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 static int get_next_char(void)
  20 {
  21         int c;
  22         FILE *f;
  23
  24         c = '\n';
  25         if ((f = config_file) != NULL) {
  26                 c = fgetc(f);
  27                 if (c == '\r') {
  28                         /* DOS like systems */
  29                         c = fgetc(f);
  30                         if (c != '\n') {
  31                                 ungetc(c, f);
  32                                 c = '\r';
  33                         }
  34                 }
  35                 if (c == '\n')
  36                         config_linenr++;
  37                 if (c == EOF) {
  38                         config_file_eof = 1;
  39                         c = '\n';
  40                 }
  41         }
  42         return c;
  43 }
  44
  45 static char *parse_value(void)
  46 {
  47         static char value[1024];
  48         int quote = 0, comment = 0, len = 0, space = 0;
  49
  50         for (;;) {
  51                 int c = get_next_char();
  52                 if (len >= sizeof(value))
  53                         return NULL;
  54                 if (c == '\n') {
  55                         if (quote)
  56                                 return NULL;
  57                         value[len] = 0;
  58                         return value;
  59                 }
  60                 if (comment)
  61                         continue;
  62                 if (isspace(c) && !quote) {
  63                         space = 1;
  64                         continue;
  65                 }
  66                 if (!quote) {
  67                         if (c == ';' || c == '#') {
  68                                 comment = 1;
  69                                 continue;
  70                         }
  71                 }
  72                 if (space) {
  73                         if (len)
  74                                 value[len++] = ' ';
  75                         space = 0;
  76                 }
  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         for (;;) {
 207                 int c = get_next_char();
 208                 if (c == '\n') {
 209                         if (config_file_eof)
 210                                 return 0;
 211                         comment = 0;
 212                         continue;
 213                 }
 214                 if (comment || isspace(c))
 215                         continue;
 216                 if (c == '#' || c == ';') {
 217                         comment = 1;
 218                         continue;
 219                 }
 220                 if (c == '[') {
 221                         baselen = get_base_var(var);
 222                         if (baselen <= 0)
 223                                 break;
 224                         var[baselen++] = '.';
 225                         var[baselen] = 0;
 226                         continue;
 227                 }
 228                 if (!isalpha(c))
 229                         break;
 230                 var[baselen] = tolower(c);
 231                 if (get_value(fn, data, var, baselen+1) < 0)
 232                         break;
 233         }
 234         die("bad config file line %d in %s", config_linenr, config_file_name);
 235 }
 236
 237 static int parse_unit_factor(const char *end, unsigned long *val)
 238 {
 239         if (!*end)
 240                 return 1;
 241         else if (!strcasecmp(end, "k")) {
 242                 *val *= 1024;
 243                 return 1;
 244         }
 245         else if (!strcasecmp(end, "m")) {
 246                 *val *= 1024 * 1024;
 247                 return 1;
 248         }
 249         else if (!strcasecmp(end, "g")) {
 250                 *val *= 1024 * 1024 * 1024;
 251                 return 1;
 252         }
 253         return 0;
 254 }
 255
 256 int git_parse_long(const char *value, long *ret)
 257 {
 258         if (value && *value) {
 259                 char *end;
 260                 long val = strtol(value, &end, 0);
 261                 unsigned long factor = 1;
 262                 if (!parse_unit_factor(end, &factor))
 263                         return 0;
 264                 *ret = val * factor;
 265                 return 1;
 266         }
 267         return 0;
 268 }
 269
 270 int git_parse_ulong(const char *value, unsigned long *ret)
 271 {
 272         if (value && *value) {
 273                 char *end;
 274                 unsigned long val = strtoul(value, &end, 0);
 275                 if (!parse_unit_factor(end, &val))
 276                         return 0;
 277                 *ret = val;
 278                 return 1;
 279         }
 280         return 0;
 281 }
 282
 283 static void die_bad_config(const char *name)
 284 {
 285         if (config_file_name)
 286                 die("bad config value for '%s' in %s", name, config_file_name);
 287         die("bad config value for '%s'", name);
 288 }
 289
 290 int git_config_int(const char *name, const char *value)
 291 {
 292         long ret;
 293         if (!git_parse_long(value, &ret))
 294                 die_bad_config(name);
 295         return ret;
 296 }
 297
 298 unsigned long git_config_ulong(const char *name, const char *value)
 299 {
 300         unsigned long ret;
 301         if (!git_parse_ulong(value, &ret))
 302                 die_bad_config(name);
 303         return ret;
 304 }
 305
 306 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 307 {
 308         *is_bool = 1;
 309         if (!value)
 310                 return 1;
 311         if (!*value)
 312                 return 0;
 313         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 314                 return 1;
 315         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 316                 return 0;
 317         *is_bool = 0;
 318         return git_config_int(name, value);
 319 }
 320
 321 int git_config_bool(const char *name, const char *value)
 322 {
 323         int discard;
 324         return !!git_config_bool_or_int(name, value, &discard);
 325 }
 326
 327 int git_config_string(const char **dest, const char *var, const char *value)
 328 {
 329         if (!value)
 330                 return config_error_nonbool(var);
 331         *dest = xstrdup(value);
 332         return 0;
 333 }
 334
 335 static int git_default_core_config(const char *var, const char *value)
 336 {
 337         /* This needs a better name */
 338         if (!strcmp(var, "core.filemode")) {
 339                 trust_executable_bit = git_config_bool(var, value);
 340                 return 0;
 341         }
 342
 343         if (!strcmp(var, "core.quotepath")) {
 344                 quote_path_fully = git_config_bool(var, value);
 345                 return 0;
 346         }
 347
 348         if (!strcmp(var, "core.symlinks")) {
 349                 has_symlinks = git_config_bool(var, value);
 350                 return 0;
 351         }
 352
 353         if (!strcmp(var, "core.ignorecase")) {
 354                 ignore_case = git_config_bool(var, value);
 355                 return 0;
 356         }
 357
 358         if (!strcmp(var, "core.bare")) {
 359                 is_bare_repository_cfg = git_config_bool(var, value);
 360                 return 0;
 361         }
 362
 363         if (!strcmp(var, "core.ignorestat")) {
 364                 assume_unchanged = git_config_bool(var, value);
 365                 return 0;
 366         }
 367
 368         if (!strcmp(var, "core.prefersymlinkrefs")) {
 369                 prefer_symlink_refs = git_config_bool(var, value);
 370                 return 0;
 371         }
 372
 373         if (!strcmp(var, "core.logallrefupdates")) {
 374                 log_all_ref_updates = git_config_bool(var, value);
 375                 return 0;
 376         }
 377
 378         if (!strcmp(var, "core.warnambiguousrefs")) {
 379                 warn_ambiguous_refs = git_config_bool(var, value);
 380                 return 0;
 381         }
 382
 383         if (!strcmp(var, "core.loosecompression")) {
 384                 int level = git_config_int(var, value);
 385                 if (level == -1)
 386                         level = Z_DEFAULT_COMPRESSION;
 387                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 388                         die("bad zlib compression level %d", level);
 389                 zlib_compression_level = level;
 390                 zlib_compression_seen = 1;
 391                 return 0;
 392         }
 393
 394         if (!strcmp(var, "core.compression")) {
 395                 int level = git_config_int(var, value);
 396                 if (level == -1)
 397                         level = Z_DEFAULT_COMPRESSION;
 398                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 399                         die("bad zlib compression level %d", level);
 400                 core_compression_level = level;
 401                 core_compression_seen = 1;
 402                 if (!zlib_compression_seen)
 403                         zlib_compression_level = level;
 404                 return 0;
 405         }
 406
 407         if (!strcmp(var, "core.packedgitwindowsize")) {
 408                 int pgsz_x2 = getpagesize() * 2;
 409                 packed_git_window_size = git_config_int(var, value);
 410
 411                 /* This value must be multiple of (pagesize * 2) */
 412                 packed_git_window_size /= pgsz_x2;
 413                 if (packed_git_window_size < 1)
 414                         packed_git_window_size = 1;
 415                 packed_git_window_size *= pgsz_x2;
 416                 return 0;
 417         }
 418
 419         if (!strcmp(var, "core.packedgitlimit")) {
 420                 packed_git_limit = git_config_int(var, value);
 421                 return 0;
 422         }
 423
 424         if (!strcmp(var, "core.deltabasecachelimit")) {
 425                 delta_base_cache_limit = git_config_int(var, value);
 426                 return 0;
 427         }
 428
 429         if (!strcmp(var, "core.autocrlf")) {
 430                 if (value && !strcasecmp(value, "input")) {
 431                         auto_crlf = -1;
 432                         return 0;
 433                 }
 434                 auto_crlf = git_config_bool(var, value);
 435                 return 0;
 436         }
 437
 438         if (!strcmp(var, "core.safecrlf")) {
 439                 if (value && !strcasecmp(value, "warn")) {
 440                         safe_crlf = SAFE_CRLF_WARN;
 441                         return 0;
 442                 }
 443                 safe_crlf = git_config_bool(var, value);
 444                 return 0;
 445         }
 446
 447         if (!strcmp(var, "core.pager"))
 448                 return git_config_string(&pager_program, var, value);
 449
 450         if (!strcmp(var, "core.editor"))
 451                 return git_config_string(&editor_program, var, value);
 452
 453         if (!strcmp(var, "core.excludesfile"))
 454                 return git_config_string(&excludes_file, var, value);
 455
 456         if (!strcmp(var, "core.whitespace")) {
 457                 if (!value)
 458                         return config_error_nonbool(var);
 459                 whitespace_rule_cfg = parse_whitespace_rule(value);
 460                 return 0;
 461         }
 462
 463         /* Add other config variables here and to Documentation/config.txt. */
 464         return 0;
 465 }
 466
 467 static int git_default_user_config(const char *var, const char *value)
 468 {
 469         if (!strcmp(var, "user.name")) {
 470                 if (!value)
 471                         return config_error_nonbool(var);
 472                 strlcpy(git_default_name, value, sizeof(git_default_name));
 473                 if (git_default_email[0])
 474                         user_ident_explicitly_given = 1;
 475                 return 0;
 476         }
 477
 478         if (!strcmp(var, "user.email")) {
 479                 if (!value)
 480                         return config_error_nonbool(var);
 481                 strlcpy(git_default_email, value, sizeof(git_default_email));
 482                 if (git_default_name[0])
 483                         user_ident_explicitly_given = 1;
 484                 return 0;
 485         }
 486
 487         /* Add other config variables here and to Documentation/config.txt. */
 488         return 0;
 489 }
 490
 491 static int git_default_i18n_config(const char *var, const char *value)
 492 {
 493         if (!strcmp(var, "i18n.commitencoding"))
 494                 return git_config_string(&git_commit_encoding, var, value);
 495
 496         if (!strcmp(var, "i18n.logoutputencoding"))
 497                 return git_config_string(&git_log_output_encoding, var, value);
 498
 499         /* Add other config variables here and to Documentation/config.txt. */
 500         return 0;
 501 }
 502
 503 static int git_default_branch_config(const char *var, const char *value)
 504 {
 505         if (!strcmp(var, "branch.autosetupmerge")) {
 506                 if (value && !strcasecmp(value, "always")) {
 507                         git_branch_track = BRANCH_TRACK_ALWAYS;
 508                         return 0;
 509                 }
 510                 git_branch_track = git_config_bool(var, value);
 511                 return 0;
 512         }
 513         if (!strcmp(var, "branch.autosetuprebase")) {
 514                 if (!value)
 515                         return config_error_nonbool(var);
 516                 else if (!strcmp(value, "never"))
 517                         autorebase = AUTOREBASE_NEVER;
 518                 else if (!strcmp(value, "local"))
 519                         autorebase = AUTOREBASE_LOCAL;
 520                 else if (!strcmp(value, "remote"))
 521                         autorebase = AUTOREBASE_REMOTE;
 522                 else if (!strcmp(value, "always"))
 523                         autorebase = AUTOREBASE_ALWAYS;
 524                 else
 525                         return error("Malformed value for %s", var);
 526                 return 0;
 527         }
 528
 529         /* Add other config variables here and to Documentation/config.txt. */
 530         return 0;
 531 }
 532
 533 int git_default_config(const char *var, const char *value, void *dummy)
 534 {
 535         if (!prefixcmp(var, "core."))
 536                 return git_default_core_config(var, value);
 537
 538         if (!prefixcmp(var, "user."))
 539                 return git_default_user_config(var, value);
 540
 541         if (!prefixcmp(var, "i18n."))
 542                 return git_default_i18n_config(var, value);
 543
 544         if (!prefixcmp(var, "branch."))
 545                 return git_default_branch_config(var, value);
 546
 547         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 548                 pager_use_color = git_config_bool(var,value);
 549                 return 0;
 550         }
 551
 552         /* Add other config variables here and to Documentation/config.txt. */
 553         return 0;
 554 }
 555
 556 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 557 {
 558         int ret;
 559         FILE *f = fopen(filename, "r");
 560
 561         ret = -1;
 562         if (f) {
 563                 config_file = f;
 564                 config_file_name = filename;
 565                 config_linenr = 1;
 566                 config_file_eof = 0;
 567                 ret = git_parse_file(fn, data);
 568                 fclose(f);
 569                 config_file_name = NULL;
 570         }
 571         return ret;
 572 }
 573
 574 const char *git_etc_gitconfig(void)
 575 {
 576         static const char *system_wide;
 577         if (!system_wide) {
 578                 system_wide = ETC_GITCONFIG;
 579                 if (!is_absolute_path(system_wide)) {
 580                         /* interpret path relative to exec-dir */
 581                         struct strbuf d = STRBUF_INIT;
 582                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 583                         system_wide = strbuf_detach(&d, NULL);
 584                 }
 585         }
 586         return system_wide;
 587 }
 588
 589 int git_env_bool(const char *k, int def)
 590 {
 591         const char *v = getenv(k);
 592         return v ? git_config_bool(k, v) : def;
 593 }
 594
 595 int git_config_system(void)
 596 {
 597         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 598 }
 599
 600 int git_config_global(void)
 601 {
 602         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 603 }
 604
 605 int git_config(config_fn_t fn, void *data)
 606 {
 607         int ret = 0;
 608         char *repo_config = NULL;
 609         const char *home = NULL, *filename;
 610
 611         /* $GIT_CONFIG makes git read _only_ the given config file,
 612          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 613          * global config file, the same way it would the per-repository
 614          * config file otherwise. */
 615         filename = getenv(CONFIG_ENVIRONMENT);
 616         if (!filename) {
 617                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 618                         ret += git_config_from_file(fn, git_etc_gitconfig(),
 619                                 data);
 620                 home = getenv("HOME");
 621                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 622                 if (!filename)
 623                         filename = repo_config = xstrdup(git_path("config"));
 624         }
 625
 626         if (git_config_global() && home) {
 627                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 628                 if (!access(user_config, R_OK))
 629                         ret = git_config_from_file(fn, user_config, data);
 630                 free(user_config);
 631         }
 632
 633         ret += git_config_from_file(fn, filename, data);
 634         free(repo_config);
 635         return ret;
 636 }
 637
 638 /*
 639  * Find all the stuff for git_config_set() below.
 640  */
 641
 642 #define MAX_MATCHES 512
 643
 644 static struct {
 645         int baselen;
 646         char* key;
 647         int do_not_match;
 648         regex_t* value_regex;
 649         int multi_replace;
 650         size_t offset[MAX_MATCHES];
 651         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 652         int seen;
 653 } store;
 654
 655 static int matches(const char* key, const char* value)
 656 {
 657         return !strcmp(key, store.key) &&
 658                 (store.value_regex == NULL ||
 659                  (store.do_not_match ^
 660                   !regexec(store.value_regex, value, 0, NULL, 0)));
 661 }
 662
 663 static int store_aux(const char* key, const char* value, void *cb)
 664 {
 665         const char *ep;
 666         size_t section_len;
 667
 668         switch (store.state) {
 669         case KEY_SEEN:
 670                 if (matches(key, value)) {
 671                         if (store.seen == 1 && store.multi_replace == 0) {
 672                                 warning("%s has multiple values", key);
 673                         } else if (store.seen >= MAX_MATCHES) {
 674                                 error("too many matches for %s", key);
 675                                 return 1;
 676                         }
 677
 678                         store.offset[store.seen] = ftell(config_file);
 679                         store.seen++;
 680                 }
 681                 break;
 682         case SECTION_SEEN:
 683                 /*
 684                  * What we are looking for is in store.key (both
 685                  * section and var), and its section part is baselen
 686                  * long.  We found key (again, both section and var).
 687                  * We would want to know if this key is in the same
 688                  * section as what we are looking for.  We already
 689                  * know we are in the same section as what should
 690                  * hold store.key.
 691                  */
 692                 ep = strrchr(key, '.');
 693                 section_len = ep - key;
 694
 695                 if ((section_len != store.baselen) ||
 696                     memcmp(key, store.key, section_len+1)) {
 697                         store.state = SECTION_END_SEEN;
 698                         break;
 699                 }
 700
 701                 /*
 702                  * Do not increment matches: this is no match, but we
 703                  * just made sure we are in the desired section.
 704                  */
 705                 store.offset[store.seen] = ftell(config_file);
 706                 /* fallthru */
 707         case SECTION_END_SEEN:
 708         case START:
 709                 if (matches(key, value)) {
 710                         store.offset[store.seen] = ftell(config_file);
 711                         store.state = KEY_SEEN;
 712                         store.seen++;
 713                 } else {
 714                         if (strrchr(key, '.') - key == store.baselen &&
 715                               !strncmp(key, store.key, store.baselen)) {
 716                                         store.state = SECTION_SEEN;
 717                                         store.offset[store.seen] = ftell(config_file);
 718                         }
 719                 }
 720         }
 721         return 0;
 722 }
 723
 724 static int write_error(const char *filename)
 725 {
 726         error("failed to write new configuration file %s", filename);
 727
 728         /* Same error code as "failed to rename". */
 729         return 4;
 730 }
 731
 732 static int store_write_section(int fd, const char* key)
 733 {
 734         const char *dot;
 735         int i, success;
 736         struct strbuf sb;
 737
 738         strbuf_init(&sb, 0);
 739         dot = memchr(key, '.', store.baselen);
 740         if (dot) {
 741                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 742                 for (i = dot - key + 1; i < store.baselen; i++) {
 743                         if (key[i] == '"' || key[i] == '\\')
 744                                 strbuf_addch(&sb, '\\');
 745                         strbuf_addch(&sb, key[i]);
 746                 }
 747                 strbuf_addstr(&sb, "\"]\n");
 748         } else {
 749                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 750         }
 751
 752         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 753         strbuf_release(&sb);
 754
 755         return success;
 756 }
 757
 758 static int store_write_pair(int fd, const char* key, const char* value)
 759 {
 760         int i, success;
 761         int length = strlen(key + store.baselen + 1);
 762         const char *quote = "";
 763         struct strbuf sb;
 764
 765         /*
 766          * Check to see if the value needs to be surrounded with a dq pair.
 767          * Note that problematic characters are always backslash-quoted; this
 768          * check is about not losing leading or trailing SP and strings that
 769          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 770          * configuration parser.
 771          */
 772         if (value[0] == ' ')
 773                 quote = "\"";
 774         for (i = 0; value[i]; i++)
 775                 if (value[i] == ';' || value[i] == '#')
 776                         quote = "\"";
 777         if (i && value[i - 1] == ' ')
 778                 quote = "\"";
 779
 780         strbuf_init(&sb, 0);
 781         strbuf_addf(&sb, "\t%.*s = %s",
 782                     length, key + store.baselen + 1, quote);
 783
 784         for (i = 0; value[i]; i++)
 785                 switch (value[i]) {
 786                 case '\n':
 787                         strbuf_addstr(&sb, "\\n");
 788                         break;
 789                 case '\t':
 790                         strbuf_addstr(&sb, "\\t");
 791                         break;
 792                 case '"':
 793                 case '\\':
 794                         strbuf_addch(&sb, '\\');
 795                 default:
 796                         strbuf_addch(&sb, value[i]);
 797                         break;
 798                 }
 799         strbuf_addf(&sb, "%s\n", quote);
 800
 801         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 802         strbuf_release(&sb);
 803
 804         return success;
 805 }
 806
 807 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 808         size_t offset_, int* found_bracket)
 809 {
 810         size_t equal_offset = size, bracket_offset = size;
 811         ssize_t offset;
 812
 813 contline:
 814         for (offset = offset_-2; offset > 0
 815                         && contents[offset] != '\n'; offset--)
 816                 switch (contents[offset]) {
 817                         case '=': equal_offset = offset; break;
 818                         case ']': bracket_offset = offset; break;
 819                 }
 820         if (offset > 0 && contents[offset-1] == '\\') {
 821                 offset_ = offset;
 822                 goto contline;
 823         }
 824         if (bracket_offset < equal_offset) {
 825                 *found_bracket = 1;
 826                 offset = bracket_offset+1;
 827         } else
 828                 offset++;
 829
 830         return offset;
 831 }
 832
 833 int git_config_set(const char* key, const char* value)
 834 {
 835         return git_config_set_multivar(key, value, NULL, 0);
 836 }
 837
 838 /*
 839  * If value==NULL, unset in (remove from) config,
 840  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 841  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 842  *     else all matching key/values (regardless how many) are removed,
 843  *     before the new pair is written.
 844  *
 845  * Returns 0 on success.
 846  *
 847  * This function does this:
 848  *
 849  * - it locks the config file by creating ".git/config.lock"
 850  *
 851  * - it then parses the config using store_aux() as validator to find
 852  *   the position on the key/value pair to replace. If it is to be unset,
 853  *   it must be found exactly once.
 854  *
 855  * - the config file is mmap()ed and the part before the match (if any) is
 856  *   written to the lock file, then the changed part and the rest.
 857  *
 858  * - the config file is removed and the lock file rename()d to it.
 859  *
 860  */
 861 int git_config_set_multivar(const char* key, const char* value,
 862         const char* value_regex, int multi_replace)
 863 {
 864         int i, dot;
 865         int fd = -1, in_fd;
 866         int ret;
 867         char* config_filename;
 868         struct lock_file *lock = NULL;
 869         const char* last_dot = strrchr(key, '.');
 870
 871         config_filename = getenv(CONFIG_ENVIRONMENT);
 872         if (!config_filename) {
 873                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 874                 if (!config_filename)
 875                         config_filename  = git_path("config");
 876         }
 877         config_filename = xstrdup(config_filename);
 878
 879         /*
 880          * Since "key" actually contains the section name and the real
 881          * key name separated by a dot, we have to know where the dot is.
 882          */
 883
 884         if (last_dot == NULL) {
 885                 error("key does not contain a section: %s", key);
 886                 ret = 2;
 887                 goto out_free;
 888         }
 889         store.baselen = last_dot - key;
 890
 891         store.multi_replace = multi_replace;
 892
 893         /*
 894          * Validate the key and while at it, lower case it for matching.
 895          */
 896         store.key = xmalloc(strlen(key) + 1);
 897         dot = 0;
 898         for (i = 0; key[i]; i++) {
 899                 unsigned char c = key[i];
 900                 if (c == '.')
 901                         dot = 1;
 902                 /* Leave the extended basename untouched.. */
 903                 if (!dot || i > store.baselen) {
 904                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 905                                 error("invalid key: %s", key);
 906                                 free(store.key);
 907                                 ret = 1;
 908                                 goto out_free;
 909                         }
 910                         c = tolower(c);
 911                 } else if (c == '\n') {
 912                         error("invalid key (newline): %s", key);
 913                         free(store.key);
 914                         ret = 1;
 915                         goto out_free;
 916                 }
 917                 store.key[i] = c;
 918         }
 919         store.key[i] = 0;
 920
 921         /*
 922          * The lock serves a purpose in addition to locking: the new
 923          * contents of .git/config will be written into it.
 924          */
 925         lock = xcalloc(sizeof(struct lock_file), 1);
 926         fd = hold_lock_file_for_update(lock, config_filename, 0);
 927         if (fd < 0) {
 928                 error("could not lock config file %s", config_filename);
 929                 free(store.key);
 930                 ret = -1;
 931                 goto out_free;
 932         }
 933
 934         /*
 935          * If .git/config does not exist yet, write a minimal version.
 936          */
 937         in_fd = open(config_filename, O_RDONLY);
 938         if ( in_fd < 0 ) {
 939                 free(store.key);
 940
 941                 if ( ENOENT != errno ) {
 942                         error("opening %s: %s", config_filename,
 943                               strerror(errno));
 944                         ret = 3; /* same as "invalid config file" */
 945                         goto out_free;
 946                 }
 947                 /* if nothing to unset, error out */
 948                 if (value == NULL) {
 949                         ret = 5;
 950                         goto out_free;
 951                 }
 952
 953                 store.key = (char*)key;
 954                 if (!store_write_section(fd, key) ||
 955                     !store_write_pair(fd, key, value))
 956                         goto write_err_out;
 957         } else {
 958                 struct stat st;
 959                 char* contents;
 960                 size_t contents_sz, copy_begin, copy_end;
 961                 int i, new_line = 0;
 962
 963                 if (value_regex == NULL)
 964                         store.value_regex = NULL;
 965                 else {
 966                         if (value_regex[0] == '!') {
 967                                 store.do_not_match = 1;
 968                                 value_regex++;
 969                         } else
 970                                 store.do_not_match = 0;
 971
 972                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 973                         if (regcomp(store.value_regex, value_regex,
 974                                         REG_EXTENDED)) {
 975                                 error("invalid pattern: %s", value_regex);
 976                                 free(store.value_regex);
 977                                 ret = 6;
 978                                 goto out_free;
 979                         }
 980                 }
 981
 982                 store.offset[0] = 0;
 983                 store.state = START;
 984                 store.seen = 0;
 985
 986                 /*
 987                  * After this, store.offset will contain the *end* offset
 988                  * of the last match, or remain at 0 if no match was found.
 989                  * As a side effect, we make sure to transform only a valid
 990                  * existing config file.
 991                  */
 992                 if (git_config_from_file(store_aux, config_filename, NULL)) {
 993                         error("invalid config file %s", config_filename);
 994                         free(store.key);
 995                         if (store.value_regex != NULL) {
 996                                 regfree(store.value_regex);
 997                                 free(store.value_regex);
 998                         }
 999                         ret = 3;
1000                         goto out_free;
1001                 }
1002
1003                 free(store.key);
1004                 if (store.value_regex != NULL) {
1005                         regfree(store.value_regex);
1006                         free(store.value_regex);
1007                 }
1008
1009                 /* if nothing to unset, or too many matches, error out */
1010                 if ((store.seen == 0 && value == NULL) ||
1011                                 (store.seen > 1 && multi_replace == 0)) {
1012                         ret = 5;
1013                         goto out_free;
1014                 }
1015
1016                 fstat(in_fd, &st);
1017                 contents_sz = xsize_t(st.st_size);
1018                 contents = xmmap(NULL, contents_sz, PROT_READ,
1019                         MAP_PRIVATE, in_fd, 0);
1020                 close(in_fd);
1021
1022                 if (store.seen == 0)
1023                         store.seen = 1;
1024
1025                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1026                         if (store.offset[i] == 0) {
1027                                 store.offset[i] = copy_end = contents_sz;
1028                         } else if (store.state != KEY_SEEN) {
1029                                 copy_end = store.offset[i];
1030                         } else
1031                                 copy_end = find_beginning_of_line(
1032                                         contents, contents_sz,
1033                                         store.offset[i]-2, &new_line);
1034
1035                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1036                                 new_line = 1;
1037
1038                         /* write the first part of the config */
1039                         if (copy_end > copy_begin) {
1040                                 if (write_in_full(fd, contents + copy_begin,
1041                                                   copy_end - copy_begin) <
1042                                     copy_end - copy_begin)
1043                                         goto write_err_out;
1044                                 if (new_line &&
1045                                     write_in_full(fd, "\n", 1) != 1)
1046                                         goto write_err_out;
1047                         }
1048                         copy_begin = store.offset[i];
1049                 }
1050
1051                 /* write the pair (value == NULL means unset) */
1052                 if (value != NULL) {
1053                         if (store.state == START) {
1054                                 if (!store_write_section(fd, key))
1055                                         goto write_err_out;
1056                         }
1057                         if (!store_write_pair(fd, key, value))
1058                                 goto write_err_out;
1059                 }
1060
1061                 /* write the rest of the config */
1062                 if (copy_begin < contents_sz)
1063                         if (write_in_full(fd, contents + copy_begin,
1064                                           contents_sz - copy_begin) <
1065                             contents_sz - copy_begin)
1066                                 goto write_err_out;
1067
1068                 munmap(contents, contents_sz);
1069         }
1070
1071         if (commit_lock_file(lock) < 0) {
1072                 error("could not commit config file %s", config_filename);
1073                 ret = 4;
1074                 goto out_free;
1075         }
1076
1077         /*
1078          * lock is committed, so don't try to roll it back below.
1079          * NOTE: Since lockfile.c keeps a linked list of all created
1080          * lock_file structures, it isn't safe to free(lock).  It's
1081          * better to just leave it hanging around.
1082          */
1083         lock = NULL;
1084         ret = 0;
1085
1086 out_free:
1087         if (lock)
1088                 rollback_lock_file(lock);
1089         free(config_filename);
1090         return ret;
1091
1092 write_err_out:
1093         ret = write_error(lock->filename);
1094         goto out_free;
1095
1096 }
1097
1098 static int section_name_match (const char *buf, const char *name)
1099 {
1100         int i = 0, j = 0, dot = 0;
1101         for (; buf[i] && buf[i] != ']'; i++) {
1102                 if (!dot && isspace(buf[i])) {
1103                         dot = 1;
1104                         if (name[j++] != '.')
1105                                 break;
1106                         for (i++; isspace(buf[i]); i++)
1107                                 ; /* do nothing */
1108                         if (buf[i] != '"')
1109                                 break;
1110                         continue;
1111                 }
1112                 if (buf[i] == '\\' && dot)
1113                         i++;
1114                 else if (buf[i] == '"' && dot) {
1115                         for (i++; isspace(buf[i]); i++)
1116                                 ; /* do_nothing */
1117                         break;
1118                 }
1119                 if (buf[i] != name[j++])
1120                         break;
1121         }
1122         return (buf[i] == ']' && name[j] == 0);
1123 }
1124
1125 /* if new_name == NULL, the section is removed instead */
1126 int git_config_rename_section(const char *old_name, const char *new_name)
1127 {
1128         int ret = 0, remove = 0;
1129         char *config_filename;
1130         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1131         int out_fd;
1132         char buf[1024];
1133
1134         config_filename = getenv(CONFIG_ENVIRONMENT);
1135         if (!config_filename) {
1136                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1137                 if (!config_filename)
1138                         config_filename  = git_path("config");
1139         }
1140         config_filename = xstrdup(config_filename);
1141         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1142         if (out_fd < 0) {
1143                 ret = error("could not lock config file %s", config_filename);
1144                 goto out;
1145         }
1146
1147         if (!(config_file = fopen(config_filename, "rb"))) {
1148                 /* no config file means nothing to rename, no error */
1149                 goto unlock_and_out;
1150         }
1151
1152         while (fgets(buf, sizeof(buf), config_file)) {
1153                 int i;
1154                 int length;
1155                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1156                         ; /* do nothing */
1157                 if (buf[i] == '[') {
1158                         /* it's a section */
1159                         if (section_name_match (&buf[i+1], old_name)) {
1160                                 ret++;
1161                                 if (new_name == NULL) {
1162                                         remove = 1;
1163                                         continue;
1164                                 }
1165                                 store.baselen = strlen(new_name);
1166                                 if (!store_write_section(out_fd, new_name)) {
1167                                         ret = write_error(lock->filename);
1168                                         goto out;
1169                                 }
1170                                 continue;
1171                         }
1172                         remove = 0;
1173                 }
1174                 if (remove)
1175                         continue;
1176                 length = strlen(buf);
1177                 if (write_in_full(out_fd, buf, length) != length) {
1178                         ret = write_error(lock->filename);
1179                         goto out;
1180                 }
1181         }
1182         fclose(config_file);
1183  unlock_and_out:
1184         if (commit_lock_file(lock) < 0)
1185                 ret = error("could not commit config file %s", config_filename);
1186  out:
1187         free(config_filename);
1188         return ret;
1189 }
1190
1191 /*
1192  * Call this to report error for your variable that should not
1193  * get a boolean value (i.e. "[my] var" means "true").
1194  */
1195 int config_error_nonbool(const char *var)
1196 {
1197         return error("Missing value for '%s'", var);
1198 }