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