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))
  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                         space = 1;
  66                         continue;
  67                 }
  68                 if (!quote) {
  69                         if (c == ';' || c == '#') {
  70                                 comment = 1;
  71                                 continue;
  72                         }
  73                 }
  74                 if (space) {
  75                         if (len)
  76                                 value[len++] = ' ';
  77                         space = 0;
  78                 }
  79                 if (c == '\\') {
  80                         c = get_next_char();
  81                         switch (c) {
  82                         case '\n':
  83                                 continue;
  84                         case 't':
  85                                 c = '\t';
  86                                 break;
  87                         case 'b':
  88                                 c = '\b';
  89                                 break;
  90                         case 'n':
  91                                 c = '\n';
  92                                 break;
  93                         /* Some characters escape as themselves */
  94                         case '\\': case '"':
  95                                 break;
  96                         /* Reject unknown escape sequences */
  97                         default:
  98                                 return NULL;
  99                         }
 100                         value[len++] = c;
 101                         continue;
 102                 }
 103                 if (c == '"') {
 104                         quote = 1-quote;
 105                         continue;
 106                 }
 107                 value[len++] = c;
 108         }
 109 }
 110
 111 static inline int iskeychar(int c)
 112 {
 113         return isalnum(c) || c == '-';
 114 }
 115
 116 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 117 {
 118         int c;
 119         char *value;
 120
 121         /* Get the full name */
 122         for (;;) {
 123                 c = get_next_char();
 124                 if (config_file_eof)
 125                         break;
 126                 if (!iskeychar(c))
 127                         break;
 128                 name[len++] = tolower(c);
 129                 if (len >= MAXNAME)
 130                         return -1;
 131         }
 132         name[len] = 0;
 133         while (c == ' ' || c == '\t')
 134                 c = get_next_char();
 135
 136         value = NULL;
 137         if (c != '\n') {
 138                 if (c != '=')
 139                         return -1;
 140                 value = parse_value();
 141                 if (!value)
 142                         return -1;
 143         }
 144         return fn(name, value, data);
 145 }
 146
 147 static int get_extended_base_var(char *name, int baselen, int c)
 148 {
 149         do {
 150                 if (c == '\n')
 151                         return -1;
 152                 c = get_next_char();
 153         } while (isspace(c));
 154
 155         /* We require the format to be '[base "extension"]' */
 156         if (c != '"')
 157                 return -1;
 158         name[baselen++] = '.';
 159
 160         for (;;) {
 161                 int c = get_next_char();
 162                 if (c == '\n')
 163                         return -1;
 164                 if (c == '"')
 165                         break;
 166                 if (c == '\\') {
 167                         c = get_next_char();
 168                         if (c == '\n')
 169                                 return -1;
 170                 }
 171                 name[baselen++] = c;
 172                 if (baselen > MAXNAME / 2)
 173                         return -1;
 174         }
 175
 176         /* Final ']' */
 177         if (get_next_char() != ']')
 178                 return -1;
 179         return baselen;
 180 }
 181
 182 static int get_base_var(char *name)
 183 {
 184         int baselen = 0;
 185
 186         for (;;) {
 187                 int c = get_next_char();
 188                 if (config_file_eof)
 189                         return -1;
 190                 if (c == ']')
 191                         return baselen;
 192                 if (isspace(c))
 193                         return get_extended_base_var(name, baselen, c);
 194                 if (!iskeychar(c) && c != '.')
 195                         return -1;
 196                 if (baselen > MAXNAME / 2)
 197                         return -1;
 198                 name[baselen++] = tolower(c);
 199         }
 200 }
 201
 202 static int git_parse_file(config_fn_t fn, void *data)
 203 {
 204         int comment = 0;
 205         int baselen = 0;
 206         static char var[MAXNAME];
 207
 208         /* U+FEFF Byte Order Mark in UTF8 */
 209         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 210         const unsigned char *bomptr = utf8_bom;
 211
 212         for (;;) {
 213                 int c = get_next_char();
 214                 if (bomptr && *bomptr) {
 215                         /* We are at the file beginning; skip UTF8-encoded BOM
 216                          * if present. Sane editors won't put this in on their
 217                          * own, but e.g. Windows Notepad will do it happily. */
 218                         if ((unsigned char) c == *bomptr) {
 219                                 bomptr++;
 220                                 continue;
 221                         } else {
 222                                 /* Do not tolerate partial BOM. */
 223                                 if (bomptr != utf8_bom)
 224                                         break;
 225                                 /* No BOM at file beginning. Cool. */
 226                                 bomptr = NULL;
 227                         }
 228                 }
 229                 if (c == '\n') {
 230                         if (config_file_eof)
 231                                 return 0;
 232                         comment = 0;
 233                         continue;
 234                 }
 235                 if (comment || isspace(c))
 236                         continue;
 237                 if (c == '#' || c == ';') {
 238                         comment = 1;
 239                         continue;
 240                 }
 241                 if (c == '[') {
 242                         baselen = get_base_var(var);
 243                         if (baselen <= 0)
 244                                 break;
 245                         var[baselen++] = '.';
 246                         var[baselen] = 0;
 247                         continue;
 248                 }
 249                 if (!isalpha(c))
 250                         break;
 251                 var[baselen] = tolower(c);
 252                 if (get_value(fn, data, var, baselen+1) < 0)
 253                         break;
 254         }
 255         die("bad config file line %d in %s", config_linenr, config_file_name);
 256 }
 257
 258 static int parse_unit_factor(const char *end, unsigned long *val)
 259 {
 260         if (!*end)
 261                 return 1;
 262         else if (!strcasecmp(end, "k")) {
 263                 *val *= 1024;
 264                 return 1;
 265         }
 266         else if (!strcasecmp(end, "m")) {
 267                 *val *= 1024 * 1024;
 268                 return 1;
 269         }
 270         else if (!strcasecmp(end, "g")) {
 271                 *val *= 1024 * 1024 * 1024;
 272                 return 1;
 273         }
 274         return 0;
 275 }
 276
 277 static int git_parse_long(const char *value, long *ret)
 278 {
 279         if (value && *value) {
 280                 char *end;
 281                 long val = strtol(value, &end, 0);
 282                 unsigned long factor = 1;
 283                 if (!parse_unit_factor(end, &factor))
 284                         return 0;
 285                 *ret = val * factor;
 286                 return 1;
 287         }
 288         return 0;
 289 }
 290
 291 int git_parse_ulong(const char *value, unsigned long *ret)
 292 {
 293         if (value && *value) {
 294                 char *end;
 295                 unsigned long val = strtoul(value, &end, 0);
 296                 if (!parse_unit_factor(end, &val))
 297                         return 0;
 298                 *ret = val;
 299                 return 1;
 300         }
 301         return 0;
 302 }
 303
 304 static void die_bad_config(const char *name)
 305 {
 306         if (config_file_name)
 307                 die("bad config value for '%s' in %s", name, config_file_name);
 308         die("bad config value for '%s'", name);
 309 }
 310
 311 int git_config_int(const char *name, const char *value)
 312 {
 313         long ret = 0;
 314         if (!git_parse_long(value, &ret))
 315                 die_bad_config(name);
 316         return ret;
 317 }
 318
 319 unsigned long git_config_ulong(const char *name, const char *value)
 320 {
 321         unsigned long ret;
 322         if (!git_parse_ulong(value, &ret))
 323                 die_bad_config(name);
 324         return ret;
 325 }
 326
 327 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 328 {
 329         *is_bool = 1;
 330         if (!value)
 331                 return 1;
 332         if (!*value)
 333                 return 0;
 334         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 335                 return 1;
 336         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 337                 return 0;
 338         *is_bool = 0;
 339         return git_config_int(name, value);
 340 }
 341
 342 int git_config_bool(const char *name, const char *value)
 343 {
 344         int discard;
 345         return !!git_config_bool_or_int(name, value, &discard);
 346 }
 347
 348 int git_config_string(const char **dest, const char *var, const char *value)
 349 {
 350         if (!value)
 351                 return config_error_nonbool(var);
 352         *dest = xstrdup(value);
 353         return 0;
 354 }
 355
 356 static int git_default_core_config(const char *var, const char *value)
 357 {
 358         /* This needs a better name */
 359         if (!strcmp(var, "core.filemode")) {
 360                 trust_executable_bit = git_config_bool(var, value);
 361                 return 0;
 362         }
 363         if (!strcmp(var, "core.trustctime")) {
 364                 trust_ctime = git_config_bool(var, value);
 365                 return 0;
 366         }
 367
 368         if (!strcmp(var, "core.quotepath")) {
 369                 quote_path_fully = git_config_bool(var, value);
 370                 return 0;
 371         }
 372
 373         if (!strcmp(var, "core.symlinks")) {
 374                 has_symlinks = git_config_bool(var, value);
 375                 return 0;
 376         }
 377
 378         if (!strcmp(var, "core.ignorecase")) {
 379                 ignore_case = git_config_bool(var, value);
 380                 return 0;
 381         }
 382
 383         if (!strcmp(var, "core.bare")) {
 384                 is_bare_repository_cfg = git_config_bool(var, value);
 385                 return 0;
 386         }
 387
 388         if (!strcmp(var, "core.ignorestat")) {
 389                 assume_unchanged = git_config_bool(var, value);
 390                 return 0;
 391         }
 392
 393         if (!strcmp(var, "core.prefersymlinkrefs")) {
 394                 prefer_symlink_refs = git_config_bool(var, value);
 395                 return 0;
 396         }
 397
 398         if (!strcmp(var, "core.logallrefupdates")) {
 399                 log_all_ref_updates = git_config_bool(var, value);
 400                 return 0;
 401         }
 402
 403         if (!strcmp(var, "core.warnambiguousrefs")) {
 404                 warn_ambiguous_refs = git_config_bool(var, value);
 405                 return 0;
 406         }
 407
 408         if (!strcmp(var, "core.loosecompression")) {
 409                 int level = git_config_int(var, value);
 410                 if (level == -1)
 411                         level = Z_DEFAULT_COMPRESSION;
 412                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 413                         die("bad zlib compression level %d", level);
 414                 zlib_compression_level = level;
 415                 zlib_compression_seen = 1;
 416                 return 0;
 417         }
 418
 419         if (!strcmp(var, "core.compression")) {
 420                 int level = git_config_int(var, value);
 421                 if (level == -1)
 422                         level = Z_DEFAULT_COMPRESSION;
 423                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 424                         die("bad zlib compression level %d", level);
 425                 core_compression_level = level;
 426                 core_compression_seen = 1;
 427                 if (!zlib_compression_seen)
 428                         zlib_compression_level = level;
 429                 return 0;
 430         }
 431
 432         if (!strcmp(var, "core.packedgitwindowsize")) {
 433                 int pgsz_x2 = getpagesize() * 2;
 434                 packed_git_window_size = git_config_int(var, value);
 435
 436                 /* This value must be multiple of (pagesize * 2) */
 437                 packed_git_window_size /= pgsz_x2;
 438                 if (packed_git_window_size < 1)
 439                         packed_git_window_size = 1;
 440                 packed_git_window_size *= pgsz_x2;
 441                 return 0;
 442         }
 443
 444         if (!strcmp(var, "core.packedgitlimit")) {
 445                 packed_git_limit = git_config_int(var, value);
 446                 return 0;
 447         }
 448
 449         if (!strcmp(var, "core.deltabasecachelimit")) {
 450                 delta_base_cache_limit = git_config_int(var, value);
 451                 return 0;
 452         }
 453
 454         if (!strcmp(var, "core.autocrlf")) {
 455                 if (value && !strcasecmp(value, "input")) {
 456                         auto_crlf = -1;
 457                         return 0;
 458                 }
 459                 auto_crlf = git_config_bool(var, value);
 460                 return 0;
 461         }
 462
 463         if (!strcmp(var, "core.safecrlf")) {
 464                 if (value && !strcasecmp(value, "warn")) {
 465                         safe_crlf = SAFE_CRLF_WARN;
 466                         return 0;
 467                 }
 468                 safe_crlf = git_config_bool(var, value);
 469                 return 0;
 470         }
 471
 472         if (!strcmp(var, "core.pager"))
 473                 return git_config_string(&pager_program, var, value);
 474
 475         if (!strcmp(var, "core.editor"))
 476                 return git_config_string(&editor_program, var, value);
 477
 478         if (!strcmp(var, "core.excludesfile"))
 479                 return git_config_string(&excludes_file, var, value);
 480
 481         if (!strcmp(var, "core.whitespace")) {
 482                 if (!value)
 483                         return config_error_nonbool(var);
 484                 whitespace_rule_cfg = parse_whitespace_rule(value);
 485                 return 0;
 486         }
 487
 488         if (!strcmp(var, "core.fsyncobjectfiles")) {
 489                 fsync_object_files = git_config_bool(var, value);
 490                 return 0;
 491         }
 492
 493         if (!strcmp(var, "core.preloadindex")) {
 494                 core_preload_index = git_config_bool(var, value);
 495                 return 0;
 496         }
 497
 498         /* Add other config variables here and to Documentation/config.txt. */
 499         return 0;
 500 }
 501
 502 static int git_default_user_config(const char *var, const char *value)
 503 {
 504         if (!strcmp(var, "user.name")) {
 505                 if (!value)
 506                         return config_error_nonbool(var);
 507                 strlcpy(git_default_name, value, sizeof(git_default_name));
 508                 if (git_default_email[0])
 509                         user_ident_explicitly_given = 1;
 510                 return 0;
 511         }
 512
 513         if (!strcmp(var, "user.email")) {
 514                 if (!value)
 515                         return config_error_nonbool(var);
 516                 strlcpy(git_default_email, value, sizeof(git_default_email));
 517                 if (git_default_name[0])
 518                         user_ident_explicitly_given = 1;
 519                 return 0;
 520         }
 521
 522         /* Add other config variables here and to Documentation/config.txt. */
 523         return 0;
 524 }
 525
 526 static int git_default_i18n_config(const char *var, const char *value)
 527 {
 528         if (!strcmp(var, "i18n.commitencoding"))
 529                 return git_config_string(&git_commit_encoding, var, value);
 530
 531         if (!strcmp(var, "i18n.logoutputencoding"))
 532                 return git_config_string(&git_log_output_encoding, var, value);
 533
 534         /* Add other config variables here and to Documentation/config.txt. */
 535         return 0;
 536 }
 537
 538 static int git_default_branch_config(const char *var, const char *value)
 539 {
 540         if (!strcmp(var, "branch.autosetupmerge")) {
 541                 if (value && !strcasecmp(value, "always")) {
 542                         git_branch_track = BRANCH_TRACK_ALWAYS;
 543                         return 0;
 544                 }
 545                 git_branch_track = git_config_bool(var, value);
 546                 return 0;
 547         }
 548         if (!strcmp(var, "branch.autosetuprebase")) {
 549                 if (!value)
 550                         return config_error_nonbool(var);
 551                 else if (!strcmp(value, "never"))
 552                         autorebase = AUTOREBASE_NEVER;
 553                 else if (!strcmp(value, "local"))
 554                         autorebase = AUTOREBASE_LOCAL;
 555                 else if (!strcmp(value, "remote"))
 556                         autorebase = AUTOREBASE_REMOTE;
 557                 else if (!strcmp(value, "always"))
 558                         autorebase = AUTOREBASE_ALWAYS;
 559                 else
 560                         return error("Malformed value for %s", var);
 561                 return 0;
 562         }
 563
 564         /* Add other config variables here and to Documentation/config.txt. */
 565         return 0;
 566 }
 567
 568 int git_default_config(const char *var, const char *value, void *dummy)
 569 {
 570         if (!prefixcmp(var, "core."))
 571                 return git_default_core_config(var, value);
 572
 573         if (!prefixcmp(var, "user."))
 574                 return git_default_user_config(var, value);
 575
 576         if (!prefixcmp(var, "i18n."))
 577                 return git_default_i18n_config(var, value);
 578
 579         if (!prefixcmp(var, "branch."))
 580                 return git_default_branch_config(var, value);
 581
 582         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 583                 pager_use_color = git_config_bool(var,value);
 584                 return 0;
 585         }
 586
 587         /* Add other config variables here and to Documentation/config.txt. */
 588         return 0;
 589 }
 590
 591 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 592 {
 593         int ret;
 594         FILE *f = fopen(filename, "r");
 595
 596         ret = -1;
 597         if (f) {
 598                 config_file = f;
 599                 config_file_name = filename;
 600                 config_linenr = 1;
 601                 config_file_eof = 0;
 602                 ret = git_parse_file(fn, data);
 603                 fclose(f);
 604                 config_file_name = NULL;
 605         }
 606         return ret;
 607 }
 608
 609 const char *git_etc_gitconfig(void)
 610 {
 611         static const char *system_wide;
 612         if (!system_wide)
 613                 system_wide = system_path(ETC_GITCONFIG);
 614         return system_wide;
 615 }
 616
 617 static int git_env_bool(const char *k, int def)
 618 {
 619         const char *v = getenv(k);
 620         return v ? git_config_bool(k, v) : def;
 621 }
 622
 623 int git_config_system(void)
 624 {
 625         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 626 }
 627
 628 int git_config_global(void)
 629 {
 630         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 631 }
 632
 633 int git_config(config_fn_t fn, void *data)
 634 {
 635         int ret = 0;
 636         char *repo_config = NULL;
 637         const char *home = NULL;
 638
 639         /* $GIT_CONFIG makes git read _only_ the given config file,
 640          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 641          * global config file, the same way it would the per-repository
 642          * config file otherwise. */
 643         if (config_exclusive_filename)
 644                 return git_config_from_file(fn, config_exclusive_filename, data);
 645         if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 646                 ret += git_config_from_file(fn, git_etc_gitconfig(),
 647                                             data);
 648
 649         home = getenv("HOME");
 650         if (git_config_global() && home) {
 651                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 652                 if (!access(user_config, R_OK))
 653                         ret += git_config_from_file(fn, user_config, data);
 654                 free(user_config);
 655         }
 656
 657         repo_config = git_pathdup("config");
 658         ret += git_config_from_file(fn, repo_config, data);
 659         free(repo_config);
 660         return ret;
 661 }
 662
 663 /*
 664  * Find all the stuff for git_config_set() below.
 665  */
 666
 667 #define MAX_MATCHES 512
 668
 669 static struct {
 670         int baselen;
 671         char* key;
 672         int do_not_match;
 673         regex_t* value_regex;
 674         int multi_replace;
 675         size_t offset[MAX_MATCHES];
 676         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 677         int seen;
 678 } store;
 679
 680 static int matches(const char* key, const char* value)
 681 {
 682         return !strcmp(key, store.key) &&
 683                 (store.value_regex == NULL ||
 684                  (store.do_not_match ^
 685                   !regexec(store.value_regex, value, 0, NULL, 0)));
 686 }
 687
 688 static int store_aux(const char* key, const char* value, void *cb)
 689 {
 690         const char *ep;
 691         size_t section_len;
 692
 693         switch (store.state) {
 694         case KEY_SEEN:
 695                 if (matches(key, value)) {
 696                         if (store.seen == 1 && store.multi_replace == 0) {
 697                                 warning("%s has multiple values", key);
 698                         } else if (store.seen >= MAX_MATCHES) {
 699                                 error("too many matches for %s", key);
 700                                 return 1;
 701                         }
 702
 703                         store.offset[store.seen] = ftell(config_file);
 704                         store.seen++;
 705                 }
 706                 break;
 707         case SECTION_SEEN:
 708                 /*
 709                  * What we are looking for is in store.key (both
 710                  * section and var), and its section part is baselen
 711                  * long.  We found key (again, both section and var).
 712                  * We would want to know if this key is in the same
 713                  * section as what we are looking for.  We already
 714                  * know we are in the same section as what should
 715                  * hold store.key.
 716                  */
 717                 ep = strrchr(key, '.');
 718                 section_len = ep - key;
 719
 720                 if ((section_len != store.baselen) ||
 721                     memcmp(key, store.key, section_len+1)) {
 722                         store.state = SECTION_END_SEEN;
 723                         break;
 724                 }
 725
 726                 /*
 727                  * Do not increment matches: this is no match, but we
 728                  * just made sure we are in the desired section.
 729                  */
 730                 store.offset[store.seen] = ftell(config_file);
 731                 /* fallthru */
 732         case SECTION_END_SEEN:
 733         case START:
 734                 if (matches(key, value)) {
 735                         store.offset[store.seen] = ftell(config_file);
 736                         store.state = KEY_SEEN;
 737                         store.seen++;
 738                 } else {
 739                         if (strrchr(key, '.') - key == store.baselen &&
 740                               !strncmp(key, store.key, store.baselen)) {
 741                                         store.state = SECTION_SEEN;
 742                                         store.offset[store.seen] = ftell(config_file);
 743                         }
 744                 }
 745         }
 746         return 0;
 747 }
 748
 749 static int write_error(const char *filename)
 750 {
 751         error("failed to write new configuration file %s", filename);
 752
 753         /* Same error code as "failed to rename". */
 754         return 4;
 755 }
 756
 757 static int store_write_section(int fd, const char* key)
 758 {
 759         const char *dot;
 760         int i, success;
 761         struct strbuf sb = STRBUF_INIT;
 762
 763         dot = memchr(key, '.', store.baselen);
 764         if (dot) {
 765                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 766                 for (i = dot - key + 1; i < store.baselen; i++) {
 767                         if (key[i] == '"' || key[i] == '\\')
 768                                 strbuf_addch(&sb, '\\');
 769                         strbuf_addch(&sb, key[i]);
 770                 }
 771                 strbuf_addstr(&sb, "\"]\n");
 772         } else {
 773                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 774         }
 775
 776         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 777         strbuf_release(&sb);
 778
 779         return success;
 780 }
 781
 782 static int store_write_pair(int fd, const char* key, const char* value)
 783 {
 784         int i, success;
 785         int length = strlen(key + store.baselen + 1);
 786         const char *quote = "";
 787         struct strbuf sb = STRBUF_INIT;
 788
 789         /*
 790          * Check to see if the value needs to be surrounded with a dq pair.
 791          * Note that problematic characters are always backslash-quoted; this
 792          * check is about not losing leading or trailing SP and strings that
 793          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 794          * configuration parser.
 795          */
 796         if (value[0] == ' ')
 797                 quote = "\"";
 798         for (i = 0; value[i]; i++)
 799                 if (value[i] == ';' || value[i] == '#')
 800                         quote = "\"";
 801         if (i && value[i - 1] == ' ')
 802                 quote = "\"";
 803
 804         strbuf_addf(&sb, "\t%.*s = %s",
 805                     length, key + store.baselen + 1, quote);
 806
 807         for (i = 0; value[i]; i++)
 808                 switch (value[i]) {
 809                 case '\n':
 810                         strbuf_addstr(&sb, "\\n");
 811                         break;
 812                 case '\t':
 813                         strbuf_addstr(&sb, "\\t");
 814                         break;
 815                 case '"':
 816                 case '\\':
 817                         strbuf_addch(&sb, '\\');
 818                 default:
 819                         strbuf_addch(&sb, value[i]);
 820                         break;
 821                 }
 822         strbuf_addf(&sb, "%s\n", quote);
 823
 824         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 825         strbuf_release(&sb);
 826
 827         return success;
 828 }
 829
 830 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 831         size_t offset_, int* found_bracket)
 832 {
 833         size_t equal_offset = size, bracket_offset = size;
 834         ssize_t offset;
 835
 836 contline:
 837         for (offset = offset_-2; offset > 0
 838                         && contents[offset] != '\n'; offset--)
 839                 switch (contents[offset]) {
 840                         case '=': equal_offset = offset; break;
 841                         case ']': bracket_offset = offset; break;
 842                 }
 843         if (offset > 0 && contents[offset-1] == '\\') {
 844                 offset_ = offset;
 845                 goto contline;
 846         }
 847         if (bracket_offset < equal_offset) {
 848                 *found_bracket = 1;
 849                 offset = bracket_offset+1;
 850         } else
 851                 offset++;
 852
 853         return offset;
 854 }
 855
 856 int git_config_set(const char* key, const char* value)
 857 {
 858         return git_config_set_multivar(key, value, NULL, 0);
 859 }
 860
 861 /*
 862  * If value==NULL, unset in (remove from) config,
 863  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 864  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 865  *     else all matching key/values (regardless how many) are removed,
 866  *     before the new pair is written.
 867  *
 868  * Returns 0 on success.
 869  *
 870  * This function does this:
 871  *
 872  * - it locks the config file by creating ".git/config.lock"
 873  *
 874  * - it then parses the config using store_aux() as validator to find
 875  *   the position on the key/value pair to replace. If it is to be unset,
 876  *   it must be found exactly once.
 877  *
 878  * - the config file is mmap()ed and the part before the match (if any) is
 879  *   written to the lock file, then the changed part and the rest.
 880  *
 881  * - the config file is removed and the lock file rename()d to it.
 882  *
 883  */
 884 int git_config_set_multivar(const char* key, const char* value,
 885         const char* value_regex, int multi_replace)
 886 {
 887         int i, dot;
 888         int fd = -1, in_fd;
 889         int ret;
 890         char* config_filename;
 891         struct lock_file *lock = NULL;
 892         const char* last_dot = strrchr(key, '.');
 893
 894         if (config_exclusive_filename)
 895                 config_filename = xstrdup(config_exclusive_filename);
 896         else
 897                 config_filename = git_pathdup("config");
 898
 899         /*
 900          * Since "key" actually contains the section name and the real
 901          * key name separated by a dot, we have to know where the dot is.
 902          */
 903
 904         if (last_dot == NULL) {
 905                 error("key does not contain a section: %s", key);
 906                 ret = 2;
 907                 goto out_free;
 908         }
 909         store.baselen = last_dot - key;
 910
 911         store.multi_replace = multi_replace;
 912
 913         /*
 914          * Validate the key and while at it, lower case it for matching.
 915          */
 916         store.key = xmalloc(strlen(key) + 1);
 917         dot = 0;
 918         for (i = 0; key[i]; i++) {
 919                 unsigned char c = key[i];
 920                 if (c == '.')
 921                         dot = 1;
 922                 /* Leave the extended basename untouched.. */
 923                 if (!dot || i > store.baselen) {
 924                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 925                                 error("invalid key: %s", key);
 926                                 free(store.key);
 927                                 ret = 1;
 928                                 goto out_free;
 929                         }
 930                         c = tolower(c);
 931                 } else if (c == '\n') {
 932                         error("invalid key (newline): %s", key);
 933                         free(store.key);
 934                         ret = 1;
 935                         goto out_free;
 936                 }
 937                 store.key[i] = c;
 938         }
 939         store.key[i] = 0;
 940
 941         /*
 942          * The lock serves a purpose in addition to locking: the new
 943          * contents of .git/config will be written into it.
 944          */
 945         lock = xcalloc(sizeof(struct lock_file), 1);
 946         fd = hold_lock_file_for_update(lock, config_filename, 0);
 947         if (fd < 0) {
 948                 error("could not lock config file %s", config_filename);
 949                 free(store.key);
 950                 ret = -1;
 951                 goto out_free;
 952         }
 953
 954         /*
 955          * If .git/config does not exist yet, write a minimal version.
 956          */
 957         in_fd = open(config_filename, O_RDONLY);
 958         if ( in_fd < 0 ) {
 959                 free(store.key);
 960
 961                 if ( ENOENT != errno ) {
 962                         error("opening %s: %s", config_filename,
 963                               strerror(errno));
 964                         ret = 3; /* same as "invalid config file" */
 965                         goto out_free;
 966                 }
 967                 /* if nothing to unset, error out */
 968                 if (value == NULL) {
 969                         ret = 5;
 970                         goto out_free;
 971                 }
 972
 973                 store.key = (char*)key;
 974                 if (!store_write_section(fd, key) ||
 975                     !store_write_pair(fd, key, value))
 976                         goto write_err_out;
 977         } else {
 978                 struct stat st;
 979                 char* contents;
 980                 size_t contents_sz, copy_begin, copy_end;
 981                 int i, new_line = 0;
 982
 983                 if (value_regex == NULL)
 984                         store.value_regex = NULL;
 985                 else {
 986                         if (value_regex[0] == '!') {
 987                                 store.do_not_match = 1;
 988                                 value_regex++;
 989                         } else
 990                                 store.do_not_match = 0;
 991
 992                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 993                         if (regcomp(store.value_regex, value_regex,
 994                                         REG_EXTENDED)) {
 995                                 error("invalid pattern: %s", value_regex);
 996                                 free(store.value_regex);
 997                                 ret = 6;
 998                                 goto out_free;
 999                         }
1000                 }
1001
1002                 store.offset[0] = 0;
1003                 store.state = START;
1004                 store.seen = 0;
1005
1006                 /*
1007                  * After this, store.offset will contain the *end* offset
1008                  * of the last match, or remain at 0 if no match was found.
1009                  * As a side effect, we make sure to transform only a valid
1010                  * existing config file.
1011                  */
1012                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1013                         error("invalid config file %s", config_filename);
1014                         free(store.key);
1015                         if (store.value_regex != NULL) {
1016                                 regfree(store.value_regex);
1017                                 free(store.value_regex);
1018                         }
1019                         ret = 3;
1020                         goto out_free;
1021                 }
1022
1023                 free(store.key);
1024                 if (store.value_regex != NULL) {
1025                         regfree(store.value_regex);
1026                         free(store.value_regex);
1027                 }
1028
1029                 /* if nothing to unset, or too many matches, error out */
1030                 if ((store.seen == 0 && value == NULL) ||
1031                                 (store.seen > 1 && multi_replace == 0)) {
1032                         ret = 5;
1033                         goto out_free;
1034                 }
1035
1036                 fstat(in_fd, &st);
1037                 contents_sz = xsize_t(st.st_size);
1038                 contents = xmmap(NULL, contents_sz, PROT_READ,
1039                         MAP_PRIVATE, in_fd, 0);
1040                 close(in_fd);
1041
1042                 if (store.seen == 0)
1043                         store.seen = 1;
1044
1045                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1046                         if (store.offset[i] == 0) {
1047                                 store.offset[i] = copy_end = contents_sz;
1048                         } else if (store.state != KEY_SEEN) {
1049                                 copy_end = store.offset[i];
1050                         } else
1051                                 copy_end = find_beginning_of_line(
1052                                         contents, contents_sz,
1053                                         store.offset[i]-2, &new_line);
1054
1055                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1056                                 new_line = 1;
1057
1058                         /* write the first part of the config */
1059                         if (copy_end > copy_begin) {
1060                                 if (write_in_full(fd, contents + copy_begin,
1061                                                   copy_end - copy_begin) <
1062                                     copy_end - copy_begin)
1063                                         goto write_err_out;
1064                                 if (new_line &&
1065                                     write_in_full(fd, "\n", 1) != 1)
1066                                         goto write_err_out;
1067                         }
1068                         copy_begin = store.offset[i];
1069                 }
1070
1071                 /* write the pair (value == NULL means unset) */
1072                 if (value != NULL) {
1073                         if (store.state == START) {
1074                                 if (!store_write_section(fd, key))
1075                                         goto write_err_out;
1076                         }
1077                         if (!store_write_pair(fd, key, value))
1078                                 goto write_err_out;
1079                 }
1080
1081                 /* write the rest of the config */
1082                 if (copy_begin < contents_sz)
1083                         if (write_in_full(fd, contents + copy_begin,
1084                                           contents_sz - copy_begin) <
1085                             contents_sz - copy_begin)
1086                                 goto write_err_out;
1087
1088                 munmap(contents, contents_sz);
1089         }
1090
1091         if (commit_lock_file(lock) < 0) {
1092                 error("could not commit config file %s", config_filename);
1093                 ret = 4;
1094                 goto out_free;
1095         }
1096
1097         /*
1098          * lock is committed, so don't try to roll it back below.
1099          * NOTE: Since lockfile.c keeps a linked list of all created
1100          * lock_file structures, it isn't safe to free(lock).  It's
1101          * better to just leave it hanging around.
1102          */
1103         lock = NULL;
1104         ret = 0;
1105
1106 out_free:
1107         if (lock)
1108                 rollback_lock_file(lock);
1109         free(config_filename);
1110         return ret;
1111
1112 write_err_out:
1113         ret = write_error(lock->filename);
1114         goto out_free;
1115
1116 }
1117
1118 static int section_name_match (const char *buf, const char *name)
1119 {
1120         int i = 0, j = 0, dot = 0;
1121         for (; buf[i] && buf[i] != ']'; i++) {
1122                 if (!dot && isspace(buf[i])) {
1123                         dot = 1;
1124                         if (name[j++] != '.')
1125                                 break;
1126                         for (i++; isspace(buf[i]); i++)
1127                                 ; /* do nothing */
1128                         if (buf[i] != '"')
1129                                 break;
1130                         continue;
1131                 }
1132                 if (buf[i] == '\\' && dot)
1133                         i++;
1134                 else if (buf[i] == '"' && dot) {
1135                         for (i++; isspace(buf[i]); i++)
1136                                 ; /* do_nothing */
1137                         break;
1138                 }
1139                 if (buf[i] != name[j++])
1140                         break;
1141         }
1142         return (buf[i] == ']' && name[j] == 0);
1143 }
1144
1145 /* if new_name == NULL, the section is removed instead */
1146 int git_config_rename_section(const char *old_name, const char *new_name)
1147 {
1148         int ret = 0, remove = 0;
1149         char *config_filename;
1150         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1151         int out_fd;
1152         char buf[1024];
1153
1154         if (config_exclusive_filename)
1155                 config_filename = xstrdup(config_exclusive_filename);
1156         else
1157                 config_filename = git_pathdup("config");
1158         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1159         if (out_fd < 0) {
1160                 ret = error("could not lock config file %s", config_filename);
1161                 goto out;
1162         }
1163
1164         if (!(config_file = fopen(config_filename, "rb"))) {
1165                 /* no config file means nothing to rename, no error */
1166                 goto unlock_and_out;
1167         }
1168
1169         while (fgets(buf, sizeof(buf), config_file)) {
1170                 int i;
1171                 int length;
1172                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1173                         ; /* do nothing */
1174                 if (buf[i] == '[') {
1175                         /* it's a section */
1176                         if (section_name_match (&buf[i+1], old_name)) {
1177                                 ret++;
1178                                 if (new_name == NULL) {
1179                                         remove = 1;
1180                                         continue;
1181                                 }
1182                                 store.baselen = strlen(new_name);
1183                                 if (!store_write_section(out_fd, new_name)) {
1184                                         ret = write_error(lock->filename);
1185                                         goto out;
1186                                 }
1187                                 continue;
1188                         }
1189                         remove = 0;
1190                 }
1191                 if (remove)
1192                         continue;
1193                 length = strlen(buf);
1194                 if (write_in_full(out_fd, buf, length) != length) {
1195                         ret = write_error(lock->filename);
1196                         goto out;
1197                 }
1198         }
1199         fclose(config_file);
1200  unlock_and_out:
1201         if (commit_lock_file(lock) < 0)
1202                 ret = error("could not commit config file %s", config_filename);
1203  out:
1204         free(config_filename);
1205         return ret;
1206 }
1207
1208 /*
1209  * Call this to report error for your variable that should not
1210  * get a boolean value (i.e. "[my] var" means "true").
1211  */
1212 int config_error_nonbool(const char *var)
1213 {
1214         return error("Missing value for '%s'", var);
1215 }