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         if (!strcmp(var, "branch.autosetuprebase")) {
 496                 if (!value)
 497                         return config_error_nonbool(var);
 498                 else if (!strcmp(value, "never"))
 499                         autorebase = AUTOREBASE_NEVER;
 500                 else if (!strcmp(value, "local"))
 501                         autorebase = AUTOREBASE_LOCAL;
 502                 else if (!strcmp(value, "remote"))
 503                         autorebase = AUTOREBASE_REMOTE;
 504                 else if (!strcmp(value, "always"))
 505                         autorebase = AUTOREBASE_ALWAYS;
 506                 else
 507                         return error("Malformed value for %s", var);
 508                 return 0;
 509         }
 510
 511         /* Add other config variables here and to Documentation/config.txt. */
 512         return 0;
 513 }
 514
 515 int git_config_from_file(config_fn_t fn, const char *filename)
 516 {
 517         int ret;
 518         FILE *f = fopen(filename, "r");
 519
 520         ret = -1;
 521         if (f) {
 522                 config_file = f;
 523                 config_file_name = filename;
 524                 config_linenr = 1;
 525                 config_file_eof = 0;
 526                 ret = git_parse_file(fn);
 527                 fclose(f);
 528                 config_file_name = NULL;
 529         }
 530         return ret;
 531 }
 532
 533 const char *git_etc_gitconfig(void)
 534 {
 535         static const char *system_wide;
 536         if (!system_wide) {
 537                 system_wide = ETC_GITCONFIG;
 538                 if (!is_absolute_path(system_wide)) {
 539                         /* interpret path relative to exec-dir */
 540                         struct strbuf d = STRBUF_INIT;
 541                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 542                         system_wide = strbuf_detach(&d, NULL);
 543                 }
 544         }
 545         return system_wide;
 546 }
 547
 548 int git_env_bool(const char *k, int def)
 549 {
 550         const char *v = getenv(k);
 551         return v ? git_config_bool(k, v) : def;
 552 }
 553
 554 int git_config_system(void)
 555 {
 556         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 557 }
 558
 559 int git_config_global(void)
 560 {
 561         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 562 }
 563
 564 int git_config(config_fn_t fn)
 565 {
 566         int ret = 0;
 567         char *repo_config = NULL;
 568         const char *home = NULL, *filename;
 569
 570         /* $GIT_CONFIG makes git read _only_ the given config file,
 571          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 572          * global config file, the same way it would the per-repository
 573          * config file otherwise. */
 574         filename = getenv(CONFIG_ENVIRONMENT);
 575         if (!filename) {
 576                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 577                         ret += git_config_from_file(fn, git_etc_gitconfig());
 578                 home = getenv("HOME");
 579                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 580                 if (!filename)
 581                         filename = repo_config = xstrdup(git_path("config"));
 582         }
 583
 584         if (git_config_global() && home) {
 585                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 586                 if (!access(user_config, R_OK))
 587                         ret = git_config_from_file(fn, user_config);
 588                 free(user_config);
 589         }
 590
 591         ret += git_config_from_file(fn, filename);
 592         free(repo_config);
 593         return ret;
 594 }
 595
 596 /*
 597  * Find all the stuff for git_config_set() below.
 598  */
 599
 600 #define MAX_MATCHES 512
 601
 602 static struct {
 603         int baselen;
 604         char* key;
 605         int do_not_match;
 606         regex_t* value_regex;
 607         int multi_replace;
 608         size_t offset[MAX_MATCHES];
 609         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 610         int seen;
 611 } store;
 612
 613 static int matches(const char* key, const char* value)
 614 {
 615         return !strcmp(key, store.key) &&
 616                 (store.value_regex == NULL ||
 617                  (store.do_not_match ^
 618                   !regexec(store.value_regex, value, 0, NULL, 0)));
 619 }
 620
 621 static int store_aux(const char* key, const char* value)
 622 {
 623         const char *ep;
 624         size_t section_len;
 625
 626         switch (store.state) {
 627         case KEY_SEEN:
 628                 if (matches(key, value)) {
 629                         if (store.seen == 1 && store.multi_replace == 0) {
 630                                 fprintf(stderr,
 631                                         "Warning: %s has multiple values\n",
 632                                         key);
 633                         } else if (store.seen >= MAX_MATCHES) {
 634                                 fprintf(stderr, "Too many matches\n");
 635                                 return 1;
 636                         }
 637
 638                         store.offset[store.seen] = ftell(config_file);
 639                         store.seen++;
 640                 }
 641                 break;
 642         case SECTION_SEEN:
 643                 /*
 644                  * What we are looking for is in store.key (both
 645                  * section and var), and its section part is baselen
 646                  * long.  We found key (again, both section and var).
 647                  * We would want to know if this key is in the same
 648                  * section as what we are looking for.  We already
 649                  * know we are in the same section as what should
 650                  * hold store.key.
 651                  */
 652                 ep = strrchr(key, '.');
 653                 section_len = ep - key;
 654
 655                 if ((section_len != store.baselen) ||
 656                     memcmp(key, store.key, section_len+1)) {
 657                         store.state = SECTION_END_SEEN;
 658                         break;
 659                 }
 660
 661                 /*
 662                  * Do not increment matches: this is no match, but we
 663                  * just made sure we are in the desired section.
 664                  */
 665                 store.offset[store.seen] = ftell(config_file);
 666                 /* fallthru */
 667         case SECTION_END_SEEN:
 668         case START:
 669                 if (matches(key, value)) {
 670                         store.offset[store.seen] = ftell(config_file);
 671                         store.state = KEY_SEEN;
 672                         store.seen++;
 673                 } else {
 674                         if (strrchr(key, '.') - key == store.baselen &&
 675                               !strncmp(key, store.key, store.baselen)) {
 676                                         store.state = SECTION_SEEN;
 677                                         store.offset[store.seen] = ftell(config_file);
 678                         }
 679                 }
 680         }
 681         return 0;
 682 }
 683
 684 static int write_error(void)
 685 {
 686         fprintf(stderr, "Failed to write new configuration file\n");
 687
 688         /* Same error code as "failed to rename". */
 689         return 4;
 690 }
 691
 692 static int store_write_section(int fd, const char* key)
 693 {
 694         const char *dot;
 695         int i, success;
 696         struct strbuf sb;
 697
 698         strbuf_init(&sb, 0);
 699         dot = memchr(key, '.', store.baselen);
 700         if (dot) {
 701                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 702                 for (i = dot - key + 1; i < store.baselen; i++) {
 703                         if (key[i] == '"' || key[i] == '\\')
 704                                 strbuf_addch(&sb, '\\');
 705                         strbuf_addch(&sb, key[i]);
 706                 }
 707                 strbuf_addstr(&sb, "\"]\n");
 708         } else {
 709                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 710         }
 711
 712         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 713         strbuf_release(&sb);
 714
 715         return success;
 716 }
 717
 718 static int store_write_pair(int fd, const char* key, const char* value)
 719 {
 720         int i, success;
 721         int length = strlen(key + store.baselen + 1);
 722         const char *quote = "";
 723         struct strbuf sb;
 724
 725         /*
 726          * Check to see if the value needs to be surrounded with a dq pair.
 727          * Note that problematic characters are always backslash-quoted; this
 728          * check is about not losing leading or trailing SP and strings that
 729          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 730          * configuration parser.
 731          */
 732         if (value[0] == ' ')
 733                 quote = "\"";
 734         for (i = 0; value[i]; i++)
 735                 if (value[i] == ';' || value[i] == '#')
 736                         quote = "\"";
 737         if (i && value[i - 1] == ' ')
 738                 quote = "\"";
 739
 740         strbuf_init(&sb, 0);
 741         strbuf_addf(&sb, "\t%.*s = %s",
 742                     length, key + store.baselen + 1, quote);
 743
 744         for (i = 0; value[i]; i++)
 745                 switch (value[i]) {
 746                 case '\n':
 747                         strbuf_addstr(&sb, "\\n");
 748                         break;
 749                 case '\t':
 750                         strbuf_addstr(&sb, "\\t");
 751                         break;
 752                 case '"':
 753                 case '\\':
 754                         strbuf_addch(&sb, '\\');
 755                 default:
 756                         strbuf_addch(&sb, value[i]);
 757                         break;
 758                 }
 759         strbuf_addf(&sb, "%s\n", quote);
 760
 761         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 762         strbuf_release(&sb);
 763
 764         return success;
 765 }
 766
 767 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 768         size_t offset_, int* found_bracket)
 769 {
 770         size_t equal_offset = size, bracket_offset = size;
 771         ssize_t offset;
 772
 773 contline:
 774         for (offset = offset_-2; offset > 0
 775                         && contents[offset] != '\n'; offset--)
 776                 switch (contents[offset]) {
 777                         case '=': equal_offset = offset; break;
 778                         case ']': bracket_offset = offset; break;
 779                 }
 780         if (offset > 0 && contents[offset-1] == '\\') {
 781                 offset_ = offset;
 782                 goto contline;
 783         }
 784         if (bracket_offset < equal_offset) {
 785                 *found_bracket = 1;
 786                 offset = bracket_offset+1;
 787         } else
 788                 offset++;
 789
 790         return offset;
 791 }
 792
 793 int git_config_set(const char* key, const char* value)
 794 {
 795         return git_config_set_multivar(key, value, NULL, 0);
 796 }
 797
 798 /*
 799  * If value==NULL, unset in (remove from) config,
 800  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 801  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 802  *     else all matching key/values (regardless how many) are removed,
 803  *     before the new pair is written.
 804  *
 805  * Returns 0 on success.
 806  *
 807  * This function does this:
 808  *
 809  * - it locks the config file by creating ".git/config.lock"
 810  *
 811  * - it then parses the config using store_aux() as validator to find
 812  *   the position on the key/value pair to replace. If it is to be unset,
 813  *   it must be found exactly once.
 814  *
 815  * - the config file is mmap()ed and the part before the match (if any) is
 816  *   written to the lock file, then the changed part and the rest.
 817  *
 818  * - the config file is removed and the lock file rename()d to it.
 819  *
 820  */
 821 int git_config_set_multivar(const char* key, const char* value,
 822         const char* value_regex, int multi_replace)
 823 {
 824         int i, dot;
 825         int fd = -1, in_fd;
 826         int ret;
 827         char* config_filename;
 828         struct lock_file *lock = NULL;
 829         const char* last_dot = strrchr(key, '.');
 830
 831         config_filename = getenv(CONFIG_ENVIRONMENT);
 832         if (!config_filename) {
 833                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 834                 if (!config_filename)
 835                         config_filename  = git_path("config");
 836         }
 837         config_filename = xstrdup(config_filename);
 838
 839         /*
 840          * Since "key" actually contains the section name and the real
 841          * key name separated by a dot, we have to know where the dot is.
 842          */
 843
 844         if (last_dot == NULL) {
 845                 fprintf(stderr, "key does not contain a section: %s\n", key);
 846                 ret = 2;
 847                 goto out_free;
 848         }
 849         store.baselen = last_dot - key;
 850
 851         store.multi_replace = multi_replace;
 852
 853         /*
 854          * Validate the key and while at it, lower case it for matching.
 855          */
 856         store.key = xmalloc(strlen(key) + 1);
 857         dot = 0;
 858         for (i = 0; key[i]; i++) {
 859                 unsigned char c = key[i];
 860                 if (c == '.')
 861                         dot = 1;
 862                 /* Leave the extended basename untouched.. */
 863                 if (!dot || i > store.baselen) {
 864                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 865                                 fprintf(stderr, "invalid key: %s\n", key);
 866                                 free(store.key);
 867                                 ret = 1;
 868                                 goto out_free;
 869                         }
 870                         c = tolower(c);
 871                 } else if (c == '\n') {
 872                         fprintf(stderr, "invalid key (newline): %s\n", key);
 873                         free(store.key);
 874                         ret = 1;
 875                         goto out_free;
 876                 }
 877                 store.key[i] = c;
 878         }
 879         store.key[i] = 0;
 880
 881         /*
 882          * The lock serves a purpose in addition to locking: the new
 883          * contents of .git/config will be written into it.
 884          */
 885         lock = xcalloc(sizeof(struct lock_file), 1);
 886         fd = hold_lock_file_for_update(lock, config_filename, 0);
 887         if (fd < 0) {
 888                 fprintf(stderr, "could not lock config file\n");
 889                 free(store.key);
 890                 ret = -1;
 891                 goto out_free;
 892         }
 893
 894         /*
 895          * If .git/config does not exist yet, write a minimal version.
 896          */
 897         in_fd = open(config_filename, O_RDONLY);
 898         if ( in_fd < 0 ) {
 899                 free(store.key);
 900
 901                 if ( ENOENT != errno ) {
 902                         error("opening %s: %s", config_filename,
 903                               strerror(errno));
 904                         ret = 3; /* same as "invalid config file" */
 905                         goto out_free;
 906                 }
 907                 /* if nothing to unset, error out */
 908                 if (value == NULL) {
 909                         ret = 5;
 910                         goto out_free;
 911                 }
 912
 913                 store.key = (char*)key;
 914                 if (!store_write_section(fd, key) ||
 915                     !store_write_pair(fd, key, value))
 916                         goto write_err_out;
 917         } else {
 918                 struct stat st;
 919                 char* contents;
 920                 size_t contents_sz, copy_begin, copy_end;
 921                 int i, new_line = 0;
 922
 923                 if (value_regex == NULL)
 924                         store.value_regex = NULL;
 925                 else {
 926                         if (value_regex[0] == '!') {
 927                                 store.do_not_match = 1;
 928                                 value_regex++;
 929                         } else
 930                                 store.do_not_match = 0;
 931
 932                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 933                         if (regcomp(store.value_regex, value_regex,
 934                                         REG_EXTENDED)) {
 935                                 fprintf(stderr, "Invalid pattern: %s\n",
 936                                         value_regex);
 937                                 free(store.value_regex);
 938                                 ret = 6;
 939                                 goto out_free;
 940                         }
 941                 }
 942
 943                 store.offset[0] = 0;
 944                 store.state = START;
 945                 store.seen = 0;
 946
 947                 /*
 948                  * After this, store.offset will contain the *end* offset
 949                  * of the last match, or remain at 0 if no match was found.
 950                  * As a side effect, we make sure to transform only a valid
 951                  * existing config file.
 952                  */
 953                 if (git_config_from_file(store_aux, config_filename)) {
 954                         fprintf(stderr, "invalid config file\n");
 955                         free(store.key);
 956                         if (store.value_regex != NULL) {
 957                                 regfree(store.value_regex);
 958                                 free(store.value_regex);
 959                         }
 960                         ret = 3;
 961                         goto out_free;
 962                 }
 963
 964                 free(store.key);
 965                 if (store.value_regex != NULL) {
 966                         regfree(store.value_regex);
 967                         free(store.value_regex);
 968                 }
 969
 970                 /* if nothing to unset, or too many matches, error out */
 971                 if ((store.seen == 0 && value == NULL) ||
 972                                 (store.seen > 1 && multi_replace == 0)) {
 973                         ret = 5;
 974                         goto out_free;
 975                 }
 976
 977                 fstat(in_fd, &st);
 978                 contents_sz = xsize_t(st.st_size);
 979                 contents = xmmap(NULL, contents_sz, PROT_READ,
 980                         MAP_PRIVATE, in_fd, 0);
 981                 close(in_fd);
 982
 983                 if (store.seen == 0)
 984                         store.seen = 1;
 985
 986                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 987                         if (store.offset[i] == 0) {
 988                                 store.offset[i] = copy_end = contents_sz;
 989                         } else if (store.state != KEY_SEEN) {
 990                                 copy_end = store.offset[i];
 991                         } else
 992                                 copy_end = find_beginning_of_line(
 993                                         contents, contents_sz,
 994                                         store.offset[i]-2, &new_line);
 995
 996                         if (copy_end > 0 && contents[copy_end-1] != '\n')
 997                                 new_line = 1;
 998
 999                         /* write the first part of the config */
1000                         if (copy_end > copy_begin) {
1001                                 if (write_in_full(fd, contents + copy_begin,
1002                                                   copy_end - copy_begin) <
1003                                     copy_end - copy_begin)
1004                                         goto write_err_out;
1005                                 if (new_line &&
1006                                     write_in_full(fd, "\n", 1) != 1)
1007                                         goto write_err_out;
1008                         }
1009                         copy_begin = store.offset[i];
1010                 }
1011
1012                 /* write the pair (value == NULL means unset) */
1013                 if (value != NULL) {
1014                         if (store.state == START) {
1015                                 if (!store_write_section(fd, key))
1016                                         goto write_err_out;
1017                         }
1018                         if (!store_write_pair(fd, key, value))
1019                                 goto write_err_out;
1020                 }
1021
1022                 /* write the rest of the config */
1023                 if (copy_begin < contents_sz)
1024                         if (write_in_full(fd, contents + copy_begin,
1025                                           contents_sz - copy_begin) <
1026                             contents_sz - copy_begin)
1027                                 goto write_err_out;
1028
1029                 munmap(contents, contents_sz);
1030         }
1031
1032         if (commit_lock_file(lock) < 0) {
1033                 fprintf(stderr, "Cannot commit config file!\n");
1034                 ret = 4;
1035                 goto out_free;
1036         }
1037
1038         /*
1039          * lock is committed, so don't try to roll it back below.
1040          * NOTE: Since lockfile.c keeps a linked list of all created
1041          * lock_file structures, it isn't safe to free(lock).  It's
1042          * better to just leave it hanging around.
1043          */
1044         lock = NULL;
1045         ret = 0;
1046
1047 out_free:
1048         if (lock)
1049                 rollback_lock_file(lock);
1050         free(config_filename);
1051         return ret;
1052
1053 write_err_out:
1054         ret = write_error();
1055         goto out_free;
1056
1057 }
1058
1059 static int section_name_match (const char *buf, const char *name)
1060 {
1061         int i = 0, j = 0, dot = 0;
1062         for (; buf[i] && buf[i] != ']'; i++) {
1063                 if (!dot && isspace(buf[i])) {
1064                         dot = 1;
1065                         if (name[j++] != '.')
1066                                 break;
1067                         for (i++; isspace(buf[i]); i++)
1068                                 ; /* do nothing */
1069                         if (buf[i] != '"')
1070                                 break;
1071                         continue;
1072                 }
1073                 if (buf[i] == '\\' && dot)
1074                         i++;
1075                 else if (buf[i] == '"' && dot) {
1076                         for (i++; isspace(buf[i]); i++)
1077                                 ; /* do_nothing */
1078                         break;
1079                 }
1080                 if (buf[i] != name[j++])
1081                         break;
1082         }
1083         return (buf[i] == ']' && name[j] == 0);
1084 }
1085
1086 /* if new_name == NULL, the section is removed instead */
1087 int git_config_rename_section(const char *old_name, const char *new_name)
1088 {
1089         int ret = 0, remove = 0;
1090         char *config_filename;
1091         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1092         int out_fd;
1093         char buf[1024];
1094
1095         config_filename = getenv(CONFIG_ENVIRONMENT);
1096         if (!config_filename) {
1097                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1098                 if (!config_filename)
1099                         config_filename  = git_path("config");
1100         }
1101         config_filename = xstrdup(config_filename);
1102         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1103         if (out_fd < 0) {
1104                 ret = error("Could not lock config file!");
1105                 goto out;
1106         }
1107
1108         if (!(config_file = fopen(config_filename, "rb"))) {
1109                 /* no config file means nothing to rename, no error */
1110                 goto unlock_and_out;
1111         }
1112
1113         while (fgets(buf, sizeof(buf), config_file)) {
1114                 int i;
1115                 int length;
1116                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1117                         ; /* do nothing */
1118                 if (buf[i] == '[') {
1119                         /* it's a section */
1120                         if (section_name_match (&buf[i+1], old_name)) {
1121                                 ret++;
1122                                 if (new_name == NULL) {
1123                                         remove = 1;
1124                                         continue;
1125                                 }
1126                                 store.baselen = strlen(new_name);
1127                                 if (!store_write_section(out_fd, new_name)) {
1128                                         ret = write_error();
1129                                         goto out;
1130                                 }
1131                                 continue;
1132                         }
1133                         remove = 0;
1134                 }
1135                 if (remove)
1136                         continue;
1137                 length = strlen(buf);
1138                 if (write_in_full(out_fd, buf, length) != length) {
1139                         ret = write_error();
1140                         goto out;
1141                 }
1142         }
1143         fclose(config_file);
1144  unlock_and_out:
1145         if (commit_lock_file(lock) < 0)
1146                         ret = error("Cannot commit config file!");
1147  out:
1148         free(config_filename);
1149         return ret;
1150 }
1151
1152 /*
1153  * Call this to report error for your variable that should not
1154  * get a boolean value (i.e. "[my] var" means "true").
1155  */
1156 int config_error_nonbool(const char *var)
1157 {
1158         return error("Missing value for '%s'", var);
1159 }