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) - 1)
  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                         if (len)
  66                                 space++;
  67                         continue;
  68                 }
  69                 if (!quote) {
  70                         if (c == ';' || c == '#') {
  71                                 comment = 1;
  72                                 continue;
  73                         }
  74                 }
  75                 for (; space; space--)
  76                         value[len++] = ' ';
  77                 if (c == '\\') {
  78                         c = get_next_char();
  79                         switch (c) {
  80                         case '\n':
  81                                 continue;
  82                         case 't':
  83                                 c = '\t';
  84                                 break;
  85                         case 'b':
  86                                 c = '\b';
  87                                 break;
  88                         case 'n':
  89                                 c = '\n';
  90                                 break;
  91                         /* Some characters escape as themselves */
  92                         case '\\': case '"':
  93                                 break;
  94                         /* Reject unknown escape sequences */
  95                         default:
  96                                 return NULL;
  97                         }
  98                         value[len++] = c;
  99                         continue;
 100                 }
 101                 if (c == '"') {
 102                         quote = 1-quote;
 103                         continue;
 104                 }
 105                 value[len++] = c;
 106         }
 107 }
 108
 109 static inline int iskeychar(int c)
 110 {
 111         return isalnum(c) || c == '-';
 112 }
 113
 114 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 115 {
 116         int c;
 117         char *value;
 118
 119         /* Get the full name */
 120         for (;;) {
 121                 c = get_next_char();
 122                 if (config_file_eof)
 123                         break;
 124                 if (!iskeychar(c))
 125                         break;
 126                 name[len++] = tolower(c);
 127                 if (len >= MAXNAME)
 128                         return -1;
 129         }
 130         name[len] = 0;
 131         while (c == ' ' || c == '\t')
 132                 c = get_next_char();
 133
 134         value = NULL;
 135         if (c != '\n') {
 136                 if (c != '=')
 137                         return -1;
 138                 value = parse_value();
 139                 if (!value)
 140                         return -1;
 141         }
 142         return fn(name, value, data);
 143 }
 144
 145 static int get_extended_base_var(char *name, int baselen, int c)
 146 {
 147         do {
 148                 if (c == '\n')
 149                         return -1;
 150                 c = get_next_char();
 151         } while (isspace(c));
 152
 153         /* We require the format to be '[base "extension"]' */
 154         if (c != '"')
 155                 return -1;
 156         name[baselen++] = '.';
 157
 158         for (;;) {
 159                 int c = get_next_char();
 160                 if (c == '\n')
 161                         return -1;
 162                 if (c == '"')
 163                         break;
 164                 if (c == '\\') {
 165                         c = get_next_char();
 166                         if (c == '\n')
 167                                 return -1;
 168                 }
 169                 name[baselen++] = c;
 170                 if (baselen > MAXNAME / 2)
 171                         return -1;
 172         }
 173
 174         /* Final ']' */
 175         if (get_next_char() != ']')
 176                 return -1;
 177         return baselen;
 178 }
 179
 180 static int get_base_var(char *name)
 181 {
 182         int baselen = 0;
 183
 184         for (;;) {
 185                 int c = get_next_char();
 186                 if (config_file_eof)
 187                         return -1;
 188                 if (c == ']')
 189                         return baselen;
 190                 if (isspace(c))
 191                         return get_extended_base_var(name, baselen, c);
 192                 if (!iskeychar(c) && c != '.')
 193                         return -1;
 194                 if (baselen > MAXNAME / 2)
 195                         return -1;
 196                 name[baselen++] = tolower(c);
 197         }
 198 }
 199
 200 static int git_parse_file(config_fn_t fn, void *data)
 201 {
 202         int comment = 0;
 203         int baselen = 0;
 204         static char var[MAXNAME];
 205
 206         /* U+FEFF Byte Order Mark in UTF8 */
 207         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 208         const unsigned char *bomptr = utf8_bom;
 209
 210         for (;;) {
 211                 int c = get_next_char();
 212                 if (bomptr && *bomptr) {
 213                         /* We are at the file beginning; skip UTF8-encoded BOM
 214                          * if present. Sane editors won't put this in on their
 215                          * own, but e.g. Windows Notepad will do it happily. */
 216                         if ((unsigned char) c == *bomptr) {
 217                                 bomptr++;
 218                                 continue;
 219                         } else {
 220                                 /* Do not tolerate partial BOM. */
 221                                 if (bomptr != utf8_bom)
 222                                         break;
 223                                 /* No BOM at file beginning. Cool. */
 224                                 bomptr = NULL;
 225                         }
 226                 }
 227                 if (c == '\n') {
 228                         if (config_file_eof)
 229                                 return 0;
 230                         comment = 0;
 231                         continue;
 232                 }
 233                 if (comment || isspace(c))
 234                         continue;
 235                 if (c == '#' || c == ';') {
 236                         comment = 1;
 237                         continue;
 238                 }
 239                 if (c == '[') {
 240                         baselen = get_base_var(var);
 241                         if (baselen <= 0)
 242                                 break;
 243                         var[baselen++] = '.';
 244                         var[baselen] = 0;
 245                         continue;
 246                 }
 247                 if (!isalpha(c))
 248                         break;
 249                 var[baselen] = tolower(c);
 250                 if (get_value(fn, data, var, baselen+1) < 0)
 251                         break;
 252         }
 253         die("bad config file line %d in %s", config_linenr, config_file_name);
 254 }
 255
 256 static int parse_unit_factor(const char *end, unsigned long *val)
 257 {
 258         if (!*end)
 259                 return 1;
 260         else if (!strcasecmp(end, "k")) {
 261                 *val *= 1024;
 262                 return 1;
 263         }
 264         else if (!strcasecmp(end, "m")) {
 265                 *val *= 1024 * 1024;
 266                 return 1;
 267         }
 268         else if (!strcasecmp(end, "g")) {
 269                 *val *= 1024 * 1024 * 1024;
 270                 return 1;
 271         }
 272         return 0;
 273 }
 274
 275 static int git_parse_long(const char *value, long *ret)
 276 {
 277         if (value && *value) {
 278                 char *end;
 279                 long val = strtol(value, &end, 0);
 280                 unsigned long factor = 1;
 281                 if (!parse_unit_factor(end, &factor))
 282                         return 0;
 283                 *ret = val * factor;
 284                 return 1;
 285         }
 286         return 0;
 287 }
 288
 289 int git_parse_ulong(const char *value, unsigned long *ret)
 290 {
 291         if (value && *value) {
 292                 char *end;
 293                 unsigned long val = strtoul(value, &end, 0);
 294                 if (!parse_unit_factor(end, &val))
 295                         return 0;
 296                 *ret = val;
 297                 return 1;
 298         }
 299         return 0;
 300 }
 301
 302 static void die_bad_config(const char *name)
 303 {
 304         if (config_file_name)
 305                 die("bad config value for '%s' in %s", name, config_file_name);
 306         die("bad config value for '%s'", name);
 307 }
 308
 309 int git_config_int(const char *name, const char *value)
 310 {
 311         long ret = 0;
 312         if (!git_parse_long(value, &ret))
 313                 die_bad_config(name);
 314         return ret;
 315 }
 316
 317 unsigned long git_config_ulong(const char *name, const char *value)
 318 {
 319         unsigned long ret;
 320         if (!git_parse_ulong(value, &ret))
 321                 die_bad_config(name);
 322         return ret;
 323 }
 324
 325 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 326 {
 327         *is_bool = 1;
 328         if (!value)
 329                 return 1;
 330         if (!*value)
 331                 return 0;
 332         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 333                 return 1;
 334         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 335                 return 0;
 336         *is_bool = 0;
 337         return git_config_int(name, value);
 338 }
 339
 340 int git_config_bool(const char *name, const char *value)
 341 {
 342         int discard;
 343         return !!git_config_bool_or_int(name, value, &discard);
 344 }
 345
 346 int git_config_string(const char **dest, const char *var, const char *value)
 347 {
 348         if (!value)
 349                 return config_error_nonbool(var);
 350         *dest = xstrdup(value);
 351         return 0;
 352 }
 353
 354 static int git_default_core_config(const char *var, const char *value)
 355 {
 356         /* This needs a better name */
 357         if (!strcmp(var, "core.filemode")) {
 358                 trust_executable_bit = git_config_bool(var, value);
 359                 return 0;
 360         }
 361         if (!strcmp(var, "core.trustctime")) {
 362                 trust_ctime = git_config_bool(var, value);
 363                 return 0;
 364         }
 365
 366         if (!strcmp(var, "core.quotepath")) {
 367                 quote_path_fully = git_config_bool(var, value);
 368                 return 0;
 369         }
 370
 371         if (!strcmp(var, "core.symlinks")) {
 372                 has_symlinks = git_config_bool(var, value);
 373                 return 0;
 374         }
 375
 376         if (!strcmp(var, "core.ignorecase")) {
 377                 ignore_case = git_config_bool(var, value);
 378                 return 0;
 379         }
 380
 381         if (!strcmp(var, "core.bare")) {
 382                 is_bare_repository_cfg = git_config_bool(var, value);
 383                 return 0;
 384         }
 385
 386         if (!strcmp(var, "core.ignorestat")) {
 387                 assume_unchanged = git_config_bool(var, value);
 388                 return 0;
 389         }
 390
 391         if (!strcmp(var, "core.prefersymlinkrefs")) {
 392                 prefer_symlink_refs = git_config_bool(var, value);
 393                 return 0;
 394         }
 395
 396         if (!strcmp(var, "core.logallrefupdates")) {
 397                 log_all_ref_updates = git_config_bool(var, value);
 398                 return 0;
 399         }
 400
 401         if (!strcmp(var, "core.warnambiguousrefs")) {
 402                 warn_ambiguous_refs = git_config_bool(var, value);
 403                 return 0;
 404         }
 405
 406         if (!strcmp(var, "core.loosecompression")) {
 407                 int level = git_config_int(var, value);
 408                 if (level == -1)
 409                         level = Z_DEFAULT_COMPRESSION;
 410                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 411                         die("bad zlib compression level %d", level);
 412                 zlib_compression_level = level;
 413                 zlib_compression_seen = 1;
 414                 return 0;
 415         }
 416
 417         if (!strcmp(var, "core.compression")) {
 418                 int level = git_config_int(var, value);
 419                 if (level == -1)
 420                         level = Z_DEFAULT_COMPRESSION;
 421                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 422                         die("bad zlib compression level %d", level);
 423                 core_compression_level = level;
 424                 core_compression_seen = 1;
 425                 if (!zlib_compression_seen)
 426                         zlib_compression_level = level;
 427                 return 0;
 428         }
 429
 430         if (!strcmp(var, "core.packedgitwindowsize")) {
 431                 int pgsz_x2 = getpagesize() * 2;
 432                 packed_git_window_size = git_config_int(var, value);
 433
 434                 /* This value must be multiple of (pagesize * 2) */
 435                 packed_git_window_size /= pgsz_x2;
 436                 if (packed_git_window_size < 1)
 437                         packed_git_window_size = 1;
 438                 packed_git_window_size *= pgsz_x2;
 439                 return 0;
 440         }
 441
 442         if (!strcmp(var, "core.packedgitlimit")) {
 443                 packed_git_limit = git_config_int(var, value);
 444                 return 0;
 445         }
 446
 447         if (!strcmp(var, "core.deltabasecachelimit")) {
 448                 delta_base_cache_limit = git_config_int(var, value);
 449                 return 0;
 450         }
 451
 452         if (!strcmp(var, "core.autocrlf")) {
 453                 if (value && !strcasecmp(value, "input")) {
 454                         auto_crlf = -1;
 455                         return 0;
 456                 }
 457                 auto_crlf = git_config_bool(var, value);
 458                 return 0;
 459         }
 460
 461         if (!strcmp(var, "core.safecrlf")) {
 462                 if (value && !strcasecmp(value, "warn")) {
 463                         safe_crlf = SAFE_CRLF_WARN;
 464                         return 0;
 465                 }
 466                 safe_crlf = git_config_bool(var, value);
 467                 return 0;
 468         }
 469
 470         if (!strcmp(var, "core.pager"))
 471                 return git_config_string(&pager_program, var, value);
 472
 473         if (!strcmp(var, "core.editor"))
 474                 return git_config_string(&editor_program, var, value);
 475
 476         if (!strcmp(var, "core.excludesfile"))
 477                 return git_config_string(&excludes_file, var, value);
 478
 479         if (!strcmp(var, "core.whitespace")) {
 480                 if (!value)
 481                         return config_error_nonbool(var);
 482                 whitespace_rule_cfg = parse_whitespace_rule(value);
 483                 return 0;
 484         }
 485
 486         if (!strcmp(var, "core.fsyncobjectfiles")) {
 487                 fsync_object_files = git_config_bool(var, value);
 488                 return 0;
 489         }
 490
 491         if (!strcmp(var, "core.preloadindex")) {
 492                 core_preload_index = git_config_bool(var, value);
 493                 return 0;
 494         }
 495
 496         if (!strcmp(var, "core.createobject")) {
 497                 if (!strcmp(value, "rename"))
 498                         object_creation_mode = OBJECT_CREATION_USES_RENAMES;
 499                 else if (!strcmp(value, "link"))
 500                         object_creation_mode = OBJECT_CREATION_USES_HARDLINKS;
 501                 else
 502                         die("Invalid mode for object creation: %s", value);
 503                 return 0;
 504         }
 505
 506         /* Add other config variables here and to Documentation/config.txt. */
 507         return 0;
 508 }
 509
 510 static int git_default_user_config(const char *var, const char *value)
 511 {
 512         if (!strcmp(var, "user.name")) {
 513                 if (!value)
 514                         return config_error_nonbool(var);
 515                 strlcpy(git_default_name, value, sizeof(git_default_name));
 516                 if (git_default_email[0])
 517                         user_ident_explicitly_given = 1;
 518                 return 0;
 519         }
 520
 521         if (!strcmp(var, "user.email")) {
 522                 if (!value)
 523                         return config_error_nonbool(var);
 524                 strlcpy(git_default_email, value, sizeof(git_default_email));
 525                 if (git_default_name[0])
 526                         user_ident_explicitly_given = 1;
 527                 return 0;
 528         }
 529
 530         /* Add other config variables here and to Documentation/config.txt. */
 531         return 0;
 532 }
 533
 534 static int git_default_i18n_config(const char *var, const char *value)
 535 {
 536         if (!strcmp(var, "i18n.commitencoding"))
 537                 return git_config_string(&git_commit_encoding, var, value);
 538
 539         if (!strcmp(var, "i18n.logoutputencoding"))
 540                 return git_config_string(&git_log_output_encoding, var, value);
 541
 542         /* Add other config variables here and to Documentation/config.txt. */
 543         return 0;
 544 }
 545
 546 static int git_default_branch_config(const char *var, const char *value)
 547 {
 548         if (!strcmp(var, "branch.autosetupmerge")) {
 549                 if (value && !strcasecmp(value, "always")) {
 550                         git_branch_track = BRANCH_TRACK_ALWAYS;
 551                         return 0;
 552                 }
 553                 git_branch_track = git_config_bool(var, value);
 554                 return 0;
 555         }
 556         if (!strcmp(var, "branch.autosetuprebase")) {
 557                 if (!value)
 558                         return config_error_nonbool(var);
 559                 else if (!strcmp(value, "never"))
 560                         autorebase = AUTOREBASE_NEVER;
 561                 else if (!strcmp(value, "local"))
 562                         autorebase = AUTOREBASE_LOCAL;
 563                 else if (!strcmp(value, "remote"))
 564                         autorebase = AUTOREBASE_REMOTE;
 565                 else if (!strcmp(value, "always"))
 566                         autorebase = AUTOREBASE_ALWAYS;
 567                 else
 568                         return error("Malformed value for %s", var);
 569                 return 0;
 570         }
 571
 572         /* Add other config variables here and to Documentation/config.txt. */
 573         return 0;
 574 }
 575
 576 static int git_default_push_config(const char *var, const char *value)
 577 {
 578         if (!strcmp(var, "push.default")) {
 579                 if (!value)
 580                         return config_error_nonbool(var);
 581                 else if (!strcmp(value, "nothing"))
 582                         push_default = PUSH_DEFAULT_NOTHING;
 583                 else if (!strcmp(value, "matching"))
 584                         push_default = PUSH_DEFAULT_MATCHING;
 585                 else if (!strcmp(value, "tracking"))
 586                         push_default = PUSH_DEFAULT_TRACKING;
 587                 else if (!strcmp(value, "current"))
 588                         push_default = PUSH_DEFAULT_CURRENT;
 589                 else {
 590                         error("Malformed value for %s: %s", var, value);
 591                         return error("Must be one of nothing, matching, "
 592                                      "tracking or current.");
 593                 }
 594                 return 0;
 595         }
 596
 597         /* Add other config variables here and to Documentation/config.txt. */
 598         return 0;
 599 }
 600
 601 static int git_default_mailmap_config(const char *var, const char *value)
 602 {
 603         if (!strcmp(var, "mailmap.file"))
 604                 return git_config_string(&git_mailmap_file, var, value);
 605
 606         /* Add other config variables here and to Documentation/config.txt. */
 607         return 0;
 608 }
 609
 610 int git_default_config(const char *var, const char *value, void *dummy)
 611 {
 612         if (!prefixcmp(var, "core."))
 613                 return git_default_core_config(var, value);
 614
 615         if (!prefixcmp(var, "user."))
 616                 return git_default_user_config(var, value);
 617
 618         if (!prefixcmp(var, "i18n."))
 619                 return git_default_i18n_config(var, value);
 620
 621         if (!prefixcmp(var, "branch."))
 622                 return git_default_branch_config(var, value);
 623
 624         if (!prefixcmp(var, "push."))
 625                 return git_default_push_config(var, value);
 626
 627         if (!prefixcmp(var, "mailmap."))
 628                 return git_default_mailmap_config(var, value);
 629
 630         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 631                 pager_use_color = git_config_bool(var,value);
 632                 return 0;
 633         }
 634
 635         /* Add other config variables here and to Documentation/config.txt. */
 636         return 0;
 637 }
 638
 639 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 640 {
 641         int ret;
 642         FILE *f = fopen(filename, "r");
 643
 644         ret = -1;
 645         if (f) {
 646                 config_file = f;
 647                 config_file_name = filename;
 648                 config_linenr = 1;
 649                 config_file_eof = 0;
 650                 ret = git_parse_file(fn, data);
 651                 fclose(f);
 652                 config_file_name = NULL;
 653         }
 654         return ret;
 655 }
 656
 657 const char *git_etc_gitconfig(void)
 658 {
 659         static const char *system_wide;
 660         if (!system_wide)
 661                 system_wide = system_path(ETC_GITCONFIG);
 662         return system_wide;
 663 }
 664
 665 static int git_env_bool(const char *k, int def)
 666 {
 667         const char *v = getenv(k);
 668         return v ? git_config_bool(k, v) : def;
 669 }
 670
 671 int git_config_system(void)
 672 {
 673         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 674 }
 675
 676 int git_config_global(void)
 677 {
 678         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 679 }
 680
 681 int git_config(config_fn_t fn, void *data)
 682 {
 683         int ret = 0, found = 0;
 684         char *repo_config = NULL;
 685         const char *home = NULL;
 686
 687         /* Setting $GIT_CONFIG makes git read _only_ the given config file. */
 688         if (config_exclusive_filename)
 689                 return git_config_from_file(fn, config_exclusive_filename, data);
 690         if (git_config_system() && !access(git_etc_gitconfig(), R_OK)) {
 691                 ret += git_config_from_file(fn, git_etc_gitconfig(),
 692                                             data);
 693                 found += 1;
 694         }
 695
 696         home = getenv("HOME");
 697         if (git_config_global() && home) {
 698                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 699                 if (!access(user_config, R_OK)) {
 700                         ret += git_config_from_file(fn, user_config, data);
 701                         found += 1;
 702                 }
 703                 free(user_config);
 704         }
 705
 706         repo_config = git_pathdup("config");
 707         if (!access(repo_config, R_OK)) {
 708                 ret += git_config_from_file(fn, repo_config, data);
 709                 found += 1;
 710         }
 711         free(repo_config);
 712         if (found == 0)
 713                 return -1;
 714         return ret;
 715 }
 716
 717 /*
 718  * Find all the stuff for git_config_set() below.
 719  */
 720
 721 #define MAX_MATCHES 512
 722
 723 static struct {
 724         int baselen;
 725         char *key;
 726         int do_not_match;
 727         regex_t *value_regex;
 728         int multi_replace;
 729         size_t offset[MAX_MATCHES];
 730         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 731         int seen;
 732 } store;
 733
 734 static int matches(const char *key, const char *value)
 735 {
 736         return !strcmp(key, store.key) &&
 737                 (store.value_regex == NULL ||
 738                  (store.do_not_match ^
 739                   !regexec(store.value_regex, value, 0, NULL, 0)));
 740 }
 741
 742 static int store_aux(const char *key, const char *value, void *cb)
 743 {
 744         const char *ep;
 745         size_t section_len;
 746
 747         switch (store.state) {
 748         case KEY_SEEN:
 749                 if (matches(key, value)) {
 750                         if (store.seen == 1 && store.multi_replace == 0) {
 751                                 warning("%s has multiple values", key);
 752                         } else if (store.seen >= MAX_MATCHES) {
 753                                 error("too many matches for %s", key);
 754                                 return 1;
 755                         }
 756
 757                         store.offset[store.seen] = ftell(config_file);
 758                         store.seen++;
 759                 }
 760                 break;
 761         case SECTION_SEEN:
 762                 /*
 763                  * What we are looking for is in store.key (both
 764                  * section and var), and its section part is baselen
 765                  * long.  We found key (again, both section and var).
 766                  * We would want to know if this key is in the same
 767                  * section as what we are looking for.  We already
 768                  * know we are in the same section as what should
 769                  * hold store.key.
 770                  */
 771                 ep = strrchr(key, '.');
 772                 section_len = ep - key;
 773
 774                 if ((section_len != store.baselen) ||
 775                     memcmp(key, store.key, section_len+1)) {
 776                         store.state = SECTION_END_SEEN;
 777                         break;
 778                 }
 779
 780                 /*
 781                  * Do not increment matches: this is no match, but we
 782                  * just made sure we are in the desired section.
 783                  */
 784                 store.offset[store.seen] = ftell(config_file);
 785                 /* fallthru */
 786         case SECTION_END_SEEN:
 787         case START:
 788                 if (matches(key, value)) {
 789                         store.offset[store.seen] = ftell(config_file);
 790                         store.state = KEY_SEEN;
 791                         store.seen++;
 792                 } else {
 793                         if (strrchr(key, '.') - key == store.baselen &&
 794                               !strncmp(key, store.key, store.baselen)) {
 795                                         store.state = SECTION_SEEN;
 796                                         store.offset[store.seen] = ftell(config_file);
 797                         }
 798                 }
 799         }
 800         return 0;
 801 }
 802
 803 static int write_error(const char *filename)
 804 {
 805         error("failed to write new configuration file %s", filename);
 806
 807         /* Same error code as "failed to rename". */
 808         return 4;
 809 }
 810
 811 static int store_write_section(int fd, const char *key)
 812 {
 813         const char *dot;
 814         int i, success;
 815         struct strbuf sb = STRBUF_INIT;
 816
 817         dot = memchr(key, '.', store.baselen);
 818         if (dot) {
 819                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 820                 for (i = dot - key + 1; i < store.baselen; i++) {
 821                         if (key[i] == '"' || key[i] == '\\')
 822                                 strbuf_addch(&sb, '\\');
 823                         strbuf_addch(&sb, key[i]);
 824                 }
 825                 strbuf_addstr(&sb, "\"]\n");
 826         } else {
 827                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 828         }
 829
 830         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 831         strbuf_release(&sb);
 832
 833         return success;
 834 }
 835
 836 static int store_write_pair(int fd, const char *key, const char *value)
 837 {
 838         int i, success;
 839         int length = strlen(key + store.baselen + 1);
 840         const char *quote = "";
 841         struct strbuf sb = STRBUF_INIT;
 842
 843         /*
 844          * Check to see if the value needs to be surrounded with a dq pair.
 845          * Note that problematic characters are always backslash-quoted; this
 846          * check is about not losing leading or trailing SP and strings that
 847          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 848          * configuration parser.
 849          */
 850         if (value[0] == ' ')
 851                 quote = "\"";
 852         for (i = 0; value[i]; i++)
 853                 if (value[i] == ';' || value[i] == '#')
 854                         quote = "\"";
 855         if (i && value[i - 1] == ' ')
 856                 quote = "\"";
 857
 858         strbuf_addf(&sb, "\t%.*s = %s",
 859                     length, key + store.baselen + 1, quote);
 860
 861         for (i = 0; value[i]; i++)
 862                 switch (value[i]) {
 863                 case '\n':
 864                         strbuf_addstr(&sb, "\\n");
 865                         break;
 866                 case '\t':
 867                         strbuf_addstr(&sb, "\\t");
 868                         break;
 869                 case '"':
 870                 case '\\':
 871                         strbuf_addch(&sb, '\\');
 872                 default:
 873                         strbuf_addch(&sb, value[i]);
 874                         break;
 875                 }
 876         strbuf_addf(&sb, "%s\n", quote);
 877
 878         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 879         strbuf_release(&sb);
 880
 881         return success;
 882 }
 883
 884 static ssize_t find_beginning_of_line(const char *contents, size_t size,
 885         size_t offset_, int *found_bracket)
 886 {
 887         size_t equal_offset = size, bracket_offset = size;
 888         ssize_t offset;
 889
 890 contline:
 891         for (offset = offset_-2; offset > 0
 892                         && contents[offset] != '\n'; offset--)
 893                 switch (contents[offset]) {
 894                         case '=': equal_offset = offset; break;
 895                         case ']': bracket_offset = offset; break;
 896                 }
 897         if (offset > 0 && contents[offset-1] == '\\') {
 898                 offset_ = offset;
 899                 goto contline;
 900         }
 901         if (bracket_offset < equal_offset) {
 902                 *found_bracket = 1;
 903                 offset = bracket_offset+1;
 904         } else
 905                 offset++;
 906
 907         return offset;
 908 }
 909
 910 int git_config_set(const char *key, const char *value)
 911 {
 912         return git_config_set_multivar(key, value, NULL, 0);
 913 }
 914
 915 /*
 916  * If value==NULL, unset in (remove from) config,
 917  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 918  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 919  *     else all matching key/values (regardless how many) are removed,
 920  *     before the new pair is written.
 921  *
 922  * Returns 0 on success.
 923  *
 924  * This function does this:
 925  *
 926  * - it locks the config file by creating ".git/config.lock"
 927  *
 928  * - it then parses the config using store_aux() as validator to find
 929  *   the position on the key/value pair to replace. If it is to be unset,
 930  *   it must be found exactly once.
 931  *
 932  * - the config file is mmap()ed and the part before the match (if any) is
 933  *   written to the lock file, then the changed part and the rest.
 934  *
 935  * - the config file is removed and the lock file rename()d to it.
 936  *
 937  */
 938 int git_config_set_multivar(const char *key, const char *value,
 939         const char *value_regex, int multi_replace)
 940 {
 941         int i, dot;
 942         int fd = -1, in_fd;
 943         int ret;
 944         char *config_filename;
 945         struct lock_file *lock = NULL;
 946         const char *last_dot = strrchr(key, '.');
 947
 948         if (config_exclusive_filename)
 949                 config_filename = xstrdup(config_exclusive_filename);
 950         else
 951                 config_filename = git_pathdup("config");
 952
 953         /*
 954          * Since "key" actually contains the section name and the real
 955          * key name separated by a dot, we have to know where the dot is.
 956          */
 957
 958         if (last_dot == NULL) {
 959                 error("key does not contain a section: %s", key);
 960                 ret = 2;
 961                 goto out_free;
 962         }
 963         store.baselen = last_dot - key;
 964
 965         store.multi_replace = multi_replace;
 966
 967         /*
 968          * Validate the key and while at it, lower case it for matching.
 969          */
 970         store.key = xmalloc(strlen(key) + 1);
 971         dot = 0;
 972         for (i = 0; key[i]; i++) {
 973                 unsigned char c = key[i];
 974                 if (c == '.')
 975                         dot = 1;
 976                 /* Leave the extended basename untouched.. */
 977                 if (!dot || i > store.baselen) {
 978                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 979                                 error("invalid key: %s", key);
 980                                 free(store.key);
 981                                 ret = 1;
 982                                 goto out_free;
 983                         }
 984                         c = tolower(c);
 985                 } else if (c == '\n') {
 986                         error("invalid key (newline): %s", key);
 987                         free(store.key);
 988                         ret = 1;
 989                         goto out_free;
 990                 }
 991                 store.key[i] = c;
 992         }
 993         store.key[i] = 0;
 994
 995         /*
 996          * The lock serves a purpose in addition to locking: the new
 997          * contents of .git/config will be written into it.
 998          */
 999         lock = xcalloc(sizeof(struct lock_file), 1);
1000         fd = hold_lock_file_for_update(lock, config_filename, 0);
1001         if (fd < 0) {
1002                 error("could not lock config file %s: %s", config_filename, strerror(errno));
1003                 free(store.key);
1004                 ret = -1;
1005                 goto out_free;
1006         }
1007
1008         /*
1009          * If .git/config does not exist yet, write a minimal version.
1010          */
1011         in_fd = open(config_filename, O_RDONLY);
1012         if ( in_fd < 0 ) {
1013                 free(store.key);
1014
1015                 if ( ENOENT != errno ) {
1016                         error("opening %s: %s", config_filename,
1017                               strerror(errno));
1018                         ret = 3; /* same as "invalid config file" */
1019                         goto out_free;
1020                 }
1021                 /* if nothing to unset, error out */
1022                 if (value == NULL) {
1023                         ret = 5;
1024                         goto out_free;
1025                 }
1026
1027                 store.key = (char *)key;
1028                 if (!store_write_section(fd, key) ||
1029                     !store_write_pair(fd, key, value))
1030                         goto write_err_out;
1031         } else {
1032                 struct stat st;
1033                 char *contents;
1034                 size_t contents_sz, copy_begin, copy_end;
1035                 int i, new_line = 0;
1036
1037                 if (value_regex == NULL)
1038                         store.value_regex = NULL;
1039                 else {
1040                         if (value_regex[0] == '!') {
1041                                 store.do_not_match = 1;
1042                                 value_regex++;
1043                         } else
1044                                 store.do_not_match = 0;
1045
1046                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
1047                         if (regcomp(store.value_regex, value_regex,
1048                                         REG_EXTENDED)) {
1049                                 error("invalid pattern: %s", value_regex);
1050                                 free(store.value_regex);
1051                                 ret = 6;
1052                                 goto out_free;
1053                         }
1054                 }
1055
1056                 store.offset[0] = 0;
1057                 store.state = START;
1058                 store.seen = 0;
1059
1060                 /*
1061                  * After this, store.offset will contain the *end* offset
1062                  * of the last match, or remain at 0 if no match was found.
1063                  * As a side effect, we make sure to transform only a valid
1064                  * existing config file.
1065                  */
1066                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1067                         error("invalid config file %s", config_filename);
1068                         free(store.key);
1069                         if (store.value_regex != NULL) {
1070                                 regfree(store.value_regex);
1071                                 free(store.value_regex);
1072                         }
1073                         ret = 3;
1074                         goto out_free;
1075                 }
1076
1077                 free(store.key);
1078                 if (store.value_regex != NULL) {
1079                         regfree(store.value_regex);
1080                         free(store.value_regex);
1081                 }
1082
1083                 /* if nothing to unset, or too many matches, error out */
1084                 if ((store.seen == 0 && value == NULL) ||
1085                                 (store.seen > 1 && multi_replace == 0)) {
1086                         ret = 5;
1087                         goto out_free;
1088                 }
1089
1090                 fstat(in_fd, &st);
1091                 contents_sz = xsize_t(st.st_size);
1092                 contents = xmmap(NULL, contents_sz, PROT_READ,
1093                         MAP_PRIVATE, in_fd, 0);
1094                 close(in_fd);
1095
1096                 if (store.seen == 0)
1097                         store.seen = 1;
1098
1099                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1100                         if (store.offset[i] == 0) {
1101                                 store.offset[i] = copy_end = contents_sz;
1102                         } else if (store.state != KEY_SEEN) {
1103                                 copy_end = store.offset[i];
1104                         } else
1105                                 copy_end = find_beginning_of_line(
1106                                         contents, contents_sz,
1107                                         store.offset[i]-2, &new_line);
1108
1109                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1110                                 new_line = 1;
1111
1112                         /* write the first part of the config */
1113                         if (copy_end > copy_begin) {
1114                                 if (write_in_full(fd, contents + copy_begin,
1115                                                   copy_end - copy_begin) <
1116                                     copy_end - copy_begin)
1117                                         goto write_err_out;
1118                                 if (new_line &&
1119                                     write_in_full(fd, "\n", 1) != 1)
1120                                         goto write_err_out;
1121                         }
1122                         copy_begin = store.offset[i];
1123                 }
1124
1125                 /* write the pair (value == NULL means unset) */
1126                 if (value != NULL) {
1127                         if (store.state == START) {
1128                                 if (!store_write_section(fd, key))
1129                                         goto write_err_out;
1130                         }
1131                         if (!store_write_pair(fd, key, value))
1132                                 goto write_err_out;
1133                 }
1134
1135                 /* write the rest of the config */
1136                 if (copy_begin < contents_sz)
1137                         if (write_in_full(fd, contents + copy_begin,
1138                                           contents_sz - copy_begin) <
1139                             contents_sz - copy_begin)
1140                                 goto write_err_out;
1141
1142                 munmap(contents, contents_sz);
1143         }
1144
1145         if (commit_lock_file(lock) < 0) {
1146                 error("could not commit config file %s", config_filename);
1147                 ret = 4;
1148                 goto out_free;
1149         }
1150
1151         /*
1152          * lock is committed, so don't try to roll it back below.
1153          * NOTE: Since lockfile.c keeps a linked list of all created
1154          * lock_file structures, it isn't safe to free(lock).  It's
1155          * better to just leave it hanging around.
1156          */
1157         lock = NULL;
1158         ret = 0;
1159
1160 out_free:
1161         if (lock)
1162                 rollback_lock_file(lock);
1163         free(config_filename);
1164         return ret;
1165
1166 write_err_out:
1167         ret = write_error(lock->filename);
1168         goto out_free;
1169
1170 }
1171
1172 static int section_name_match (const char *buf, const char *name)
1173 {
1174         int i = 0, j = 0, dot = 0;
1175         for (; buf[i] && buf[i] != ']'; i++) {
1176                 if (!dot && isspace(buf[i])) {
1177                         dot = 1;
1178                         if (name[j++] != '.')
1179                                 break;
1180                         for (i++; isspace(buf[i]); i++)
1181                                 ; /* do nothing */
1182                         if (buf[i] != '"')
1183                                 break;
1184                         continue;
1185                 }
1186                 if (buf[i] == '\\' && dot)
1187                         i++;
1188                 else if (buf[i] == '"' && dot) {
1189                         for (i++; isspace(buf[i]); i++)
1190                                 ; /* do_nothing */
1191                         break;
1192                 }
1193                 if (buf[i] != name[j++])
1194                         break;
1195         }
1196         return (buf[i] == ']' && name[j] == 0);
1197 }
1198
1199 /* if new_name == NULL, the section is removed instead */
1200 int git_config_rename_section(const char *old_name, const char *new_name)
1201 {
1202         int ret = 0, remove = 0;
1203         char *config_filename;
1204         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1205         int out_fd;
1206         char buf[1024];
1207
1208         if (config_exclusive_filename)
1209                 config_filename = xstrdup(config_exclusive_filename);
1210         else
1211                 config_filename = git_pathdup("config");
1212         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1213         if (out_fd < 0) {
1214                 ret = error("could not lock config file %s", config_filename);
1215                 goto out;
1216         }
1217
1218         if (!(config_file = fopen(config_filename, "rb"))) {
1219                 /* no config file means nothing to rename, no error */
1220                 goto unlock_and_out;
1221         }
1222
1223         while (fgets(buf, sizeof(buf), config_file)) {
1224                 int i;
1225                 int length;
1226                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1227                         ; /* do nothing */
1228                 if (buf[i] == '[') {
1229                         /* it's a section */
1230                         if (section_name_match (&buf[i+1], old_name)) {
1231                                 ret++;
1232                                 if (new_name == NULL) {
1233                                         remove = 1;
1234                                         continue;
1235                                 }
1236                                 store.baselen = strlen(new_name);
1237                                 if (!store_write_section(out_fd, new_name)) {
1238                                         ret = write_error(lock->filename);
1239                                         goto out;
1240                                 }
1241                                 continue;
1242                         }
1243                         remove = 0;
1244                 }
1245                 if (remove)
1246                         continue;
1247                 length = strlen(buf);
1248                 if (write_in_full(out_fd, buf, length) != length) {
1249                         ret = write_error(lock->filename);
1250                         goto out;
1251                 }
1252         }
1253         fclose(config_file);
1254  unlock_and_out:
1255         if (commit_lock_file(lock) < 0)
1256                 ret = error("could not commit config file %s", config_filename);
1257  out:
1258         free(config_filename);
1259         return ret;
1260 }
1261
1262 /*
1263  * Call this to report error for your variable that should not
1264  * get a boolean value (i.e. "[my] var" means "true").
1265  */
1266 int config_error_nonbool(const char *var)
1267 {
1268         return error("Missing value for '%s'", var);
1269 }