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