Andrew's git / gitweb.git / config.c
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config.con commit Make git-remote a builtin (211c896)
   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(const char *name, const char *value)
 307{
 308        if (!value)
 309                return 1;
 310        if (!*value)
 311                return 0;
 312        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 313                return 1;
 314        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 315                return 0;
 316        return git_config_int(name, value) != 0;
 317}
 318
 319int git_config_string(const char **dest, const char *var, const char *value)
 320{
 321        if (!value)
 322                return config_error_nonbool(var);
 323        *dest = xstrdup(value);
 324        return 0;
 325}
 326
 327int git_default_config(const char *var, const char *value)
 328{
 329        /* This needs a better name */
 330        if (!strcmp(var, "core.filemode")) {
 331                trust_executable_bit = git_config_bool(var, value);
 332                return 0;
 333        }
 334
 335        if (!strcmp(var, "core.quotepath")) {
 336                quote_path_fully = git_config_bool(var, value);
 337                return 0;
 338        }
 339
 340        if (!strcmp(var, "core.symlinks")) {
 341                has_symlinks = git_config_bool(var, value);
 342                return 0;
 343        }
 344
 345        if (!strcmp(var, "core.bare")) {
 346                is_bare_repository_cfg = git_config_bool(var, value);
 347                return 0;
 348        }
 349
 350        if (!strcmp(var, "core.ignorestat")) {
 351                assume_unchanged = git_config_bool(var, value);
 352                return 0;
 353        }
 354
 355        if (!strcmp(var, "core.prefersymlinkrefs")) {
 356                prefer_symlink_refs = git_config_bool(var, value);
 357                return 0;
 358        }
 359
 360        if (!strcmp(var, "core.logallrefupdates")) {
 361                log_all_ref_updates = git_config_bool(var, value);
 362                return 0;
 363        }
 364
 365        if (!strcmp(var, "core.warnambiguousrefs")) {
 366                warn_ambiguous_refs = git_config_bool(var, value);
 367                return 0;
 368        }
 369
 370        if (!strcmp(var, "core.loosecompression")) {
 371                int level = git_config_int(var, value);
 372                if (level == -1)
 373                        level = Z_DEFAULT_COMPRESSION;
 374                else if (level < 0 || level > Z_BEST_COMPRESSION)
 375                        die("bad zlib compression level %d", level);
 376                zlib_compression_level = level;
 377                zlib_compression_seen = 1;
 378                return 0;
 379        }
 380
 381        if (!strcmp(var, "core.compression")) {
 382                int level = git_config_int(var, value);
 383                if (level == -1)
 384                        level = Z_DEFAULT_COMPRESSION;
 385                else if (level < 0 || level > Z_BEST_COMPRESSION)
 386                        die("bad zlib compression level %d", level);
 387                core_compression_level = level;
 388                core_compression_seen = 1;
 389                if (!zlib_compression_seen)
 390                        zlib_compression_level = level;
 391                return 0;
 392        }
 393
 394        if (!strcmp(var, "core.packedgitwindowsize")) {
 395                int pgsz_x2 = getpagesize() * 2;
 396                packed_git_window_size = git_config_int(var, value);
 397
 398                /* This value must be multiple of (pagesize * 2) */
 399                packed_git_window_size /= pgsz_x2;
 400                if (packed_git_window_size < 1)
 401                        packed_git_window_size = 1;
 402                packed_git_window_size *= pgsz_x2;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "core.packedgitlimit")) {
 407                packed_git_limit = git_config_int(var, value);
 408                return 0;
 409        }
 410
 411        if (!strcmp(var, "core.deltabasecachelimit")) {
 412                delta_base_cache_limit = git_config_int(var, value);
 413                return 0;
 414        }
 415
 416        if (!strcmp(var, "core.autocrlf")) {
 417                if (value && !strcasecmp(value, "input")) {
 418                        auto_crlf = -1;
 419                        return 0;
 420                }
 421                auto_crlf = git_config_bool(var, value);
 422                return 0;
 423        }
 424
 425        if (!strcmp(var, "core.safecrlf")) {
 426                if (value && !strcasecmp(value, "warn")) {
 427                        safe_crlf = SAFE_CRLF_WARN;
 428                        return 0;
 429                }
 430                safe_crlf = git_config_bool(var, value);
 431                return 0;
 432        }
 433
 434        if (!strcmp(var, "user.name")) {
 435                if (!value)
 436                        return config_error_nonbool(var);
 437                strlcpy(git_default_name, value, sizeof(git_default_name));
 438                return 0;
 439        }
 440
 441        if (!strcmp(var, "user.email")) {
 442                if (!value)
 443                        return config_error_nonbool(var);
 444                strlcpy(git_default_email, value, sizeof(git_default_email));
 445                return 0;
 446        }
 447
 448        if (!strcmp(var, "i18n.commitencoding"))
 449                return git_config_string(&git_commit_encoding, var, value);
 450
 451        if (!strcmp(var, "i18n.logoutputencoding"))
 452                return git_config_string(&git_log_output_encoding, var, value);
 453
 454        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 455                pager_use_color = git_config_bool(var,value);
 456                return 0;
 457        }
 458
 459        if (!strcmp(var, "core.pager"))
 460                return git_config_string(&pager_program, var, value);
 461
 462        if (!strcmp(var, "core.editor"))
 463                return git_config_string(&editor_program, var, value);
 464
 465        if (!strcmp(var, "core.excludesfile"))
 466                return git_config_string(&excludes_file, var, value);
 467
 468        if (!strcmp(var, "core.whitespace")) {
 469                if (!value)
 470                        return config_error_nonbool(var);
 471                whitespace_rule_cfg = parse_whitespace_rule(value);
 472                return 0;
 473        }
 474        if (!strcmp(var, "branch.autosetupmerge")) {
 475                if (value && !strcasecmp(value, "always")) {
 476                        git_branch_track = BRANCH_TRACK_ALWAYS;
 477                        return 0;
 478                }
 479                git_branch_track = git_config_bool(var, value);
 480                return 0;
 481        }
 482
 483        /* Add other config variables here and to Documentation/config.txt. */
 484        return 0;
 485}
 486
 487int git_config_from_file(config_fn_t fn, const char *filename)
 488{
 489        int ret;
 490        FILE *f = fopen(filename, "r");
 491
 492        ret = -1;
 493        if (f) {
 494                config_file = f;
 495                config_file_name = filename;
 496                config_linenr = 1;
 497                config_file_eof = 0;
 498                ret = git_parse_file(fn);
 499                fclose(f);
 500                config_file_name = NULL;
 501        }
 502        return ret;
 503}
 504
 505const char *git_etc_gitconfig(void)
 506{
 507        static const char *system_wide;
 508        if (!system_wide) {
 509                system_wide = ETC_GITCONFIG;
 510                if (!is_absolute_path(system_wide)) {
 511                        /* interpret path relative to exec-dir */
 512                        struct strbuf d = STRBUF_INIT;
 513                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 514                        system_wide = strbuf_detach(&d, NULL);
 515                }
 516        }
 517        return system_wide;
 518}
 519
 520int git_env_bool(const char *k, int def)
 521{
 522        const char *v = getenv(k);
 523        return v ? git_config_bool(k, v) : def;
 524}
 525
 526int git_config_system(void)
 527{
 528        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 529}
 530
 531int git_config_global(void)
 532{
 533        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 534}
 535
 536int git_config(config_fn_t fn)
 537{
 538        int ret = 0;
 539        char *repo_config = NULL;
 540        const char *home = NULL, *filename;
 541
 542        /* $GIT_CONFIG makes git read _only_ the given config file,
 543         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 544         * global config file, the same way it would the per-repository
 545         * config file otherwise. */
 546        filename = getenv(CONFIG_ENVIRONMENT);
 547        if (!filename) {
 548                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 549                        ret += git_config_from_file(fn, git_etc_gitconfig());
 550                home = getenv("HOME");
 551                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 552                if (!filename)
 553                        filename = repo_config = xstrdup(git_path("config"));
 554        }
 555
 556        if (git_config_global() && home) {
 557                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 558                if (!access(user_config, R_OK))
 559                        ret = git_config_from_file(fn, user_config);
 560                free(user_config);
 561        }
 562
 563        ret += git_config_from_file(fn, filename);
 564        free(repo_config);
 565        return ret;
 566}
 567
 568/*
 569 * Find all the stuff for git_config_set() below.
 570 */
 571
 572#define MAX_MATCHES 512
 573
 574static struct {
 575        int baselen;
 576        char* key;
 577        int do_not_match;
 578        regex_t* value_regex;
 579        int multi_replace;
 580        size_t offset[MAX_MATCHES];
 581        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 582        int seen;
 583} store;
 584
 585static int matches(const char* key, const char* value)
 586{
 587        return !strcmp(key, store.key) &&
 588                (store.value_regex == NULL ||
 589                 (store.do_not_match ^
 590                  !regexec(store.value_regex, value, 0, NULL, 0)));
 591}
 592
 593static int store_aux(const char* key, const char* value)
 594{
 595        const char *ep;
 596        size_t section_len;
 597
 598        switch (store.state) {
 599        case KEY_SEEN:
 600                if (matches(key, value)) {
 601                        if (store.seen == 1 && store.multi_replace == 0) {
 602                                fprintf(stderr,
 603                                        "Warning: %s has multiple values\n",
 604                                        key);
 605                        } else if (store.seen >= MAX_MATCHES) {
 606                                fprintf(stderr, "Too many matches\n");
 607                                return 1;
 608                        }
 609
 610                        store.offset[store.seen] = ftell(config_file);
 611                        store.seen++;
 612                }
 613                break;
 614        case SECTION_SEEN:
 615                /*
 616                 * What we are looking for is in store.key (both
 617                 * section and var), and its section part is baselen
 618                 * long.  We found key (again, both section and var).
 619                 * We would want to know if this key is in the same
 620                 * section as what we are looking for.  We already
 621                 * know we are in the same section as what should
 622                 * hold store.key.
 623                 */
 624                ep = strrchr(key, '.');
 625                section_len = ep - key;
 626
 627                if ((section_len != store.baselen) ||
 628                    memcmp(key, store.key, section_len+1)) {
 629                        store.state = SECTION_END_SEEN;
 630                        break;
 631                }
 632
 633                /*
 634                 * Do not increment matches: this is no match, but we
 635                 * just made sure we are in the desired section.
 636                 */
 637                store.offset[store.seen] = ftell(config_file);
 638                /* fallthru */
 639        case SECTION_END_SEEN:
 640        case START:
 641                if (matches(key, value)) {
 642                        store.offset[store.seen] = ftell(config_file);
 643                        store.state = KEY_SEEN;
 644                        store.seen++;
 645                } else {
 646                        if (strrchr(key, '.') - key == store.baselen &&
 647                              !strncmp(key, store.key, store.baselen)) {
 648                                        store.state = SECTION_SEEN;
 649                                        store.offset[store.seen] = ftell(config_file);
 650                        }
 651                }
 652        }
 653        return 0;
 654}
 655
 656static int write_error(void)
 657{
 658        fprintf(stderr, "Failed to write new configuration file\n");
 659
 660        /* Same error code as "failed to rename". */
 661        return 4;
 662}
 663
 664static int store_write_section(int fd, const char* key)
 665{
 666        const char *dot;
 667        int i, success;
 668        struct strbuf sb;
 669
 670        strbuf_init(&sb, 0);
 671        dot = memchr(key, '.', store.baselen);
 672        if (dot) {
 673                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 674                for (i = dot - key + 1; i < store.baselen; i++) {
 675                        if (key[i] == '"')
 676                                strbuf_addch(&sb, '\\');
 677                        strbuf_addch(&sb, key[i]);
 678                }
 679                strbuf_addstr(&sb, "\"]\n");
 680        } else {
 681                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 682        }
 683
 684        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 685        strbuf_release(&sb);
 686
 687        return success;
 688}
 689
 690static int store_write_pair(int fd, const char* key, const char* value)
 691{
 692        int i, success;
 693        int length = strlen(key + store.baselen + 1);
 694        const char *quote = "";
 695        struct strbuf sb;
 696
 697        /*
 698         * Check to see if the value needs to be surrounded with a dq pair.
 699         * Note that problematic characters are always backslash-quoted; this
 700         * check is about not losing leading or trailing SP and strings that
 701         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 702         * configuration parser.
 703         */
 704        if (value[0] == ' ')
 705                quote = "\"";
 706        for (i = 0; value[i]; i++)
 707                if (value[i] == ';' || value[i] == '#')
 708                        quote = "\"";
 709        if (i && value[i - 1] == ' ')
 710                quote = "\"";
 711
 712        strbuf_init(&sb, 0);
 713        strbuf_addf(&sb, "\t%.*s = %s",
 714                    length, key + store.baselen + 1, quote);
 715
 716        for (i = 0; value[i]; i++)
 717                switch (value[i]) {
 718                case '\n':
 719                        strbuf_addstr(&sb, "\\n");
 720                        break;
 721                case '\t':
 722                        strbuf_addstr(&sb, "\\t");
 723                        break;
 724                case '"':
 725                case '\\':
 726                        strbuf_addch(&sb, '\\');
 727                default:
 728                        strbuf_addch(&sb, value[i]);
 729                        break;
 730                }
 731        strbuf_addf(&sb, "%s\n", quote);
 732
 733        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 734        strbuf_release(&sb);
 735
 736        return success;
 737}
 738
 739static ssize_t find_beginning_of_line(const char* contents, size_t size,
 740        size_t offset_, int* found_bracket)
 741{
 742        size_t equal_offset = size, bracket_offset = size;
 743        ssize_t offset;
 744
 745contline:
 746        for (offset = offset_-2; offset > 0
 747                        && contents[offset] != '\n'; offset--)
 748                switch (contents[offset]) {
 749                        case '=': equal_offset = offset; break;
 750                        case ']': bracket_offset = offset; break;
 751                }
 752        if (offset > 0 && contents[offset-1] == '\\') {
 753                offset_ = offset;
 754                goto contline;
 755        }
 756        if (bracket_offset < equal_offset) {
 757                *found_bracket = 1;
 758                offset = bracket_offset+1;
 759        } else
 760                offset++;
 761
 762        return offset;
 763}
 764
 765int git_config_set(const char* key, const char* value)
 766{
 767        return git_config_set_multivar(key, value, NULL, 0);
 768}
 769
 770/*
 771 * If value==NULL, unset in (remove from) config,
 772 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 773 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 774 *     else all matching key/values (regardless how many) are removed,
 775 *     before the new pair is written.
 776 *
 777 * Returns 0 on success.
 778 *
 779 * This function does this:
 780 *
 781 * - it locks the config file by creating ".git/config.lock"
 782 *
 783 * - it then parses the config using store_aux() as validator to find
 784 *   the position on the key/value pair to replace. If it is to be unset,
 785 *   it must be found exactly once.
 786 *
 787 * - the config file is mmap()ed and the part before the match (if any) is
 788 *   written to the lock file, then the changed part and the rest.
 789 *
 790 * - the config file is removed and the lock file rename()d to it.
 791 *
 792 */
 793int git_config_set_multivar(const char* key, const char* value,
 794        const char* value_regex, int multi_replace)
 795{
 796        int i, dot;
 797        int fd = -1, in_fd;
 798        int ret;
 799        char* config_filename;
 800        struct lock_file *lock = NULL;
 801        const char* last_dot = strrchr(key, '.');
 802
 803        config_filename = getenv(CONFIG_ENVIRONMENT);
 804        if (!config_filename) {
 805                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 806                if (!config_filename)
 807                        config_filename  = git_path("config");
 808        }
 809        config_filename = xstrdup(config_filename);
 810
 811        /*
 812         * Since "key" actually contains the section name and the real
 813         * key name separated by a dot, we have to know where the dot is.
 814         */
 815
 816        if (last_dot == NULL) {
 817                fprintf(stderr, "key does not contain a section: %s\n", key);
 818                ret = 2;
 819                goto out_free;
 820        }
 821        store.baselen = last_dot - key;
 822
 823        store.multi_replace = multi_replace;
 824
 825        /*
 826         * Validate the key and while at it, lower case it for matching.
 827         */
 828        store.key = xmalloc(strlen(key) + 1);
 829        dot = 0;
 830        for (i = 0; key[i]; i++) {
 831                unsigned char c = key[i];
 832                if (c == '.')
 833                        dot = 1;
 834                /* Leave the extended basename untouched.. */
 835                if (!dot || i > store.baselen) {
 836                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 837                                fprintf(stderr, "invalid key: %s\n", key);
 838                                free(store.key);
 839                                ret = 1;
 840                                goto out_free;
 841                        }
 842                        c = tolower(c);
 843                } else if (c == '\n') {
 844                        fprintf(stderr, "invalid key (newline): %s\n", key);
 845                        free(store.key);
 846                        ret = 1;
 847                        goto out_free;
 848                }
 849                store.key[i] = c;
 850        }
 851        store.key[i] = 0;
 852
 853        /*
 854         * The lock serves a purpose in addition to locking: the new
 855         * contents of .git/config will be written into it.
 856         */
 857        lock = xcalloc(sizeof(struct lock_file), 1);
 858        fd = hold_lock_file_for_update(lock, config_filename, 0);
 859        if (fd < 0) {
 860                fprintf(stderr, "could not lock config file\n");
 861                free(store.key);
 862                ret = -1;
 863                goto out_free;
 864        }
 865
 866        /*
 867         * If .git/config does not exist yet, write a minimal version.
 868         */
 869        in_fd = open(config_filename, O_RDONLY);
 870        if ( in_fd < 0 ) {
 871                free(store.key);
 872
 873                if ( ENOENT != errno ) {
 874                        error("opening %s: %s", config_filename,
 875                              strerror(errno));
 876                        ret = 3; /* same as "invalid config file" */
 877                        goto out_free;
 878                }
 879                /* if nothing to unset, error out */
 880                if (value == NULL) {
 881                        ret = 5;
 882                        goto out_free;
 883                }
 884
 885                store.key = (char*)key;
 886                if (!store_write_section(fd, key) ||
 887                    !store_write_pair(fd, key, value))
 888                        goto write_err_out;
 889        } else {
 890                struct stat st;
 891                char* contents;
 892                size_t contents_sz, copy_begin, copy_end;
 893                int i, new_line = 0;
 894
 895                if (value_regex == NULL)
 896                        store.value_regex = NULL;
 897                else {
 898                        if (value_regex[0] == '!') {
 899                                store.do_not_match = 1;
 900                                value_regex++;
 901                        } else
 902                                store.do_not_match = 0;
 903
 904                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 905                        if (regcomp(store.value_regex, value_regex,
 906                                        REG_EXTENDED)) {
 907                                fprintf(stderr, "Invalid pattern: %s\n",
 908                                        value_regex);
 909                                free(store.value_regex);
 910                                ret = 6;
 911                                goto out_free;
 912                        }
 913                }
 914
 915                store.offset[0] = 0;
 916                store.state = START;
 917                store.seen = 0;
 918
 919                /*
 920                 * After this, store.offset will contain the *end* offset
 921                 * of the last match, or remain at 0 if no match was found.
 922                 * As a side effect, we make sure to transform only a valid
 923                 * existing config file.
 924                 */
 925                if (git_config_from_file(store_aux, config_filename)) {
 926                        fprintf(stderr, "invalid config file\n");
 927                        free(store.key);
 928                        if (store.value_regex != NULL) {
 929                                regfree(store.value_regex);
 930                                free(store.value_regex);
 931                        }
 932                        ret = 3;
 933                        goto out_free;
 934                }
 935
 936                free(store.key);
 937                if (store.value_regex != NULL) {
 938                        regfree(store.value_regex);
 939                        free(store.value_regex);
 940                }
 941
 942                /* if nothing to unset, or too many matches, error out */
 943                if ((store.seen == 0 && value == NULL) ||
 944                                (store.seen > 1 && multi_replace == 0)) {
 945                        ret = 5;
 946                        goto out_free;
 947                }
 948
 949                fstat(in_fd, &st);
 950                contents_sz = xsize_t(st.st_size);
 951                contents = xmmap(NULL, contents_sz, PROT_READ,
 952                        MAP_PRIVATE, in_fd, 0);
 953                close(in_fd);
 954
 955                if (store.seen == 0)
 956                        store.seen = 1;
 957
 958                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 959                        if (store.offset[i] == 0) {
 960                                store.offset[i] = copy_end = contents_sz;
 961                        } else if (store.state != KEY_SEEN) {
 962                                copy_end = store.offset[i];
 963                        } else
 964                                copy_end = find_beginning_of_line(
 965                                        contents, contents_sz,
 966                                        store.offset[i]-2, &new_line);
 967
 968                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 969                                new_line = 1;
 970
 971                        /* write the first part of the config */
 972                        if (copy_end > copy_begin) {
 973                                if (write_in_full(fd, contents + copy_begin,
 974                                                  copy_end - copy_begin) <
 975                                    copy_end - copy_begin)
 976                                        goto write_err_out;
 977                                if (new_line &&
 978                                    write_in_full(fd, "\n", 1) != 1)
 979                                        goto write_err_out;
 980                        }
 981                        copy_begin = store.offset[i];
 982                }
 983
 984                /* write the pair (value == NULL means unset) */
 985                if (value != NULL) {
 986                        if (store.state == START) {
 987                                if (!store_write_section(fd, key))
 988                                        goto write_err_out;
 989                        }
 990                        if (!store_write_pair(fd, key, value))
 991                                goto write_err_out;
 992                }
 993
 994                /* write the rest of the config */
 995                if (copy_begin < contents_sz)
 996                        if (write_in_full(fd, contents + copy_begin,
 997                                          contents_sz - copy_begin) <
 998                            contents_sz - copy_begin)
 999                                goto write_err_out;
1000
1001                munmap(contents, contents_sz);
1002        }
1003
1004        if (commit_lock_file(lock) < 0) {
1005                fprintf(stderr, "Cannot commit config file!\n");
1006                ret = 4;
1007                goto out_free;
1008        }
1009
1010        /*
1011         * lock is committed, so don't try to roll it back below.
1012         * NOTE: Since lockfile.c keeps a linked list of all created
1013         * lock_file structures, it isn't safe to free(lock).  It's
1014         * better to just leave it hanging around.
1015         */
1016        lock = NULL;
1017        ret = 0;
1018
1019out_free:
1020        if (lock)
1021                rollback_lock_file(lock);
1022        free(config_filename);
1023        return ret;
1024
1025write_err_out:
1026        ret = write_error();
1027        goto out_free;
1028
1029}
1030
1031static int section_name_match (const char *buf, const char *name)
1032{
1033        int i = 0, j = 0, dot = 0;
1034        for (; buf[i] && buf[i] != ']'; i++) {
1035                if (!dot && isspace(buf[i])) {
1036                        dot = 1;
1037                        if (name[j++] != '.')
1038                                break;
1039                        for (i++; isspace(buf[i]); i++)
1040                                ; /* do nothing */
1041                        if (buf[i] != '"')
1042                                break;
1043                        continue;
1044                }
1045                if (buf[i] == '\\' && dot)
1046                        i++;
1047                else if (buf[i] == '"' && dot) {
1048                        for (i++; isspace(buf[i]); i++)
1049                                ; /* do_nothing */
1050                        break;
1051                }
1052                if (buf[i] != name[j++])
1053                        break;
1054        }
1055        return (buf[i] == ']' && name[j] == 0);
1056}
1057
1058/* if new_name == NULL, the section is removed instead */
1059int git_config_rename_section(const char *old_name, const char *new_name)
1060{
1061        int ret = 0, remove = 0;
1062        char *config_filename;
1063        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1064        int out_fd;
1065        char buf[1024];
1066
1067        config_filename = getenv(CONFIG_ENVIRONMENT);
1068        if (!config_filename) {
1069                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1070                if (!config_filename)
1071                        config_filename  = git_path("config");
1072        }
1073        config_filename = xstrdup(config_filename);
1074        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1075        if (out_fd < 0) {
1076                ret = error("Could not lock config file!");
1077                goto out;
1078        }
1079
1080        if (!(config_file = fopen(config_filename, "rb"))) {
1081                /* no config file means nothing to rename, no error */
1082                goto unlock_and_out;
1083        }
1084
1085        while (fgets(buf, sizeof(buf), config_file)) {
1086                int i;
1087                int length;
1088                for (i = 0; buf[i] && isspace(buf[i]); i++)
1089                        ; /* do nothing */
1090                if (buf[i] == '[') {
1091                        /* it's a section */
1092                        if (section_name_match (&buf[i+1], old_name)) {
1093                                ret++;
1094                                if (new_name == NULL) {
1095                                        remove = 1;
1096                                        continue;
1097                                }
1098                                store.baselen = strlen(new_name);
1099                                if (!store_write_section(out_fd, new_name)) {
1100                                        ret = write_error();
1101                                        goto out;
1102                                }
1103                                continue;
1104                        }
1105                        remove = 0;
1106                }
1107                if (remove)
1108                        continue;
1109                length = strlen(buf);
1110                if (write_in_full(out_fd, buf, length) != length) {
1111                        ret = write_error();
1112                        goto out;
1113                }
1114        }
1115        fclose(config_file);
1116 unlock_and_out:
1117        if (commit_lock_file(lock) < 0)
1118                        ret = error("Cannot commit config file!");
1119 out:
1120        free(config_filename);
1121        return ret;
1122}
1123
1124/*
1125 * Call this to report error for your variable that should not
1126 * get a boolean value (i.e. "[my] var" means "true").
1127 */
1128int config_error_nonbool(const char *var)
1129{
1130        return error("Missing value for '%s'", var);
1131}