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