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.bare")) {
 354                 is_bare_repository_cfg = git_config_bool(var, value);
 355                 return 0;
 356         }
 357
 358         if (!strcmp(var, "core.ignorestat")) {
 359                 assume_unchanged = git_config_bool(var, value);
 360                 return 0;
 361         }
 362
 363         if (!strcmp(var, "core.prefersymlinkrefs")) {
 364                 prefer_symlink_refs = git_config_bool(var, value);
 365                 return 0;
 366         }
 367
 368         if (!strcmp(var, "core.logallrefupdates")) {
 369                 log_all_ref_updates = git_config_bool(var, value);
 370                 return 0;
 371         }
 372
 373         if (!strcmp(var, "core.warnambiguousrefs")) {
 374                 warn_ambiguous_refs = git_config_bool(var, value);
 375                 return 0;
 376         }
 377
 378         if (!strcmp(var, "core.loosecompression")) {
 379                 int level = git_config_int(var, value);
 380                 if (level == -1)
 381                         level = Z_DEFAULT_COMPRESSION;
 382                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 383                         die("bad zlib compression level %d", level);
 384                 zlib_compression_level = level;
 385                 zlib_compression_seen = 1;
 386                 return 0;
 387         }
 388
 389         if (!strcmp(var, "core.compression")) {
 390                 int level = git_config_int(var, value);
 391                 if (level == -1)
 392                         level = Z_DEFAULT_COMPRESSION;
 393                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 394                         die("bad zlib compression level %d", level);
 395                 core_compression_level = level;
 396                 core_compression_seen = 1;
 397                 if (!zlib_compression_seen)
 398                         zlib_compression_level = level;
 399                 return 0;
 400         }
 401
 402         if (!strcmp(var, "core.packedgitwindowsize")) {
 403                 int pgsz_x2 = getpagesize() * 2;
 404                 packed_git_window_size = git_config_int(var, value);
 405
 406                 /* This value must be multiple of (pagesize * 2) */
 407                 packed_git_window_size /= pgsz_x2;
 408                 if (packed_git_window_size < 1)
 409                         packed_git_window_size = 1;
 410                 packed_git_window_size *= pgsz_x2;
 411                 return 0;
 412         }
 413
 414         if (!strcmp(var, "core.packedgitlimit")) {
 415                 packed_git_limit = git_config_int(var, value);
 416                 return 0;
 417         }
 418
 419         if (!strcmp(var, "core.deltabasecachelimit")) {
 420                 delta_base_cache_limit = git_config_int(var, value);
 421                 return 0;
 422         }
 423
 424         if (!strcmp(var, "core.autocrlf")) {
 425                 if (value && !strcasecmp(value, "input")) {
 426                         auto_crlf = -1;
 427                         return 0;
 428                 }
 429                 auto_crlf = git_config_bool(var, value);
 430                 return 0;
 431         }
 432
 433         if (!strcmp(var, "core.safecrlf")) {
 434                 if (value && !strcasecmp(value, "warn")) {
 435                         safe_crlf = SAFE_CRLF_WARN;
 436                         return 0;
 437                 }
 438                 safe_crlf = git_config_bool(var, value);
 439                 return 0;
 440         }
 441
 442         if (!strcmp(var, "user.name")) {
 443                 if (!value)
 444                         return config_error_nonbool(var);
 445                 strlcpy(git_default_name, value, sizeof(git_default_name));
 446                 return 0;
 447         }
 448
 449         if (!strcmp(var, "user.email")) {
 450                 if (!value)
 451                         return config_error_nonbool(var);
 452                 strlcpy(git_default_email, value, sizeof(git_default_email));
 453                 return 0;
 454         }
 455
 456         if (!strcmp(var, "i18n.commitencoding"))
 457                 return git_config_string(&git_commit_encoding, var, value);
 458
 459         if (!strcmp(var, "i18n.logoutputencoding"))
 460                 return git_config_string(&git_log_output_encoding, var, value);
 461
 462         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 463                 pager_use_color = git_config_bool(var,value);
 464                 return 0;
 465         }
 466
 467         if (!strcmp(var, "core.pager"))
 468                 return git_config_string(&pager_program, var, value);
 469
 470         if (!strcmp(var, "core.editor"))
 471                 return git_config_string(&editor_program, var, value);
 472
 473         if (!strcmp(var, "core.excludesfile"))
 474                 return git_config_string(&excludes_file, var, value);
 475
 476         if (!strcmp(var, "core.whitespace")) {
 477                 if (!value)
 478                         return config_error_nonbool(var);
 479                 whitespace_rule_cfg = parse_whitespace_rule(value);
 480                 return 0;
 481         }
 482         if (!strcmp(var, "branch.autosetupmerge")) {
 483                 if (value && !strcasecmp(value, "always")) {
 484                         git_branch_track = BRANCH_TRACK_ALWAYS;
 485                         return 0;
 486                 }
 487                 git_branch_track = git_config_bool(var, value);
 488                 return 0;
 489         }
 490
 491         /* Add other config variables here and to Documentation/config.txt. */
 492         return 0;
 493 }
 494
 495 int git_config_from_file(config_fn_t fn, const char *filename)
 496 {
 497         int ret;
 498         FILE *f = fopen(filename, "r");
 499
 500         ret = -1;
 501         if (f) {
 502                 config_file = f;
 503                 config_file_name = filename;
 504                 config_linenr = 1;
 505                 config_file_eof = 0;
 506                 ret = git_parse_file(fn);
 507                 fclose(f);
 508                 config_file_name = NULL;
 509         }
 510         return ret;
 511 }
 512
 513 const char *git_etc_gitconfig(void)
 514 {
 515         static const char *system_wide;
 516         if (!system_wide) {
 517                 system_wide = ETC_GITCONFIG;
 518                 if (!is_absolute_path(system_wide)) {
 519                         /* interpret path relative to exec-dir */
 520                         struct strbuf d = STRBUF_INIT;
 521                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 522                         system_wide = strbuf_detach(&d, NULL);
 523                 }
 524         }
 525         return system_wide;
 526 }
 527
 528 int git_env_bool(const char *k, int def)
 529 {
 530         const char *v = getenv(k);
 531         return v ? git_config_bool(k, v) : def;
 532 }
 533
 534 int git_config_system(void)
 535 {
 536         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 537 }
 538
 539 int git_config_global(void)
 540 {
 541         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 542 }
 543
 544 int git_config(config_fn_t fn)
 545 {
 546         int ret = 0;
 547         char *repo_config = NULL;
 548         const char *home = NULL, *filename;
 549
 550         /* $GIT_CONFIG makes git read _only_ the given config file,
 551          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 552          * global config file, the same way it would the per-repository
 553          * config file otherwise. */
 554         filename = getenv(CONFIG_ENVIRONMENT);
 555         if (!filename) {
 556                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 557                         ret += git_config_from_file(fn, git_etc_gitconfig());
 558                 home = getenv("HOME");
 559                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 560                 if (!filename)
 561                         filename = repo_config = xstrdup(git_path("config"));
 562         }
 563
 564         if (git_config_global() && home) {
 565                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 566                 if (!access(user_config, R_OK))
 567                         ret = git_config_from_file(fn, user_config);
 568                 free(user_config);
 569         }
 570
 571         ret += git_config_from_file(fn, filename);
 572         free(repo_config);
 573         return ret;
 574 }
 575
 576 /*
 577  * Find all the stuff for git_config_set() below.
 578  */
 579
 580 #define MAX_MATCHES 512
 581
 582 static struct {
 583         int baselen;
 584         char* key;
 585         int do_not_match;
 586         regex_t* value_regex;
 587         int multi_replace;
 588         size_t offset[MAX_MATCHES];
 589         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 590         int seen;
 591 } store;
 592
 593 static int matches(const char* key, const char* value)
 594 {
 595         return !strcmp(key, store.key) &&
 596                 (store.value_regex == NULL ||
 597                  (store.do_not_match ^
 598                   !regexec(store.value_regex, value, 0, NULL, 0)));
 599 }
 600
 601 static int store_aux(const char* key, const char* value)
 602 {
 603         const char *ep;
 604         size_t section_len;
 605
 606         switch (store.state) {
 607         case KEY_SEEN:
 608                 if (matches(key, value)) {
 609                         if (store.seen == 1 && store.multi_replace == 0) {
 610                                 fprintf(stderr,
 611                                         "Warning: %s has multiple values\n",
 612                                         key);
 613                         } else if (store.seen >= MAX_MATCHES) {
 614                                 fprintf(stderr, "Too many matches\n");
 615                                 return 1;
 616                         }
 617
 618                         store.offset[store.seen] = ftell(config_file);
 619                         store.seen++;
 620                 }
 621                 break;
 622         case SECTION_SEEN:
 623                 /*
 624                  * What we are looking for is in store.key (both
 625                  * section and var), and its section part is baselen
 626                  * long.  We found key (again, both section and var).
 627                  * We would want to know if this key is in the same
 628                  * section as what we are looking for.  We already
 629                  * know we are in the same section as what should
 630                  * hold store.key.
 631                  */
 632                 ep = strrchr(key, '.');
 633                 section_len = ep - key;
 634
 635                 if ((section_len != store.baselen) ||
 636                     memcmp(key, store.key, section_len+1)) {
 637                         store.state = SECTION_END_SEEN;
 638                         break;
 639                 }
 640
 641                 /*
 642                  * Do not increment matches: this is no match, but we
 643                  * just made sure we are in the desired section.
 644                  */
 645                 store.offset[store.seen] = ftell(config_file);
 646                 /* fallthru */
 647         case SECTION_END_SEEN:
 648         case START:
 649                 if (matches(key, value)) {
 650                         store.offset[store.seen] = ftell(config_file);
 651                         store.state = KEY_SEEN;
 652                         store.seen++;
 653                 } else {
 654                         if (strrchr(key, '.') - key == store.baselen &&
 655                               !strncmp(key, store.key, store.baselen)) {
 656                                         store.state = SECTION_SEEN;
 657                                         store.offset[store.seen] = ftell(config_file);
 658                         }
 659                 }
 660         }
 661         return 0;
 662 }
 663
 664 static int write_error(void)
 665 {
 666         fprintf(stderr, "Failed to write new configuration file\n");
 667
 668         /* Same error code as "failed to rename". */
 669         return 4;
 670 }
 671
 672 static int store_write_section(int fd, const char* key)
 673 {
 674         const char *dot;
 675         int i, success;
 676         struct strbuf sb;
 677
 678         strbuf_init(&sb, 0);
 679         dot = memchr(key, '.', store.baselen);
 680         if (dot) {
 681                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 682                 for (i = dot - key + 1; i < store.baselen; i++) {
 683                         if (key[i] == '"' || key[i] == '\\')
 684                                 strbuf_addch(&sb, '\\');
 685                         strbuf_addch(&sb, key[i]);
 686                 }
 687                 strbuf_addstr(&sb, "\"]\n");
 688         } else {
 689                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 690         }
 691
 692         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 693         strbuf_release(&sb);
 694
 695         return success;
 696 }
 697
 698 static int store_write_pair(int fd, const char* key, const char* value)
 699 {
 700         int i, success;
 701         int length = strlen(key + store.baselen + 1);
 702         const char *quote = "";
 703         struct strbuf sb;
 704
 705         /*
 706          * Check to see if the value needs to be surrounded with a dq pair.
 707          * Note that problematic characters are always backslash-quoted; this
 708          * check is about not losing leading or trailing SP and strings that
 709          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 710          * configuration parser.
 711          */
 712         if (value[0] == ' ')
 713                 quote = "\"";
 714         for (i = 0; value[i]; i++)
 715                 if (value[i] == ';' || value[i] == '#')
 716                         quote = "\"";
 717         if (i && value[i - 1] == ' ')
 718                 quote = "\"";
 719
 720         strbuf_init(&sb, 0);
 721         strbuf_addf(&sb, "\t%.*s = %s",
 722                     length, key + store.baselen + 1, quote);
 723
 724         for (i = 0; value[i]; i++)
 725                 switch (value[i]) {
 726                 case '\n':
 727                         strbuf_addstr(&sb, "\\n");
 728                         break;
 729                 case '\t':
 730                         strbuf_addstr(&sb, "\\t");
 731                         break;
 732                 case '"':
 733                 case '\\':
 734                         strbuf_addch(&sb, '\\');
 735                 default:
 736                         strbuf_addch(&sb, value[i]);
 737                         break;
 738                 }
 739         strbuf_addf(&sb, "%s\n", quote);
 740
 741         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 742         strbuf_release(&sb);
 743
 744         return success;
 745 }
 746
 747 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 748         size_t offset_, int* found_bracket)
 749 {
 750         size_t equal_offset = size, bracket_offset = size;
 751         ssize_t offset;
 752
 753 contline:
 754         for (offset = offset_-2; offset > 0
 755                         && contents[offset] != '\n'; offset--)
 756                 switch (contents[offset]) {
 757                         case '=': equal_offset = offset; break;
 758                         case ']': bracket_offset = offset; break;
 759                 }
 760         if (offset > 0 && contents[offset-1] == '\\') {
 761                 offset_ = offset;
 762                 goto contline;
 763         }
 764         if (bracket_offset < equal_offset) {
 765                 *found_bracket = 1;
 766                 offset = bracket_offset+1;
 767         } else
 768                 offset++;
 769
 770         return offset;
 771 }
 772
 773 int git_config_set(const char* key, const char* value)
 774 {
 775         return git_config_set_multivar(key, value, NULL, 0);
 776 }
 777
 778 /*
 779  * If value==NULL, unset in (remove from) config,
 780  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 781  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 782  *     else all matching key/values (regardless how many) are removed,
 783  *     before the new pair is written.
 784  *
 785  * Returns 0 on success.
 786  *
 787  * This function does this:
 788  *
 789  * - it locks the config file by creating ".git/config.lock"
 790  *
 791  * - it then parses the config using store_aux() as validator to find
 792  *   the position on the key/value pair to replace. If it is to be unset,
 793  *   it must be found exactly once.
 794  *
 795  * - the config file is mmap()ed and the part before the match (if any) is
 796  *   written to the lock file, then the changed part and the rest.
 797  *
 798  * - the config file is removed and the lock file rename()d to it.
 799  *
 800  */
 801 int git_config_set_multivar(const char* key, const char* value,
 802         const char* value_regex, int multi_replace)
 803 {
 804         int i, dot;
 805         int fd = -1, in_fd;
 806         int ret;
 807         char* config_filename;
 808         struct lock_file *lock = NULL;
 809         const char* last_dot = strrchr(key, '.');
 810
 811         config_filename = getenv(CONFIG_ENVIRONMENT);
 812         if (!config_filename) {
 813                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 814                 if (!config_filename)
 815                         config_filename  = git_path("config");
 816         }
 817         config_filename = xstrdup(config_filename);
 818
 819         /*
 820          * Since "key" actually contains the section name and the real
 821          * key name separated by a dot, we have to know where the dot is.
 822          */
 823
 824         if (last_dot == NULL) {
 825                 fprintf(stderr, "key does not contain a section: %s\n", key);
 826                 ret = 2;
 827                 goto out_free;
 828         }
 829         store.baselen = last_dot - key;
 830
 831         store.multi_replace = multi_replace;
 832
 833         /*
 834          * Validate the key and while at it, lower case it for matching.
 835          */
 836         store.key = xmalloc(strlen(key) + 1);
 837         dot = 0;
 838         for (i = 0; key[i]; i++) {
 839                 unsigned char c = key[i];
 840                 if (c == '.')
 841                         dot = 1;
 842                 /* Leave the extended basename untouched.. */
 843                 if (!dot || i > store.baselen) {
 844                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 845                                 fprintf(stderr, "invalid key: %s\n", key);
 846                                 free(store.key);
 847                                 ret = 1;
 848                                 goto out_free;
 849                         }
 850                         c = tolower(c);
 851                 } else if (c == '\n') {
 852                         fprintf(stderr, "invalid key (newline): %s\n", key);
 853                         free(store.key);
 854                         ret = 1;
 855                         goto out_free;
 856                 }
 857                 store.key[i] = c;
 858         }
 859         store.key[i] = 0;
 860
 861         /*
 862          * The lock serves a purpose in addition to locking: the new
 863          * contents of .git/config will be written into it.
 864          */
 865         lock = xcalloc(sizeof(struct lock_file), 1);
 866         fd = hold_lock_file_for_update(lock, config_filename, 0);
 867         if (fd < 0) {
 868                 fprintf(stderr, "could not lock config file\n");
 869                 free(store.key);
 870                 ret = -1;
 871                 goto out_free;
 872         }
 873
 874         /*
 875          * If .git/config does not exist yet, write a minimal version.
 876          */
 877         in_fd = open(config_filename, O_RDONLY);
 878         if ( in_fd < 0 ) {
 879                 free(store.key);
 880
 881                 if ( ENOENT != errno ) {
 882                         error("opening %s: %s", config_filename,
 883                               strerror(errno));
 884                         ret = 3; /* same as "invalid config file" */
 885                         goto out_free;
 886                 }
 887                 /* if nothing to unset, error out */
 888                 if (value == NULL) {
 889                         ret = 5;
 890                         goto out_free;
 891                 }
 892
 893                 store.key = (char*)key;
 894                 if (!store_write_section(fd, key) ||
 895                     !store_write_pair(fd, key, value))
 896                         goto write_err_out;
 897         } else {
 898                 struct stat st;
 899                 char* contents;
 900                 size_t contents_sz, copy_begin, copy_end;
 901                 int i, new_line = 0;
 902
 903                 if (value_regex == NULL)
 904                         store.value_regex = NULL;
 905                 else {
 906                         if (value_regex[0] == '!') {
 907                                 store.do_not_match = 1;
 908                                 value_regex++;
 909                         } else
 910                                 store.do_not_match = 0;
 911
 912                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 913                         if (regcomp(store.value_regex, value_regex,
 914                                         REG_EXTENDED)) {
 915                                 fprintf(stderr, "Invalid pattern: %s\n",
 916                                         value_regex);
 917                                 free(store.value_regex);
 918                                 ret = 6;
 919                                 goto out_free;
 920                         }
 921                 }
 922
 923                 store.offset[0] = 0;
 924                 store.state = START;
 925                 store.seen = 0;
 926
 927                 /*
 928                  * After this, store.offset will contain the *end* offset
 929                  * of the last match, or remain at 0 if no match was found.
 930                  * As a side effect, we make sure to transform only a valid
 931                  * existing config file.
 932                  */
 933                 if (git_config_from_file(store_aux, config_filename)) {
 934                         fprintf(stderr, "invalid config file\n");
 935                         free(store.key);
 936                         if (store.value_regex != NULL) {
 937                                 regfree(store.value_regex);
 938                                 free(store.value_regex);
 939                         }
 940                         ret = 3;
 941                         goto out_free;
 942                 }
 943
 944                 free(store.key);
 945                 if (store.value_regex != NULL) {
 946                         regfree(store.value_regex);
 947                         free(store.value_regex);
 948                 }
 949
 950                 /* if nothing to unset, or too many matches, error out */
 951                 if ((store.seen == 0 && value == NULL) ||
 952                                 (store.seen > 1 && multi_replace == 0)) {
 953                         ret = 5;
 954                         goto out_free;
 955                 }
 956
 957                 fstat(in_fd, &st);
 958                 contents_sz = xsize_t(st.st_size);
 959                 contents = xmmap(NULL, contents_sz, PROT_READ,
 960                         MAP_PRIVATE, in_fd, 0);
 961                 close(in_fd);
 962
 963                 if (store.seen == 0)
 964                         store.seen = 1;
 965
 966                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 967                         if (store.offset[i] == 0) {
 968                                 store.offset[i] = copy_end = contents_sz;
 969                         } else if (store.state != KEY_SEEN) {
 970                                 copy_end = store.offset[i];
 971                         } else
 972                                 copy_end = find_beginning_of_line(
 973                                         contents, contents_sz,
 974                                         store.offset[i]-2, &new_line);
 975
 976                         if (copy_end > 0 && contents[copy_end-1] != '\n')
 977                                 new_line = 1;
 978
 979                         /* write the first part of the config */
 980                         if (copy_end > copy_begin) {
 981                                 if (write_in_full(fd, contents + copy_begin,
 982                                                   copy_end - copy_begin) <
 983                                     copy_end - copy_begin)
 984                                         goto write_err_out;
 985                                 if (new_line &&
 986                                     write_in_full(fd, "\n", 1) != 1)
 987                                         goto write_err_out;
 988                         }
 989                         copy_begin = store.offset[i];
 990                 }
 991
 992                 /* write the pair (value == NULL means unset) */
 993                 if (value != NULL) {
 994                         if (store.state == START) {
 995                                 if (!store_write_section(fd, key))
 996                                         goto write_err_out;
 997                         }
 998                         if (!store_write_pair(fd, key, value))
 999                                 goto write_err_out;
1000                 }
1001
1002                 /* write the rest of the config */
1003                 if (copy_begin < contents_sz)
1004                         if (write_in_full(fd, contents + copy_begin,
1005                                           contents_sz - copy_begin) <
1006                             contents_sz - copy_begin)
1007                                 goto write_err_out;
1008
1009                 munmap(contents, contents_sz);
1010         }
1011
1012         if (commit_lock_file(lock) < 0) {
1013                 fprintf(stderr, "Cannot commit config file!\n");
1014                 ret = 4;
1015                 goto out_free;
1016         }
1017
1018         /*
1019          * lock is committed, so don't try to roll it back below.
1020          * NOTE: Since lockfile.c keeps a linked list of all created
1021          * lock_file structures, it isn't safe to free(lock).  It's
1022          * better to just leave it hanging around.
1023          */
1024         lock = NULL;
1025         ret = 0;
1026
1027 out_free:
1028         if (lock)
1029                 rollback_lock_file(lock);
1030         free(config_filename);
1031         return ret;
1032
1033 write_err_out:
1034         ret = write_error();
1035         goto out_free;
1036
1037 }
1038
1039 static int section_name_match (const char *buf, const char *name)
1040 {
1041         int i = 0, j = 0, dot = 0;
1042         for (; buf[i] && buf[i] != ']'; i++) {
1043                 if (!dot && isspace(buf[i])) {
1044                         dot = 1;
1045                         if (name[j++] != '.')
1046                                 break;
1047                         for (i++; isspace(buf[i]); i++)
1048                                 ; /* do nothing */
1049                         if (buf[i] != '"')
1050                                 break;
1051                         continue;
1052                 }
1053                 if (buf[i] == '\\' && dot)
1054                         i++;
1055                 else if (buf[i] == '"' && dot) {
1056                         for (i++; isspace(buf[i]); i++)
1057                                 ; /* do_nothing */
1058                         break;
1059                 }
1060                 if (buf[i] != name[j++])
1061                         break;
1062         }
1063         return (buf[i] == ']' && name[j] == 0);
1064 }
1065
1066 /* if new_name == NULL, the section is removed instead */
1067 int git_config_rename_section(const char *old_name, const char *new_name)
1068 {
1069         int ret = 0, remove = 0;
1070         char *config_filename;
1071         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1072         int out_fd;
1073         char buf[1024];
1074
1075         config_filename = getenv(CONFIG_ENVIRONMENT);
1076         if (!config_filename) {
1077                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1078                 if (!config_filename)
1079                         config_filename  = git_path("config");
1080         }
1081         config_filename = xstrdup(config_filename);
1082         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1083         if (out_fd < 0) {
1084                 ret = error("Could not lock config file!");
1085                 goto out;
1086         }
1087
1088         if (!(config_file = fopen(config_filename, "rb"))) {
1089                 /* no config file means nothing to rename, no error */
1090                 goto unlock_and_out;
1091         }
1092
1093         while (fgets(buf, sizeof(buf), config_file)) {
1094                 int i;
1095                 int length;
1096                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1097                         ; /* do nothing */
1098                 if (buf[i] == '[') {
1099                         /* it's a section */
1100                         if (section_name_match (&buf[i+1], old_name)) {
1101                                 ret++;
1102                                 if (new_name == NULL) {
1103                                         remove = 1;
1104                                         continue;
1105                                 }
1106                                 store.baselen = strlen(new_name);
1107                                 if (!store_write_section(out_fd, new_name)) {
1108                                         ret = write_error();
1109                                         goto out;
1110                                 }
1111                                 continue;
1112                         }
1113                         remove = 0;
1114                 }
1115                 if (remove)
1116                         continue;
1117                 length = strlen(buf);
1118                 if (write_in_full(out_fd, buf, length) != length) {
1119                         ret = write_error();
1120                         goto out;
1121                 }
1122         }
1123         fclose(config_file);
1124  unlock_and_out:
1125         if (commit_lock_file(lock) < 0)
1126                         ret = error("Cannot commit config file!");
1127  out:
1128         free(config_filename);
1129         return ret;
1130 }
1131
1132 /*
1133  * Call this to report error for your variable that should not
1134  * get a boolean value (i.e. "[my] var" means "true").
1135  */
1136 int config_error_nonbool(const char *var)
1137 {
1138         return error("Missing value for '%s'", var);
1139 }