Andrew's git - gitweb.git/blob

b0ada515b9d839fc8691bc9af320353ff323b251
   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
  19static int get_next_char(void)
  20{
  21        int c;
  22        FILE *f;
  23
  24        c = '\n';
  25        if ((f = config_file) != NULL) {
  26                c = fgetc(f);
  27                if (c == '\r') {
  28                        /* DOS like systems */
  29                        c = fgetc(f);
  30                        if (c != '\n') {
  31                                ungetc(c, f);
  32                                c = '\r';
  33                        }
  34                }
  35                if (c == '\n')
  36                        config_linenr++;
  37                if (c == EOF) {
  38                        config_file_eof = 1;
  39                        c = '\n';
  40                }
  41        }
  42        return c;
  43}
  44
  45static char *parse_value(void)
  46{
  47        static char value[1024];
  48        int quote = 0, comment = 0, len = 0, space = 0;
  49
  50        for (;;) {
  51                int c = get_next_char();
  52                if (len >= sizeof(value))
  53                        return NULL;
  54                if (c == '\n') {
  55                        if (quote)
  56                                return NULL;
  57                        value[len] = 0;
  58                        return value;
  59                }
  60                if (comment)
  61                        continue;
  62                if (isspace(c) && !quote) {
  63                        space = 1;
  64                        continue;
  65                }
  66                if (!quote) {
  67                        if (c == ';' || c == '#') {
  68                                comment = 1;
  69                                continue;
  70                        }
  71                }
  72                if (space) {
  73                        if (len)
  74                                value[len++] = ' ';
  75                        space = 0;
  76                }
  77                if (c == '\\') {
  78                        c = get_next_char();
  79                        switch (c) {
  80                        case '\n':
  81                                continue;
  82                        case 't':
  83                                c = '\t';
  84                                break;
  85                        case 'b':
  86                                c = '\b';
  87                                break;
  88                        case 'n':
  89                                c = '\n';
  90                                break;
  91                        /* Some characters escape as themselves */
  92                        case '\\': case '"':
  93                                break;
  94                        /* Reject unknown escape sequences */
  95                        default:
  96                                return NULL;
  97                        }
  98                        value[len++] = c;
  99                        continue;
 100                }
 101                if (c == '"') {
 102                        quote = 1-quote;
 103                        continue;
 104                }
 105                value[len++] = c;
 106        }
 107}
 108
 109static inline int iskeychar(int c)
 110{
 111        return isalnum(c) || c == '-';
 112}
 113
 114static int get_value(config_fn_t fn, char *name, unsigned int len)
 115{
 116        int c;
 117        char *value;
 118
 119        /* Get the full name */
 120        for (;;) {
 121                c = get_next_char();
 122                if (config_file_eof)
 123                        break;
 124                if (!iskeychar(c))
 125                        break;
 126                name[len++] = tolower(c);
 127                if (len >= MAXNAME)
 128                        return -1;
 129        }
 130        name[len] = 0;
 131        while (c == ' ' || c == '\t')
 132                c = get_next_char();
 133
 134        value = NULL;
 135        if (c != '\n') {
 136                if (c != '=')
 137                        return -1;
 138                value = parse_value();
 139                if (!value)
 140                        return -1;
 141        }
 142        return fn(name, value);
 143}
 144
 145static int get_extended_base_var(char *name, int baselen, int c)
 146{
 147        do {
 148                if (c == '\n')
 149                        return -1;
 150                c = get_next_char();
 151        } while (isspace(c));
 152
 153        /* We require the format to be '[base "extension"]' */
 154        if (c != '"')
 155                return -1;
 156        name[baselen++] = '.';
 157
 158        for (;;) {
 159                int c = get_next_char();
 160                if (c == '\n')
 161                        return -1;
 162                if (c == '"')
 163                        break;
 164                if (c == '\\') {
 165                        c = get_next_char();
 166                        if (c == '\n')
 167                                return -1;
 168                }
 169                name[baselen++] = c;
 170                if (baselen > MAXNAME / 2)
 171                        return -1;
 172        }
 173
 174        /* Final ']' */
 175        if (get_next_char() != ']')
 176                return -1;
 177        return baselen;
 178}
 179
 180static int get_base_var(char *name)
 181{
 182        int baselen = 0;
 183
 184        for (;;) {
 185                int c = get_next_char();
 186                if (config_file_eof)
 187                        return -1;
 188                if (c == ']')
 189                        return baselen;
 190                if (isspace(c))
 191                        return get_extended_base_var(name, baselen, c);
 192                if (!iskeychar(c) && c != '.')
 193                        return -1;
 194                if (baselen > MAXNAME / 2)
 195                        return -1;
 196                name[baselen++] = tolower(c);
 197        }
 198}
 199
 200static int git_parse_file(config_fn_t fn)
 201{
 202        int comment = 0;
 203        int baselen = 0;
 204        static char var[MAXNAME];
 205
 206        for (;;) {
 207                int c = get_next_char();
 208                if (c == '\n') {
 209                        if (config_file_eof)
 210                                return 0;
 211                        comment = 0;
 212                        continue;
 213                }
 214                if (comment || isspace(c))
 215                        continue;
 216                if (c == '#' || c == ';') {
 217                        comment = 1;
 218                        continue;
 219                }
 220                if (c == '[') {
 221                        baselen = get_base_var(var);
 222                        if (baselen <= 0)
 223                                break;
 224                        var[baselen++] = '.';
 225                        var[baselen] = 0;
 226                        continue;
 227                }
 228                if (!isalpha(c))
 229                        break;
 230                var[baselen] = tolower(c);
 231                if (get_value(fn, var, baselen+1) < 0)
 232                        break;
 233        }
 234        die("bad config file line %d in %s", config_linenr, config_file_name);
 235}
 236
 237static int parse_unit_factor(const char *end, unsigned long *val)
 238{
 239        if (!*end)
 240                return 1;
 241        else if (!strcasecmp(end, "k")) {
 242                *val *= 1024;
 243                return 1;
 244        }
 245        else if (!strcasecmp(end, "m")) {
 246                *val *= 1024 * 1024;
 247                return 1;
 248        }
 249        else if (!strcasecmp(end, "g")) {
 250                *val *= 1024 * 1024 * 1024;
 251                return 1;
 252        }
 253        return 0;
 254}
 255
 256int git_parse_long(const char *value, long *ret)
 257{
 258        if (value && *value) {
 259                char *end;
 260                long val = strtol(value, &end, 0);
 261                unsigned long factor = 1;
 262                if (!parse_unit_factor(end, &factor))
 263                        return 0;
 264                *ret = val * factor;
 265                return 1;
 266        }
 267        return 0;
 268}
 269
 270int git_parse_ulong(const char *value, unsigned long *ret)
 271{
 272        if (value && *value) {
 273                char *end;
 274                unsigned long val = strtoul(value, &end, 0);
 275                if (!parse_unit_factor(end, &val))
 276                        return 0;
 277                *ret = val;
 278                return 1;
 279        }
 280        return 0;
 281}
 282
 283static void die_bad_config(const char *name)
 284{
 285        if (config_file_name)
 286                die("bad config value for '%s' in %s", name, config_file_name);
 287        die("bad config value for '%s'", name);
 288}
 289
 290int git_config_int(const char *name, const char *value)
 291{
 292        long ret;
 293        if (!git_parse_long(value, &ret))
 294                die_bad_config(name);
 295        return ret;
 296}
 297
 298unsigned long git_config_ulong(const char *name, const char *value)
 299{
 300        unsigned long ret;
 301        if (!git_parse_ulong(value, &ret))
 302                die_bad_config(name);
 303        return ret;
 304}
 305
 306int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 307{
 308        *is_bool = 1;
 309        if (!value)
 310                return 1;
 311        if (!*value)
 312                return 0;
 313        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 314                return 1;
 315        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 316                return 0;
 317        *is_bool = 0;
 318        return git_config_int(name, value);
 319}
 320
 321int git_config_bool(const char *name, const char *value)
 322{
 323        int discard;
 324        return !!git_config_bool_or_int(name, value, &discard);
 325}
 326
 327int git_config_string(const char **dest, const char *var, const char *value)
 328{
 329        if (!value)
 330                return config_error_nonbool(var);
 331        *dest = xstrdup(value);
 332        return 0;
 333}
 334
 335int git_default_config(const char *var, const char *value)
 336{
 337        /* This needs a better name */
 338        if (!strcmp(var, "core.filemode")) {
 339                trust_executable_bit = git_config_bool(var, value);
 340                return 0;
 341        }
 342
 343        if (!strcmp(var, "core.quotepath")) {
 344                quote_path_fully = git_config_bool(var, value);
 345                return 0;
 346        }
 347
 348        if (!strcmp(var, "core.symlinks")) {
 349                has_symlinks = git_config_bool(var, value);
 350                return 0;
 351        }
 352
 353        if (!strcmp(var, "core.bare")) {
 354                is_bare_repository_cfg = git_config_bool(var, value);
 355                return 0;
 356        }
 357
 358        if (!strcmp(var, "core.ignorestat")) {
 359                assume_unchanged = git_config_bool(var, value);
 360                return 0;
 361        }
 362
 363        if (!strcmp(var, "core.prefersymlinkrefs")) {
 364                prefer_symlink_refs = git_config_bool(var, value);
 365                return 0;
 366        }
 367
 368        if (!strcmp(var, "core.logallrefupdates")) {
 369                log_all_ref_updates = git_config_bool(var, value);
 370                return 0;
 371        }
 372
 373        if (!strcmp(var, "core.warnambiguousrefs")) {
 374                warn_ambiguous_refs = git_config_bool(var, value);
 375                return 0;
 376        }
 377
 378        if (!strcmp(var, "core.loosecompression")) {
 379                int level = git_config_int(var, value);
 380                if (level == -1)
 381                        level = Z_DEFAULT_COMPRESSION;
 382                else if (level < 0 || level > Z_BEST_COMPRESSION)
 383                        die("bad zlib compression level %d", level);
 384                zlib_compression_level = level;
 385                zlib_compression_seen = 1;
 386                return 0;
 387        }
 388
 389        if (!strcmp(var, "core.compression")) {
 390                int level = git_config_int(var, value);
 391                if (level == -1)
 392                        level = Z_DEFAULT_COMPRESSION;
 393                else if (level < 0 || level > Z_BEST_COMPRESSION)
 394                        die("bad zlib compression level %d", level);
 395                core_compression_level = level;
 396                core_compression_seen = 1;
 397                if (!zlib_compression_seen)
 398                        zlib_compression_level = level;
 399                return 0;
 400        }
 401
 402        if (!strcmp(var, "core.packedgitwindowsize")) {
 403                int pgsz_x2 = getpagesize() * 2;
 404                packed_git_window_size = git_config_int(var, value);
 405
 406                /* This value must be multiple of (pagesize * 2) */
 407                packed_git_window_size /= pgsz_x2;
 408                if (packed_git_window_size < 1)
 409                        packed_git_window_size = 1;
 410                packed_git_window_size *= pgsz_x2;
 411                return 0;
 412        }
 413
 414        if (!strcmp(var, "core.packedgitlimit")) {
 415                packed_git_limit = git_config_int(var, value);
 416                return 0;
 417        }
 418
 419        if (!strcmp(var, "core.deltabasecachelimit")) {
 420                delta_base_cache_limit = git_config_int(var, value);
 421                return 0;
 422        }
 423
 424        if (!strcmp(var, "core.autocrlf")) {
 425                if (value && !strcasecmp(value, "input")) {
 426                        auto_crlf = -1;
 427                        return 0;
 428                }
 429                auto_crlf = git_config_bool(var, value);
 430                return 0;
 431        }
 432
 433        if (!strcmp(var, "core.safecrlf")) {
 434                if (value && !strcasecmp(value, "warn")) {
 435                        safe_crlf = SAFE_CRLF_WARN;
 436                        return 0;
 437                }
 438                safe_crlf = git_config_bool(var, value);
 439                return 0;
 440        }
 441
 442        if (!strcmp(var, "user.name")) {
 443                if (!value)
 444                        return config_error_nonbool(var);
 445                strlcpy(git_default_name, value, sizeof(git_default_name));
 446                return 0;
 447        }
 448
 449        if (!strcmp(var, "user.email")) {
 450                if (!value)
 451                        return config_error_nonbool(var);
 452                strlcpy(git_default_email, value, sizeof(git_default_email));
 453                return 0;
 454        }
 455
 456        if (!strcmp(var, "i18n.commitencoding"))
 457                return git_config_string(&git_commit_encoding, var, value);
 458
 459        if (!strcmp(var, "i18n.logoutputencoding"))
 460                return git_config_string(&git_log_output_encoding, var, value);
 461
 462        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 463                pager_use_color = git_config_bool(var,value);
 464                return 0;
 465        }
 466
 467        if (!strcmp(var, "core.pager"))
 468                return git_config_string(&pager_program, var, value);
 469
 470        if (!strcmp(var, "core.editor"))
 471                return git_config_string(&editor_program, var, value);
 472
 473        if (!strcmp(var, "core.excludesfile"))
 474                return git_config_string(&excludes_file, var, value);
 475
 476        if (!strcmp(var, "core.whitespace")) {
 477                if (!value)
 478                        return config_error_nonbool(var);
 479                whitespace_rule_cfg = parse_whitespace_rule(value);
 480                return 0;
 481        }
 482        if (!strcmp(var, "branch.autosetupmerge")) {
 483                if (value && !strcasecmp(value, "always")) {
 484                        git_branch_track = BRANCH_TRACK_ALWAYS;
 485                        return 0;
 486                }
 487                git_branch_track = git_config_bool(var, value);
 488                return 0;
 489        }
 490
 491        /* Add other config variables here and to Documentation/config.txt. */
 492        return 0;
 493}
 494
 495int git_config_from_file(config_fn_t fn, const char *filename)
 496{
 497        int ret;
 498        FILE *f = fopen(filename, "r");
 499
 500        ret = -1;
 501        if (f) {
 502                config_file = f;
 503                config_file_name = filename;
 504                config_linenr = 1;
 505                config_file_eof = 0;
 506                ret = git_parse_file(fn);
 507                fclose(f);
 508                config_file_name = NULL;
 509        }
 510        return ret;
 511}
 512
 513const char *git_etc_gitconfig(void)
 514{
 515        static const char *system_wide;
 516        if (!system_wide) {
 517                system_wide = ETC_GITCONFIG;
 518                if (!is_absolute_path(system_wide)) {
 519                        /* interpret path relative to exec-dir */
 520                        struct strbuf d = STRBUF_INIT;
 521                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 522                        system_wide = strbuf_detach(&d, NULL);
 523                }
 524        }
 525        return system_wide;
 526}
 527
 528int git_env_bool(const char *k, int def)
 529{
 530        const char *v = getenv(k);
 531        return v ? git_config_bool(k, v) : def;
 532}
 533
 534int git_config_system(void)
 535{
 536        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 537}
 538
 539int git_config_global(void)
 540{
 541        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 542}
 543
 544int git_config(config_fn_t fn)
 545{
 546        int ret = 0;
 547        char *repo_config = NULL;
 548        const char *home = NULL, *filename;
 549
 550        /* $GIT_CONFIG makes git read _only_ the given config file,
 551         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 552         * global config file, the same way it would the per-repository
 553         * config file otherwise. */
 554        filename = getenv(CONFIG_ENVIRONMENT);
 555        if (!filename) {
 556                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 557                        ret += git_config_from_file(fn, git_etc_gitconfig());
 558                home = getenv("HOME");
 559                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 560                if (!filename)
 561                        filename = repo_config = xstrdup(git_path("config"));
 562        }
 563
 564        if (git_config_global() && home) {
 565                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 566                if (!access(user_config, R_OK))
 567                        ret = git_config_from_file(fn, user_config);
 568                free(user_config);
 569        }
 570
 571        ret += git_config_from_file(fn, filename);
 572        free(repo_config);
 573        return ret;
 574}
 575
 576/*
 577 * Find all the stuff for git_config_set() below.
 578 */
 579
 580#define MAX_MATCHES 512
 581
 582static struct {
 583        int baselen;
 584        char* key;
 585        int do_not_match;
 586        regex_t* value_regex;
 587        int multi_replace;
 588        size_t offset[MAX_MATCHES];
 589        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 590        int seen;
 591} store;
 592
 593static int matches(const char* key, const char* value)
 594{
 595        return !strcmp(key, store.key) &&
 596                (store.value_regex == NULL ||
 597                 (store.do_not_match ^
 598                  !regexec(store.value_regex, value, 0, NULL, 0)));
 599}
 600
 601static int store_aux(const char* key, const char* value)
 602{
 603        const char *ep;
 604        size_t section_len;
 605
 606        switch (store.state) {
 607        case KEY_SEEN:
 608                if (matches(key, value)) {
 609                        if (store.seen == 1 && store.multi_replace == 0) {
 610                                fprintf(stderr,
 611                                        "Warning: %s has multiple values\n",
 612                                        key);
 613                        } else if (store.seen >= MAX_MATCHES) {
 614                                fprintf(stderr, "Too many matches\n");
 615                                return 1;
 616                        }
 617
 618                        store.offset[store.seen] = ftell(config_file);
 619                        store.seen++;
 620                }
 621                break;
 622        case SECTION_SEEN:
 623                /*
 624                 * What we are looking for is in store.key (both
 625                 * section and var), and its section part is baselen
 626                 * long.  We found key (again, both section and var).
 627                 * We would want to know if this key is in the same
 628                 * section as what we are looking for.  We already
 629                 * know we are in the same section as what should
 630                 * hold store.key.
 631                 */
 632                ep = strrchr(key, '.');
 633                section_len = ep - key;
 634
 635                if ((section_len != store.baselen) ||
 636                    memcmp(key, store.key, section_len+1)) {
 637                        store.state = SECTION_END_SEEN;
 638                        break;
 639                }
 640
 641                /*
 642                 * Do not increment matches: this is no match, but we
 643                 * just made sure we are in the desired section.
 644                 */
 645                store.offset[store.seen] = ftell(config_file);
 646                /* fallthru */
 647        case SECTION_END_SEEN:
 648        case START:
 649                if (matches(key, value)) {
 650                        store.offset[store.seen] = ftell(config_file);
 651                        store.state = KEY_SEEN;
 652                        store.seen++;
 653                } else {
 654                        if (strrchr(key, '.') - key == store.baselen &&
 655                              !strncmp(key, store.key, store.baselen)) {
 656                                        store.state = SECTION_SEEN;
 657                                        store.offset[store.seen] = ftell(config_file);
 658                        }
 659                }
 660        }
 661        return 0;
 662}
 663
 664static int write_error(void)
 665{
 666        fprintf(stderr, "Failed to write new configuration file\n");
 667
 668        /* Same error code as "failed to rename". */
 669        return 4;
 670}
 671
 672static int store_write_section(int fd, const char* key)
 673{
 674        const char *dot;
 675        int i, success;
 676        struct strbuf sb;
 677
 678        strbuf_init(&sb, 0);
 679        dot = memchr(key, '.', store.baselen);
 680        if (dot) {
 681                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 682                for (i = dot - key + 1; i < store.baselen; i++) {
 683                        if (key[i] == '"')
 684                                strbuf_addch(&sb, '\\');
 685                        strbuf_addch(&sb, key[i]);
 686                }
 687                strbuf_addstr(&sb, "\"]\n");
 688        } else {
 689                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 690        }
 691
 692        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 693        strbuf_release(&sb);
 694
 695        return success;
 696}
 697
 698static int store_write_pair(int fd, const char* key, const char* value)
 699{
 700        int i, success;
 701        int length = strlen(key + store.baselen + 1);
 702        const char *quote = "";
 703        struct strbuf sb;
 704
 705        /*
 706         * Check to see if the value needs to be surrounded with a dq pair.
 707         * Note that problematic characters are always backslash-quoted; this
 708         * check is about not losing leading or trailing SP and strings that
 709         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 710         * configuration parser.
 711         */
 712        if (value[0] == ' ')
 713                quote = "\"";
 714        for (i = 0; value[i]; i++)
 715                if (value[i] == ';' || value[i] == '#')
 716                        quote = "\"";
 717        if (i && value[i - 1] == ' ')
 718                quote = "\"";
 719
 720        strbuf_init(&sb, 0);
 721        strbuf_addf(&sb, "\t%.*s = %s",
 722                    length, key + store.baselen + 1, quote);
 723
 724        for (i = 0; value[i]; i++)
 725                switch (value[i]) {
 726                case '\n':
 727                        strbuf_addstr(&sb, "\\n");
 728                        break;
 729                case '\t':
 730                        strbuf_addstr(&sb, "\\t");
 731                        break;
 732                case '"':
 733                case '\\':
 734                        strbuf_addch(&sb, '\\');
 735                default:
 736                        strbuf_addch(&sb, value[i]);
 737                        break;
 738                }
 739        strbuf_addf(&sb, "%s\n", quote);
 740
 741        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 742        strbuf_release(&sb);
 743
 744        return success;
 745}
 746
 747static ssize_t find_beginning_of_line(const char* contents, size_t size,
 748        size_t offset_, int* found_bracket)
 749{
 750        size_t equal_offset = size, bracket_offset = size;
 751        ssize_t offset;
 752
 753contline:
 754        for (offset = offset_-2; offset > 0
 755                        && contents[offset] != '\n'; offset--)
 756                switch (contents[offset]) {
 757                        case '=': equal_offset = offset; break;
 758                        case ']': bracket_offset = offset; break;
 759                }
 760        if (offset > 0 && contents[offset-1] == '\\') {
 761                offset_ = offset;
 762                goto contline;
 763        }
 764        if (bracket_offset < equal_offset) {
 765                *found_bracket = 1;
 766                offset = bracket_offset+1;
 767        } else
 768                offset++;
 769
 770        return offset;
 771}
 772
 773int git_config_set(const char* key, const char* value)
 774{
 775        return git_config_set_multivar(key, value, NULL, 0);
 776}
 777
 778/*
 779 * If value==NULL, unset in (remove from) config,
 780 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 781 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 782 *     else all matching key/values (regardless how many) are removed,
 783 *     before the new pair is written.
 784 *
 785 * Returns 0 on success.
 786 *
 787 * This function does this:
 788 *
 789 * - it locks the config file by creating ".git/config.lock"
 790 *
 791 * - it then parses the config using store_aux() as validator to find
 792 *   the position on the key/value pair to replace. If it is to be unset,
 793 *   it must be found exactly once.
 794 *
 795 * - the config file is mmap()ed and the part before the match (if any) is
 796 *   written to the lock file, then the changed part and the rest.
 797 *
 798 * - the config file is removed and the lock file rename()d to it.
 799 *
 800 */
 801int git_config_set_multivar(const char* key, const char* value,
 802        const char* value_regex, int multi_replace)
 803{
 804        int i, dot;
 805        int fd = -1, in_fd;
 806        int ret;
 807        char* config_filename;
 808        struct lock_file *lock = NULL;
 809        const char* last_dot = strrchr(key, '.');
 810
 811        config_filename = getenv(CONFIG_ENVIRONMENT);
 812        if (!config_filename) {
 813                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 814                if (!config_filename)
 815                        config_filename  = git_path("config");
 816        }
 817        config_filename = xstrdup(config_filename);
 818
 819        /*
 820         * Since "key" actually contains the section name and the real
 821         * key name separated by a dot, we have to know where the dot is.
 822         */
 823
 824        if (last_dot == NULL) {
 825                fprintf(stderr, "key does not contain a section: %s\n", key);
 826                ret = 2;
 827                goto out_free;
 828        }
 829        store.baselen = last_dot - key;
 830
 831        store.multi_replace = multi_replace;
 832
 833        /*
 834         * Validate the key and while at it, lower case it for matching.
 835         */
 836        store.key = xmalloc(strlen(key) + 1);
 837        dot = 0;
 838        for (i = 0; key[i]; i++) {
 839                unsigned char c = key[i];
 840                if (c == '.')
 841                        dot = 1;
 842                /* Leave the extended basename untouched.. */
 843                if (!dot || i > store.baselen) {
 844                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 845                                fprintf(stderr, "invalid key: %s\n", key);
 846                                free(store.key);
 847                                ret = 1;
 848                                goto out_free;
 849                        }
 850                        c = tolower(c);
 851                } else if (c == '\n') {
 852                        fprintf(stderr, "invalid key (newline): %s\n", key);
 853                        free(store.key);
 854                        ret = 1;
 855                        goto out_free;
 856                }
 857                store.key[i] = c;
 858        }
 859        store.key[i] = 0;
 860
 861        /*
 862         * The lock serves a purpose in addition to locking: the new
 863         * contents of .git/config will be written into it.
 864         */
 865        lock = xcalloc(sizeof(struct lock_file), 1);
 866        fd = hold_lock_file_for_update(lock, config_filename, 0);
 867        if (fd < 0) {
 868                fprintf(stderr, "could not lock config file\n");
 869                free(store.key);
 870                ret = -1;
 871                goto out_free;
 872        }
 873
 874        /*
 875         * If .git/config does not exist yet, write a minimal version.
 876         */
 877        in_fd = open(config_filename, O_RDONLY);
 878        if ( in_fd < 0 ) {
 879                free(store.key);
 880
 881                if ( ENOENT != errno ) {
 882                        error("opening %s: %s", config_filename,
 883                              strerror(errno));
 884                        ret = 3; /* same as "invalid config file" */
 885                        goto out_free;
 886                }
 887                /* if nothing to unset, error out */
 888                if (value == NULL) {
 889                        ret = 5;
 890                        goto out_free;
 891                }
 892
 893                store.key = (char*)key;
 894                if (!store_write_section(fd, key) ||
 895                    !store_write_pair(fd, key, value))
 896                        goto write_err_out;
 897        } else {
 898                struct stat st;
 899                char* contents;
 900                size_t contents_sz, copy_begin, copy_end;
 901                int i, new_line = 0;
 902
 903                if (value_regex == NULL)
 904                        store.value_regex = NULL;
 905                else {
 906                        if (value_regex[0] == '!') {
 907                                store.do_not_match = 1;
 908                                value_regex++;
 909                        } else
 910                                store.do_not_match = 0;
 911
 912                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 913                        if (regcomp(store.value_regex, value_regex,
 914                                        REG_EXTENDED)) {
 915                                fprintf(stderr, "Invalid pattern: %s\n",
 916                                        value_regex);
 917                                free(store.value_regex);
 918                                ret = 6;
 919                                goto out_free;
 920                        }
 921                }
 922
 923                store.offset[0] = 0;
 924                store.state = START;
 925                store.seen = 0;
 926
 927                /*
 928                 * After this, store.offset will contain the *end* offset
 929                 * of the last match, or remain at 0 if no match was found.
 930                 * As a side effect, we make sure to transform only a valid
 931                 * existing config file.
 932                 */
 933                if (git_config_from_file(store_aux, config_filename)) {
 934                        fprintf(stderr, "invalid config file\n");
 935                        free(store.key);
 936                        if (store.value_regex != NULL) {
 937                                regfree(store.value_regex);
 938                                free(store.value_regex);
 939                        }
 940                        ret = 3;
 941                        goto out_free;
 942                }
 943
 944                free(store.key);
 945                if (store.value_regex != NULL) {
 946                        regfree(store.value_regex);
 947                        free(store.value_regex);
 948                }
 949
 950                /* if nothing to unset, or too many matches, error out */
 951                if ((store.seen == 0 && value == NULL) ||
 952                                (store.seen > 1 && multi_replace == 0)) {
 953                        ret = 5;
 954                        goto out_free;
 955                }
 956
 957                fstat(in_fd, &st);
 958                contents_sz = xsize_t(st.st_size);
 959                contents = xmmap(NULL, contents_sz, PROT_READ,
 960                        MAP_PRIVATE, in_fd, 0);
 961                close(in_fd);
 962
 963                if (store.seen == 0)
 964                        store.seen = 1;
 965
 966                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 967                        if (store.offset[i] == 0) {
 968                                store.offset[i] = copy_end = contents_sz;
 969                        } else if (store.state != KEY_SEEN) {
 970                                copy_end = store.offset[i];
 971                        } else
 972                                copy_end = find_beginning_of_line(
 973                                        contents, contents_sz,
 974                                        store.offset[i]-2, &new_line);
 975
 976                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 977                                new_line = 1;
 978
 979                        /* write the first part of the config */
 980                        if (copy_end > copy_begin) {
 981                                if (write_in_full(fd, contents + copy_begin,
 982                                                  copy_end - copy_begin) <
 983                                    copy_end - copy_begin)
 984                                        goto write_err_out;
 985                                if (new_line &&
 986                                    write_in_full(fd, "\n", 1) != 1)
 987                                        goto write_err_out;
 988                        }
 989                        copy_begin = store.offset[i];
 990                }
 991
 992                /* write the pair (value == NULL means unset) */
 993                if (value != NULL) {
 994                        if (store.state == START) {
 995                                if (!store_write_section(fd, key))
 996                                        goto write_err_out;
 997                        }
 998                        if (!store_write_pair(fd, key, value))
 999                                goto write_err_out;
1000                }
1001
1002                /* write the rest of the config */
1003                if (copy_begin < contents_sz)
1004                        if (write_in_full(fd, contents + copy_begin,
1005                                          contents_sz - copy_begin) <
1006                            contents_sz - copy_begin)
1007                                goto write_err_out;
1008
1009                munmap(contents, contents_sz);
1010        }
1011
1012        if (commit_lock_file(lock) < 0) {
1013                fprintf(stderr, "Cannot commit config file!\n");
1014                ret = 4;
1015                goto out_free;
1016        }
1017
1018        /*
1019         * lock is committed, so don't try to roll it back below.
1020         * NOTE: Since lockfile.c keeps a linked list of all created
1021         * lock_file structures, it isn't safe to free(lock).  It's
1022         * better to just leave it hanging around.
1023         */
1024        lock = NULL;
1025        ret = 0;
1026
1027out_free:
1028        if (lock)
1029                rollback_lock_file(lock);
1030        free(config_filename);
1031        return ret;
1032
1033write_err_out:
1034        ret = write_error();
1035        goto out_free;
1036
1037}
1038
1039static int section_name_match (const char *buf, const char *name)
1040{
1041        int i = 0, j = 0, dot = 0;
1042        for (; buf[i] && buf[i] != ']'; i++) {
1043                if (!dot && isspace(buf[i])) {
1044                        dot = 1;
1045                        if (name[j++] != '.')
1046                                break;
1047                        for (i++; isspace(buf[i]); i++)
1048                                ; /* do nothing */
1049                        if (buf[i] != '"')
1050                                break;
1051                        continue;
1052                }
1053                if (buf[i] == '\\' && dot)
1054                        i++;
1055                else if (buf[i] == '"' && dot) {
1056                        for (i++; isspace(buf[i]); i++)
1057                                ; /* do_nothing */
1058                        break;
1059                }
1060                if (buf[i] != name[j++])
1061                        break;
1062        }
1063        return (buf[i] == ']' && name[j] == 0);
1064}
1065
1066/* if new_name == NULL, the section is removed instead */
1067int git_config_rename_section(const char *old_name, const char *new_name)
1068{
1069        int ret = 0, remove = 0;
1070        char *config_filename;
1071        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1072        int out_fd;
1073        char buf[1024];
1074
1075        config_filename = getenv(CONFIG_ENVIRONMENT);
1076        if (!config_filename) {
1077                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1078                if (!config_filename)
1079                        config_filename  = git_path("config");
1080        }
1081        config_filename = xstrdup(config_filename);
1082        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1083        if (out_fd < 0) {
1084                ret = error("Could not lock config file!");
1085                goto out;
1086        }
1087
1088        if (!(config_file = fopen(config_filename, "rb"))) {
1089                /* no config file means nothing to rename, no error */
1090                goto unlock_and_out;
1091        }
1092
1093        while (fgets(buf, sizeof(buf), config_file)) {
1094                int i;
1095                int length;
1096                for (i = 0; buf[i] && isspace(buf[i]); i++)
1097                        ; /* do nothing */
1098                if (buf[i] == '[') {
1099                        /* it's a section */
1100                        if (section_name_match (&buf[i+1], old_name)) {
1101                                ret++;
1102                                if (new_name == NULL) {
1103                                        remove = 1;
1104                                        continue;
1105                                }
1106                                store.baselen = strlen(new_name);
1107                                if (!store_write_section(out_fd, new_name)) {
1108                                        ret = write_error();
1109                                        goto out;
1110                                }
1111                                continue;
1112                        }
1113                        remove = 0;
1114                }
1115                if (remove)
1116                        continue;
1117                length = strlen(buf);
1118                if (write_in_full(out_fd, buf, length) != length) {
1119                        ret = write_error();
1120                        goto out;
1121                }
1122        }
1123        fclose(config_file);
1124 unlock_and_out:
1125        if (commit_lock_file(lock) < 0)
1126                        ret = error("Cannot commit config file!");
1127 out:
1128        free(config_filename);
1129        return ret;
1130}
1131
1132/*
1133 * Call this to report error for your variable that should not
1134 * get a boolean value (i.e. "[my] var" means "true").
1135 */
1136int config_error_nonbool(const char *var)
1137{
1138        return error("Missing value for '%s'", var);
1139}