Andrew's git / gitweb.git / config.c
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config.con commit Optimize symlink/directory detection (c40641b)
   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.ignorecase")) {
 354                ignore_case = git_config_bool(var, value);
 355                return 0;
 356        }
 357
 358        if (!strcmp(var, "core.bare")) {
 359                is_bare_repository_cfg = git_config_bool(var, value);
 360                return 0;
 361        }
 362
 363        if (!strcmp(var, "core.ignorestat")) {
 364                assume_unchanged = git_config_bool(var, value);
 365                return 0;
 366        }
 367
 368        if (!strcmp(var, "core.prefersymlinkrefs")) {
 369                prefer_symlink_refs = git_config_bool(var, value);
 370                return 0;
 371        }
 372
 373        if (!strcmp(var, "core.logallrefupdates")) {
 374                log_all_ref_updates = git_config_bool(var, value);
 375                return 0;
 376        }
 377
 378        if (!strcmp(var, "core.warnambiguousrefs")) {
 379                warn_ambiguous_refs = git_config_bool(var, value);
 380                return 0;
 381        }
 382
 383        if (!strcmp(var, "core.loosecompression")) {
 384                int level = git_config_int(var, value);
 385                if (level == -1)
 386                        level = Z_DEFAULT_COMPRESSION;
 387                else if (level < 0 || level > Z_BEST_COMPRESSION)
 388                        die("bad zlib compression level %d", level);
 389                zlib_compression_level = level;
 390                zlib_compression_seen = 1;
 391                return 0;
 392        }
 393
 394        if (!strcmp(var, "core.compression")) {
 395                int level = git_config_int(var, value);
 396                if (level == -1)
 397                        level = Z_DEFAULT_COMPRESSION;
 398                else if (level < 0 || level > Z_BEST_COMPRESSION)
 399                        die("bad zlib compression level %d", level);
 400                core_compression_level = level;
 401                core_compression_seen = 1;
 402                if (!zlib_compression_seen)
 403                        zlib_compression_level = level;
 404                return 0;
 405        }
 406
 407        if (!strcmp(var, "core.packedgitwindowsize")) {
 408                int pgsz_x2 = getpagesize() * 2;
 409                packed_git_window_size = git_config_int(var, value);
 410
 411                /* This value must be multiple of (pagesize * 2) */
 412                packed_git_window_size /= pgsz_x2;
 413                if (packed_git_window_size < 1)
 414                        packed_git_window_size = 1;
 415                packed_git_window_size *= pgsz_x2;
 416                return 0;
 417        }
 418
 419        if (!strcmp(var, "core.packedgitlimit")) {
 420                packed_git_limit = git_config_int(var, value);
 421                return 0;
 422        }
 423
 424        if (!strcmp(var, "core.deltabasecachelimit")) {
 425                delta_base_cache_limit = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (!strcmp(var, "core.autocrlf")) {
 430                if (value && !strcasecmp(value, "input")) {
 431                        auto_crlf = -1;
 432                        return 0;
 433                }
 434                auto_crlf = git_config_bool(var, value);
 435                return 0;
 436        }
 437
 438        if (!strcmp(var, "core.safecrlf")) {
 439                if (value && !strcasecmp(value, "warn")) {
 440                        safe_crlf = SAFE_CRLF_WARN;
 441                        return 0;
 442                }
 443                safe_crlf = git_config_bool(var, value);
 444                return 0;
 445        }
 446
 447        if (!strcmp(var, "user.name")) {
 448                if (!value)
 449                        return config_error_nonbool(var);
 450                strlcpy(git_default_name, value, sizeof(git_default_name));
 451                return 0;
 452        }
 453
 454        if (!strcmp(var, "user.email")) {
 455                if (!value)
 456                        return config_error_nonbool(var);
 457                strlcpy(git_default_email, value, sizeof(git_default_email));
 458                return 0;
 459        }
 460
 461        if (!strcmp(var, "i18n.commitencoding"))
 462                return git_config_string(&git_commit_encoding, var, value);
 463
 464        if (!strcmp(var, "i18n.logoutputencoding"))
 465                return git_config_string(&git_log_output_encoding, var, value);
 466
 467        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 468                pager_use_color = 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        if (!strcmp(var, "branch.autosetupmerge")) {
 488                if (value && !strcasecmp(value, "always")) {
 489                        git_branch_track = BRANCH_TRACK_ALWAYS;
 490                        return 0;
 491                }
 492                git_branch_track = git_config_bool(var, value);
 493                return 0;
 494        }
 495
 496        /* Add other config variables here and to Documentation/config.txt. */
 497        return 0;
 498}
 499
 500int git_config_from_file(config_fn_t fn, const char *filename)
 501{
 502        int ret;
 503        FILE *f = fopen(filename, "r");
 504
 505        ret = -1;
 506        if (f) {
 507                config_file = f;
 508                config_file_name = filename;
 509                config_linenr = 1;
 510                config_file_eof = 0;
 511                ret = git_parse_file(fn);
 512                fclose(f);
 513                config_file_name = NULL;
 514        }
 515        return ret;
 516}
 517
 518const char *git_etc_gitconfig(void)
 519{
 520        static const char *system_wide;
 521        if (!system_wide) {
 522                system_wide = ETC_GITCONFIG;
 523                if (!is_absolute_path(system_wide)) {
 524                        /* interpret path relative to exec-dir */
 525                        struct strbuf d = STRBUF_INIT;
 526                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 527                        system_wide = strbuf_detach(&d, NULL);
 528                }
 529        }
 530        return system_wide;
 531}
 532
 533int git_env_bool(const char *k, int def)
 534{
 535        const char *v = getenv(k);
 536        return v ? git_config_bool(k, v) : def;
 537}
 538
 539int git_config_system(void)
 540{
 541        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 542}
 543
 544int git_config_global(void)
 545{
 546        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 547}
 548
 549int git_config(config_fn_t fn)
 550{
 551        int ret = 0;
 552        char *repo_config = NULL;
 553        const char *home = NULL, *filename;
 554
 555        /* $GIT_CONFIG makes git read _only_ the given config file,
 556         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 557         * global config file, the same way it would the per-repository
 558         * config file otherwise. */
 559        filename = getenv(CONFIG_ENVIRONMENT);
 560        if (!filename) {
 561                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 562                        ret += git_config_from_file(fn, git_etc_gitconfig());
 563                home = getenv("HOME");
 564                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 565                if (!filename)
 566                        filename = repo_config = xstrdup(git_path("config"));
 567        }
 568
 569        if (git_config_global() && home) {
 570                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 571                if (!access(user_config, R_OK))
 572                        ret = git_config_from_file(fn, user_config);
 573                free(user_config);
 574        }
 575
 576        ret += git_config_from_file(fn, filename);
 577        free(repo_config);
 578        return ret;
 579}
 580
 581/*
 582 * Find all the stuff for git_config_set() below.
 583 */
 584
 585#define MAX_MATCHES 512
 586
 587static struct {
 588        int baselen;
 589        char* key;
 590        int do_not_match;
 591        regex_t* value_regex;
 592        int multi_replace;
 593        size_t offset[MAX_MATCHES];
 594        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 595        int seen;
 596} store;
 597
 598static int matches(const char* key, const char* value)
 599{
 600        return !strcmp(key, store.key) &&
 601                (store.value_regex == NULL ||
 602                 (store.do_not_match ^
 603                  !regexec(store.value_regex, value, 0, NULL, 0)));
 604}
 605
 606static int store_aux(const char* key, const char* value)
 607{
 608        const char *ep;
 609        size_t section_len;
 610
 611        switch (store.state) {
 612        case KEY_SEEN:
 613                if (matches(key, value)) {
 614                        if (store.seen == 1 && store.multi_replace == 0) {
 615                                fprintf(stderr,
 616                                        "Warning: %s has multiple values\n",
 617                                        key);
 618                        } else if (store.seen >= MAX_MATCHES) {
 619                                fprintf(stderr, "Too many matches\n");
 620                                return 1;
 621                        }
 622
 623                        store.offset[store.seen] = ftell(config_file);
 624                        store.seen++;
 625                }
 626                break;
 627        case SECTION_SEEN:
 628                /*
 629                 * What we are looking for is in store.key (both
 630                 * section and var), and its section part is baselen
 631                 * long.  We found key (again, both section and var).
 632                 * We would want to know if this key is in the same
 633                 * section as what we are looking for.  We already
 634                 * know we are in the same section as what should
 635                 * hold store.key.
 636                 */
 637                ep = strrchr(key, '.');
 638                section_len = ep - key;
 639
 640                if ((section_len != store.baselen) ||
 641                    memcmp(key, store.key, section_len+1)) {
 642                        store.state = SECTION_END_SEEN;
 643                        break;
 644                }
 645
 646                /*
 647                 * Do not increment matches: this is no match, but we
 648                 * just made sure we are in the desired section.
 649                 */
 650                store.offset[store.seen] = ftell(config_file);
 651                /* fallthru */
 652        case SECTION_END_SEEN:
 653        case START:
 654                if (matches(key, value)) {
 655                        store.offset[store.seen] = ftell(config_file);
 656                        store.state = KEY_SEEN;
 657                        store.seen++;
 658                } else {
 659                        if (strrchr(key, '.') - key == store.baselen &&
 660                              !strncmp(key, store.key, store.baselen)) {
 661                                        store.state = SECTION_SEEN;
 662                                        store.offset[store.seen] = ftell(config_file);
 663                        }
 664                }
 665        }
 666        return 0;
 667}
 668
 669static int write_error(void)
 670{
 671        fprintf(stderr, "Failed to write new configuration file\n");
 672
 673        /* Same error code as "failed to rename". */
 674        return 4;
 675}
 676
 677static int store_write_section(int fd, const char* key)
 678{
 679        const char *dot;
 680        int i, success;
 681        struct strbuf sb;
 682
 683        strbuf_init(&sb, 0);
 684        dot = memchr(key, '.', store.baselen);
 685        if (dot) {
 686                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 687                for (i = dot - key + 1; i < store.baselen; i++) {
 688                        if (key[i] == '"')
 689                                strbuf_addch(&sb, '\\');
 690                        strbuf_addch(&sb, key[i]);
 691                }
 692                strbuf_addstr(&sb, "\"]\n");
 693        } else {
 694                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 695        }
 696
 697        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 698        strbuf_release(&sb);
 699
 700        return success;
 701}
 702
 703static int store_write_pair(int fd, const char* key, const char* value)
 704{
 705        int i, success;
 706        int length = strlen(key + store.baselen + 1);
 707        const char *quote = "";
 708        struct strbuf sb;
 709
 710        /*
 711         * Check to see if the value needs to be surrounded with a dq pair.
 712         * Note that problematic characters are always backslash-quoted; this
 713         * check is about not losing leading or trailing SP and strings that
 714         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 715         * configuration parser.
 716         */
 717        if (value[0] == ' ')
 718                quote = "\"";
 719        for (i = 0; value[i]; i++)
 720                if (value[i] == ';' || value[i] == '#')
 721                        quote = "\"";
 722        if (i && value[i - 1] == ' ')
 723                quote = "\"";
 724
 725        strbuf_init(&sb, 0);
 726        strbuf_addf(&sb, "\t%.*s = %s",
 727                    length, key + store.baselen + 1, quote);
 728
 729        for (i = 0; value[i]; i++)
 730                switch (value[i]) {
 731                case '\n':
 732                        strbuf_addstr(&sb, "\\n");
 733                        break;
 734                case '\t':
 735                        strbuf_addstr(&sb, "\\t");
 736                        break;
 737                case '"':
 738                case '\\':
 739                        strbuf_addch(&sb, '\\');
 740                default:
 741                        strbuf_addch(&sb, value[i]);
 742                        break;
 743                }
 744        strbuf_addf(&sb, "%s\n", quote);
 745
 746        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 747        strbuf_release(&sb);
 748
 749        return success;
 750}
 751
 752static ssize_t find_beginning_of_line(const char* contents, size_t size,
 753        size_t offset_, int* found_bracket)
 754{
 755        size_t equal_offset = size, bracket_offset = size;
 756        ssize_t offset;
 757
 758contline:
 759        for (offset = offset_-2; offset > 0
 760                        && contents[offset] != '\n'; offset--)
 761                switch (contents[offset]) {
 762                        case '=': equal_offset = offset; break;
 763                        case ']': bracket_offset = offset; break;
 764                }
 765        if (offset > 0 && contents[offset-1] == '\\') {
 766                offset_ = offset;
 767                goto contline;
 768        }
 769        if (bracket_offset < equal_offset) {
 770                *found_bracket = 1;
 771                offset = bracket_offset+1;
 772        } else
 773                offset++;
 774
 775        return offset;
 776}
 777
 778int git_config_set(const char* key, const char* value)
 779{
 780        return git_config_set_multivar(key, value, NULL, 0);
 781}
 782
 783/*
 784 * If value==NULL, unset in (remove from) config,
 785 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 786 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 787 *     else all matching key/values (regardless how many) are removed,
 788 *     before the new pair is written.
 789 *
 790 * Returns 0 on success.
 791 *
 792 * This function does this:
 793 *
 794 * - it locks the config file by creating ".git/config.lock"
 795 *
 796 * - it then parses the config using store_aux() as validator to find
 797 *   the position on the key/value pair to replace. If it is to be unset,
 798 *   it must be found exactly once.
 799 *
 800 * - the config file is mmap()ed and the part before the match (if any) is
 801 *   written to the lock file, then the changed part and the rest.
 802 *
 803 * - the config file is removed and the lock file rename()d to it.
 804 *
 805 */
 806int git_config_set_multivar(const char* key, const char* value,
 807        const char* value_regex, int multi_replace)
 808{
 809        int i, dot;
 810        int fd = -1, in_fd;
 811        int ret;
 812        char* config_filename;
 813        struct lock_file *lock = NULL;
 814        const char* last_dot = strrchr(key, '.');
 815
 816        config_filename = getenv(CONFIG_ENVIRONMENT);
 817        if (!config_filename) {
 818                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 819                if (!config_filename)
 820                        config_filename  = git_path("config");
 821        }
 822        config_filename = xstrdup(config_filename);
 823
 824        /*
 825         * Since "key" actually contains the section name and the real
 826         * key name separated by a dot, we have to know where the dot is.
 827         */
 828
 829        if (last_dot == NULL) {
 830                fprintf(stderr, "key does not contain a section: %s\n", key);
 831                ret = 2;
 832                goto out_free;
 833        }
 834        store.baselen = last_dot - key;
 835
 836        store.multi_replace = multi_replace;
 837
 838        /*
 839         * Validate the key and while at it, lower case it for matching.
 840         */
 841        store.key = xmalloc(strlen(key) + 1);
 842        dot = 0;
 843        for (i = 0; key[i]; i++) {
 844                unsigned char c = key[i];
 845                if (c == '.')
 846                        dot = 1;
 847                /* Leave the extended basename untouched.. */
 848                if (!dot || i > store.baselen) {
 849                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 850                                fprintf(stderr, "invalid key: %s\n", key);
 851                                free(store.key);
 852                                ret = 1;
 853                                goto out_free;
 854                        }
 855                        c = tolower(c);
 856                } else if (c == '\n') {
 857                        fprintf(stderr, "invalid key (newline): %s\n", key);
 858                        free(store.key);
 859                        ret = 1;
 860                        goto out_free;
 861                }
 862                store.key[i] = c;
 863        }
 864        store.key[i] = 0;
 865
 866        /*
 867         * The lock serves a purpose in addition to locking: the new
 868         * contents of .git/config will be written into it.
 869         */
 870        lock = xcalloc(sizeof(struct lock_file), 1);
 871        fd = hold_lock_file_for_update(lock, config_filename, 0);
 872        if (fd < 0) {
 873                fprintf(stderr, "could not lock config file\n");
 874                free(store.key);
 875                ret = -1;
 876                goto out_free;
 877        }
 878
 879        /*
 880         * If .git/config does not exist yet, write a minimal version.
 881         */
 882        in_fd = open(config_filename, O_RDONLY);
 883        if ( in_fd < 0 ) {
 884                free(store.key);
 885
 886                if ( ENOENT != errno ) {
 887                        error("opening %s: %s", config_filename,
 888                              strerror(errno));
 889                        ret = 3; /* same as "invalid config file" */
 890                        goto out_free;
 891                }
 892                /* if nothing to unset, error out */
 893                if (value == NULL) {
 894                        ret = 5;
 895                        goto out_free;
 896                }
 897
 898                store.key = (char*)key;
 899                if (!store_write_section(fd, key) ||
 900                    !store_write_pair(fd, key, value))
 901                        goto write_err_out;
 902        } else {
 903                struct stat st;
 904                char* contents;
 905                size_t contents_sz, copy_begin, copy_end;
 906                int i, new_line = 0;
 907
 908                if (value_regex == NULL)
 909                        store.value_regex = NULL;
 910                else {
 911                        if (value_regex[0] == '!') {
 912                                store.do_not_match = 1;
 913                                value_regex++;
 914                        } else
 915                                store.do_not_match = 0;
 916
 917                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 918                        if (regcomp(store.value_regex, value_regex,
 919                                        REG_EXTENDED)) {
 920                                fprintf(stderr, "Invalid pattern: %s\n",
 921                                        value_regex);
 922                                free(store.value_regex);
 923                                ret = 6;
 924                                goto out_free;
 925                        }
 926                }
 927
 928                store.offset[0] = 0;
 929                store.state = START;
 930                store.seen = 0;
 931
 932                /*
 933                 * After this, store.offset will contain the *end* offset
 934                 * of the last match, or remain at 0 if no match was found.
 935                 * As a side effect, we make sure to transform only a valid
 936                 * existing config file.
 937                 */
 938                if (git_config_from_file(store_aux, config_filename)) {
 939                        fprintf(stderr, "invalid config file\n");
 940                        free(store.key);
 941                        if (store.value_regex != NULL) {
 942                                regfree(store.value_regex);
 943                                free(store.value_regex);
 944                        }
 945                        ret = 3;
 946                        goto out_free;
 947                }
 948
 949                free(store.key);
 950                if (store.value_regex != NULL) {
 951                        regfree(store.value_regex);
 952                        free(store.value_regex);
 953                }
 954
 955                /* if nothing to unset, or too many matches, error out */
 956                if ((store.seen == 0 && value == NULL) ||
 957                                (store.seen > 1 && multi_replace == 0)) {
 958                        ret = 5;
 959                        goto out_free;
 960                }
 961
 962                fstat(in_fd, &st);
 963                contents_sz = xsize_t(st.st_size);
 964                contents = xmmap(NULL, contents_sz, PROT_READ,
 965                        MAP_PRIVATE, in_fd, 0);
 966                close(in_fd);
 967
 968                if (store.seen == 0)
 969                        store.seen = 1;
 970
 971                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 972                        if (store.offset[i] == 0) {
 973                                store.offset[i] = copy_end = contents_sz;
 974                        } else if (store.state != KEY_SEEN) {
 975                                copy_end = store.offset[i];
 976                        } else
 977                                copy_end = find_beginning_of_line(
 978                                        contents, contents_sz,
 979                                        store.offset[i]-2, &new_line);
 980
 981                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 982                                new_line = 1;
 983
 984                        /* write the first part of the config */
 985                        if (copy_end > copy_begin) {
 986                                if (write_in_full(fd, contents + copy_begin,
 987                                                  copy_end - copy_begin) <
 988                                    copy_end - copy_begin)
 989                                        goto write_err_out;
 990                                if (new_line &&
 991                                    write_in_full(fd, "\n", 1) != 1)
 992                                        goto write_err_out;
 993                        }
 994                        copy_begin = store.offset[i];
 995                }
 996
 997                /* write the pair (value == NULL means unset) */
 998                if (value != NULL) {
 999                        if (store.state == START) {
1000                                if (!store_write_section(fd, key))
1001                                        goto write_err_out;
1002                        }
1003                        if (!store_write_pair(fd, key, value))
1004                                goto write_err_out;
1005                }
1006
1007                /* write the rest of the config */
1008                if (copy_begin < contents_sz)
1009                        if (write_in_full(fd, contents + copy_begin,
1010                                          contents_sz - copy_begin) <
1011                            contents_sz - copy_begin)
1012                                goto write_err_out;
1013
1014                munmap(contents, contents_sz);
1015        }
1016
1017        if (commit_lock_file(lock) < 0) {
1018                fprintf(stderr, "Cannot commit config file!\n");
1019                ret = 4;
1020                goto out_free;
1021        }
1022
1023        /*
1024         * lock is committed, so don't try to roll it back below.
1025         * NOTE: Since lockfile.c keeps a linked list of all created
1026         * lock_file structures, it isn't safe to free(lock).  It's
1027         * better to just leave it hanging around.
1028         */
1029        lock = NULL;
1030        ret = 0;
1031
1032out_free:
1033        if (lock)
1034                rollback_lock_file(lock);
1035        free(config_filename);
1036        return ret;
1037
1038write_err_out:
1039        ret = write_error();
1040        goto out_free;
1041
1042}
1043
1044static int section_name_match (const char *buf, const char *name)
1045{
1046        int i = 0, j = 0, dot = 0;
1047        for (; buf[i] && buf[i] != ']'; i++) {
1048                if (!dot && isspace(buf[i])) {
1049                        dot = 1;
1050                        if (name[j++] != '.')
1051                                break;
1052                        for (i++; isspace(buf[i]); i++)
1053                                ; /* do nothing */
1054                        if (buf[i] != '"')
1055                                break;
1056                        continue;
1057                }
1058                if (buf[i] == '\\' && dot)
1059                        i++;
1060                else if (buf[i] == '"' && dot) {
1061                        for (i++; isspace(buf[i]); i++)
1062                                ; /* do_nothing */
1063                        break;
1064                }
1065                if (buf[i] != name[j++])
1066                        break;
1067        }
1068        return (buf[i] == ']' && name[j] == 0);
1069}
1070
1071/* if new_name == NULL, the section is removed instead */
1072int git_config_rename_section(const char *old_name, const char *new_name)
1073{
1074        int ret = 0, remove = 0;
1075        char *config_filename;
1076        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1077        int out_fd;
1078        char buf[1024];
1079
1080        config_filename = getenv(CONFIG_ENVIRONMENT);
1081        if (!config_filename) {
1082                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1083                if (!config_filename)
1084                        config_filename  = git_path("config");
1085        }
1086        config_filename = xstrdup(config_filename);
1087        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1088        if (out_fd < 0) {
1089                ret = error("Could not lock config file!");
1090                goto out;
1091        }
1092
1093        if (!(config_file = fopen(config_filename, "rb"))) {
1094                /* no config file means nothing to rename, no error */
1095                goto unlock_and_out;
1096        }
1097
1098        while (fgets(buf, sizeof(buf), config_file)) {
1099                int i;
1100                int length;
1101                for (i = 0; buf[i] && isspace(buf[i]); i++)
1102                        ; /* do nothing */
1103                if (buf[i] == '[') {
1104                        /* it's a section */
1105                        if (section_name_match (&buf[i+1], old_name)) {
1106                                ret++;
1107                                if (new_name == NULL) {
1108                                        remove = 1;
1109                                        continue;
1110                                }
1111                                store.baselen = strlen(new_name);
1112                                if (!store_write_section(out_fd, new_name)) {
1113                                        ret = write_error();
1114                                        goto out;
1115                                }
1116                                continue;
1117                        }
1118                        remove = 0;
1119                }
1120                if (remove)
1121                        continue;
1122                length = strlen(buf);
1123                if (write_in_full(out_fd, buf, length) != length) {
1124                        ret = write_error();
1125                        goto out;
1126                }
1127        }
1128        fclose(config_file);
1129 unlock_and_out:
1130        if (commit_lock_file(lock) < 0)
1131                        ret = error("Cannot commit config file!");
1132 out:
1133        free(config_filename);
1134        return ret;
1135}
1136
1137/*
1138 * Call this to report error for your variable that should not
1139 * get a boolean value (i.e. "[my] var" means "true").
1140 */
1141int config_error_nonbool(const char *var)
1142{
1143        return error("Missing value for '%s'", var);
1144}