Andrew's git / gitweb.git / config.c
?
config.con commit apply: get rid of --index-info in favor of --build-fake-ancestor (7a98869)
   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
  10#define MAXNAME (256)
  11
  12static FILE *config_file;
  13static const char *config_file_name;
  14static int config_linenr;
  15static int zlib_compression_seen;
  16
  17static int get_next_char(void)
  18{
  19        int c;
  20        FILE *f;
  21
  22        c = '\n';
  23        if ((f = config_file) != NULL) {
  24                c = fgetc(f);
  25                if (c == '\r') {
  26                        /* DOS like systems */
  27                        c = fgetc(f);
  28                        if (c != '\n') {
  29                                ungetc(c, f);
  30                                c = '\r';
  31                        }
  32                }
  33                if (c == '\n')
  34                        config_linenr++;
  35                if (c == EOF) {
  36                        config_file = NULL;
  37                        c = '\n';
  38                }
  39        }
  40        return c;
  41}
  42
  43static char *parse_value(void)
  44{
  45        static char value[1024];
  46        int quote = 0, comment = 0, len = 0, space = 0;
  47
  48        for (;;) {
  49                int c = get_next_char();
  50                if (len >= sizeof(value))
  51                        return NULL;
  52                if (c == '\n') {
  53                        if (quote)
  54                                return NULL;
  55                        value[len] = 0;
  56                        return value;
  57                }
  58                if (comment)
  59                        continue;
  60                if (isspace(c) && !quote) {
  61                        space = 1;
  62                        continue;
  63                }
  64                if (!quote) {
  65                        if (c == ';' || c == '#') {
  66                                comment = 1;
  67                                continue;
  68                        }
  69                }
  70                if (space) {
  71                        if (len)
  72                                value[len++] = ' ';
  73                        space = 0;
  74                }
  75                if (c == '\\') {
  76                        c = get_next_char();
  77                        switch (c) {
  78                        case '\n':
  79                                continue;
  80                        case 't':
  81                                c = '\t';
  82                                break;
  83                        case 'b':
  84                                c = '\b';
  85                                break;
  86                        case 'n':
  87                                c = '\n';
  88                                break;
  89                        /* Some characters escape as themselves */
  90                        case '\\': case '"':
  91                                break;
  92                        /* Reject unknown escape sequences */
  93                        default:
  94                                return NULL;
  95                        }
  96                        value[len++] = c;
  97                        continue;
  98                }
  99                if (c == '"') {
 100                        quote = 1-quote;
 101                        continue;
 102                }
 103                value[len++] = c;
 104        }
 105}
 106
 107static inline int iskeychar(int c)
 108{
 109        return isalnum(c) || c == '-';
 110}
 111
 112static int get_value(config_fn_t fn, char *name, unsigned int len)
 113{
 114        int c;
 115        char *value;
 116
 117        /* Get the full name */
 118        for (;;) {
 119                c = get_next_char();
 120                if (c == EOF)
 121                        break;
 122                if (!iskeychar(c))
 123                        break;
 124                name[len++] = tolower(c);
 125                if (len >= MAXNAME)
 126                        return -1;
 127        }
 128        name[len] = 0;
 129        while (c == ' ' || c == '\t')
 130                c = get_next_char();
 131
 132        value = NULL;
 133        if (c != '\n') {
 134                if (c != '=')
 135                        return -1;
 136                value = parse_value();
 137                if (!value)
 138                        return -1;
 139        }
 140        return fn(name, value);
 141}
 142
 143static int get_extended_base_var(char *name, int baselen, int c)
 144{
 145        do {
 146                if (c == '\n')
 147                        return -1;
 148                c = get_next_char();
 149        } while (isspace(c));
 150
 151        /* We require the format to be '[base "extension"]' */
 152        if (c != '"')
 153                return -1;
 154        name[baselen++] = '.';
 155
 156        for (;;) {
 157                int c = get_next_char();
 158                if (c == '\n')
 159                        return -1;
 160                if (c == '"')
 161                        break;
 162                if (c == '\\') {
 163                        c = get_next_char();
 164                        if (c == '\n')
 165                                return -1;
 166                }
 167                name[baselen++] = c;
 168                if (baselen > MAXNAME / 2)
 169                        return -1;
 170        }
 171
 172        /* Final ']' */
 173        if (get_next_char() != ']')
 174                return -1;
 175        return baselen;
 176}
 177
 178static int get_base_var(char *name)
 179{
 180        int baselen = 0;
 181
 182        for (;;) {
 183                int c = get_next_char();
 184                if (c == EOF)
 185                        return -1;
 186                if (c == ']')
 187                        return baselen;
 188                if (isspace(c))
 189                        return get_extended_base_var(name, baselen, c);
 190                if (!iskeychar(c) && c != '.')
 191                        return -1;
 192                if (baselen > MAXNAME / 2)
 193                        return -1;
 194                name[baselen++] = tolower(c);
 195        }
 196}
 197
 198static int git_parse_file(config_fn_t fn)
 199{
 200        int comment = 0;
 201        int baselen = 0;
 202        static char var[MAXNAME];
 203
 204        for (;;) {
 205                int c = get_next_char();
 206                if (c == '\n') {
 207                        /* EOF? */
 208                        if (!config_file)
 209                                return 0;
 210                        comment = 0;
 211                        continue;
 212                }
 213                if (comment || isspace(c))
 214                        continue;
 215                if (c == '#' || c == ';') {
 216                        comment = 1;
 217                        continue;
 218                }
 219                if (c == '[') {
 220                        baselen = get_base_var(var);
 221                        if (baselen <= 0)
 222                                break;
 223                        var[baselen++] = '.';
 224                        var[baselen] = 0;
 225                        continue;
 226                }
 227                if (!isalpha(c))
 228                        break;
 229                var[baselen] = tolower(c);
 230                if (get_value(fn, var, baselen+1) < 0)
 231                        break;
 232        }
 233        die("bad config file line %d in %s", config_linenr, config_file_name);
 234}
 235
 236static unsigned long get_unit_factor(const char *end)
 237{
 238        if (!*end)
 239                return 1;
 240        else if (!strcasecmp(end, "k"))
 241                return 1024;
 242        else if (!strcasecmp(end, "m"))
 243                return 1024 * 1024;
 244        else if (!strcasecmp(end, "g"))
 245                return 1024 * 1024 * 1024;
 246        die("unknown unit: '%s'", end);
 247}
 248
 249int git_parse_long(const char *value, long *ret)
 250{
 251        if (value && *value) {
 252                char *end;
 253                long val = strtol(value, &end, 0);
 254                *ret = val * get_unit_factor(end);
 255                return 1;
 256        }
 257        return 0;
 258}
 259
 260int git_parse_ulong(const char *value, unsigned long *ret)
 261{
 262        if (value && *value) {
 263                char *end;
 264                unsigned long val = strtoul(value, &end, 0);
 265                *ret = val * get_unit_factor(end);
 266                return 1;
 267        }
 268        return 0;
 269}
 270
 271int git_config_int(const char *name, const char *value)
 272{
 273        long ret;
 274        if (!git_parse_long(value, &ret))
 275                die("bad config value for '%s' in %s", name, config_file_name);
 276        return ret;
 277}
 278
 279unsigned long git_config_ulong(const char *name, const char *value)
 280{
 281        unsigned long ret;
 282        if (!git_parse_ulong(value, &ret))
 283                die("bad config value for '%s' in %s", name, config_file_name);
 284        return ret;
 285}
 286
 287int git_config_bool(const char *name, const char *value)
 288{
 289        if (!value)
 290                return 1;
 291        if (!*value)
 292                return 0;
 293        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 294                return 1;
 295        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 296                return 0;
 297        return git_config_int(name, value) != 0;
 298}
 299
 300int git_default_config(const char *var, const char *value)
 301{
 302        /* This needs a better name */
 303        if (!strcmp(var, "core.filemode")) {
 304                trust_executable_bit = git_config_bool(var, value);
 305                return 0;
 306        }
 307
 308        if (!strcmp(var, "core.quotepath")) {
 309                quote_path_fully = git_config_bool(var, value);
 310                return 0;
 311        }
 312
 313        if (!strcmp(var, "core.symlinks")) {
 314                has_symlinks = git_config_bool(var, value);
 315                return 0;
 316        }
 317
 318        if (!strcmp(var, "core.bare")) {
 319                is_bare_repository_cfg = git_config_bool(var, value);
 320                return 0;
 321        }
 322
 323        if (!strcmp(var, "core.ignorestat")) {
 324                assume_unchanged = git_config_bool(var, value);
 325                return 0;
 326        }
 327
 328        if (!strcmp(var, "core.prefersymlinkrefs")) {
 329                prefer_symlink_refs = git_config_bool(var, value);
 330                return 0;
 331        }
 332
 333        if (!strcmp(var, "core.logallrefupdates")) {
 334                log_all_ref_updates = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "core.warnambiguousrefs")) {
 339                warn_ambiguous_refs = git_config_bool(var, value);
 340                return 0;
 341        }
 342
 343        if (!strcmp(var, "core.loosecompression")) {
 344                int level = git_config_int(var, value);
 345                if (level == -1)
 346                        level = Z_DEFAULT_COMPRESSION;
 347                else if (level < 0 || level > Z_BEST_COMPRESSION)
 348                        die("bad zlib compression level %d", level);
 349                zlib_compression_level = level;
 350                zlib_compression_seen = 1;
 351                return 0;
 352        }
 353
 354        if (!strcmp(var, "core.compression")) {
 355                int level = git_config_int(var, value);
 356                if (level == -1)
 357                        level = Z_DEFAULT_COMPRESSION;
 358                else if (level < 0 || level > Z_BEST_COMPRESSION)
 359                        die("bad zlib compression level %d", level);
 360                core_compression_level = level;
 361                core_compression_seen = 1;
 362                if (!zlib_compression_seen)
 363                        zlib_compression_level = level;
 364                return 0;
 365        }
 366
 367        if (!strcmp(var, "core.packedgitwindowsize")) {
 368                int pgsz_x2 = getpagesize() * 2;
 369                packed_git_window_size = git_config_int(var, value);
 370
 371                /* This value must be multiple of (pagesize * 2) */
 372                packed_git_window_size /= pgsz_x2;
 373                if (packed_git_window_size < 1)
 374                        packed_git_window_size = 1;
 375                packed_git_window_size *= pgsz_x2;
 376                return 0;
 377        }
 378
 379        if (!strcmp(var, "core.packedgitlimit")) {
 380                packed_git_limit = git_config_int(var, value);
 381                return 0;
 382        }
 383
 384        if (!strcmp(var, "core.deltabasecachelimit")) {
 385                delta_base_cache_limit = git_config_int(var, value);
 386                return 0;
 387        }
 388
 389        if (!strcmp(var, "core.autocrlf")) {
 390                if (value && !strcasecmp(value, "input")) {
 391                        auto_crlf = -1;
 392                        return 0;
 393                }
 394                auto_crlf = git_config_bool(var, value);
 395                return 0;
 396        }
 397
 398        if (!strcmp(var, "user.name")) {
 399                strlcpy(git_default_name, value, sizeof(git_default_name));
 400                return 0;
 401        }
 402
 403        if (!strcmp(var, "user.email")) {
 404                strlcpy(git_default_email, value, sizeof(git_default_email));
 405                return 0;
 406        }
 407
 408        if (!strcmp(var, "i18n.commitencoding")) {
 409                git_commit_encoding = xstrdup(value);
 410                return 0;
 411        }
 412
 413        if (!strcmp(var, "i18n.logoutputencoding")) {
 414                git_log_output_encoding = xstrdup(value);
 415                return 0;
 416        }
 417
 418
 419        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 420                pager_use_color = git_config_bool(var,value);
 421                return 0;
 422        }
 423
 424        if (!strcmp(var, "core.pager")) {
 425                pager_program = xstrdup(value);
 426                return 0;
 427        }
 428
 429        if (!strcmp(var, "core.editor")) {
 430                editor_program = xstrdup(value);
 431                return 0;
 432        }
 433
 434        /* Add other config variables here and to Documentation/config.txt. */
 435        return 0;
 436}
 437
 438int git_config_from_file(config_fn_t fn, const char *filename)
 439{
 440        int ret;
 441        FILE *f = fopen(filename, "r");
 442
 443        ret = -1;
 444        if (f) {
 445                config_file = f;
 446                config_file_name = filename;
 447                config_linenr = 1;
 448                ret = git_parse_file(fn);
 449                fclose(f);
 450                config_file_name = NULL;
 451        }
 452        return ret;
 453}
 454
 455int git_config(config_fn_t fn)
 456{
 457        int ret = 0;
 458        char *repo_config = NULL;
 459        const char *home = NULL, *filename;
 460
 461        /* $GIT_CONFIG makes git read _only_ the given config file,
 462         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 463         * global config file, the same way it would the per-repository
 464         * config file otherwise. */
 465        filename = getenv(CONFIG_ENVIRONMENT);
 466        if (!filename) {
 467                if (!access(ETC_GITCONFIG, R_OK))
 468                        ret += git_config_from_file(fn, ETC_GITCONFIG);
 469                home = getenv("HOME");
 470                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 471                if (!filename)
 472                        filename = repo_config = xstrdup(git_path("config"));
 473        }
 474
 475        if (home) {
 476                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 477                if (!access(user_config, R_OK))
 478                        ret = git_config_from_file(fn, user_config);
 479                free(user_config);
 480        }
 481
 482        ret += git_config_from_file(fn, filename);
 483        free(repo_config);
 484        return ret;
 485}
 486
 487/*
 488 * Find all the stuff for git_config_set() below.
 489 */
 490
 491#define MAX_MATCHES 512
 492
 493static struct {
 494        int baselen;
 495        char* key;
 496        int do_not_match;
 497        regex_t* value_regex;
 498        int multi_replace;
 499        size_t offset[MAX_MATCHES];
 500        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 501        int seen;
 502} store;
 503
 504static int matches(const char* key, const char* value)
 505{
 506        return !strcmp(key, store.key) &&
 507                (store.value_regex == NULL ||
 508                 (store.do_not_match ^
 509                  !regexec(store.value_regex, value, 0, NULL, 0)));
 510}
 511
 512static int store_aux(const char* key, const char* value)
 513{
 514        const char *ep;
 515        size_t section_len;
 516
 517        switch (store.state) {
 518        case KEY_SEEN:
 519                if (matches(key, value)) {
 520                        if (store.seen == 1 && store.multi_replace == 0) {
 521                                fprintf(stderr,
 522                                        "Warning: %s has multiple values\n",
 523                                        key);
 524                        } else if (store.seen >= MAX_MATCHES) {
 525                                fprintf(stderr, "Too many matches\n");
 526                                return 1;
 527                        }
 528
 529                        store.offset[store.seen] = ftell(config_file);
 530                        store.seen++;
 531                }
 532                break;
 533        case SECTION_SEEN:
 534                /*
 535                 * What we are looking for is in store.key (both
 536                 * section and var), and its section part is baselen
 537                 * long.  We found key (again, both section and var).
 538                 * We would want to know if this key is in the same
 539                 * section as what we are looking for.  We already
 540                 * know we are in the same section as what should
 541                 * hold store.key.
 542                 */
 543                ep = strrchr(key, '.');
 544                section_len = ep - key;
 545
 546                if ((section_len != store.baselen) ||
 547                    memcmp(key, store.key, section_len+1)) {
 548                        store.state = SECTION_END_SEEN;
 549                        break;
 550                }
 551
 552                /*
 553                 * Do not increment matches: this is no match, but we
 554                 * just made sure we are in the desired section.
 555                 */
 556                store.offset[store.seen] = ftell(config_file);
 557                /* fallthru */
 558        case SECTION_END_SEEN:
 559        case START:
 560                if (matches(key, value)) {
 561                        store.offset[store.seen] = ftell(config_file);
 562                        store.state = KEY_SEEN;
 563                        store.seen++;
 564                } else {
 565                        if (strrchr(key, '.') - key == store.baselen &&
 566                              !strncmp(key, store.key, store.baselen)) {
 567                                        store.state = SECTION_SEEN;
 568                                        store.offset[store.seen] = ftell(config_file);
 569                        }
 570                }
 571        }
 572        return 0;
 573}
 574
 575static int write_error(void)
 576{
 577        fprintf(stderr, "Failed to write new configuration file\n");
 578
 579        /* Same error code as "failed to rename". */
 580        return 4;
 581}
 582
 583static int store_write_section(int fd, const char* key)
 584{
 585        const char *dot = strchr(key, '.');
 586        int len1 = store.baselen, len2 = -1;
 587
 588        dot = strchr(key, '.');
 589        if (dot) {
 590                int dotlen = dot - key;
 591                if (dotlen < len1) {
 592                        len2 = len1 - dotlen - 1;
 593                        len1 = dotlen;
 594                }
 595        }
 596
 597        if (write_in_full(fd, "[", 1) != 1 ||
 598            write_in_full(fd, key, len1) != len1)
 599                return 0;
 600        if (len2 >= 0) {
 601                if (write_in_full(fd, " \"", 2) != 2)
 602                        return 0;
 603                while (--len2 >= 0) {
 604                        unsigned char c = *++dot;
 605                        if (c == '"')
 606                                if (write_in_full(fd, "\\", 1) != 1)
 607                                        return 0;
 608                        if (write_in_full(fd, &c, 1) != 1)
 609                                return 0;
 610                }
 611                if (write_in_full(fd, "\"", 1) != 1)
 612                        return 0;
 613        }
 614        if (write_in_full(fd, "]\n", 2) != 2)
 615                return 0;
 616
 617        return 1;
 618}
 619
 620static int store_write_pair(int fd, const char* key, const char* value)
 621{
 622        int i;
 623        int length = strlen(key+store.baselen+1);
 624        int quote = 0;
 625
 626        /* Check to see if the value needs to be quoted. */
 627        if (value[0] == ' ')
 628                quote = 1;
 629        for (i = 0; value[i]; i++)
 630                if (value[i] == ';' || value[i] == '#')
 631                        quote = 1;
 632        if (value[i-1] == ' ')
 633                quote = 1;
 634
 635        if (write_in_full(fd, "\t", 1) != 1 ||
 636            write_in_full(fd, key+store.baselen+1, length) != length ||
 637            write_in_full(fd, " = ", 3) != 3)
 638                return 0;
 639        if (quote && write_in_full(fd, "\"", 1) != 1)
 640                return 0;
 641        for (i = 0; value[i]; i++)
 642                switch (value[i]) {
 643                case '\n':
 644                        if (write_in_full(fd, "\\n", 2) != 2)
 645                                return 0;
 646                        break;
 647                case '\t':
 648                        if (write_in_full(fd, "\\t", 2) != 2)
 649                                return 0;
 650                        break;
 651                case '"':
 652                case '\\':
 653                        if (write_in_full(fd, "\\", 1) != 1)
 654                                return 0;
 655                default:
 656                        if (write_in_full(fd, value+i, 1) != 1)
 657                                return 0;
 658                        break;
 659                }
 660        if (quote && write_in_full(fd, "\"", 1) != 1)
 661                return 0;
 662        if (write_in_full(fd, "\n", 1) != 1)
 663                return 0;
 664        return 1;
 665}
 666
 667static ssize_t find_beginning_of_line(const char* contents, size_t size,
 668        size_t offset_, int* found_bracket)
 669{
 670        size_t equal_offset = size, bracket_offset = size;
 671        ssize_t offset;
 672
 673        for (offset = offset_-2; offset > 0
 674                        && contents[offset] != '\n'; offset--)
 675                switch (contents[offset]) {
 676                        case '=': equal_offset = offset; break;
 677                        case ']': bracket_offset = offset; break;
 678                }
 679        if (bracket_offset < equal_offset) {
 680                *found_bracket = 1;
 681                offset = bracket_offset+1;
 682        } else
 683                offset++;
 684
 685        return offset;
 686}
 687
 688int git_config_set(const char* key, const char* value)
 689{
 690        return git_config_set_multivar(key, value, NULL, 0);
 691}
 692
 693/*
 694 * If value==NULL, unset in (remove from) config,
 695 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 696 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 697 *     else all matching key/values (regardless how many) are removed,
 698 *     before the new pair is written.
 699 *
 700 * Returns 0 on success.
 701 *
 702 * This function does this:
 703 *
 704 * - it locks the config file by creating ".git/config.lock"
 705 *
 706 * - it then parses the config using store_aux() as validator to find
 707 *   the position on the key/value pair to replace. If it is to be unset,
 708 *   it must be found exactly once.
 709 *
 710 * - the config file is mmap()ed and the part before the match (if any) is
 711 *   written to the lock file, then the changed part and the rest.
 712 *
 713 * - the config file is removed and the lock file rename()d to it.
 714 *
 715 */
 716int git_config_set_multivar(const char* key, const char* value,
 717        const char* value_regex, int multi_replace)
 718{
 719        int i, dot;
 720        int fd = -1, in_fd;
 721        int ret;
 722        char* config_filename;
 723        struct lock_file *lock = NULL;
 724        const char* last_dot = strrchr(key, '.');
 725
 726        config_filename = getenv(CONFIG_ENVIRONMENT);
 727        if (!config_filename) {
 728                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 729                if (!config_filename)
 730                        config_filename  = git_path("config");
 731        }
 732        config_filename = xstrdup(config_filename);
 733
 734        /*
 735         * Since "key" actually contains the section name and the real
 736         * key name separated by a dot, we have to know where the dot is.
 737         */
 738
 739        if (last_dot == NULL) {
 740                fprintf(stderr, "key does not contain a section: %s\n", key);
 741                ret = 2;
 742                goto out_free;
 743        }
 744        store.baselen = last_dot - key;
 745
 746        store.multi_replace = multi_replace;
 747
 748        /*
 749         * Validate the key and while at it, lower case it for matching.
 750         */
 751        store.key = xmalloc(strlen(key) + 1);
 752        dot = 0;
 753        for (i = 0; key[i]; i++) {
 754                unsigned char c = key[i];
 755                if (c == '.')
 756                        dot = 1;
 757                /* Leave the extended basename untouched.. */
 758                if (!dot || i > store.baselen) {
 759                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 760                                fprintf(stderr, "invalid key: %s\n", key);
 761                                free(store.key);
 762                                ret = 1;
 763                                goto out_free;
 764                        }
 765                        c = tolower(c);
 766                } else if (c == '\n') {
 767                        fprintf(stderr, "invalid key (newline): %s\n", key);
 768                        free(store.key);
 769                        ret = 1;
 770                        goto out_free;
 771                }
 772                store.key[i] = c;
 773        }
 774        store.key[i] = 0;
 775
 776        /*
 777         * The lock serves a purpose in addition to locking: the new
 778         * contents of .git/config will be written into it.
 779         */
 780        lock = xcalloc(sizeof(struct lock_file), 1);
 781        fd = hold_lock_file_for_update(lock, config_filename, 0);
 782        if (fd < 0) {
 783                fprintf(stderr, "could not lock config file\n");
 784                free(store.key);
 785                ret = -1;
 786                goto out_free;
 787        }
 788
 789        /*
 790         * If .git/config does not exist yet, write a minimal version.
 791         */
 792        in_fd = open(config_filename, O_RDONLY);
 793        if ( in_fd < 0 ) {
 794                free(store.key);
 795
 796                if ( ENOENT != errno ) {
 797                        error("opening %s: %s", config_filename,
 798                              strerror(errno));
 799                        ret = 3; /* same as "invalid config file" */
 800                        goto out_free;
 801                }
 802                /* if nothing to unset, error out */
 803                if (value == NULL) {
 804                        ret = 5;
 805                        goto out_free;
 806                }
 807
 808                store.key = (char*)key;
 809                if (!store_write_section(fd, key) ||
 810                    !store_write_pair(fd, key, value))
 811                        goto write_err_out;
 812        } else {
 813                struct stat st;
 814                char* contents;
 815                size_t contents_sz, copy_begin, copy_end;
 816                int i, new_line = 0;
 817
 818                if (value_regex == NULL)
 819                        store.value_regex = NULL;
 820                else {
 821                        if (value_regex[0] == '!') {
 822                                store.do_not_match = 1;
 823                                value_regex++;
 824                        } else
 825                                store.do_not_match = 0;
 826
 827                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 828                        if (regcomp(store.value_regex, value_regex,
 829                                        REG_EXTENDED)) {
 830                                fprintf(stderr, "Invalid pattern: %s\n",
 831                                        value_regex);
 832                                free(store.value_regex);
 833                                ret = 6;
 834                                goto out_free;
 835                        }
 836                }
 837
 838                store.offset[0] = 0;
 839                store.state = START;
 840                store.seen = 0;
 841
 842                /*
 843                 * After this, store.offset will contain the *end* offset
 844                 * of the last match, or remain at 0 if no match was found.
 845                 * As a side effect, we make sure to transform only a valid
 846                 * existing config file.
 847                 */
 848                if (git_config_from_file(store_aux, config_filename)) {
 849                        fprintf(stderr, "invalid config file\n");
 850                        free(store.key);
 851                        if (store.value_regex != NULL) {
 852                                regfree(store.value_regex);
 853                                free(store.value_regex);
 854                        }
 855                        ret = 3;
 856                        goto out_free;
 857                }
 858
 859                free(store.key);
 860                if (store.value_regex != NULL) {
 861                        regfree(store.value_regex);
 862                        free(store.value_regex);
 863                }
 864
 865                /* if nothing to unset, or too many matches, error out */
 866                if ((store.seen == 0 && value == NULL) ||
 867                                (store.seen > 1 && multi_replace == 0)) {
 868                        ret = 5;
 869                        goto out_free;
 870                }
 871
 872                fstat(in_fd, &st);
 873                contents_sz = xsize_t(st.st_size);
 874                contents = xmmap(NULL, contents_sz, PROT_READ,
 875                        MAP_PRIVATE, in_fd, 0);
 876                close(in_fd);
 877
 878                if (store.seen == 0)
 879                        store.seen = 1;
 880
 881                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 882                        if (store.offset[i] == 0) {
 883                                store.offset[i] = copy_end = contents_sz;
 884                        } else if (store.state != KEY_SEEN) {
 885                                copy_end = store.offset[i];
 886                        } else
 887                                copy_end = find_beginning_of_line(
 888                                        contents, contents_sz,
 889                                        store.offset[i]-2, &new_line);
 890
 891                        /* write the first part of the config */
 892                        if (copy_end > copy_begin) {
 893                                if (write_in_full(fd, contents + copy_begin,
 894                                                  copy_end - copy_begin) <
 895                                    copy_end - copy_begin)
 896                                        goto write_err_out;
 897                                if (new_line &&
 898                                    write_in_full(fd, "\n", 1) != 1)
 899                                        goto write_err_out;
 900                        }
 901                        copy_begin = store.offset[i];
 902                }
 903
 904                /* write the pair (value == NULL means unset) */
 905                if (value != NULL) {
 906                        if (store.state == START) {
 907                                if (!store_write_section(fd, key))
 908                                        goto write_err_out;
 909                        }
 910                        if (!store_write_pair(fd, key, value))
 911                                goto write_err_out;
 912                }
 913
 914                /* write the rest of the config */
 915                if (copy_begin < contents_sz)
 916                        if (write_in_full(fd, contents + copy_begin,
 917                                          contents_sz - copy_begin) <
 918                            contents_sz - copy_begin)
 919                                goto write_err_out;
 920
 921                munmap(contents, contents_sz);
 922        }
 923
 924        if (close(fd) || commit_lock_file(lock) < 0) {
 925                fprintf(stderr, "Cannot commit config file!\n");
 926                ret = 4;
 927                goto out_free;
 928        }
 929
 930        /* fd is closed, so don't try to close it below. */
 931        fd = -1;
 932        /*
 933         * lock is committed, so don't try to roll it back below.
 934         * NOTE: Since lockfile.c keeps a linked list of all created
 935         * lock_file structures, it isn't safe to free(lock).  It's
 936         * better to just leave it hanging around.
 937         */
 938        lock = NULL;
 939        ret = 0;
 940
 941out_free:
 942        if (0 <= fd)
 943                close(fd);
 944        if (lock)
 945                rollback_lock_file(lock);
 946        free(config_filename);
 947        return ret;
 948
 949write_err_out:
 950        ret = write_error();
 951        goto out_free;
 952
 953}
 954
 955static int section_name_match (const char *buf, const char *name)
 956{
 957        int i = 0, j = 0, dot = 0;
 958        for (; buf[i] && buf[i] != ']'; i++) {
 959                if (!dot && isspace(buf[i])) {
 960                        dot = 1;
 961                        if (name[j++] != '.')
 962                                break;
 963                        for (i++; isspace(buf[i]); i++)
 964                                ; /* do nothing */
 965                        if (buf[i] != '"')
 966                                break;
 967                        continue;
 968                }
 969                if (buf[i] == '\\' && dot)
 970                        i++;
 971                else if (buf[i] == '"' && dot) {
 972                        for (i++; isspace(buf[i]); i++)
 973                                ; /* do_nothing */
 974                        break;
 975                }
 976                if (buf[i] != name[j++])
 977                        break;
 978        }
 979        return (buf[i] == ']' && name[j] == 0);
 980}
 981
 982/* if new_name == NULL, the section is removed instead */
 983int git_config_rename_section(const char *old_name, const char *new_name)
 984{
 985        int ret = 0, remove = 0;
 986        char *config_filename;
 987        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
 988        int out_fd;
 989        char buf[1024];
 990
 991        config_filename = getenv(CONFIG_ENVIRONMENT);
 992        if (!config_filename) {
 993                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 994                if (!config_filename)
 995                        config_filename  = git_path("config");
 996        }
 997        config_filename = xstrdup(config_filename);
 998        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 999        if (out_fd < 0) {
1000                ret = error("Could not lock config file!");
1001                goto out;
1002        }
1003
1004        if (!(config_file = fopen(config_filename, "rb"))) {
1005                /* no config file means nothing to rename, no error */
1006                goto unlock_and_out;
1007        }
1008
1009        while (fgets(buf, sizeof(buf), config_file)) {
1010                int i;
1011                int length;
1012                for (i = 0; buf[i] && isspace(buf[i]); i++)
1013                        ; /* do nothing */
1014                if (buf[i] == '[') {
1015                        /* it's a section */
1016                        if (section_name_match (&buf[i+1], old_name)) {
1017                                ret++;
1018                                if (new_name == NULL) {
1019                                        remove = 1;
1020                                        continue;
1021                                }
1022                                store.baselen = strlen(new_name);
1023                                if (!store_write_section(out_fd, new_name)) {
1024                                        ret = write_error();
1025                                        goto out;
1026                                }
1027                                continue;
1028                        }
1029                        remove = 0;
1030                }
1031                if (remove)
1032                        continue;
1033                length = strlen(buf);
1034                if (write_in_full(out_fd, buf, length) != length) {
1035                        ret = write_error();
1036                        goto out;
1037                }
1038        }
1039        fclose(config_file);
1040 unlock_and_out:
1041        if (close(out_fd) || commit_lock_file(lock) < 0)
1042                        ret = error("Cannot commit config file!");
1043 out:
1044        free(config_filename);
1045        return ret;
1046}