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
 345         if (!strcmp(var, "core.quotepath")) {
 346                 quote_path_fully = git_config_bool(var, value);
 347                 return 0;
 348         }
 349
 350         if (!strcmp(var, "core.symlinks")) {
 351                 has_symlinks = git_config_bool(var, value);
 352                 return 0;
 353         }
 354
 355         if (!strcmp(var, "core.ignorecase")) {
 356                 ignore_case = git_config_bool(var, value);
 357                 return 0;
 358         }
 359
 360         if (!strcmp(var, "core.bare")) {
 361                 is_bare_repository_cfg = git_config_bool(var, value);
 362                 return 0;
 363         }
 364
 365         if (!strcmp(var, "core.ignorestat")) {
 366                 assume_unchanged = git_config_bool(var, value);
 367                 return 0;
 368         }
 369
 370         if (!strcmp(var, "core.prefersymlinkrefs")) {
 371                 prefer_symlink_refs = git_config_bool(var, value);
 372                 return 0;
 373         }
 374
 375         if (!strcmp(var, "core.logallrefupdates")) {
 376                 log_all_ref_updates = git_config_bool(var, value);
 377                 return 0;
 378         }
 379
 380         if (!strcmp(var, "core.warnambiguousrefs")) {
 381                 warn_ambiguous_refs = git_config_bool(var, value);
 382                 return 0;
 383         }
 384
 385         if (!strcmp(var, "core.loosecompression")) {
 386                 int level = git_config_int(var, value);
 387                 if (level == -1)
 388                         level = Z_DEFAULT_COMPRESSION;
 389                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 390                         die("bad zlib compression level %d", level);
 391                 zlib_compression_level = level;
 392                 zlib_compression_seen = 1;
 393                 return 0;
 394         }
 395
 396         if (!strcmp(var, "core.compression")) {
 397                 int level = git_config_int(var, value);
 398                 if (level == -1)
 399                         level = Z_DEFAULT_COMPRESSION;
 400                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 401                         die("bad zlib compression level %d", level);
 402                 core_compression_level = level;
 403                 core_compression_seen = 1;
 404                 if (!zlib_compression_seen)
 405                         zlib_compression_level = level;
 406                 return 0;
 407         }
 408
 409         if (!strcmp(var, "core.packedgitwindowsize")) {
 410                 int pgsz_x2 = getpagesize() * 2;
 411                 packed_git_window_size = git_config_int(var, value);
 412
 413                 /* This value must be multiple of (pagesize * 2) */
 414                 packed_git_window_size /= pgsz_x2;
 415                 if (packed_git_window_size < 1)
 416                         packed_git_window_size = 1;
 417                 packed_git_window_size *= pgsz_x2;
 418                 return 0;
 419         }
 420
 421         if (!strcmp(var, "core.packedgitlimit")) {
 422                 packed_git_limit = git_config_int(var, value);
 423                 return 0;
 424         }
 425
 426         if (!strcmp(var, "core.deltabasecachelimit")) {
 427                 delta_base_cache_limit = git_config_int(var, value);
 428                 return 0;
 429         }
 430
 431         if (!strcmp(var, "core.autocrlf")) {
 432                 if (value && !strcasecmp(value, "input")) {
 433                         auto_crlf = -1;
 434                         return 0;
 435                 }
 436                 auto_crlf = git_config_bool(var, value);
 437                 return 0;
 438         }
 439
 440         if (!strcmp(var, "core.safecrlf")) {
 441                 if (value && !strcasecmp(value, "warn")) {
 442                         safe_crlf = SAFE_CRLF_WARN;
 443                         return 0;
 444                 }
 445                 safe_crlf = git_config_bool(var, value);
 446                 return 0;
 447         }
 448
 449         if (!strcmp(var, "core.pager"))
 450                 return git_config_string(&pager_program, var, value);
 451
 452         if (!strcmp(var, "core.editor"))
 453                 return git_config_string(&editor_program, var, value);
 454
 455         if (!strcmp(var, "core.excludesfile"))
 456                 return git_config_string(&excludes_file, var, value);
 457
 458         if (!strcmp(var, "core.whitespace")) {
 459                 if (!value)
 460                         return config_error_nonbool(var);
 461                 whitespace_rule_cfg = parse_whitespace_rule(value);
 462                 return 0;
 463         }
 464
 465         if (!strcmp(var, "core.fsyncobjectfiles")) {
 466                 fsync_object_files = git_config_bool(var, value);
 467                 return 0;
 468         }
 469
 470         /* Add other config variables here and to Documentation/config.txt. */
 471         return 0;
 472 }
 473
 474 static int git_default_user_config(const char *var, const char *value)
 475 {
 476         if (!strcmp(var, "user.name")) {
 477                 if (!value)
 478                         return config_error_nonbool(var);
 479                 strlcpy(git_default_name, value, sizeof(git_default_name));
 480                 if (git_default_email[0])
 481                         user_ident_explicitly_given = 1;
 482                 return 0;
 483         }
 484
 485         if (!strcmp(var, "user.email")) {
 486                 if (!value)
 487                         return config_error_nonbool(var);
 488                 strlcpy(git_default_email, value, sizeof(git_default_email));
 489                 if (git_default_name[0])
 490                         user_ident_explicitly_given = 1;
 491                 return 0;
 492         }
 493
 494         /* Add other config variables here and to Documentation/config.txt. */
 495         return 0;
 496 }
 497
 498 static int git_default_i18n_config(const char *var, const char *value)
 499 {
 500         if (!strcmp(var, "i18n.commitencoding"))
 501                 return git_config_string(&git_commit_encoding, var, value);
 502
 503         if (!strcmp(var, "i18n.logoutputencoding"))
 504                 return git_config_string(&git_log_output_encoding, var, value);
 505
 506         /* Add other config variables here and to Documentation/config.txt. */
 507         return 0;
 508 }
 509
 510 static int git_default_branch_config(const char *var, const char *value)
 511 {
 512         if (!strcmp(var, "branch.autosetupmerge")) {
 513                 if (value && !strcasecmp(value, "always")) {
 514                         git_branch_track = BRANCH_TRACK_ALWAYS;
 515                         return 0;
 516                 }
 517                 git_branch_track = git_config_bool(var, value);
 518                 return 0;
 519         }
 520         if (!strcmp(var, "branch.autosetuprebase")) {
 521                 if (!value)
 522                         return config_error_nonbool(var);
 523                 else if (!strcmp(value, "never"))
 524                         autorebase = AUTOREBASE_NEVER;
 525                 else if (!strcmp(value, "local"))
 526                         autorebase = AUTOREBASE_LOCAL;
 527                 else if (!strcmp(value, "remote"))
 528                         autorebase = AUTOREBASE_REMOTE;
 529                 else if (!strcmp(value, "always"))
 530                         autorebase = AUTOREBASE_ALWAYS;
 531                 else
 532                         return error("Malformed value for %s", var);
 533                 return 0;
 534         }
 535
 536         /* Add other config variables here and to Documentation/config.txt. */
 537         return 0;
 538 }
 539
 540 int git_default_config(const char *var, const char *value, void *dummy)
 541 {
 542         if (!prefixcmp(var, "core."))
 543                 return git_default_core_config(var, value);
 544
 545         if (!prefixcmp(var, "user."))
 546                 return git_default_user_config(var, value);
 547
 548         if (!prefixcmp(var, "i18n."))
 549                 return git_default_i18n_config(var, value);
 550
 551         if (!prefixcmp(var, "branch."))
 552                 return git_default_branch_config(var, value);
 553
 554         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 555                 pager_use_color = git_config_bool(var,value);
 556                 return 0;
 557         }
 558
 559         /* Add other config variables here and to Documentation/config.txt. */
 560         return 0;
 561 }
 562
 563 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 564 {
 565         int ret;
 566         FILE *f = fopen(filename, "r");
 567
 568         ret = -1;
 569         if (f) {
 570                 config_file = f;
 571                 config_file_name = filename;
 572                 config_linenr = 1;
 573                 config_file_eof = 0;
 574                 ret = git_parse_file(fn, data);
 575                 fclose(f);
 576                 config_file_name = NULL;
 577         }
 578         return ret;
 579 }
 580
 581 const char *git_etc_gitconfig(void)
 582 {
 583         static const char *system_wide;
 584         if (!system_wide) {
 585                 system_wide = ETC_GITCONFIG;
 586                 if (!is_absolute_path(system_wide)) {
 587                         /* interpret path relative to exec-dir */
 588                         struct strbuf d = STRBUF_INIT;
 589                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 590                         system_wide = strbuf_detach(&d, NULL);
 591                 }
 592         }
 593         return system_wide;
 594 }
 595
 596 static int git_env_bool(const char *k, int def)
 597 {
 598         const char *v = getenv(k);
 599         return v ? git_config_bool(k, v) : def;
 600 }
 601
 602 int git_config_system(void)
 603 {
 604         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 605 }
 606
 607 int git_config_global(void)
 608 {
 609         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 610 }
 611
 612 int git_config(config_fn_t fn, void *data)
 613 {
 614         int ret = 0;
 615         char *repo_config = NULL;
 616         const char *home = NULL;
 617
 618         /* $GIT_CONFIG makes git read _only_ the given config file,
 619          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 620          * global config file, the same way it would the per-repository
 621          * config file otherwise. */
 622         if (config_exclusive_filename)
 623                 return git_config_from_file(fn, config_exclusive_filename, data);
 624         if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 625                 ret += git_config_from_file(fn, git_etc_gitconfig(),
 626                                             data);
 627
 628         home = getenv("HOME");
 629         if (git_config_global() && home) {
 630                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 631                 if (!access(user_config, R_OK))
 632                         ret += git_config_from_file(fn, user_config, data);
 633                 free(user_config);
 634         }
 635
 636         repo_config = xstrdup(git_path("config"));
 637         ret += git_config_from_file(fn, repo_config, data);
 638         free(repo_config);
 639         return ret;
 640 }
 641
 642 /*
 643  * Find all the stuff for git_config_set() below.
 644  */
 645
 646 #define MAX_MATCHES 512
 647
 648 static struct {
 649         int baselen;
 650         char* key;
 651         int do_not_match;
 652         regex_t* value_regex;
 653         int multi_replace;
 654         size_t offset[MAX_MATCHES];
 655         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 656         int seen;
 657 } store;
 658
 659 static int matches(const char* key, const char* value)
 660 {
 661         return !strcmp(key, store.key) &&
 662                 (store.value_regex == NULL ||
 663                  (store.do_not_match ^
 664                   !regexec(store.value_regex, value, 0, NULL, 0)));
 665 }
 666
 667 static int store_aux(const char* key, const char* value, void *cb)
 668 {
 669         const char *ep;
 670         size_t section_len;
 671
 672         switch (store.state) {
 673         case KEY_SEEN:
 674                 if (matches(key, value)) {
 675                         if (store.seen == 1 && store.multi_replace == 0) {
 676                                 warning("%s has multiple values", key);
 677                         } else if (store.seen >= MAX_MATCHES) {
 678                                 error("too many matches for %s", key);
 679                                 return 1;
 680                         }
 681
 682                         store.offset[store.seen] = ftell(config_file);
 683                         store.seen++;
 684                 }
 685                 break;
 686         case SECTION_SEEN:
 687                 /*
 688                  * What we are looking for is in store.key (both
 689                  * section and var), and its section part is baselen
 690                  * long.  We found key (again, both section and var).
 691                  * We would want to know if this key is in the same
 692                  * section as what we are looking for.  We already
 693                  * know we are in the same section as what should
 694                  * hold store.key.
 695                  */
 696                 ep = strrchr(key, '.');
 697                 section_len = ep - key;
 698
 699                 if ((section_len != store.baselen) ||
 700                     memcmp(key, store.key, section_len+1)) {
 701                         store.state = SECTION_END_SEEN;
 702                         break;
 703                 }
 704
 705                 /*
 706                  * Do not increment matches: this is no match, but we
 707                  * just made sure we are in the desired section.
 708                  */
 709                 store.offset[store.seen] = ftell(config_file);
 710                 /* fallthru */
 711         case SECTION_END_SEEN:
 712         case START:
 713                 if (matches(key, value)) {
 714                         store.offset[store.seen] = ftell(config_file);
 715                         store.state = KEY_SEEN;
 716                         store.seen++;
 717                 } else {
 718                         if (strrchr(key, '.') - key == store.baselen &&
 719                               !strncmp(key, store.key, store.baselen)) {
 720                                         store.state = SECTION_SEEN;
 721                                         store.offset[store.seen] = ftell(config_file);
 722                         }
 723                 }
 724         }
 725         return 0;
 726 }
 727
 728 static int write_error(const char *filename)
 729 {
 730         error("failed to write new configuration file %s", filename);
 731
 732         /* Same error code as "failed to rename". */
 733         return 4;
 734 }
 735
 736 static int store_write_section(int fd, const char* key)
 737 {
 738         const char *dot;
 739         int i, success;
 740         struct strbuf sb;
 741
 742         strbuf_init(&sb, 0);
 743         dot = memchr(key, '.', store.baselen);
 744         if (dot) {
 745                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 746                 for (i = dot - key + 1; i < store.baselen; i++) {
 747                         if (key[i] == '"' || key[i] == '\\')
 748                                 strbuf_addch(&sb, '\\');
 749                         strbuf_addch(&sb, key[i]);
 750                 }
 751                 strbuf_addstr(&sb, "\"]\n");
 752         } else {
 753                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 754         }
 755
 756         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 757         strbuf_release(&sb);
 758
 759         return success;
 760 }
 761
 762 static int store_write_pair(int fd, const char* key, const char* value)
 763 {
 764         int i, success;
 765         int length = strlen(key + store.baselen + 1);
 766         const char *quote = "";
 767         struct strbuf sb;
 768
 769         /*
 770          * Check to see if the value needs to be surrounded with a dq pair.
 771          * Note that problematic characters are always backslash-quoted; this
 772          * check is about not losing leading or trailing SP and strings that
 773          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 774          * configuration parser.
 775          */
 776         if (value[0] == ' ')
 777                 quote = "\"";
 778         for (i = 0; value[i]; i++)
 779                 if (value[i] == ';' || value[i] == '#')
 780                         quote = "\"";
 781         if (i && value[i - 1] == ' ')
 782                 quote = "\"";
 783
 784         strbuf_init(&sb, 0);
 785         strbuf_addf(&sb, "\t%.*s = %s",
 786                     length, key + store.baselen + 1, quote);
 787
 788         for (i = 0; value[i]; i++)
 789                 switch (value[i]) {
 790                 case '\n':
 791                         strbuf_addstr(&sb, "\\n");
 792                         break;
 793                 case '\t':
 794                         strbuf_addstr(&sb, "\\t");
 795                         break;
 796                 case '"':
 797                 case '\\':
 798                         strbuf_addch(&sb, '\\');
 799                 default:
 800                         strbuf_addch(&sb, value[i]);
 801                         break;
 802                 }
 803         strbuf_addf(&sb, "%s\n", quote);
 804
 805         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 806         strbuf_release(&sb);
 807
 808         return success;
 809 }
 810
 811 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 812         size_t offset_, int* found_bracket)
 813 {
 814         size_t equal_offset = size, bracket_offset = size;
 815         ssize_t offset;
 816
 817 contline:
 818         for (offset = offset_-2; offset > 0
 819                         && contents[offset] != '\n'; offset--)
 820                 switch (contents[offset]) {
 821                         case '=': equal_offset = offset; break;
 822                         case ']': bracket_offset = offset; break;
 823                 }
 824         if (offset > 0 && contents[offset-1] == '\\') {
 825                 offset_ = offset;
 826                 goto contline;
 827         }
 828         if (bracket_offset < equal_offset) {
 829                 *found_bracket = 1;
 830                 offset = bracket_offset+1;
 831         } else
 832                 offset++;
 833
 834         return offset;
 835 }
 836
 837 int git_config_set(const char* key, const char* value)
 838 {
 839         return git_config_set_multivar(key, value, NULL, 0);
 840 }
 841
 842 /*
 843  * If value==NULL, unset in (remove from) config,
 844  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 845  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 846  *     else all matching key/values (regardless how many) are removed,
 847  *     before the new pair is written.
 848  *
 849  * Returns 0 on success.
 850  *
 851  * This function does this:
 852  *
 853  * - it locks the config file by creating ".git/config.lock"
 854  *
 855  * - it then parses the config using store_aux() as validator to find
 856  *   the position on the key/value pair to replace. If it is to be unset,
 857  *   it must be found exactly once.
 858  *
 859  * - the config file is mmap()ed and the part before the match (if any) is
 860  *   written to the lock file, then the changed part and the rest.
 861  *
 862  * - the config file is removed and the lock file rename()d to it.
 863  *
 864  */
 865 int git_config_set_multivar(const char* key, const char* value,
 866         const char* value_regex, int multi_replace)
 867 {
 868         int i, dot;
 869         int fd = -1, in_fd;
 870         int ret;
 871         char* config_filename;
 872         struct lock_file *lock = NULL;
 873         const char* last_dot = strrchr(key, '.');
 874
 875         if (config_exclusive_filename)
 876                 config_filename = xstrdup(config_exclusive_filename);
 877         else
 878                 config_filename = xstrdup(git_path("config"));
 879
 880         /*
 881          * Since "key" actually contains the section name and the real
 882          * key name separated by a dot, we have to know where the dot is.
 883          */
 884
 885         if (last_dot == NULL) {
 886                 error("key does not contain a section: %s", key);
 887                 ret = 2;
 888                 goto out_free;
 889         }
 890         store.baselen = last_dot - key;
 891
 892         store.multi_replace = multi_replace;
 893
 894         /*
 895          * Validate the key and while at it, lower case it for matching.
 896          */
 897         store.key = xmalloc(strlen(key) + 1);
 898         dot = 0;
 899         for (i = 0; key[i]; i++) {
 900                 unsigned char c = key[i];
 901                 if (c == '.')
 902                         dot = 1;
 903                 /* Leave the extended basename untouched.. */
 904                 if (!dot || i > store.baselen) {
 905                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 906                                 error("invalid key: %s", key);
 907                                 free(store.key);
 908                                 ret = 1;
 909                                 goto out_free;
 910                         }
 911                         c = tolower(c);
 912                 } else if (c == '\n') {
 913                         error("invalid key (newline): %s", key);
 914                         free(store.key);
 915                         ret = 1;
 916                         goto out_free;
 917                 }
 918                 store.key[i] = c;
 919         }
 920         store.key[i] = 0;
 921
 922         /*
 923          * The lock serves a purpose in addition to locking: the new
 924          * contents of .git/config will be written into it.
 925          */
 926         lock = xcalloc(sizeof(struct lock_file), 1);
 927         fd = hold_lock_file_for_update(lock, config_filename, 0);
 928         if (fd < 0) {
 929                 error("could not lock config file %s", config_filename);
 930                 free(store.key);
 931                 ret = -1;
 932                 goto out_free;
 933         }
 934
 935         /*
 936          * If .git/config does not exist yet, write a minimal version.
 937          */
 938         in_fd = open(config_filename, O_RDONLY);
 939         if ( in_fd < 0 ) {
 940                 free(store.key);
 941
 942                 if ( ENOENT != errno ) {
 943                         error("opening %s: %s", config_filename,
 944                               strerror(errno));
 945                         ret = 3; /* same as "invalid config file" */
 946                         goto out_free;
 947                 }
 948                 /* if nothing to unset, error out */
 949                 if (value == NULL) {
 950                         ret = 5;
 951                         goto out_free;
 952                 }
 953
 954                 store.key = (char*)key;
 955                 if (!store_write_section(fd, key) ||
 956                     !store_write_pair(fd, key, value))
 957                         goto write_err_out;
 958         } else {
 959                 struct stat st;
 960                 char* contents;
 961                 size_t contents_sz, copy_begin, copy_end;
 962                 int i, new_line = 0;
 963
 964                 if (value_regex == NULL)
 965                         store.value_regex = NULL;
 966                 else {
 967                         if (value_regex[0] == '!') {
 968                                 store.do_not_match = 1;
 969                                 value_regex++;
 970                         } else
 971                                 store.do_not_match = 0;
 972
 973                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 974                         if (regcomp(store.value_regex, value_regex,
 975                                         REG_EXTENDED)) {
 976                                 error("invalid pattern: %s", value_regex);
 977                                 free(store.value_regex);
 978                                 ret = 6;
 979                                 goto out_free;
 980                         }
 981                 }
 982
 983                 store.offset[0] = 0;
 984                 store.state = START;
 985                 store.seen = 0;
 986
 987                 /*
 988                  * After this, store.offset will contain the *end* offset
 989                  * of the last match, or remain at 0 if no match was found.
 990                  * As a side effect, we make sure to transform only a valid
 991                  * existing config file.
 992                  */
 993                 if (git_config_from_file(store_aux, config_filename, NULL)) {
 994                         error("invalid config file %s", config_filename);
 995                         free(store.key);
 996                         if (store.value_regex != NULL) {
 997                                 regfree(store.value_regex);
 998                                 free(store.value_regex);
 999                         }
1000                         ret = 3;
1001                         goto out_free;
1002                 }
1003
1004                 free(store.key);
1005                 if (store.value_regex != NULL) {
1006                         regfree(store.value_regex);
1007                         free(store.value_regex);
1008                 }
1009
1010                 /* if nothing to unset, or too many matches, error out */
1011                 if ((store.seen == 0 && value == NULL) ||
1012                                 (store.seen > 1 && multi_replace == 0)) {
1013                         ret = 5;
1014                         goto out_free;
1015                 }
1016
1017                 fstat(in_fd, &st);
1018                 contents_sz = xsize_t(st.st_size);
1019                 contents = xmmap(NULL, contents_sz, PROT_READ,
1020                         MAP_PRIVATE, in_fd, 0);
1021                 close(in_fd);
1022
1023                 if (store.seen == 0)
1024                         store.seen = 1;
1025
1026                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1027                         if (store.offset[i] == 0) {
1028                                 store.offset[i] = copy_end = contents_sz;
1029                         } else if (store.state != KEY_SEEN) {
1030                                 copy_end = store.offset[i];
1031                         } else
1032                                 copy_end = find_beginning_of_line(
1033                                         contents, contents_sz,
1034                                         store.offset[i]-2, &new_line);
1035
1036                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1037                                 new_line = 1;
1038
1039                         /* write the first part of the config */
1040                         if (copy_end > copy_begin) {
1041                                 if (write_in_full(fd, contents + copy_begin,
1042                                                   copy_end - copy_begin) <
1043                                     copy_end - copy_begin)
1044                                         goto write_err_out;
1045                                 if (new_line &&
1046                                     write_in_full(fd, "\n", 1) != 1)
1047                                         goto write_err_out;
1048                         }
1049                         copy_begin = store.offset[i];
1050                 }
1051
1052                 /* write the pair (value == NULL means unset) */
1053                 if (value != NULL) {
1054                         if (store.state == START) {
1055                                 if (!store_write_section(fd, key))
1056                                         goto write_err_out;
1057                         }
1058                         if (!store_write_pair(fd, key, value))
1059                                 goto write_err_out;
1060                 }
1061
1062                 /* write the rest of the config */
1063                 if (copy_begin < contents_sz)
1064                         if (write_in_full(fd, contents + copy_begin,
1065                                           contents_sz - copy_begin) <
1066                             contents_sz - copy_begin)
1067                                 goto write_err_out;
1068
1069                 munmap(contents, contents_sz);
1070         }
1071
1072         if (commit_lock_file(lock) < 0) {
1073                 error("could not commit config file %s", config_filename);
1074                 ret = 4;
1075                 goto out_free;
1076         }
1077
1078         /*
1079          * lock is committed, so don't try to roll it back below.
1080          * NOTE: Since lockfile.c keeps a linked list of all created
1081          * lock_file structures, it isn't safe to free(lock).  It's
1082          * better to just leave it hanging around.
1083          */
1084         lock = NULL;
1085         ret = 0;
1086
1087 out_free:
1088         if (lock)
1089                 rollback_lock_file(lock);
1090         free(config_filename);
1091         return ret;
1092
1093 write_err_out:
1094         ret = write_error(lock->filename);
1095         goto out_free;
1096
1097 }
1098
1099 static int section_name_match (const char *buf, const char *name)
1100 {
1101         int i = 0, j = 0, dot = 0;
1102         for (; buf[i] && buf[i] != ']'; i++) {
1103                 if (!dot && isspace(buf[i])) {
1104                         dot = 1;
1105                         if (name[j++] != '.')
1106                                 break;
1107                         for (i++; isspace(buf[i]); i++)
1108                                 ; /* do nothing */
1109                         if (buf[i] != '"')
1110                                 break;
1111                         continue;
1112                 }
1113                 if (buf[i] == '\\' && dot)
1114                         i++;
1115                 else if (buf[i] == '"' && dot) {
1116                         for (i++; isspace(buf[i]); i++)
1117                                 ; /* do_nothing */
1118                         break;
1119                 }
1120                 if (buf[i] != name[j++])
1121                         break;
1122         }
1123         return (buf[i] == ']' && name[j] == 0);
1124 }
1125
1126 /* if new_name == NULL, the section is removed instead */
1127 int git_config_rename_section(const char *old_name, const char *new_name)
1128 {
1129         int ret = 0, remove = 0;
1130         char *config_filename;
1131         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1132         int out_fd;
1133         char buf[1024];
1134
1135         if (config_exclusive_filename)
1136                 config_filename = xstrdup(config_exclusive_filename);
1137         else
1138                 config_filename = xstrdup(git_path("config"));
1139         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1140         if (out_fd < 0) {
1141                 ret = error("could not lock config file %s", config_filename);
1142                 goto out;
1143         }
1144
1145         if (!(config_file = fopen(config_filename, "rb"))) {
1146                 /* no config file means nothing to rename, no error */
1147                 goto unlock_and_out;
1148         }
1149
1150         while (fgets(buf, sizeof(buf), config_file)) {
1151                 int i;
1152                 int length;
1153                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1154                         ; /* do nothing */
1155                 if (buf[i] == '[') {
1156                         /* it's a section */
1157                         if (section_name_match (&buf[i+1], old_name)) {
1158                                 ret++;
1159                                 if (new_name == NULL) {
1160                                         remove = 1;
1161                                         continue;
1162                                 }
1163                                 store.baselen = strlen(new_name);
1164                                 if (!store_write_section(out_fd, new_name)) {
1165                                         ret = write_error(lock->filename);
1166                                         goto out;
1167                                 }
1168                                 continue;
1169                         }
1170                         remove = 0;
1171                 }
1172                 if (remove)
1173                         continue;
1174                 length = strlen(buf);
1175                 if (write_in_full(out_fd, buf, length) != length) {
1176                         ret = write_error(lock->filename);
1177                         goto out;
1178                 }
1179         }
1180         fclose(config_file);
1181  unlock_and_out:
1182         if (commit_lock_file(lock) < 0)
1183                 ret = error("could not commit config file %s", config_filename);
1184  out:
1185         free(config_filename);
1186         return ret;
1187 }
1188
1189 /*
1190  * Call this to report error for your variable that should not
1191  * get a boolean value (i.e. "[my] var" means "true").
1192  */
1193 int config_error_nonbool(const char *var)
1194 {
1195         return error("Missing value for '%s'", var);
1196 }