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