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 const char *config_exclusive_filename = NULL;
  20
  21 static int get_next_char(void)
  22 {
  23         int c;
  24         FILE *f;
  25
  26         c = '\n';
  27         if ((f = config_file) != NULL) {
  28                 c = fgetc(f);
  29                 if (c == '\r') {
  30                         /* DOS like systems */
  31                         c = fgetc(f);
  32                         if (c != '\n') {
  33                                 ungetc(c, f);
  34                                 c = '\r';
  35                         }
  36                 }
  37                 if (c == '\n')
  38                         config_linenr++;
  39                 if (c == EOF) {
  40                         config_file_eof = 1;
  41                         c = '\n';
  42                 }
  43         }
  44         return c;
  45 }
  46
  47 static char *parse_value(void)
  48 {
  49         static char value[1024];
  50         int quote = 0, comment = 0, len = 0, space = 0;
  51
  52         for (;;) {
  53                 int c = get_next_char();
  54                 if (len >= sizeof(value) - 1)
  55                         return NULL;
  56                 if (c == '\n') {
  57                         if (quote)
  58                                 return NULL;
  59                         value[len] = 0;
  60                         return value;
  61                 }
  62                 if (comment)
  63                         continue;
  64                 if (isspace(c) && !quote) {
  65                         if (len)
  66                                 space++;
  67                         continue;
  68                 }
  69                 if (!quote) {
  70                         if (c == ';' || c == '#') {
  71                                 comment = 1;
  72                                 continue;
  73                         }
  74                 }
  75                 for (; space; space--)
  76                         value[len++] = ' ';
  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, void *data, 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, data);
 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, void *data)
 201 {
 202         int comment = 0;
 203         int baselen = 0;
 204         static char var[MAXNAME];
 205
 206         /* U+FEFF Byte Order Mark in UTF8 */
 207         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 208         const unsigned char *bomptr = utf8_bom;
 209
 210         for (;;) {
 211                 int c = get_next_char();
 212                 if (bomptr && *bomptr) {
 213                         /* We are at the file beginning; skip UTF8-encoded BOM
 214                          * if present. Sane editors won't put this in on their
 215                          * own, but e.g. Windows Notepad will do it happily. */
 216                         if ((unsigned char) c == *bomptr) {
 217                                 bomptr++;
 218                                 continue;
 219                         } else {
 220                                 /* Do not tolerate partial BOM. */
 221                                 if (bomptr != utf8_bom)
 222                                         break;
 223                                 /* No BOM at file beginning. Cool. */
 224                                 bomptr = NULL;
 225                         }
 226                 }
 227                 if (c == '\n') {
 228                         if (config_file_eof)
 229                                 return 0;
 230                         comment = 0;
 231                         continue;
 232                 }
 233                 if (comment || isspace(c))
 234                         continue;
 235                 if (c == '#' || c == ';') {
 236                         comment = 1;
 237                         continue;
 238                 }
 239                 if (c == '[') {
 240                         baselen = get_base_var(var);
 241                         if (baselen <= 0)
 242                                 break;
 243                         var[baselen++] = '.';
 244                         var[baselen] = 0;
 245                         continue;
 246                 }
 247                 if (!isalpha(c))
 248                         break;
 249                 var[baselen] = tolower(c);
 250                 if (get_value(fn, data, var, baselen+1) < 0)
 251                         break;
 252         }
 253         die("bad config file line %d in %s", config_linenr, config_file_name);
 254 }
 255
 256 static int parse_unit_factor(const char *end, unsigned long *val)
 257 {
 258         if (!*end)
 259                 return 1;
 260         else if (!strcasecmp(end, "k")) {
 261                 *val *= 1024;
 262                 return 1;
 263         }
 264         else if (!strcasecmp(end, "m")) {
 265                 *val *= 1024 * 1024;
 266                 return 1;
 267         }
 268         else if (!strcasecmp(end, "g")) {
 269                 *val *= 1024 * 1024 * 1024;
 270                 return 1;
 271         }
 272         return 0;
 273 }
 274
 275 static int git_parse_long(const char *value, long *ret)
 276 {
 277         if (value && *value) {
 278                 char *end;
 279                 long val = strtol(value, &end, 0);
 280                 unsigned long factor = 1;
 281                 if (!parse_unit_factor(end, &factor))
 282                         return 0;
 283                 *ret = val * factor;
 284                 return 1;
 285         }
 286         return 0;
 287 }
 288
 289 int git_parse_ulong(const char *value, unsigned long *ret)
 290 {
 291         if (value && *value) {
 292                 char *end;
 293                 unsigned long val = strtoul(value, &end, 0);
 294                 if (!parse_unit_factor(end, &val))
 295                         return 0;
 296                 *ret = val;
 297                 return 1;
 298         }
 299         return 0;
 300 }
 301
 302 static void die_bad_config(const char *name)
 303 {
 304         if (config_file_name)
 305                 die("bad config value for '%s' in %s", name, config_file_name);
 306         die("bad config value for '%s'", name);
 307 }
 308
 309 int git_config_int(const char *name, const char *value)
 310 {
 311         long ret = 0;
 312         if (!git_parse_long(value, &ret))
 313                 die_bad_config(name);
 314         return ret;
 315 }
 316
 317 unsigned long git_config_ulong(const char *name, const char *value)
 318 {
 319         unsigned long ret;
 320         if (!git_parse_ulong(value, &ret))
 321                 die_bad_config(name);
 322         return ret;
 323 }
 324
 325 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 326 {
 327         *is_bool = 1;
 328         if (!value)
 329                 return 1;
 330         if (!*value)
 331                 return 0;
 332         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 333                 return 1;
 334         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 335                 return 0;
 336         *is_bool = 0;
 337         return git_config_int(name, value);
 338 }
 339
 340 int git_config_bool(const char *name, const char *value)
 341 {
 342         int discard;
 343         return !!git_config_bool_or_int(name, value, &discard);
 344 }
 345
 346 int git_config_string(const char **dest, const char *var, const char *value)
 347 {
 348         if (!value)
 349                 return config_error_nonbool(var);
 350         *dest = xstrdup(value);
 351         return 0;
 352 }
 353
 354 int git_config_pathname(const char **dest, const char *var, const char *value)
 355 {
 356         if (!value)
 357                 return config_error_nonbool(var);
 358         *dest = expand_user_path(value);
 359         if (!*dest)
 360                 die("Failed to expand user dir in: '%s'", value);
 361         return 0;
 362 }
 363
 364 static int git_default_core_config(const char *var, const char *value)
 365 {
 366         /* This needs a better name */
 367         if (!strcmp(var, "core.filemode")) {
 368                 trust_executable_bit = git_config_bool(var, value);
 369                 return 0;
 370         }
 371         if (!strcmp(var, "core.trustctime")) {
 372                 trust_ctime = git_config_bool(var, value);
 373                 return 0;
 374         }
 375
 376         if (!strcmp(var, "core.quotepath")) {
 377                 quote_path_fully = git_config_bool(var, value);
 378                 return 0;
 379         }
 380
 381         if (!strcmp(var, "core.symlinks")) {
 382                 has_symlinks = git_config_bool(var, value);
 383                 return 0;
 384         }
 385
 386         if (!strcmp(var, "core.ignorecase")) {
 387                 ignore_case = git_config_bool(var, value);
 388                 return 0;
 389         }
 390
 391         if (!strcmp(var, "core.bare")) {
 392                 is_bare_repository_cfg = git_config_bool(var, value);
 393                 return 0;
 394         }
 395
 396         if (!strcmp(var, "core.ignorestat")) {
 397                 assume_unchanged = git_config_bool(var, value);
 398                 return 0;
 399         }
 400
 401         if (!strcmp(var, "core.prefersymlinkrefs")) {
 402                 prefer_symlink_refs = git_config_bool(var, value);
 403                 return 0;
 404         }
 405
 406         if (!strcmp(var, "core.logallrefupdates")) {
 407                 log_all_ref_updates = git_config_bool(var, value);
 408                 return 0;
 409         }
 410
 411         if (!strcmp(var, "core.warnambiguousrefs")) {
 412                 warn_ambiguous_refs = git_config_bool(var, value);
 413                 return 0;
 414         }
 415
 416         if (!strcmp(var, "core.loosecompression")) {
 417                 int level = git_config_int(var, value);
 418                 if (level == -1)
 419                         level = Z_DEFAULT_COMPRESSION;
 420                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 421                         die("bad zlib compression level %d", level);
 422                 zlib_compression_level = level;
 423                 zlib_compression_seen = 1;
 424                 return 0;
 425         }
 426
 427         if (!strcmp(var, "core.compression")) {
 428                 int level = git_config_int(var, value);
 429                 if (level == -1)
 430                         level = Z_DEFAULT_COMPRESSION;
 431                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 432                         die("bad zlib compression level %d", level);
 433                 core_compression_level = level;
 434                 core_compression_seen = 1;
 435                 if (!zlib_compression_seen)
 436                         zlib_compression_level = level;
 437                 return 0;
 438         }
 439
 440         if (!strcmp(var, "core.packedgitwindowsize")) {
 441                 int pgsz_x2 = getpagesize() * 2;
 442                 packed_git_window_size = git_config_int(var, value);
 443
 444                 /* This value must be multiple of (pagesize * 2) */
 445                 packed_git_window_size /= pgsz_x2;
 446                 if (packed_git_window_size < 1)
 447                         packed_git_window_size = 1;
 448                 packed_git_window_size *= pgsz_x2;
 449                 return 0;
 450         }
 451
 452         if (!strcmp(var, "core.packedgitlimit")) {
 453                 packed_git_limit = git_config_int(var, value);
 454                 return 0;
 455         }
 456
 457         if (!strcmp(var, "core.deltabasecachelimit")) {
 458                 delta_base_cache_limit = git_config_int(var, value);
 459                 return 0;
 460         }
 461
 462         if (!strcmp(var, "core.autocrlf")) {
 463                 if (value && !strcasecmp(value, "input")) {
 464                         auto_crlf = -1;
 465                         return 0;
 466                 }
 467                 auto_crlf = git_config_bool(var, value);
 468                 return 0;
 469         }
 470
 471         if (!strcmp(var, "core.safecrlf")) {
 472                 if (value && !strcasecmp(value, "warn")) {
 473                         safe_crlf = SAFE_CRLF_WARN;
 474                         return 0;
 475                 }
 476                 safe_crlf = git_config_bool(var, value);
 477                 return 0;
 478         }
 479
 480         if (!strcmp(var, "core.notesref")) {
 481                 notes_ref_name = xstrdup(value);
 482                 return 0;
 483         }
 484
 485         if (!strcmp(var, "core.pager"))
 486                 return git_config_string(&pager_program, var, value);
 487
 488         if (!strcmp(var, "core.editor"))
 489                 return git_config_string(&editor_program, var, value);
 490
 491         if (!strcmp(var, "core.excludesfile"))
 492                 return git_config_pathname(&excludes_file, var, value);
 493
 494         if (!strcmp(var, "core.whitespace")) {
 495                 if (!value)
 496                         return config_error_nonbool(var);
 497                 whitespace_rule_cfg = parse_whitespace_rule(value);
 498                 return 0;
 499         }
 500
 501         if (!strcmp(var, "core.fsyncobjectfiles")) {
 502                 fsync_object_files = git_config_bool(var, value);
 503                 return 0;
 504         }
 505
 506         if (!strcmp(var, "core.preloadindex")) {
 507                 core_preload_index = git_config_bool(var, value);
 508                 return 0;
 509         }
 510
 511         if (!strcmp(var, "core.createobject")) {
 512                 if (!strcmp(value, "rename"))
 513                         object_creation_mode = OBJECT_CREATION_USES_RENAMES;
 514                 else if (!strcmp(value, "link"))
 515                         object_creation_mode = OBJECT_CREATION_USES_HARDLINKS;
 516                 else
 517                         die("Invalid mode for object creation: %s", value);
 518                 return 0;
 519         }
 520
 521         /* Add other config variables here and to Documentation/config.txt. */
 522         return 0;
 523 }
 524
 525 static int git_default_user_config(const char *var, const char *value)
 526 {
 527         if (!strcmp(var, "user.name")) {
 528                 if (!value)
 529                         return config_error_nonbool(var);
 530                 strlcpy(git_default_name, value, sizeof(git_default_name));
 531                 if (git_default_email[0])
 532                         user_ident_explicitly_given = 1;
 533                 return 0;
 534         }
 535
 536         if (!strcmp(var, "user.email")) {
 537                 if (!value)
 538                         return config_error_nonbool(var);
 539                 strlcpy(git_default_email, value, sizeof(git_default_email));
 540                 if (git_default_name[0])
 541                         user_ident_explicitly_given = 1;
 542                 return 0;
 543         }
 544
 545         /* Add other config variables here and to Documentation/config.txt. */
 546         return 0;
 547 }
 548
 549 static int git_default_i18n_config(const char *var, const char *value)
 550 {
 551         if (!strcmp(var, "i18n.commitencoding"))
 552                 return git_config_string(&git_commit_encoding, var, value);
 553
 554         if (!strcmp(var, "i18n.logoutputencoding"))
 555                 return git_config_string(&git_log_output_encoding, var, value);
 556
 557         /* Add other config variables here and to Documentation/config.txt. */
 558         return 0;
 559 }
 560
 561 static int git_default_branch_config(const char *var, const char *value)
 562 {
 563         if (!strcmp(var, "branch.autosetupmerge")) {
 564                 if (value && !strcasecmp(value, "always")) {
 565                         git_branch_track = BRANCH_TRACK_ALWAYS;
 566                         return 0;
 567                 }
 568                 git_branch_track = git_config_bool(var, value);
 569                 return 0;
 570         }
 571         if (!strcmp(var, "branch.autosetuprebase")) {
 572                 if (!value)
 573                         return config_error_nonbool(var);
 574                 else if (!strcmp(value, "never"))
 575                         autorebase = AUTOREBASE_NEVER;
 576                 else if (!strcmp(value, "local"))
 577                         autorebase = AUTOREBASE_LOCAL;
 578                 else if (!strcmp(value, "remote"))
 579                         autorebase = AUTOREBASE_REMOTE;
 580                 else if (!strcmp(value, "always"))
 581                         autorebase = AUTOREBASE_ALWAYS;
 582                 else
 583                         return error("Malformed value for %s", var);
 584                 return 0;
 585         }
 586
 587         /* Add other config variables here and to Documentation/config.txt. */
 588         return 0;
 589 }
 590
 591 static int git_default_push_config(const char *var, const char *value)
 592 {
 593         if (!strcmp(var, "push.default")) {
 594                 if (!value)
 595                         return config_error_nonbool(var);
 596                 else if (!strcmp(value, "nothing"))
 597                         push_default = PUSH_DEFAULT_NOTHING;
 598                 else if (!strcmp(value, "matching"))
 599                         push_default = PUSH_DEFAULT_MATCHING;
 600                 else if (!strcmp(value, "tracking"))
 601                         push_default = PUSH_DEFAULT_TRACKING;
 602                 else if (!strcmp(value, "current"))
 603                         push_default = PUSH_DEFAULT_CURRENT;
 604                 else {
 605                         error("Malformed value for %s: %s", var, value);
 606                         return error("Must be one of nothing, matching, "
 607                                      "tracking or current.");
 608                 }
 609                 return 0;
 610         }
 611
 612         /* Add other config variables here and to Documentation/config.txt. */
 613         return 0;
 614 }
 615
 616 static int git_default_mailmap_config(const char *var, const char *value)
 617 {
 618         if (!strcmp(var, "mailmap.file"))
 619                 return git_config_string(&git_mailmap_file, var, value);
 620
 621         /* Add other config variables here and to Documentation/config.txt. */
 622         return 0;
 623 }
 624
 625 int git_default_config(const char *var, const char *value, void *dummy)
 626 {
 627         if (!prefixcmp(var, "core."))
 628                 return git_default_core_config(var, value);
 629
 630         if (!prefixcmp(var, "user."))
 631                 return git_default_user_config(var, value);
 632
 633         if (!prefixcmp(var, "i18n."))
 634                 return git_default_i18n_config(var, value);
 635
 636         if (!prefixcmp(var, "branch."))
 637                 return git_default_branch_config(var, value);
 638
 639         if (!prefixcmp(var, "push."))
 640                 return git_default_push_config(var, value);
 641
 642         if (!prefixcmp(var, "mailmap."))
 643                 return git_default_mailmap_config(var, value);
 644
 645         if (!prefixcmp(var, "advice."))
 646                 return git_default_advice_config(var, value);
 647
 648         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 649                 pager_use_color = git_config_bool(var,value);
 650                 return 0;
 651         }
 652
 653         /* Add other config variables here and to Documentation/config.txt. */
 654         return 0;
 655 }
 656
 657 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 658 {
 659         int ret;
 660         FILE *f = fopen(filename, "r");
 661
 662         ret = -1;
 663         if (f) {
 664                 config_file = f;
 665                 config_file_name = filename;
 666                 config_linenr = 1;
 667                 config_file_eof = 0;
 668                 ret = git_parse_file(fn, data);
 669                 fclose(f);
 670                 config_file_name = NULL;
 671         }
 672         return ret;
 673 }
 674
 675 const char *git_etc_gitconfig(void)
 676 {
 677         static const char *system_wide;
 678         if (!system_wide)
 679                 system_wide = system_path(ETC_GITCONFIG);
 680         return system_wide;
 681 }
 682
 683 static int git_env_bool(const char *k, int def)
 684 {
 685         const char *v = getenv(k);
 686         return v ? git_config_bool(k, v) : def;
 687 }
 688
 689 int git_config_system(void)
 690 {
 691         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 692 }
 693
 694 int git_config_global(void)
 695 {
 696         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 697 }
 698
 699 int git_config(config_fn_t fn, void *data)
 700 {
 701         int ret = 0, found = 0;
 702         char *repo_config = NULL;
 703         const char *home = NULL;
 704
 705         /* Setting $GIT_CONFIG makes git read _only_ the given config file. */
 706         if (config_exclusive_filename)
 707                 return git_config_from_file(fn, config_exclusive_filename, data);
 708         if (git_config_system() && !access(git_etc_gitconfig(), R_OK)) {
 709                 ret += git_config_from_file(fn, git_etc_gitconfig(),
 710                                             data);
 711                 found += 1;
 712         }
 713
 714         home = getenv("HOME");
 715         if (git_config_global() && home) {
 716                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 717                 if (!access(user_config, R_OK)) {
 718                         ret += git_config_from_file(fn, user_config, data);
 719                         found += 1;
 720                 }
 721                 free(user_config);
 722         }
 723
 724         repo_config = git_pathdup("config");
 725         if (!access(repo_config, R_OK)) {
 726                 ret += git_config_from_file(fn, repo_config, data);
 727                 found += 1;
 728         }
 729         free(repo_config);
 730         if (found == 0)
 731                 return -1;
 732         return ret;
 733 }
 734
 735 /*
 736  * Find all the stuff for git_config_set() below.
 737  */
 738
 739 #define MAX_MATCHES 512
 740
 741 static struct {
 742         int baselen;
 743         char *key;
 744         int do_not_match;
 745         regex_t *value_regex;
 746         int multi_replace;
 747         size_t offset[MAX_MATCHES];
 748         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 749         int seen;
 750 } store;
 751
 752 static int matches(const char *key, const char *value)
 753 {
 754         return !strcmp(key, store.key) &&
 755                 (store.value_regex == NULL ||
 756                  (store.do_not_match ^
 757                   !regexec(store.value_regex, value, 0, NULL, 0)));
 758 }
 759
 760 static int store_aux(const char *key, const char *value, void *cb)
 761 {
 762         const char *ep;
 763         size_t section_len;
 764
 765         switch (store.state) {
 766         case KEY_SEEN:
 767                 if (matches(key, value)) {
 768                         if (store.seen == 1 && store.multi_replace == 0) {
 769                                 warning("%s has multiple values", key);
 770                         } else if (store.seen >= MAX_MATCHES) {
 771                                 error("too many matches for %s", key);
 772                                 return 1;
 773                         }
 774
 775                         store.offset[store.seen] = ftell(config_file);
 776                         store.seen++;
 777                 }
 778                 break;
 779         case SECTION_SEEN:
 780                 /*
 781                  * What we are looking for is in store.key (both
 782                  * section and var), and its section part is baselen
 783                  * long.  We found key (again, both section and var).
 784                  * We would want to know if this key is in the same
 785                  * section as what we are looking for.  We already
 786                  * know we are in the same section as what should
 787                  * hold store.key.
 788                  */
 789                 ep = strrchr(key, '.');
 790                 section_len = ep - key;
 791
 792                 if ((section_len != store.baselen) ||
 793                     memcmp(key, store.key, section_len+1)) {
 794                         store.state = SECTION_END_SEEN;
 795                         break;
 796                 }
 797
 798                 /*
 799                  * Do not increment matches: this is no match, but we
 800                  * just made sure we are in the desired section.
 801                  */
 802                 store.offset[store.seen] = ftell(config_file);
 803                 /* fallthru */
 804         case SECTION_END_SEEN:
 805         case START:
 806                 if (matches(key, value)) {
 807                         store.offset[store.seen] = ftell(config_file);
 808                         store.state = KEY_SEEN;
 809                         store.seen++;
 810                 } else {
 811                         if (strrchr(key, '.') - key == store.baselen &&
 812                               !strncmp(key, store.key, store.baselen)) {
 813                                         store.state = SECTION_SEEN;
 814                                         store.offset[store.seen] = ftell(config_file);
 815                         }
 816                 }
 817         }
 818         return 0;
 819 }
 820
 821 static int write_error(const char *filename)
 822 {
 823         error("failed to write new configuration file %s", filename);
 824
 825         /* Same error code as "failed to rename". */
 826         return 4;
 827 }
 828
 829 static int store_write_section(int fd, const char *key)
 830 {
 831         const char *dot;
 832         int i, success;
 833         struct strbuf sb = STRBUF_INIT;
 834
 835         dot = memchr(key, '.', store.baselen);
 836         if (dot) {
 837                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 838                 for (i = dot - key + 1; i < store.baselen; i++) {
 839                         if (key[i] == '"' || key[i] == '\\')
 840                                 strbuf_addch(&sb, '\\');
 841                         strbuf_addch(&sb, key[i]);
 842                 }
 843                 strbuf_addstr(&sb, "\"]\n");
 844         } else {
 845                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 846         }
 847
 848         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 849         strbuf_release(&sb);
 850
 851         return success;
 852 }
 853
 854 static int store_write_pair(int fd, const char *key, const char *value)
 855 {
 856         int i, success;
 857         int length = strlen(key + store.baselen + 1);
 858         const char *quote = "";
 859         struct strbuf sb = STRBUF_INIT;
 860
 861         /*
 862          * Check to see if the value needs to be surrounded with a dq pair.
 863          * Note that problematic characters are always backslash-quoted; this
 864          * check is about not losing leading or trailing SP and strings that
 865          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 866          * configuration parser.
 867          */
 868         if (value[0] == ' ')
 869                 quote = "\"";
 870         for (i = 0; value[i]; i++)
 871                 if (value[i] == ';' || value[i] == '#')
 872                         quote = "\"";
 873         if (i && value[i - 1] == ' ')
 874                 quote = "\"";
 875
 876         strbuf_addf(&sb, "\t%.*s = %s",
 877                     length, key + store.baselen + 1, quote);
 878
 879         for (i = 0; value[i]; i++)
 880                 switch (value[i]) {
 881                 case '\n':
 882                         strbuf_addstr(&sb, "\\n");
 883                         break;
 884                 case '\t':
 885                         strbuf_addstr(&sb, "\\t");
 886                         break;
 887                 case '"':
 888                 case '\\':
 889                         strbuf_addch(&sb, '\\');
 890                 default:
 891                         strbuf_addch(&sb, value[i]);
 892                         break;
 893                 }
 894         strbuf_addf(&sb, "%s\n", quote);
 895
 896         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 897         strbuf_release(&sb);
 898
 899         return success;
 900 }
 901
 902 static ssize_t find_beginning_of_line(const char *contents, size_t size,
 903         size_t offset_, int *found_bracket)
 904 {
 905         size_t equal_offset = size, bracket_offset = size;
 906         ssize_t offset;
 907
 908 contline:
 909         for (offset = offset_-2; offset > 0
 910                         && contents[offset] != '\n'; offset--)
 911                 switch (contents[offset]) {
 912                         case '=': equal_offset = offset; break;
 913                         case ']': bracket_offset = offset; break;
 914                 }
 915         if (offset > 0 && contents[offset-1] == '\\') {
 916                 offset_ = offset;
 917                 goto contline;
 918         }
 919         if (bracket_offset < equal_offset) {
 920                 *found_bracket = 1;
 921                 offset = bracket_offset+1;
 922         } else
 923                 offset++;
 924
 925         return offset;
 926 }
 927
 928 int git_config_set(const char *key, const char *value)
 929 {
 930         return git_config_set_multivar(key, value, NULL, 0);
 931 }
 932
 933 /*
 934  * If value==NULL, unset in (remove from) config,
 935  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 936  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 937  *     else all matching key/values (regardless how many) are removed,
 938  *     before the new pair is written.
 939  *
 940  * Returns 0 on success.
 941  *
 942  * This function does this:
 943  *
 944  * - it locks the config file by creating ".git/config.lock"
 945  *
 946  * - it then parses the config using store_aux() as validator to find
 947  *   the position on the key/value pair to replace. If it is to be unset,
 948  *   it must be found exactly once.
 949  *
 950  * - the config file is mmap()ed and the part before the match (if any) is
 951  *   written to the lock file, then the changed part and the rest.
 952  *
 953  * - the config file is removed and the lock file rename()d to it.
 954  *
 955  */
 956 int git_config_set_multivar(const char *key, const char *value,
 957         const char *value_regex, int multi_replace)
 958 {
 959         int i, dot;
 960         int fd = -1, in_fd;
 961         int ret;
 962         char *config_filename;
 963         struct lock_file *lock = NULL;
 964         const char *last_dot = strrchr(key, '.');
 965
 966         if (config_exclusive_filename)
 967                 config_filename = xstrdup(config_exclusive_filename);
 968         else
 969                 config_filename = git_pathdup("config");
 970
 971         /*
 972          * Since "key" actually contains the section name and the real
 973          * key name separated by a dot, we have to know where the dot is.
 974          */
 975
 976         if (last_dot == NULL) {
 977                 error("key does not contain a section: %s", key);
 978                 ret = 2;
 979                 goto out_free;
 980         }
 981         store.baselen = last_dot - key;
 982
 983         store.multi_replace = multi_replace;
 984
 985         /*
 986          * Validate the key and while at it, lower case it for matching.
 987          */
 988         store.key = xmalloc(strlen(key) + 1);
 989         dot = 0;
 990         for (i = 0; key[i]; i++) {
 991                 unsigned char c = key[i];
 992                 if (c == '.')
 993                         dot = 1;
 994                 /* Leave the extended basename untouched.. */
 995                 if (!dot || i > store.baselen) {
 996                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 997                                 error("invalid key: %s", key);
 998                                 free(store.key);
 999                                 ret = 1;
1000                                 goto out_free;
1001                         }
1002                         c = tolower(c);
1003                 } else if (c == '\n') {
1004                         error("invalid key (newline): %s", key);
1005                         free(store.key);
1006                         ret = 1;
1007                         goto out_free;
1008                 }
1009                 store.key[i] = c;
1010         }
1011         store.key[i] = 0;
1012
1013         /*
1014          * The lock serves a purpose in addition to locking: the new
1015          * contents of .git/config will be written into it.
1016          */
1017         lock = xcalloc(sizeof(struct lock_file), 1);
1018         fd = hold_lock_file_for_update(lock, config_filename, 0);
1019         if (fd < 0) {
1020                 error("could not lock config file %s: %s", config_filename, strerror(errno));
1021                 free(store.key);
1022                 ret = -1;
1023                 goto out_free;
1024         }
1025
1026         /*
1027          * If .git/config does not exist yet, write a minimal version.
1028          */
1029         in_fd = open(config_filename, O_RDONLY);
1030         if ( in_fd < 0 ) {
1031                 free(store.key);
1032
1033                 if ( ENOENT != errno ) {
1034                         error("opening %s: %s", config_filename,
1035                               strerror(errno));
1036                         ret = 3; /* same as "invalid config file" */
1037                         goto out_free;
1038                 }
1039                 /* if nothing to unset, error out */
1040                 if (value == NULL) {
1041                         ret = 5;
1042                         goto out_free;
1043                 }
1044
1045                 store.key = (char *)key;
1046                 if (!store_write_section(fd, key) ||
1047                     !store_write_pair(fd, key, value))
1048                         goto write_err_out;
1049         } else {
1050                 struct stat st;
1051                 char *contents;
1052                 size_t contents_sz, copy_begin, copy_end;
1053                 int i, new_line = 0;
1054
1055                 if (value_regex == NULL)
1056                         store.value_regex = NULL;
1057                 else {
1058                         if (value_regex[0] == '!') {
1059                                 store.do_not_match = 1;
1060                                 value_regex++;
1061                         } else
1062                                 store.do_not_match = 0;
1063
1064                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
1065                         if (regcomp(store.value_regex, value_regex,
1066                                         REG_EXTENDED)) {
1067                                 error("invalid pattern: %s", value_regex);
1068                                 free(store.value_regex);
1069                                 ret = 6;
1070                                 goto out_free;
1071                         }
1072                 }
1073
1074                 store.offset[0] = 0;
1075                 store.state = START;
1076                 store.seen = 0;
1077
1078                 /*
1079                  * After this, store.offset will contain the *end* offset
1080                  * of the last match, or remain at 0 if no match was found.
1081                  * As a side effect, we make sure to transform only a valid
1082                  * existing config file.
1083                  */
1084                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1085                         error("invalid config file %s", config_filename);
1086                         free(store.key);
1087                         if (store.value_regex != NULL) {
1088                                 regfree(store.value_regex);
1089                                 free(store.value_regex);
1090                         }
1091                         ret = 3;
1092                         goto out_free;
1093                 }
1094
1095                 free(store.key);
1096                 if (store.value_regex != NULL) {
1097                         regfree(store.value_regex);
1098                         free(store.value_regex);
1099                 }
1100
1101                 /* if nothing to unset, or too many matches, error out */
1102                 if ((store.seen == 0 && value == NULL) ||
1103                                 (store.seen > 1 && multi_replace == 0)) {
1104                         ret = 5;
1105                         goto out_free;
1106                 }
1107
1108                 fstat(in_fd, &st);
1109                 contents_sz = xsize_t(st.st_size);
1110                 contents = xmmap(NULL, contents_sz, PROT_READ,
1111                         MAP_PRIVATE, in_fd, 0);
1112                 close(in_fd);
1113
1114                 if (store.seen == 0)
1115                         store.seen = 1;
1116
1117                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1118                         if (store.offset[i] == 0) {
1119                                 store.offset[i] = copy_end = contents_sz;
1120                         } else if (store.state != KEY_SEEN) {
1121                                 copy_end = store.offset[i];
1122                         } else
1123                                 copy_end = find_beginning_of_line(
1124                                         contents, contents_sz,
1125                                         store.offset[i]-2, &new_line);
1126
1127                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1128                                 new_line = 1;
1129
1130                         /* write the first part of the config */
1131                         if (copy_end > copy_begin) {
1132                                 if (write_in_full(fd, contents + copy_begin,
1133                                                   copy_end - copy_begin) <
1134                                     copy_end - copy_begin)
1135                                         goto write_err_out;
1136                                 if (new_line &&
1137                                     write_str_in_full(fd, "\n") != 1)
1138                                         goto write_err_out;
1139                         }
1140                         copy_begin = store.offset[i];
1141                 }
1142
1143                 /* write the pair (value == NULL means unset) */
1144                 if (value != NULL) {
1145                         if (store.state == START) {
1146                                 if (!store_write_section(fd, key))
1147                                         goto write_err_out;
1148                         }
1149                         if (!store_write_pair(fd, key, value))
1150                                 goto write_err_out;
1151                 }
1152
1153                 /* write the rest of the config */
1154                 if (copy_begin < contents_sz)
1155                         if (write_in_full(fd, contents + copy_begin,
1156                                           contents_sz - copy_begin) <
1157                             contents_sz - copy_begin)
1158                                 goto write_err_out;
1159
1160                 munmap(contents, contents_sz);
1161         }
1162
1163         if (commit_lock_file(lock) < 0) {
1164                 error("could not commit config file %s", config_filename);
1165                 ret = 4;
1166                 goto out_free;
1167         }
1168
1169         /*
1170          * lock is committed, so don't try to roll it back below.
1171          * NOTE: Since lockfile.c keeps a linked list of all created
1172          * lock_file structures, it isn't safe to free(lock).  It's
1173          * better to just leave it hanging around.
1174          */
1175         lock = NULL;
1176         ret = 0;
1177
1178 out_free:
1179         if (lock)
1180                 rollback_lock_file(lock);
1181         free(config_filename);
1182         return ret;
1183
1184 write_err_out:
1185         ret = write_error(lock->filename);
1186         goto out_free;
1187
1188 }
1189
1190 static int section_name_match (const char *buf, const char *name)
1191 {
1192         int i = 0, j = 0, dot = 0;
1193         if (buf[i] != '[')
1194                 return 0;
1195         for (i = 1; buf[i] && buf[i] != ']'; i++) {
1196                 if (!dot && isspace(buf[i])) {
1197                         dot = 1;
1198                         if (name[j++] != '.')
1199                                 break;
1200                         for (i++; isspace(buf[i]); i++)
1201                                 ; /* do nothing */
1202                         if (buf[i] != '"')
1203                                 break;
1204                         continue;
1205                 }
1206                 if (buf[i] == '\\' && dot)
1207                         i++;
1208                 else if (buf[i] == '"' && dot) {
1209                         for (i++; isspace(buf[i]); i++)
1210                                 ; /* do_nothing */
1211                         break;
1212                 }
1213                 if (buf[i] != name[j++])
1214                         break;
1215         }
1216         if (buf[i] == ']' && name[j] == 0) {
1217                 /*
1218                  * We match, now just find the right length offset by
1219                  * gobbling up any whitespace after it, as well
1220                  */
1221                 i++;
1222                 for (; buf[i] && isspace(buf[i]); i++)
1223                         ; /* do nothing */
1224                 return i;
1225         }
1226         return 0;
1227 }
1228
1229 /* if new_name == NULL, the section is removed instead */
1230 int git_config_rename_section(const char *old_name, const char *new_name)
1231 {
1232         int ret = 0, remove = 0;
1233         char *config_filename;
1234         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1235         int out_fd;
1236         char buf[1024];
1237
1238         if (config_exclusive_filename)
1239                 config_filename = xstrdup(config_exclusive_filename);
1240         else
1241                 config_filename = git_pathdup("config");
1242         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1243         if (out_fd < 0) {
1244                 ret = error("could not lock config file %s", config_filename);
1245                 goto out;
1246         }
1247
1248         if (!(config_file = fopen(config_filename, "rb"))) {
1249                 /* no config file means nothing to rename, no error */
1250                 goto unlock_and_out;
1251         }
1252
1253         while (fgets(buf, sizeof(buf), config_file)) {
1254                 int i;
1255                 int length;
1256                 char *output = buf;
1257                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1258                         ; /* do nothing */
1259                 if (buf[i] == '[') {
1260                         /* it's a section */
1261                         int offset = section_name_match(&buf[i], old_name);
1262                         if (offset > 0) {
1263                                 ret++;
1264                                 if (new_name == NULL) {
1265                                         remove = 1;
1266                                         continue;
1267                                 }
1268                                 store.baselen = strlen(new_name);
1269                                 if (!store_write_section(out_fd, new_name)) {
1270                                         ret = write_error(lock->filename);
1271                                         goto out;
1272                                 }
1273                                 /*
1274                                  * We wrote out the new section, with
1275                                  * a newline, now skip the old
1276                                  * section's length
1277                                  */
1278                                 output += offset + i;
1279                                 if (strlen(output) > 0) {
1280                                         /*
1281                                          * More content means there's
1282                                          * a declaration to put on the
1283                                          * next line; indent with a
1284                                          * tab
1285                                          */
1286                                         output -= 1;
1287                                         output[0] = '\t';
1288                                 }
1289                         }
1290                         remove = 0;
1291                 }
1292                 if (remove)
1293                         continue;
1294                 length = strlen(output);
1295                 if (write_in_full(out_fd, output, length) != length) {
1296                         ret = write_error(lock->filename);
1297                         goto out;
1298                 }
1299         }
1300         fclose(config_file);
1301  unlock_and_out:
1302         if (commit_lock_file(lock) < 0)
1303                 ret = error("could not commit config file %s", config_filename);
1304  out:
1305         free(config_filename);
1306         return ret;
1307 }
1308
1309 /*
1310  * Call this to report error for your variable that should not
1311  * get a boolean value (i.e. "[my] var" means "true").
1312  */
1313 int config_error_nonbool(const char *var)
1314 {
1315         return error("Missing value for '%s'", var);
1316 }