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