Andrew's git / gitweb.git / config.c
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config.con commit blame: show "previous" information in --porcelain/--incremental format (96e1170)
   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
  13static FILE *config_file;
  14static const char *config_file_name;
  15static int config_linenr;
  16static int config_file_eof;
  17static int zlib_compression_seen;
  18
  19const char *config_exclusive_filename = NULL;
  20
  21static 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
  47static 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
 111static inline int iskeychar(int c)
 112{
 113        return isalnum(c) || c == '-';
 114}
 115
 116static 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
 147static 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
 182static 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
 202static 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
 258static 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
 277static 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
 291int 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
 304static 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
 311int 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
 319unsigned 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
 327int 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
 342int 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
 348int 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
 356static 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        /* Add other config variables here and to Documentation/config.txt. */
 494        return 0;
 495}
 496
 497static int git_default_user_config(const char *var, const char *value)
 498{
 499        if (!strcmp(var, "user.name")) {
 500                if (!value)
 501                        return config_error_nonbool(var);
 502                strlcpy(git_default_name, value, sizeof(git_default_name));
 503                if (git_default_email[0])
 504                        user_ident_explicitly_given = 1;
 505                return 0;
 506        }
 507
 508        if (!strcmp(var, "user.email")) {
 509                if (!value)
 510                        return config_error_nonbool(var);
 511                strlcpy(git_default_email, value, sizeof(git_default_email));
 512                if (git_default_name[0])
 513                        user_ident_explicitly_given = 1;
 514                return 0;
 515        }
 516
 517        /* Add other config variables here and to Documentation/config.txt. */
 518        return 0;
 519}
 520
 521static int git_default_i18n_config(const char *var, const char *value)
 522{
 523        if (!strcmp(var, "i18n.commitencoding"))
 524                return git_config_string(&git_commit_encoding, var, value);
 525
 526        if (!strcmp(var, "i18n.logoutputencoding"))
 527                return git_config_string(&git_log_output_encoding, var, value);
 528
 529        /* Add other config variables here and to Documentation/config.txt. */
 530        return 0;
 531}
 532
 533static int git_default_branch_config(const char *var, const char *value)
 534{
 535        if (!strcmp(var, "branch.autosetupmerge")) {
 536                if (value && !strcasecmp(value, "always")) {
 537                        git_branch_track = BRANCH_TRACK_ALWAYS;
 538                        return 0;
 539                }
 540                git_branch_track = git_config_bool(var, value);
 541                return 0;
 542        }
 543        if (!strcmp(var, "branch.autosetuprebase")) {
 544                if (!value)
 545                        return config_error_nonbool(var);
 546                else if (!strcmp(value, "never"))
 547                        autorebase = AUTOREBASE_NEVER;
 548                else if (!strcmp(value, "local"))
 549                        autorebase = AUTOREBASE_LOCAL;
 550                else if (!strcmp(value, "remote"))
 551                        autorebase = AUTOREBASE_REMOTE;
 552                else if (!strcmp(value, "always"))
 553                        autorebase = AUTOREBASE_ALWAYS;
 554                else
 555                        return error("Malformed value for %s", var);
 556                return 0;
 557        }
 558
 559        /* Add other config variables here and to Documentation/config.txt. */
 560        return 0;
 561}
 562
 563int git_default_config(const char *var, const char *value, void *dummy)
 564{
 565        if (!prefixcmp(var, "core."))
 566                return git_default_core_config(var, value);
 567
 568        if (!prefixcmp(var, "user."))
 569                return git_default_user_config(var, value);
 570
 571        if (!prefixcmp(var, "i18n."))
 572                return git_default_i18n_config(var, value);
 573
 574        if (!prefixcmp(var, "branch."))
 575                return git_default_branch_config(var, value);
 576
 577        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 578                pager_use_color = git_config_bool(var,value);
 579                return 0;
 580        }
 581
 582        /* Add other config variables here and to Documentation/config.txt. */
 583        return 0;
 584}
 585
 586int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 587{
 588        int ret;
 589        FILE *f = fopen(filename, "r");
 590
 591        ret = -1;
 592        if (f) {
 593                config_file = f;
 594                config_file_name = filename;
 595                config_linenr = 1;
 596                config_file_eof = 0;
 597                ret = git_parse_file(fn, data);
 598                fclose(f);
 599                config_file_name = NULL;
 600        }
 601        return ret;
 602}
 603
 604const char *git_etc_gitconfig(void)
 605{
 606        static const char *system_wide;
 607        if (!system_wide)
 608                system_wide = system_path(ETC_GITCONFIG);
 609        return system_wide;
 610}
 611
 612static int git_env_bool(const char *k, int def)
 613{
 614        const char *v = getenv(k);
 615        return v ? git_config_bool(k, v) : def;
 616}
 617
 618int git_config_system(void)
 619{
 620        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 621}
 622
 623int git_config_global(void)
 624{
 625        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 626}
 627
 628int git_config(config_fn_t fn, void *data)
 629{
 630        int ret = 0;
 631        char *repo_config = NULL;
 632        const char *home = NULL;
 633
 634        /* $GIT_CONFIG makes git read _only_ the given config file,
 635         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 636         * global config file, the same way it would the per-repository
 637         * config file otherwise. */
 638        if (config_exclusive_filename)
 639                return git_config_from_file(fn, config_exclusive_filename, data);
 640        if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 641                ret += git_config_from_file(fn, git_etc_gitconfig(),
 642                                            data);
 643
 644        home = getenv("HOME");
 645        if (git_config_global() && home) {
 646                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 647                if (!access(user_config, R_OK))
 648                        ret += git_config_from_file(fn, user_config, data);
 649                free(user_config);
 650        }
 651
 652        repo_config = xstrdup(git_path("config"));
 653        ret += git_config_from_file(fn, repo_config, data);
 654        free(repo_config);
 655        return ret;
 656}
 657
 658/*
 659 * Find all the stuff for git_config_set() below.
 660 */
 661
 662#define MAX_MATCHES 512
 663
 664static struct {
 665        int baselen;
 666        char* key;
 667        int do_not_match;
 668        regex_t* value_regex;
 669        int multi_replace;
 670        size_t offset[MAX_MATCHES];
 671        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 672        int seen;
 673} store;
 674
 675static int matches(const char* key, const char* value)
 676{
 677        return !strcmp(key, store.key) &&
 678                (store.value_regex == NULL ||
 679                 (store.do_not_match ^
 680                  !regexec(store.value_regex, value, 0, NULL, 0)));
 681}
 682
 683static int store_aux(const char* key, const char* value, void *cb)
 684{
 685        const char *ep;
 686        size_t section_len;
 687
 688        switch (store.state) {
 689        case KEY_SEEN:
 690                if (matches(key, value)) {
 691                        if (store.seen == 1 && store.multi_replace == 0) {
 692                                warning("%s has multiple values", key);
 693                        } else if (store.seen >= MAX_MATCHES) {
 694                                error("too many matches for %s", key);
 695                                return 1;
 696                        }
 697
 698                        store.offset[store.seen] = ftell(config_file);
 699                        store.seen++;
 700                }
 701                break;
 702        case SECTION_SEEN:
 703                /*
 704                 * What we are looking for is in store.key (both
 705                 * section and var), and its section part is baselen
 706                 * long.  We found key (again, both section and var).
 707                 * We would want to know if this key is in the same
 708                 * section as what we are looking for.  We already
 709                 * know we are in the same section as what should
 710                 * hold store.key.
 711                 */
 712                ep = strrchr(key, '.');
 713                section_len = ep - key;
 714
 715                if ((section_len != store.baselen) ||
 716                    memcmp(key, store.key, section_len+1)) {
 717                        store.state = SECTION_END_SEEN;
 718                        break;
 719                }
 720
 721                /*
 722                 * Do not increment matches: this is no match, but we
 723                 * just made sure we are in the desired section.
 724                 */
 725                store.offset[store.seen] = ftell(config_file);
 726                /* fallthru */
 727        case SECTION_END_SEEN:
 728        case START:
 729                if (matches(key, value)) {
 730                        store.offset[store.seen] = ftell(config_file);
 731                        store.state = KEY_SEEN;
 732                        store.seen++;
 733                } else {
 734                        if (strrchr(key, '.') - key == store.baselen &&
 735                              !strncmp(key, store.key, store.baselen)) {
 736                                        store.state = SECTION_SEEN;
 737                                        store.offset[store.seen] = ftell(config_file);
 738                        }
 739                }
 740        }
 741        return 0;
 742}
 743
 744static int write_error(const char *filename)
 745{
 746        error("failed to write new configuration file %s", filename);
 747
 748        /* Same error code as "failed to rename". */
 749        return 4;
 750}
 751
 752static int store_write_section(int fd, const char* key)
 753{
 754        const char *dot;
 755        int i, success;
 756        struct strbuf sb = STRBUF_INIT;
 757
 758        dot = memchr(key, '.', store.baselen);
 759        if (dot) {
 760                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 761                for (i = dot - key + 1; i < store.baselen; i++) {
 762                        if (key[i] == '"' || key[i] == '\\')
 763                                strbuf_addch(&sb, '\\');
 764                        strbuf_addch(&sb, key[i]);
 765                }
 766                strbuf_addstr(&sb, "\"]\n");
 767        } else {
 768                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 769        }
 770
 771        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 772        strbuf_release(&sb);
 773
 774        return success;
 775}
 776
 777static int store_write_pair(int fd, const char* key, const char* value)
 778{
 779        int i, success;
 780        int length = strlen(key + store.baselen + 1);
 781        const char *quote = "";
 782        struct strbuf sb = STRBUF_INIT;
 783
 784        /*
 785         * Check to see if the value needs to be surrounded with a dq pair.
 786         * Note that problematic characters are always backslash-quoted; this
 787         * check is about not losing leading or trailing SP and strings that
 788         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 789         * configuration parser.
 790         */
 791        if (value[0] == ' ')
 792                quote = "\"";
 793        for (i = 0; value[i]; i++)
 794                if (value[i] == ';' || value[i] == '#')
 795                        quote = "\"";
 796        if (i && value[i - 1] == ' ')
 797                quote = "\"";
 798
 799        strbuf_addf(&sb, "\t%.*s = %s",
 800                    length, key + store.baselen + 1, quote);
 801
 802        for (i = 0; value[i]; i++)
 803                switch (value[i]) {
 804                case '\n':
 805                        strbuf_addstr(&sb, "\\n");
 806                        break;
 807                case '\t':
 808                        strbuf_addstr(&sb, "\\t");
 809                        break;
 810                case '"':
 811                case '\\':
 812                        strbuf_addch(&sb, '\\');
 813                default:
 814                        strbuf_addch(&sb, value[i]);
 815                        break;
 816                }
 817        strbuf_addf(&sb, "%s\n", quote);
 818
 819        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 820        strbuf_release(&sb);
 821
 822        return success;
 823}
 824
 825static ssize_t find_beginning_of_line(const char* contents, size_t size,
 826        size_t offset_, int* found_bracket)
 827{
 828        size_t equal_offset = size, bracket_offset = size;
 829        ssize_t offset;
 830
 831contline:
 832        for (offset = offset_-2; offset > 0
 833                        && contents[offset] != '\n'; offset--)
 834                switch (contents[offset]) {
 835                        case '=': equal_offset = offset; break;
 836                        case ']': bracket_offset = offset; break;
 837                }
 838        if (offset > 0 && contents[offset-1] == '\\') {
 839                offset_ = offset;
 840                goto contline;
 841        }
 842        if (bracket_offset < equal_offset) {
 843                *found_bracket = 1;
 844                offset = bracket_offset+1;
 845        } else
 846                offset++;
 847
 848        return offset;
 849}
 850
 851int git_config_set(const char* key, const char* value)
 852{
 853        return git_config_set_multivar(key, value, NULL, 0);
 854}
 855
 856/*
 857 * If value==NULL, unset in (remove from) config,
 858 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 859 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 860 *     else all matching key/values (regardless how many) are removed,
 861 *     before the new pair is written.
 862 *
 863 * Returns 0 on success.
 864 *
 865 * This function does this:
 866 *
 867 * - it locks the config file by creating ".git/config.lock"
 868 *
 869 * - it then parses the config using store_aux() as validator to find
 870 *   the position on the key/value pair to replace. If it is to be unset,
 871 *   it must be found exactly once.
 872 *
 873 * - the config file is mmap()ed and the part before the match (if any) is
 874 *   written to the lock file, then the changed part and the rest.
 875 *
 876 * - the config file is removed and the lock file rename()d to it.
 877 *
 878 */
 879int git_config_set_multivar(const char* key, const char* value,
 880        const char* value_regex, int multi_replace)
 881{
 882        int i, dot;
 883        int fd = -1, in_fd;
 884        int ret;
 885        char* config_filename;
 886        struct lock_file *lock = NULL;
 887        const char* last_dot = strrchr(key, '.');
 888
 889        if (config_exclusive_filename)
 890                config_filename = xstrdup(config_exclusive_filename);
 891        else
 892                config_filename = xstrdup(git_path("config"));
 893
 894        /*
 895         * Since "key" actually contains the section name and the real
 896         * key name separated by a dot, we have to know where the dot is.
 897         */
 898
 899        if (last_dot == NULL) {
 900                error("key does not contain a section: %s", key);
 901                ret = 2;
 902                goto out_free;
 903        }
 904        store.baselen = last_dot - key;
 905
 906        store.multi_replace = multi_replace;
 907
 908        /*
 909         * Validate the key and while at it, lower case it for matching.
 910         */
 911        store.key = xmalloc(strlen(key) + 1);
 912        dot = 0;
 913        for (i = 0; key[i]; i++) {
 914                unsigned char c = key[i];
 915                if (c == '.')
 916                        dot = 1;
 917                /* Leave the extended basename untouched.. */
 918                if (!dot || i > store.baselen) {
 919                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 920                                error("invalid key: %s", key);
 921                                free(store.key);
 922                                ret = 1;
 923                                goto out_free;
 924                        }
 925                        c = tolower(c);
 926                } else if (c == '\n') {
 927                        error("invalid key (newline): %s", key);
 928                        free(store.key);
 929                        ret = 1;
 930                        goto out_free;
 931                }
 932                store.key[i] = c;
 933        }
 934        store.key[i] = 0;
 935
 936        /*
 937         * The lock serves a purpose in addition to locking: the new
 938         * contents of .git/config will be written into it.
 939         */
 940        lock = xcalloc(sizeof(struct lock_file), 1);
 941        fd = hold_lock_file_for_update(lock, config_filename, 0);
 942        if (fd < 0) {
 943                error("could not lock config file %s", config_filename);
 944                free(store.key);
 945                ret = -1;
 946                goto out_free;
 947        }
 948
 949        /*
 950         * If .git/config does not exist yet, write a minimal version.
 951         */
 952        in_fd = open(config_filename, O_RDONLY);
 953        if ( in_fd < 0 ) {
 954                free(store.key);
 955
 956                if ( ENOENT != errno ) {
 957                        error("opening %s: %s", config_filename,
 958                              strerror(errno));
 959                        ret = 3; /* same as "invalid config file" */
 960                        goto out_free;
 961                }
 962                /* if nothing to unset, error out */
 963                if (value == NULL) {
 964                        ret = 5;
 965                        goto out_free;
 966                }
 967
 968                store.key = (char*)key;
 969                if (!store_write_section(fd, key) ||
 970                    !store_write_pair(fd, key, value))
 971                        goto write_err_out;
 972        } else {
 973                struct stat st;
 974                char* contents;
 975                size_t contents_sz, copy_begin, copy_end;
 976                int i, new_line = 0;
 977
 978                if (value_regex == NULL)
 979                        store.value_regex = NULL;
 980                else {
 981                        if (value_regex[0] == '!') {
 982                                store.do_not_match = 1;
 983                                value_regex++;
 984                        } else
 985                                store.do_not_match = 0;
 986
 987                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 988                        if (regcomp(store.value_regex, value_regex,
 989                                        REG_EXTENDED)) {
 990                                error("invalid pattern: %s", value_regex);
 991                                free(store.value_regex);
 992                                ret = 6;
 993                                goto out_free;
 994                        }
 995                }
 996
 997                store.offset[0] = 0;
 998                store.state = START;
 999                store.seen = 0;
1000
1001                /*
1002                 * After this, store.offset will contain the *end* offset
1003                 * of the last match, or remain at 0 if no match was found.
1004                 * As a side effect, we make sure to transform only a valid
1005                 * existing config file.
1006                 */
1007                if (git_config_from_file(store_aux, config_filename, NULL)) {
1008                        error("invalid config file %s", config_filename);
1009                        free(store.key);
1010                        if (store.value_regex != NULL) {
1011                                regfree(store.value_regex);
1012                                free(store.value_regex);
1013                        }
1014                        ret = 3;
1015                        goto out_free;
1016                }
1017
1018                free(store.key);
1019                if (store.value_regex != NULL) {
1020                        regfree(store.value_regex);
1021                        free(store.value_regex);
1022                }
1023
1024                /* if nothing to unset, or too many matches, error out */
1025                if ((store.seen == 0 && value == NULL) ||
1026                                (store.seen > 1 && multi_replace == 0)) {
1027                        ret = 5;
1028                        goto out_free;
1029                }
1030
1031                fstat(in_fd, &st);
1032                contents_sz = xsize_t(st.st_size);
1033                contents = xmmap(NULL, contents_sz, PROT_READ,
1034                        MAP_PRIVATE, in_fd, 0);
1035                close(in_fd);
1036
1037                if (store.seen == 0)
1038                        store.seen = 1;
1039
1040                for (i = 0, copy_begin = 0; i < store.seen; i++) {
1041                        if (store.offset[i] == 0) {
1042                                store.offset[i] = copy_end = contents_sz;
1043                        } else if (store.state != KEY_SEEN) {
1044                                copy_end = store.offset[i];
1045                        } else
1046                                copy_end = find_beginning_of_line(
1047                                        contents, contents_sz,
1048                                        store.offset[i]-2, &new_line);
1049
1050                        if (copy_end > 0 && contents[copy_end-1] != '\n')
1051                                new_line = 1;
1052
1053                        /* write the first part of the config */
1054                        if (copy_end > copy_begin) {
1055                                if (write_in_full(fd, contents + copy_begin,
1056                                                  copy_end - copy_begin) <
1057                                    copy_end - copy_begin)
1058                                        goto write_err_out;
1059                                if (new_line &&
1060                                    write_in_full(fd, "\n", 1) != 1)
1061                                        goto write_err_out;
1062                        }
1063                        copy_begin = store.offset[i];
1064                }
1065
1066                /* write the pair (value == NULL means unset) */
1067                if (value != NULL) {
1068                        if (store.state == START) {
1069                                if (!store_write_section(fd, key))
1070                                        goto write_err_out;
1071                        }
1072                        if (!store_write_pair(fd, key, value))
1073                                goto write_err_out;
1074                }
1075
1076                /* write the rest of the config */
1077                if (copy_begin < contents_sz)
1078                        if (write_in_full(fd, contents + copy_begin,
1079                                          contents_sz - copy_begin) <
1080                            contents_sz - copy_begin)
1081                                goto write_err_out;
1082
1083                munmap(contents, contents_sz);
1084        }
1085
1086        if (commit_lock_file(lock) < 0) {
1087                error("could not commit config file %s", config_filename);
1088                ret = 4;
1089                goto out_free;
1090        }
1091
1092        /*
1093         * lock is committed, so don't try to roll it back below.
1094         * NOTE: Since lockfile.c keeps a linked list of all created
1095         * lock_file structures, it isn't safe to free(lock).  It's
1096         * better to just leave it hanging around.
1097         */
1098        lock = NULL;
1099        ret = 0;
1100
1101out_free:
1102        if (lock)
1103                rollback_lock_file(lock);
1104        free(config_filename);
1105        return ret;
1106
1107write_err_out:
1108        ret = write_error(lock->filename);
1109        goto out_free;
1110
1111}
1112
1113static int section_name_match (const char *buf, const char *name)
1114{
1115        int i = 0, j = 0, dot = 0;
1116        for (; buf[i] && buf[i] != ']'; i++) {
1117                if (!dot && isspace(buf[i])) {
1118                        dot = 1;
1119                        if (name[j++] != '.')
1120                                break;
1121                        for (i++; isspace(buf[i]); i++)
1122                                ; /* do nothing */
1123                        if (buf[i] != '"')
1124                                break;
1125                        continue;
1126                }
1127                if (buf[i] == '\\' && dot)
1128                        i++;
1129                else if (buf[i] == '"' && dot) {
1130                        for (i++; isspace(buf[i]); i++)
1131                                ; /* do_nothing */
1132                        break;
1133                }
1134                if (buf[i] != name[j++])
1135                        break;
1136        }
1137        return (buf[i] == ']' && name[j] == 0);
1138}
1139
1140/* if new_name == NULL, the section is removed instead */
1141int git_config_rename_section(const char *old_name, const char *new_name)
1142{
1143        int ret = 0, remove = 0;
1144        char *config_filename;
1145        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1146        int out_fd;
1147        char buf[1024];
1148
1149        if (config_exclusive_filename)
1150                config_filename = xstrdup(config_exclusive_filename);
1151        else
1152                config_filename = xstrdup(git_path("config"));
1153        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1154        if (out_fd < 0) {
1155                ret = error("could not lock config file %s", config_filename);
1156                goto out;
1157        }
1158
1159        if (!(config_file = fopen(config_filename, "rb"))) {
1160                /* no config file means nothing to rename, no error */
1161                goto unlock_and_out;
1162        }
1163
1164        while (fgets(buf, sizeof(buf), config_file)) {
1165                int i;
1166                int length;
1167                for (i = 0; buf[i] && isspace(buf[i]); i++)
1168                        ; /* do nothing */
1169                if (buf[i] == '[') {
1170                        /* it's a section */
1171                        if (section_name_match (&buf[i+1], old_name)) {
1172                                ret++;
1173                                if (new_name == NULL) {
1174                                        remove = 1;
1175                                        continue;
1176                                }
1177                                store.baselen = strlen(new_name);
1178                                if (!store_write_section(out_fd, new_name)) {
1179                                        ret = write_error(lock->filename);
1180                                        goto out;
1181                                }
1182                                continue;
1183                        }
1184                        remove = 0;
1185                }
1186                if (remove)
1187                        continue;
1188                length = strlen(buf);
1189                if (write_in_full(out_fd, buf, length) != length) {
1190                        ret = write_error(lock->filename);
1191                        goto out;
1192                }
1193        }
1194        fclose(config_file);
1195 unlock_and_out:
1196        if (commit_lock_file(lock) < 0)
1197                ret = error("could not commit config file %s", config_filename);
1198 out:
1199        free(config_filename);
1200        return ret;
1201}
1202
1203/*
1204 * Call this to report error for your variable that should not
1205 * get a boolean value (i.e. "[my] var" means "true").
1206 */
1207int config_error_nonbool(const char *var)
1208{
1209        return error("Missing value for '%s'", var);
1210}