure we are in the desired section.
 705                 */
 706                store.offset[store.seen] = ftell(config_file);
 707                /* fallthru */
 708        case SECTION_END_SEEN:
 709        case START:
 710                if (matches(key, value)) {
 711                        store.offset[store.seen] = ftell(config_file);
 712                        store.state = KEY_SEEN;
 713                        store.seen++;
 714                } else {
 715                        if (strrchr(key, '.') - key == store.baselen &&
 716                              !strncmp(key, store.key, store.baselen)) {
 717                                        store.state = SECTION_SEEN;
 718                                        store.offset[store.seen] = ftell(config_file);
 719                        }
 720                }
 721        }
 722        return 0;
 723}
 724
 725static int write_error(const char *filename)
 726{
 727        error("failed to write new configuration file %s", filename);
 728
 729        /* Same error code as "failed to rename". */
 730        return 4;
 731}
 732
 733static int store_write_section(int fd, const char* key)
 734{
 735        const char *dot;
 736        int i, success;
 737        struct strbuf sb;
 738
 739        strbuf_init(&sb, 0);
 740        dot = memchr(key, '.', store.baselen);
 741        if (dot) {
 742                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 743                for (i = dot - key + 1; i < store.baselen; i++) {
 744                        if (key[i] == '"' || key[i] == '\\')
 745                                strbuf_addch(&sb, '\\');
 746                        strbuf_addch(&sb, key[i]);
 747                }
 748                strbuf_addstr(&sb, "\"]\n");
 749        } else {
 750                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 751        }
 752
 753        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 754        strbuf_release(&sb);
 755
 756        return success;
 757}
 758
 759static int store_write_pair(int fd, const char* key, const char* value)
 760{
 761        int i, success;
 762        int length = strlen(key + store.baselen + 1);
 763        const char *quote = "";
 764        struct strbuf sb;
 765
 766        /*
 767         * Check to see if the value needs to be surrounded with a dq pair.
 768         * Note that problematic characters are always backslash-quoted; this
 769         * check is about not losing leading or trailing SP and strings that
 770         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 771         * configuration parser.
 772         */
 773        if (value[0] == ' ')
 774                quote = "\"";
 775        for (i = 0; value[i]; i++)
 776                if (value[i] == ';' || value[i] == '#')
 777                        quote = "\"";
 778        if (i && value[i - 1] == ' ')
 779                quote = "\"";
 780
 781        strbuf_init(&sb, 0);
 782        strbuf_addf(&sb, "\t%.*s = %s",
 783                    length, key + store.baselen + 1, quote);
 784
 785        for (i = 0; value[i]; i++)
 786                switch (value[i]) {
 787                case '\n':
 788                        strbuf_addstr(&sb, "\\n");
 789                        break;
 790                case '\t':
 791                        strbuf_addstr(&sb, "\\t");
 792                        break;
 793                case '"':
 794                case '\\':
 795                        strbuf_addch(&sb, '\\');
 796                default:
 797                        strbuf_addch(&sb, value[i]);
 798                        break;
 799                }
 800        strbuf_addf(&sb, "%s\n", quote);
 801
 802        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 803        strbuf_release(&sb);
 804
 805        return success;
 806}
 807
 808static ssize_t find_beginning_of_line(const char* contents, size_t size,
 809        size_t offset_, int* found_bracket)
 810{
 811        size_t equal_offset = size, bracket_offset = size;
 812        ssize_t offset;
 813
 814contline:
 815        for (offset = offset_-2; offset > 0
 816                        && contents[offset] != '\n'; offset--)
 817                switch (contents[offset]) {
 818                        case '=': equal_offset = offset; break;
 819                        case ']': bracket_offset = offset; break;
 820                }
 821        if (offset > 0 && contents[offset-1] == '\\') {
 822                offset_ = offset;
 823                goto contline;
 824        }
 825        if (bracket_offset < equal_offset) {
 826                *found_bracket = 1;
 827                offset = bracket_offset+1;
 828        } else
 829                offset++;
 830
 831        return offset;
 832}
 833
 834int git_config_set(const char* key, const char* value)
 835{
 836        return git_config_set_multivar(key, value, NULL, 0);
 837}
 838
 839/*
 840 * If value==NULL, unset in (remove from) config,
 841 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 842 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 843 *     else all matching key/values (regardless how many) are removed,
 844 *     before the new pair is written.
 845 *
 846 * Returns 0 on success.
 847 *
 848 * This function does this:
 849 *
 850 * - it locks the config file by creating ".git/config.lock"
 851 *
 852 * - it then parses the config using store_aux() as validator to find
 853 *   the position on the key/value pair to replace. If it is to be unset,
 854 *   it must be found exactly once.
 855 *
 856 * - the config file is mmap()ed and the part before the match (if any) is
 857 *   written to the lock file, then the changed part and the rest.
 858 *
 859 * - the config file is removed and the lock file rename()d to it.
 860 *
 861 */
 862int git_config_set_multivar(const char* key, const char* value,
 863        const char* value_regex, int multi_replace)
 864{
 865        int i, dot;
 866        int fd = -1, in_fd;
 867        int ret;
 868        char* config_filename;
 869        struct lock_file *lock = NULL;
 870        const char* last_dot = strrchr(key, '.');
 871
 872        if (config_exclusive_filename)
 873                config_filename = xstrdup(config_exclusive_filename);
 874        else
 875                config_filename = xstrdup(git_path("config"));
 876
 877        /*
 878         * Since "key" actually contains the section name and the real
 879         * key name separated by a dot, we have to know where the dot is.
 880         */
 881
 882        if (last_dot == NULL) {
 883                error("key does not contain a section: %s", key);
 884                ret = 2;
 885                goto out_free;
 886        }
 887        store.baselen = last_dot - key;
 888
 889        store.multi_replace = multi_replace;
 890
 891        /*
 892         * Validate the key and while at it, lower case it for matching.
 893         */
 894        store.key = xmalloc(strlen(key) + 1);
 895        dot = 0;
 896        for (i = 0; key[i]; i++) {
 897                unsigned char c = key[i];
 898                if (c == '.')
 899                        dot = 1;
 900                /* Leave the extended basename untouched.. */
 901                if (!dot || i > store.baselen) {
 902                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 903                                error("invalid key: %s", key);
 904                                free(store.key);
 905                                ret = 1;
 906                                goto out_free;
 907                        }
 908                        c = tolower(c);
 909                } else if (c == '\n') {
 910                        error("invalid key (newline): %s", key);
 911                        free(store.key);
 912                        ret = 1;
 913                        goto out_free;
 914                }
 915                store.key[i] = c;
 916        }
 917        store.key[i] = 0;
 918
 919        /*
 920         * The lock serves a purpose in addition to locking: the new
 921         * contents of .git/config will be written into it.
 922         */
 923        lock = xcalloc(sizeof(struct lock_file), 1);
 924        fd = hold_lock_file_for_update(lock, config_filename, 0);
 925        if (fd < 0) {
 926                error("could not lock config file %s", config_filename);
 927                free(store.key);
 928                ret = -1;
 929                goto out_free;
 930        }
 931
 932        /*
 933         * If .git/config does not exist yet, write a minimal version.
 934         */
 935        in_fd = open(config_filename, O_RDONLY);
 936        if ( in_fd < 0 ) {
 937                free(store.key);
 938
 939                if ( ENOENT != errno ) {
 940                        error("opening %s: %s", config_filename,
 941                              strerror(errno));
 942                        ret = 3; /* same as "invalid config file" */
 943                        goto out_free;
 944                }
 945                /* if nothing to unset, error out */
 946                if (value == NULL) {
 947                        ret = 5;
 948                        goto out_free;
 949                }
 950
 951                store.key = (char*)key;
 952                if (!store_write_section(fd, key) ||
 953                    !store_write_pair(fd, key, value))
 954                        goto write_err_out;
 955        } else {
 956                struct stat st;
 957                char* contents;
 958                size_t contents_sz, copy_begin, copy_end;
 959                int i, new_line = 0;
 960
 961                if (value_regex == NULL)
 962                        store.value_regex = NULL;
 963                else {
 964                        if (value_regex[0] == '!') {
 965                                store.do_not_match = 1;
 966                                value_regex++;
 967                        } else
 968                                store.do_not_match = 0;
 969
 970                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 971                        if (regcomp(store.value_regex, value_regex,
 972                                        REG_EXTENDED)) {
 973                                error("invalid pattern: %s", value_regex);
 974                                free(store.value_regex);
 975                                ret = 6;
 976                                goto out_free;
 977                        }
 978                }
 979
 980                store.offset[0] = 0;
 981                store.state = START;
 982                store.seen = 0;
 983
 984                /*
 985                 * After this, store.offset will contain the *end* offset
 986                 * of the last match, or remain at 0 if no match was found.
 987                 * As a side effect, we make sure to transform only a valid
 988                 * existing config file.
 989                 */
 990                if (git_config_from_file(store_aux, config_filename, NULL)) {
 991                        error("invalid config file %s", config_filename);
 992                        free(store.key);
 993                        if (store.value_regex != NULL) {
 994                                regfree(store.value_regex);
 995                                free(store.value_regex);
 996                        }
 997                        ret = 3;
 998                        goto out_free;
 999                }
1000
1001                free(store.key);
1002                if (store.value_regex != NULL) {
1003                        regfree(store.value_regex);
1004                        free(store.value_regex);
1005                }
1006
1007                /* if nothing to unset, or too many matches, error out */
1008                if ((store.seen == 0 && value == NULL) ||
1009                                (store.seen > 1 && multi_replace == 0)) {
1010                        ret = 5;
1011                        goto out_free;
1012                }
1013
1014                fstat(in_fd, &st);
1015                contents_sz = xsize_t(st.st_size);
1016                contents = xmmap(NULL, contents_sz, PROT_READ,
1017                        MAP_PRIVATE, in_fd, 0);
1018                close(in_fd);
1019
1020                if (store.seen == 0)
1021                        store.seen = 1;
1022
1023                for (i = 0, copy_begin = 0; i < store.seen; i++) {
1024                        if (store.offset[i] == 0) {
1025                                store.offset[i] = copy_end = contents_sz;
1026                        } else if (store.state != KEY_SEEN) {
1027                                copy_end = store.offset[i];
1028                        } else
1029                                copy_end = find_beginning_of_line(
1030                                        contents, contents_sz,
1031                                        store.offset[i]-2, &new_line);
1032
1033                        if (copy_end > 0 && contents[copy_end-1] != '\n')
1034                                new_line = 1;
1035
1036                        /* write the first part of the config */
1037                        if (copy_end > copy_begin) {
1038                                if (write_in_full(fd, contents + copy_begin,
1039                                                  copy_end - copy_begin) <
1040                                    copy_end - copy_begin)
1041                                        goto write_err_out;
1042                                if (new_line &&
1043                                    write_in_full(fd, "\n", 1) != 1)
1044                                        goto write_err_out;
1045                        }
1046                        copy_begin = store.offset[i];
1047                }
1048
1049                /* write the pair (value == NULL means unset) */
1050                if (value != NULL) {
1051                        if (store.state == START) {
1052                                if (!store_write_section(fd, key))
1053                                        goto write_err_out;
1054                        }
1055                        if (!store_write_pair(fd, key, value))
1056                                goto write_err_out;
1057                }
1058
1059                /* write the rest of the config */
1060                if (copy_begin < contents_sz)
1061                        if (write_in_full(fd, contents + copy_begin,
1062                                          contents_sz - copy_begin) <
1063                            contents_sz - copy_begin)
1064                                goto write_err_out;
1065
1066                munmap(contents, contents_sz);
1067        }
1068
1069        if (commit_lock_file(lock) < 0) {
1070                error("could not commit config file %s", config_filename);
1071                ret = 4;
1072                goto out_free;
1073        }
1074
1075        /*
1076         * lock is committed, so don't try to roll it back below.
1077         * NOTE: Since lockfile.c keeps a linked list of all created
1078         * lock_file structures, it isn't safe to free(lock).  It's
1079         * better to just leave it hanging around.
1080         */
1081        lock = NULL;
1082        ret = 0;
1083
1084out_free:
1085        if (lock)
1086                rollback_lock_file(lock);
1087        free(config_filename);
1088        return ret;
1089
1090write_err_out:
1091        ret = write_error(lock->filename);
1092        goto out_free;
1093
1094}
1095
1096static int section_name_match (const char *buf, const char *name)
1097{
1098        int i = 0, j = 0, dot = 0;
1099        for (; buf[i] && buf[i] != ']'; i++) {
1100                if (!dot && isspace(buf[i])) {
1101                        dot = 1;
1102                        if (name[j++] != '.')
1103                                break;
1104                        for (i++; isspace(buf[i]); i++)
1105                                ; /* do nothing */
1106                        if (buf[i] != '"')
1107                                break;
1108                        continue;
1109                }
1110                if (buf[i] == '\\' && dot)
1111                        i++;
1112                else if (buf[i] == '"' && dot) {
1113                        for (i++; isspace(buf[i]); i++)
1114                                ; /* do_nothing */
1115                        break;
1116                }
1117                if (buf[i] != name[j++])
1118                        break;
1119        }
1120        return (buf[i] == ']' && name[j] == 0);
1121}
1122
1123/* if new_name == NULL, the section is removed instead */
1124int git_config_rename_section(const char *old_name, const char *new_name)
1125{
1126        int ret = 0, remove = 0;
1127        char *config_filename;
1128        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1129        int out_fd;
1130        char buf[1024];
1131
1132        if (config_exclusive_filename)
1133                config_filename = xstrdup(config_exclusive_filename);
1134        else
1135                config_filename = xstrdup(git_path("config"));
1136        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1137        if (out_fd < 0) {
1138                ret = error("could not lock config file %s", config_filename);
1139                goto out;
1140        }
1141
1142        if (!(config_file = fopen(config_filename, "rb"))) {
1143                /* no config file means nothing to rename, no error */
1144                goto unlock_and_out;
1145        }
1146
1147        while (fgets(buf, sizeof(buf), config_file)) {
1148                int i;
1149                int length;
1150                for (i = 0; buf[i] && isspace(buf[i]); i++)
1151                        ; /* do nothing */
1152                if (buf[i] == '[') {
1153                        /* it's a section */
1154                        if (section_name_match (&buf[i+1], old_name)) {
1155                                ret++;
1156                                if (new_name == NULL) {
1157                                        remove = 1;
1158                                        continue;
1159                                }
1160                                store.baselen = strlen(new_name);
1161                                if (!store_write_section(out_fd, new_name)) {
1162                                        ret = write_error(lock->filename);
1163                                        goto out;
1164                                }
1165                                continue;
1166                        }
1167                        remove = 0;
1168                }
1169                if (remove)
1170                        continue;
1171                length = strlen(buf);
1172                if (write_in_full(out_fd, buf, length) != length) {
1173                        ret = write_error(lock->filename);
1174                        goto out;
1175                }
1176        }
1177        fclose(config_file);
1178 unlock_and_out:
1179        if (commit_lock_file(lock) < 0)
1180                ret = error("could not commit config file %s", config_filename);
1181 out:
1182        free(config_filename);
1183        return ret;
1184}
1185
1186/*
1187 * Call this to report error for your variable that should not
1188 * get a boolean value (i.e. "[my] var" means "true").
1189 */
1190int config_error_nonbool(const char *var)
1191{
1192        return error("Missing value for '%s'", var);
1193}