config.c

   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
  13 static FILE *config_file;
  14 static const char *config_file_name;
  15 static int config_linenr;
  16 static int get_next_char(void)
  17 {
  18         int c;
  19         FILE *f;
  20
  21         c = '\n';
  22         if ((f = config_file) != NULL) {
  23                 c = fgetc(f);
  24                 if (c == '\r') {
  25                         /* DOS like systems */
  26                         c = fgetc(f);
  27                         if (c != '\n') {
  28                                 ungetc(c, f);
  29                                 c = '\r';
  30                         }
  31                 }
  32                 if (c == '\n')
  33                         config_linenr++;
  34                 if (c == EOF) {
  35                         config_file = NULL;
  36                         c = '\n';
  37                 }
  38         }
  39         return c;
  40 }
  41
  42 static char *parse_value(void)
  43 {
  44         static char value[1024];
  45         int quote = 0, comment = 0, len = 0, space = 0;
  46
  47         for (;;) {
  48                 int c = get_next_char();
  49                 if (len >= sizeof(value))
  50                         return NULL;
  51                 if (c == '\n') {
  52                         if (quote)
  53                                 return NULL;
  54                         value[len] = 0;
  55                         return value;
  56                 }
  57                 if (comment)
  58                         continue;
  59                 if (isspace(c) && !quote) {
  60                         space = 1;
  61                         continue;
  62                 }
  63                 if (!quote) {
  64                         if (c == ';' || c == '#') {
  65                                 comment = 1;
  66                                 continue;
  67                         }
  68                 }
  69                 if (space) {
  70                         if (len)
  71                                 value[len++] = ' ';
  72                         space = 0;
  73                 }
  74                 if (c == '\\') {
  75                         c = get_next_char();
  76                         switch (c) {
  77                         case '\n':
  78                                 continue;
  79                         case 't':
  80                                 c = '\t';
  81                                 break;
  82                         case 'b':
  83                                 c = '\b';
  84                                 break;
  85                         case 'n':
  86                                 c = '\n';
  87                                 break;
  88                         /* Some characters escape as themselves */
  89                         case '\\': case '"':
  90                                 break;
  91                         /* Reject unknown escape sequences */
  92                         default:
  93                                 return NULL;
  94                         }
  95                         value[len++] = c;
  96                         continue;
  97                 }
  98                 if (c == '"') {
  99                         quote = 1-quote;
 100                         continue;
 101                 }
 102                 value[len++] = c;
 103         }
 104 }
 105
 106 static inline int iskeychar(int c)
 107 {
 108         return isalnum(c) || c == '-';
 109 }
 110
 111 static int get_value(config_fn_t fn, char *name, unsigned int len)
 112 {
 113         int c;
 114         char *value;
 115
 116         /* Get the full name */
 117         for (;;) {
 118                 c = get_next_char();
 119                 if (c == EOF)
 120                         break;
 121                 if (!iskeychar(c))
 122                         break;
 123                 name[len++] = tolower(c);
 124                 if (len >= MAXNAME)
 125                         return -1;
 126         }
 127         name[len] = 0;
 128         while (c == ' ' || c == '\t')
 129                 c = get_next_char();
 130
 131         value = NULL;
 132         if (c != '\n') {
 133                 if (c != '=')
 134                         return -1;
 135                 value = parse_value();
 136                 if (!value)
 137                         return -1;
 138         }
 139         return fn(name, value);
 140 }
 141
 142 static int get_extended_base_var(char *name, int baselen, int c)
 143 {
 144         do {
 145                 if (c == '\n')
 146                         return -1;
 147                 c = get_next_char();
 148         } while (isspace(c));
 149
 150         /* We require the format to be '[base "extension"]' */
 151         if (c != '"')
 152                 return -1;
 153         name[baselen++] = '.';
 154
 155         for (;;) {
 156                 int c = get_next_char();
 157                 if (c == '\n')
 158                         return -1;
 159                 if (c == '"')
 160                         break;
 161                 if (c == '\\') {
 162                         c = get_next_char();
 163                         if (c == '\n')
 164                                 return -1;
 165                 }
 166                 name[baselen++] = c;
 167                 if (baselen > MAXNAME / 2)
 168                         return -1;
 169         }
 170
 171         /* Final ']' */
 172         if (get_next_char() != ']')
 173                 return -1;
 174         return baselen;
 175 }
 176
 177 static int get_base_var(char *name)
 178 {
 179         int baselen = 0;
 180
 181         for (;;) {
 182                 int c = get_next_char();
 183                 if (c == EOF)
 184                         return -1;
 185                 if (c == ']')
 186                         return baselen;
 187                 if (isspace(c))
 188                         return get_extended_base_var(name, baselen, c);
 189                 if (!iskeychar(c) && c != '.')
 190                         return -1;
 191                 if (baselen > MAXNAME / 2)
 192                         return -1;
 193                 name[baselen++] = tolower(c);
 194         }
 195 }
 196
 197 static int git_parse_file(config_fn_t fn)
 198 {
 199         int comment = 0;
 200         int baselen = 0;
 201         static char var[MAXNAME];
 202
 203         for (;;) {
 204                 int c = get_next_char();
 205                 if (c == '\n') {
 206                         /* EOF? */
 207                         if (!config_file)
 208                                 return 0;
 209                         comment = 0;
 210                         continue;
 211                 }
 212                 if (comment || isspace(c))
 213                         continue;
 214                 if (c == '#' || c == ';') {
 215                         comment = 1;
 216                         continue;
 217                 }
 218                 if (c == '[') {
 219                         baselen = get_base_var(var);
 220                         if (baselen <= 0)
 221                                 break;
 222                         var[baselen++] = '.';
 223                         var[baselen] = 0;
 224                         continue;
 225                 }
 226                 if (!isalpha(c))
 227                         break;
 228                 var[baselen] = tolower(c);
 229                 if (get_value(fn, var, baselen+1) < 0)
 230                         break;
 231         }
 232         die("bad config file line %d in %s", config_linenr, config_file_name);
 233 }
 234
 235 int git_config_int(const char *name, const char *value)
 236 {
 237         if (value && *value) {
 238                 char *end;
 239                 int val = strtol(value, &end, 0);
 240                 if (!*end)
 241                         return val;
 242                 if (!strcasecmp(end, "k"))
 243                         return val * 1024;
 244                 if (!strcasecmp(end, "m"))
 245                         return val * 1024 * 1024;
 246                 if (!strcasecmp(end, "g"))
 247                         return val * 1024 * 1024 * 1024;
 248         }
 249         die("bad config value for '%s' in %s", name, config_file_name);
 250 }
 251
 252 int git_config_bool(const char *name, const char *value)
 253 {
 254         if (!value)
 255                 return 1;
 256         if (!*value)
 257                 return 0;
 258         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 259                 return 1;
 260         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 261                 return 0;
 262         return git_config_int(name, value) != 0;
 263 }
 264
 265 int git_default_config(const char *var, const char *value)
 266 {
 267         /* This needs a better name */
 268         if (!strcmp(var, "core.filemode")) {
 269                 trust_executable_bit = git_config_bool(var, value);
 270                 return 0;
 271         }
 272
 273         if (!strcmp(var, "core.symlinks")) {
 274                 has_symlinks = git_config_bool(var, value);
 275                 return 0;
 276         }
 277
 278         if (!strcmp(var, "core.bare")) {
 279                 is_bare_repository_cfg = git_config_bool(var, value);
 280                 return 0;
 281         }
 282
 283         if (!strcmp(var, "core.ignorestat")) {
 284                 assume_unchanged = git_config_bool(var, value);
 285                 return 0;
 286         }
 287
 288         if (!strcmp(var, "core.prefersymlinkrefs")) {
 289                 prefer_symlink_refs = git_config_bool(var, value);
 290                 return 0;
 291         }
 292
 293         if (!strcmp(var, "core.logallrefupdates")) {
 294                 log_all_ref_updates = git_config_bool(var, value);
 295                 return 0;
 296         }
 297
 298         if (!strcmp(var, "core.warnambiguousrefs")) {
 299                 warn_ambiguous_refs = git_config_bool(var, value);
 300                 return 0;
 301         }
 302
 303         if (!strcmp(var, "core.legacyheaders")) {
 304                 use_legacy_headers = git_config_bool(var, value);
 305                 return 0;
 306         }
 307
 308         if (!strcmp(var, "core.compression")) {
 309                 int level = git_config_int(var, value);
 310                 if (level == -1)
 311                         level = Z_DEFAULT_COMPRESSION;
 312                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 313                         die("bad zlib compression level %d", level);
 314                 zlib_compression_level = level;
 315                 return 0;
 316         }
 317
 318         if (!strcmp(var, "core.packedgitwindowsize")) {
 319                 int pgsz_x2 = getpagesize() * 2;
 320                 packed_git_window_size = git_config_int(var, value);
 321
 322                 /* This value must be multiple of (pagesize * 2) */
 323                 packed_git_window_size /= pgsz_x2;
 324                 if (packed_git_window_size < 1)
 325                         packed_git_window_size = 1;
 326                 packed_git_window_size *= pgsz_x2;
 327                 return 0;
 328         }
 329
 330         if (!strcmp(var, "core.packedgitlimit")) {
 331                 packed_git_limit = git_config_int(var, value);
 332                 return 0;
 333         }
 334
 335         if (!strcmp(var, "core.deltabasecachelimit")) {
 336                 delta_base_cache_limit = git_config_int(var, value);
 337                 return 0;
 338         }
 339
 340         if (!strcmp(var, "core.autocrlf")) {
 341                 if (value && !strcasecmp(value, "input")) {
 342                         auto_crlf = -1;
 343                         return 0;
 344                 }
 345                 auto_crlf = git_config_bool(var, value);
 346                 return 0;
 347         }
 348
 349         if (!strcmp(var, "user.name")) {
 350                 strlcpy(git_default_name, value, sizeof(git_default_name));
 351                 return 0;
 352         }
 353
 354         if (!strcmp(var, "user.email")) {
 355                 strlcpy(git_default_email, value, sizeof(git_default_email));
 356                 return 0;
 357         }
 358
 359         if (!strcmp(var, "i18n.commitencoding")) {
 360                 git_commit_encoding = xstrdup(value);
 361                 return 0;
 362         }
 363
 364         if (!strcmp(var, "i18n.logoutputencoding")) {
 365                 git_log_output_encoding = xstrdup(value);
 366                 return 0;
 367         }
 368
 369
 370         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 371                 pager_use_color = git_config_bool(var,value);
 372                 return 0;
 373         }
 374
 375         /* Add other config variables here and to Documentation/config.txt. */
 376         return 0;
 377 }
 378
 379 int git_config_from_file(config_fn_t fn, const char *filename)
 380 {
 381         int ret;
 382         FILE *f = fopen(filename, "r");
 383
 384         ret = -1;
 385         if (f) {
 386                 config_file = f;
 387                 config_file_name = filename;
 388                 config_linenr = 1;
 389                 ret = git_parse_file(fn);
 390                 fclose(f);
 391                 config_file_name = NULL;
 392         }
 393         return ret;
 394 }
 395
 396 const char *git_etc_gitconfig(void)
 397 {
 398         static const char *system_wide;
 399         if (!system_wide) {
 400                 system_wide = ETC_GITCONFIG;
 401                 /* interpret path relative to exec-dir */
 402                 if (system_wide[0] != '/' && system_wide[1] != ':') {
 403                         const char *exec_path = git_exec_path();
 404                         system_wide = prefix_path(exec_path, strlen(exec_path),
 405                                                 system_wide);
 406                 }
 407         }
 408         return system_wide;
 409 }
 410
 411 int git_config(config_fn_t fn)
 412 {
 413         int ret = 0;
 414         char *repo_config = NULL;
 415         const char *home = NULL, *filename;
 416
 417         /* $GIT_CONFIG makes git read _only_ the given config file,
 418          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 419          * global config file, the same way it would the per-repository
 420          * config file otherwise. */
 421         filename = getenv(CONFIG_ENVIRONMENT);
 422         if (!filename) {
 423                 if (!access(git_etc_gitconfig(), R_OK))
 424                         ret += git_config_from_file(fn, git_etc_gitconfig());
 425                 home = getenv("HOME");
 426                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 427                 if (!filename)
 428                         filename = repo_config = xstrdup(git_path("config"));
 429         }
 430
 431         if (home) {
 432                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 433                 if (!access(user_config, R_OK))
 434                         ret = git_config_from_file(fn, user_config);
 435                 free(user_config);
 436         }
 437
 438         ret += git_config_from_file(fn, filename);
 439         free(repo_config);
 440         return ret;
 441 }
 442
 443 /*
 444  * Find all the stuff for git_config_set() below.
 445  */
 446
 447 #define MAX_MATCHES 512
 448
 449 static struct {
 450         int baselen;
 451         char* key;
 452         int do_not_match;
 453         regex_t* value_regex;
 454         int multi_replace;
 455         size_t offset[MAX_MATCHES];
 456         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 457         int seen;
 458 } store;
 459
 460 static int matches(const char* key, const char* value)
 461 {
 462         return !strcmp(key, store.key) &&
 463                 (store.value_regex == NULL ||
 464                  (store.do_not_match ^
 465                   !regexec(store.value_regex, value, 0, NULL, 0)));
 466 }
 467
 468 static int store_aux(const char* key, const char* value)
 469 {
 470         const char *ep;
 471         size_t section_len;
 472
 473         switch (store.state) {
 474         case KEY_SEEN:
 475                 if (matches(key, value)) {
 476                         if (store.seen == 1 && store.multi_replace == 0) {
 477                                 fprintf(stderr,
 478                                         "Warning: %s has multiple values\n",
 479                                         key);
 480                         } else if (store.seen >= MAX_MATCHES) {
 481                                 fprintf(stderr, "Too many matches\n");
 482                                 return 1;
 483                         }
 484
 485                         store.offset[store.seen] = ftell(config_file);
 486                         store.seen++;
 487                 }
 488                 break;
 489         case SECTION_SEEN:
 490                 /*
 491                  * What we are looking for is in store.key (both
 492                  * section and var), and its section part is baselen
 493                  * long.  We found key (again, both section and var).
 494                  * We would want to know if this key is in the same
 495                  * section as what we are looking for.  We already
 496                  * know we are in the same section as what should
 497                  * hold store.key.
 498                  */
 499                 ep = strrchr(key, '.');
 500                 section_len = ep - key;
 501
 502                 if ((section_len != store.baselen) ||
 503                     memcmp(key, store.key, section_len+1)) {
 504                         store.state = SECTION_END_SEEN;
 505                         break;
 506                 }
 507
 508                 /*
 509                  * Do not increment matches: this is no match, but we
 510                  * just made sure we are in the desired section.
 511                  */
 512                 store.offset[store.seen] = ftell(config_file);
 513                 /* fallthru */
 514         case SECTION_END_SEEN:
 515         case START:
 516                 if (matches(key, value)) {
 517                         store.offset[store.seen] = ftell(config_file);
 518                         store.state = KEY_SEEN;
 519                         store.seen++;
 520                 } else {
 521                         if (strrchr(key, '.') - key == store.baselen &&
 522                               !strncmp(key, store.key, store.baselen)) {
 523                                         store.state = SECTION_SEEN;
 524                                         store.offset[store.seen] = ftell(config_file);
 525                         }
 526                 }
 527         }
 528         return 0;
 529 }
 530
 531 static int write_error()
 532 {
 533         fprintf(stderr, "Failed to write new configuration file\n");
 534
 535         /* Same error code as "failed to rename". */
 536         return 4;
 537 }
 538
 539 static int store_write_section(int fd, const char* key)
 540 {
 541         const char *dot = strchr(key, '.');
 542         int len1 = store.baselen, len2 = -1;
 543
 544         dot = strchr(key, '.');
 545         if (dot) {
 546                 int dotlen = dot - key;
 547                 if (dotlen < len1) {
 548                         len2 = len1 - dotlen - 1;
 549                         len1 = dotlen;
 550                 }
 551         }
 552
 553         if (write_in_full(fd, "[", 1) != 1 ||
 554             write_in_full(fd, key, len1) != len1)
 555                 return 0;
 556         if (len2 >= 0) {
 557                 if (write_in_full(fd, " \"", 2) != 2)
 558                         return 0;
 559                 while (--len2 >= 0) {
 560                         unsigned char c = *++dot;
 561                         if (c == '"')
 562                                 if (write_in_full(fd, "\\", 1) != 1)
 563                                         return 0;
 564                         if (write_in_full(fd, &c, 1) != 1)
 565                                 return 0;
 566                 }
 567                 if (write_in_full(fd, "\"", 1) != 1)
 568                         return 0;
 569         }
 570         if (write_in_full(fd, "]\n", 2) != 2)
 571                 return 0;
 572
 573         return 1;
 574 }
 575
 576 static int store_write_pair(int fd, const char* key, const char* value)
 577 {
 578         int i;
 579         int length = strlen(key+store.baselen+1);
 580         int quote = 0;
 581
 582         /* Check to see if the value needs to be quoted. */
 583         if (value[0] == ' ')
 584                 quote = 1;
 585         for (i = 0; value[i]; i++)
 586                 if (value[i] == ';' || value[i] == '#')
 587                         quote = 1;
 588         if (value[i-1] == ' ')
 589                 quote = 1;
 590
 591         if (write_in_full(fd, "\t", 1) != 1 ||
 592             write_in_full(fd, key+store.baselen+1, length) != length ||
 593             write_in_full(fd, " = ", 3) != 3)
 594                 return 0;
 595         if (quote && write_in_full(fd, "\"", 1) != 1)
 596                 return 0;
 597         for (i = 0; value[i]; i++)
 598                 switch (value[i]) {
 599                 case '\n':
 600                         if (write_in_full(fd, "\\n", 2) != 2)
 601                                 return 0;
 602                         break;
 603                 case '\t':
 604                         if (write_in_full(fd, "\\t", 2) != 2)
 605                                 return 0;
 606                         break;
 607                 case '"':
 608                 case '\\':
 609                         if (write_in_full(fd, "\\", 1) != 1)
 610                                 return 0;
 611                 default:
 612                         if (write_in_full(fd, value+i, 1) != 1)
 613                                 return 0;
 614                         break;
 615                 }
 616         if (quote && write_in_full(fd, "\"", 1) != 1)
 617                 return 0;
 618         if (write_in_full(fd, "\n", 1) != 1)
 619                 return 0;
 620         return 1;
 621 }
 622
 623 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 624         size_t offset_, int* found_bracket)
 625 {
 626         size_t equal_offset = size, bracket_offset = size;
 627         ssize_t offset;
 628
 629         for (offset = offset_-2; offset > 0
 630                         && contents[offset] != '\n'; offset--)
 631                 switch (contents[offset]) {
 632                         case '=': equal_offset = offset; break;
 633                         case ']': bracket_offset = offset; break;
 634                 }
 635         if (bracket_offset < equal_offset) {
 636                 *found_bracket = 1;
 637                 offset = bracket_offset+1;
 638         } else
 639                 offset++;
 640
 641         return offset;
 642 }
 643
 644 int git_config_set(const char* key, const char* value)
 645 {
 646         return git_config_set_multivar(key, value, NULL, 0);
 647 }
 648
 649 /*
 650  * If value==NULL, unset in (remove from) config,
 651  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 652  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 653  *     else all matching key/values (regardless how many) are removed,
 654  *     before the new pair is written.
 655  *
 656  * Returns 0 on success.
 657  *
 658  * This function does this:
 659  *
 660  * - it locks the config file by creating ".git/config.lock"
 661  *
 662  * - it then parses the config using store_aux() as validator to find
 663  *   the position on the key/value pair to replace. If it is to be unset,
 664  *   it must be found exactly once.
 665  *
 666  * - the config file is mmap()ed and the part before the match (if any) is
 667  *   written to the lock file, then the changed part and the rest.
 668  *
 669  * - the config file is removed and the lock file rename()d to it.
 670  *
 671  */
 672 int git_config_set_multivar(const char* key, const char* value,
 673         const char* value_regex, int multi_replace)
 674 {
 675         int i, dot;
 676         int fd = -1, in_fd;
 677         int ret;
 678         char* config_filename;
 679         char* lock_file;
 680         const char* last_dot = strrchr(key, '.');
 681
 682         config_filename = getenv(CONFIG_ENVIRONMENT);
 683         if (!config_filename) {
 684                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 685                 if (!config_filename)
 686                         config_filename  = git_path("config");
 687         }
 688         config_filename = xstrdup(config_filename);
 689         lock_file = xstrdup(mkpath("%s.lock", config_filename));
 690
 691         /*
 692          * Since "key" actually contains the section name and the real
 693          * key name separated by a dot, we have to know where the dot is.
 694          */
 695
 696         if (last_dot == NULL) {
 697                 fprintf(stderr, "key does not contain a section: %s\n", key);
 698                 ret = 2;
 699                 goto out_free;
 700         }
 701         store.baselen = last_dot - key;
 702
 703         store.multi_replace = multi_replace;
 704
 705         /*
 706          * Validate the key and while at it, lower case it for matching.
 707          */
 708         store.key = xmalloc(strlen(key) + 1);
 709         dot = 0;
 710         for (i = 0; key[i]; i++) {
 711                 unsigned char c = key[i];
 712                 if (c == '.')
 713                         dot = 1;
 714                 /* Leave the extended basename untouched.. */
 715                 if (!dot || i > store.baselen) {
 716                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 717                                 fprintf(stderr, "invalid key: %s\n", key);
 718                                 free(store.key);
 719                                 ret = 1;
 720                                 goto out_free;
 721                         }
 722                         c = tolower(c);
 723                 } else if (c == '\n') {
 724                         fprintf(stderr, "invalid key (newline): %s\n", key);
 725                         free(store.key);
 726                         ret = 1;
 727                         goto out_free;
 728                 }
 729                 store.key[i] = c;
 730         }
 731         store.key[i] = 0;
 732
 733         /*
 734          * The lock_file serves a purpose in addition to locking: the new
 735          * contents of .git/config will be written into it.
 736          */
 737         fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 738         if (fd < 0 || adjust_shared_perm(lock_file)) {
 739                 fprintf(stderr, "could not lock config file\n");
 740                 free(store.key);
 741                 ret = -1;
 742                 goto out_free;
 743         }
 744
 745         /*
 746          * If .git/config does not exist yet, write a minimal version.
 747          */
 748         in_fd = open(config_filename, O_RDONLY);
 749         if ( in_fd < 0 ) {
 750                 free(store.key);
 751
 752                 if ( ENOENT != errno ) {
 753                         error("opening %s: %s", config_filename,
 754                               strerror(errno));
 755                         ret = 3; /* same as "invalid config file" */
 756                         goto out_free;
 757                 }
 758                 /* if nothing to unset, error out */
 759                 if (value == NULL) {
 760                         ret = 5;
 761                         goto out_free;
 762                 }
 763
 764                 store.key = (char*)key;
 765                 if (!store_write_section(fd, key) ||
 766                     !store_write_pair(fd, key, value))
 767                         goto write_err_out;
 768         } else {
 769                 struct stat st;
 770                 char* contents;
 771                 size_t contents_sz, copy_begin, copy_end;
 772                 int i, new_line = 0;
 773
 774                 if (value_regex == NULL)
 775                         store.value_regex = NULL;
 776                 else {
 777                         if (value_regex[0] == '!') {
 778                                 store.do_not_match = 1;
 779                                 value_regex++;
 780                         } else
 781                                 store.do_not_match = 0;
 782
 783                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 784                         if (regcomp(store.value_regex, value_regex,
 785                                         REG_EXTENDED)) {
 786                                 fprintf(stderr, "Invalid pattern: %s\n",
 787                                         value_regex);
 788                                 free(store.value_regex);
 789                                 ret = 6;
 790                                 goto out_free;
 791                         }
 792                 }
 793
 794                 store.offset[0] = 0;
 795                 store.state = START;
 796                 store.seen = 0;
 797
 798                 /*
 799                  * After this, store.offset will contain the *end* offset
 800                  * of the last match, or remain at 0 if no match was found.
 801                  * As a side effect, we make sure to transform only a valid
 802                  * existing config file.
 803                  */
 804                 if (git_config_from_file(store_aux, config_filename)) {
 805                         fprintf(stderr, "invalid config file\n");
 806                         free(store.key);
 807                         if (store.value_regex != NULL) {
 808                                 regfree(store.value_regex);
 809                                 free(store.value_regex);
 810                         }
 811                         ret = 3;
 812                         goto out_free;
 813                 }
 814
 815                 free(store.key);
 816                 if (store.value_regex != NULL) {
 817                         regfree(store.value_regex);
 818                         free(store.value_regex);
 819                 }
 820
 821                 /* if nothing to unset, or too many matches, error out */
 822                 if ((store.seen == 0 && value == NULL) ||
 823                                 (store.seen > 1 && multi_replace == 0)) {
 824                         ret = 5;
 825                         goto out_free;
 826                 }
 827
 828                 fstat(in_fd, &st);
 829                 contents_sz = xsize_t(st.st_size);
 830                 contents = xmmap(NULL, contents_sz, PROT_READ,
 831                         MAP_PRIVATE, in_fd, 0);
 832                 close(in_fd);
 833
 834                 if (store.seen == 0)
 835                         store.seen = 1;
 836
 837                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 838                         if (store.offset[i] == 0) {
 839                                 store.offset[i] = copy_end = contents_sz;
 840                         } else if (store.state != KEY_SEEN) {
 841                                 copy_end = store.offset[i];
 842                         } else
 843                                 copy_end = find_beginning_of_line(
 844                                         contents, contents_sz,
 845                                         store.offset[i]-2, &new_line);
 846
 847                         /* write the first part of the config */
 848                         if (copy_end > copy_begin) {
 849                                 if (write_in_full(fd, contents + copy_begin,
 850                                                   copy_end - copy_begin) <
 851                                     copy_end - copy_begin)
 852                                         goto write_err_out;
 853                                 if (new_line &&
 854                                     write_in_full(fd, "\n", 1) != 1)
 855                                         goto write_err_out;
 856                         }
 857                         copy_begin = store.offset[i];
 858                 }
 859
 860                 /* write the pair (value == NULL means unset) */
 861                 if (value != NULL) {
 862                         if (store.state == START) {
 863                                 if (!store_write_section(fd, key))
 864                                         goto write_err_out;
 865                         }
 866                         if (!store_write_pair(fd, key, value))
 867                                 goto write_err_out;
 868                 }
 869
 870                 /* write the rest of the config */
 871                 if (copy_begin < contents_sz)
 872                         if (write_in_full(fd, contents + copy_begin,
 873                                           contents_sz - copy_begin) <
 874                             contents_sz - copy_begin)
 875                                 goto write_err_out;
 876
 877                 munmap(contents, contents_sz);
 878                 unlink(config_filename);
 879         }
 880
 881         close(fd);
 882         fd = -1;
 883         if (rename(lock_file, config_filename) < 0) {
 884                 fprintf(stderr, "Could not rename the lock file?\n");
 885                 ret = 4;
 886                 goto out_free;
 887         }
 888
 889         ret = 0;
 890
 891 out_free:
 892         if (0 <= fd)
 893                 close(fd);
 894         free(config_filename);
 895         if (lock_file) {
 896                 unlink(lock_file);
 897                 free(lock_file);
 898         }
 899         return ret;
 900
 901 write_err_out:
 902         ret = write_error();
 903         goto out_free;
 904
 905 }
 906
 907 static int section_name_match (const char *buf, const char *name)
 908 {
 909         int i = 0, j = 0, dot = 0;
 910         for (; buf[i] && buf[i] != ']'; i++) {
 911                 if (!dot && isspace(buf[i])) {
 912                         dot = 1;
 913                         if (name[j++] != '.')
 914                                 break;
 915                         for (i++; isspace(buf[i]); i++)
 916                                 ; /* do nothing */
 917                         if (buf[i] != '"')
 918                                 break;
 919                         continue;
 920                 }
 921                 if (buf[i] == '\\' && dot)
 922                         i++;
 923                 else if (buf[i] == '"' && dot) {
 924                         for (i++; isspace(buf[i]); i++)
 925                                 ; /* do_nothing */
 926                         break;
 927                 }
 928                 if (buf[i] != name[j++])
 929                         break;
 930         }
 931         return (buf[i] == ']' && name[j] == 0);
 932 }
 933
 934 /* if new_name == NULL, the section is removed instead */
 935 int git_config_rename_section(const char *old_name, const char *new_name)
 936 {
 937         int ret = 0, remove = 0;
 938         char *config_filename;
 939         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
 940         int out_fd;
 941         char buf[1024];
 942
 943         config_filename = getenv(CONFIG_ENVIRONMENT);
 944         if (!config_filename) {
 945                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 946                 if (!config_filename)
 947                         config_filename  = git_path("config");
 948         }
 949         config_filename = xstrdup(config_filename);
 950         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
 951         if (out_fd < 0) {
 952                 ret = error("Could not lock config file!");
 953                 goto out;
 954         }
 955
 956         if (!(config_file = fopen(config_filename, "rb"))) {
 957                 /* no config file means nothing to rename, no error */
 958                 goto unlock_and_out;
 959         }
 960
 961         while (fgets(buf, sizeof(buf), config_file)) {
 962                 int i;
 963                 int length;
 964                 for (i = 0; buf[i] && isspace(buf[i]); i++)
 965                         ; /* do nothing */
 966                 if (buf[i] == '[') {
 967                         /* it's a section */
 968                         if (section_name_match (&buf[i+1], old_name)) {
 969                                 ret++;
 970                                 if (new_name == NULL) {
 971                                         remove = 1;
 972                                         continue;
 973                                 }
 974                                 store.baselen = strlen(new_name);
 975                                 if (!store_write_section(out_fd, new_name)) {
 976                                         ret = write_error();
 977                                         goto out;
 978                                 }
 979                                 continue;
 980                         }
 981                         remove = 0;
 982                 }
 983                 if (remove)
 984                         continue;
 985                 length = strlen(buf);
 986                 if (write_in_full(out_fd, buf, length) != length) {
 987                         ret = write_error();
 988                         goto out;
 989                 }
 990         }
 991         fclose(config_file);
 992  unlock_and_out:
 993         if (close(out_fd) || commit_lock_file(lock) < 0)
 994                         ret = error("Cannot commit config file!");
 995  out:
 996         free(config_filename);
 997         return ret;
 998 }
 999