Andrew's git / gitweb.git / config.c
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config.con commit Merge branch 'maint' (23f1291)
   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
 283int git_config_int(const char *name, const char *value)
 284{
 285        long ret;
 286        if (!git_parse_long(value, &ret))
 287                die("bad config value for '%s' in %s", name, config_file_name);
 288        return ret;
 289}
 290
 291unsigned long git_config_ulong(const char *name, const char *value)
 292{
 293        unsigned long ret;
 294        if (!git_parse_ulong(value, &ret))
 295                die("bad config value for '%s' in %s", name, config_file_name);
 296        return ret;
 297}
 298
 299int git_config_bool(const char *name, const char *value)
 300{
 301        if (!value)
 302                return 1;
 303        if (!*value)
 304                return 0;
 305        if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 306                return 1;
 307        if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 308                return 0;
 309        return git_config_int(name, value) != 0;
 310}
 311
 312int git_config_string(const char **dest, const char *var, const char *value)
 313{
 314        if (!value)
 315                return config_error_nonbool(var);
 316        *dest = xstrdup(value);
 317        return 0;
 318}
 319
 320int git_default_config(const char *var, const char *value)
 321{
 322        /* This needs a better name */
 323        if (!strcmp(var, "core.filemode")) {
 324                trust_executable_bit = git_config_bool(var, value);
 325                return 0;
 326        }
 327
 328        if (!strcmp(var, "core.quotepath")) {
 329                quote_path_fully = git_config_bool(var, value);
 330                return 0;
 331        }
 332
 333        if (!strcmp(var, "core.symlinks")) {
 334                has_symlinks = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "core.bare")) {
 339                is_bare_repository_cfg = git_config_bool(var, value);
 340                return 0;
 341        }
 342
 343        if (!strcmp(var, "core.ignorestat")) {
 344                assume_unchanged = git_config_bool(var, value);
 345                return 0;
 346        }
 347
 348        if (!strcmp(var, "core.prefersymlinkrefs")) {
 349                prefer_symlink_refs = git_config_bool(var, value);
 350                return 0;
 351        }
 352
 353        if (!strcmp(var, "core.logallrefupdates")) {
 354                log_all_ref_updates = git_config_bool(var, value);
 355                return 0;
 356        }
 357
 358        if (!strcmp(var, "core.warnambiguousrefs")) {
 359                warn_ambiguous_refs = git_config_bool(var, value);
 360                return 0;
 361        }
 362
 363        if (!strcmp(var, "core.loosecompression")) {
 364                int level = git_config_int(var, value);
 365                if (level == -1)
 366                        level = Z_DEFAULT_COMPRESSION;
 367                else if (level < 0 || level > Z_BEST_COMPRESSION)
 368                        die("bad zlib compression level %d", level);
 369                zlib_compression_level = level;
 370                zlib_compression_seen = 1;
 371                return 0;
 372        }
 373
 374        if (!strcmp(var, "core.compression")) {
 375                int level = git_config_int(var, value);
 376                if (level == -1)
 377                        level = Z_DEFAULT_COMPRESSION;
 378                else if (level < 0 || level > Z_BEST_COMPRESSION)
 379                        die("bad zlib compression level %d", level);
 380                core_compression_level = level;
 381                core_compression_seen = 1;
 382                if (!zlib_compression_seen)
 383                        zlib_compression_level = level;
 384                return 0;
 385        }
 386
 387        if (!strcmp(var, "core.packedgitwindowsize")) {
 388                int pgsz_x2 = getpagesize() * 2;
 389                packed_git_window_size = git_config_int(var, value);
 390
 391                /* This value must be multiple of (pagesize * 2) */
 392                packed_git_window_size /= pgsz_x2;
 393                if (packed_git_window_size < 1)
 394                        packed_git_window_size = 1;
 395                packed_git_window_size *= pgsz_x2;
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "core.packedgitlimit")) {
 400                packed_git_limit = git_config_int(var, value);
 401                return 0;
 402        }
 403
 404        if (!strcmp(var, "core.deltabasecachelimit")) {
 405                delta_base_cache_limit = git_config_int(var, value);
 406                return 0;
 407        }
 408
 409        if (!strcmp(var, "core.autocrlf")) {
 410                if (value && !strcasecmp(value, "input")) {
 411                        auto_crlf = -1;
 412                        return 0;
 413                }
 414                auto_crlf = git_config_bool(var, value);
 415                return 0;
 416        }
 417
 418        if (!strcmp(var, "core.safecrlf")) {
 419                if (value && !strcasecmp(value, "warn")) {
 420                        safe_crlf = SAFE_CRLF_WARN;
 421                        return 0;
 422                }
 423                safe_crlf = git_config_bool(var, value);
 424                return 0;
 425        }
 426
 427        if (!strcmp(var, "user.name")) {
 428                if (!value)
 429                        return config_error_nonbool(var);
 430                strlcpy(git_default_name, value, sizeof(git_default_name));
 431                return 0;
 432        }
 433
 434        if (!strcmp(var, "user.email")) {
 435                if (!value)
 436                        return config_error_nonbool(var);
 437                strlcpy(git_default_email, value, sizeof(git_default_email));
 438                return 0;
 439        }
 440
 441        if (!strcmp(var, "i18n.commitencoding"))
 442                return git_config_string(&git_commit_encoding, var, value);
 443
 444        if (!strcmp(var, "i18n.logoutputencoding"))
 445                return git_config_string(&git_log_output_encoding, var, value);
 446
 447        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 448                pager_use_color = git_config_bool(var,value);
 449                return 0;
 450        }
 451
 452        if (!strcmp(var, "core.pager"))
 453                return git_config_string(&pager_program, var, value);
 454
 455        if (!strcmp(var, "core.editor"))
 456                return git_config_string(&editor_program, var, value);
 457
 458        if (!strcmp(var, "core.excludesfile"))
 459                return git_config_string(&excludes_file, var, value);
 460
 461        if (!strcmp(var, "core.whitespace")) {
 462                if (!value)
 463                        return config_error_nonbool(var);
 464                whitespace_rule_cfg = parse_whitespace_rule(value);
 465                return 0;
 466        }
 467
 468        /* Add other config variables here and to Documentation/config.txt. */
 469        return 0;
 470}
 471
 472int git_config_from_file(config_fn_t fn, const char *filename)
 473{
 474        int ret;
 475        FILE *f = fopen(filename, "r");
 476
 477        ret = -1;
 478        if (f) {
 479                config_file = f;
 480                config_file_name = filename;
 481                config_linenr = 1;
 482                config_file_eof = 0;
 483                ret = git_parse_file(fn);
 484                fclose(f);
 485                config_file_name = NULL;
 486        }
 487        return ret;
 488}
 489
 490const char *git_etc_gitconfig(void)
 491{
 492        static const char *system_wide;
 493        if (!system_wide) {
 494                system_wide = ETC_GITCONFIG;
 495                if (!is_absolute_path(system_wide)) {
 496                        /* interpret path relative to exec-dir */
 497                        struct strbuf d = STRBUF_INIT;
 498                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 499                        system_wide = strbuf_detach(&d, NULL);
 500                }
 501        }
 502        return system_wide;
 503}
 504
 505int git_env_bool(const char *k, int def)
 506{
 507        const char *v = getenv(k);
 508        return v ? git_config_bool(k, v) : def;
 509}
 510
 511int git_config_system(void)
 512{
 513        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 514}
 515
 516int git_config_global(void)
 517{
 518        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 519}
 520
 521int git_config(config_fn_t fn)
 522{
 523        int ret = 0;
 524        char *repo_config = NULL;
 525        const char *home = NULL, *filename;
 526
 527        /* $GIT_CONFIG makes git read _only_ the given config file,
 528         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 529         * global config file, the same way it would the per-repository
 530         * config file otherwise. */
 531        filename = getenv(CONFIG_ENVIRONMENT);
 532        if (!filename) {
 533                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 534                        ret += git_config_from_file(fn, git_etc_gitconfig());
 535                home = getenv("HOME");
 536                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 537                if (!filename)
 538                        filename = repo_config = xstrdup(git_path("config"));
 539        }
 540
 541        if (git_config_global() && home) {
 542                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 543                if (!access(user_config, R_OK))
 544                        ret = git_config_from_file(fn, user_config);
 545                free(user_config);
 546        }
 547
 548        ret += git_config_from_file(fn, filename);
 549        free(repo_config);
 550        return ret;
 551}
 552
 553/*
 554 * Find all the stuff for git_config_set() below.
 555 */
 556
 557#define MAX_MATCHES 512
 558
 559static struct {
 560        int baselen;
 561        char* key;
 562        int do_not_match;
 563        regex_t* value_regex;
 564        int multi_replace;
 565        size_t offset[MAX_MATCHES];
 566        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 567        int seen;
 568} store;
 569
 570static int matches(const char* key, const char* value)
 571{
 572        return !strcmp(key, store.key) &&
 573                (store.value_regex == NULL ||
 574                 (store.do_not_match ^
 575                  !regexec(store.value_regex, value, 0, NULL, 0)));
 576}
 577
 578static int store_aux(const char* key, const char* value)
 579{
 580        const char *ep;
 581        size_t section_len;
 582
 583        switch (store.state) {
 584        case KEY_SEEN:
 585                if (matches(key, value)) {
 586                        if (store.seen == 1 && store.multi_replace == 0) {
 587                                fprintf(stderr,
 588                                        "Warning: %s has multiple values\n",
 589                                        key);
 590                        } else if (store.seen >= MAX_MATCHES) {
 591                                fprintf(stderr, "Too many matches\n");
 592                                return 1;
 593                        }
 594
 595                        store.offset[store.seen] = ftell(config_file);
 596                        store.seen++;
 597                }
 598                break;
 599        case SECTION_SEEN:
 600                /*
 601                 * What we are looking for is in store.key (both
 602                 * section and var), and its section part is baselen
 603                 * long.  We found key (again, both section and var).
 604                 * We would want to know if this key is in the same
 605                 * section as what we are looking for.  We already
 606                 * know we are in the same section as what should
 607                 * hold store.key.
 608                 */
 609                ep = strrchr(key, '.');
 610                section_len = ep - key;
 611
 612                if ((section_len != store.baselen) ||
 613                    memcmp(key, store.key, section_len+1)) {
 614                        store.state = SECTION_END_SEEN;
 615                        break;
 616                }
 617
 618                /*
 619                 * Do not increment matches: this is no match, but we
 620                 * just made sure we are in the desired section.
 621                 */
 622                store.offset[store.seen] = ftell(config_file);
 623                /* fallthru */
 624        case SECTION_END_SEEN:
 625        case START:
 626                if (matches(key, value)) {
 627                        store.offset[store.seen] = ftell(config_file);
 628                        store.state = KEY_SEEN;
 629                        store.seen++;
 630                } else {
 631                        if (strrchr(key, '.') - key == store.baselen &&
 632                              !strncmp(key, store.key, store.baselen)) {
 633                                        store.state = SECTION_SEEN;
 634                                        store.offset[store.seen] = ftell(config_file);
 635                        }
 636                }
 637        }
 638        return 0;
 639}
 640
 641static int write_error(void)
 642{
 643        fprintf(stderr, "Failed to write new configuration file\n");
 644
 645        /* Same error code as "failed to rename". */
 646        return 4;
 647}
 648
 649static int store_write_section(int fd, const char* key)
 650{
 651        const char *dot;
 652        int i, success;
 653        struct strbuf sb;
 654
 655        strbuf_init(&sb, 0);
 656        dot = memchr(key, '.', store.baselen);
 657        if (dot) {
 658                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 659                for (i = dot - key + 1; i < store.baselen; i++) {
 660                        if (key[i] == '"')
 661                                strbuf_addch(&sb, '\\');
 662                        strbuf_addch(&sb, key[i]);
 663                }
 664                strbuf_addstr(&sb, "\"]\n");
 665        } else {
 666                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 667        }
 668
 669        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 670        strbuf_release(&sb);
 671
 672        return success;
 673}
 674
 675static int store_write_pair(int fd, const char* key, const char* value)
 676{
 677        int i, success;
 678        int length = strlen(key + store.baselen + 1);
 679        const char *quote = "";
 680        struct strbuf sb;
 681
 682        /*
 683         * Check to see if the value needs to be surrounded with a dq pair.
 684         * Note that problematic characters are always backslash-quoted; this
 685         * check is about not losing leading or trailing SP and strings that
 686         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 687         * configuration parser.
 688         */
 689        if (value[0] == ' ')
 690                quote = "\"";
 691        for (i = 0; value[i]; i++)
 692                if (value[i] == ';' || value[i] == '#')
 693                        quote = "\"";
 694        if (i && value[i - 1] == ' ')
 695                quote = "\"";
 696
 697        strbuf_init(&sb, 0);
 698        strbuf_addf(&sb, "\t%.*s = %s",
 699                    length, key + store.baselen + 1, quote);
 700
 701        for (i = 0; value[i]; i++)
 702                switch (value[i]) {
 703                case '\n':
 704                        strbuf_addstr(&sb, "\\n");
 705                        break;
 706                case '\t':
 707                        strbuf_addstr(&sb, "\\t");
 708                        break;
 709                case '"':
 710                case '\\':
 711                        strbuf_addch(&sb, '\\');
 712                default:
 713                        strbuf_addch(&sb, value[i]);
 714                        break;
 715                }
 716        strbuf_addf(&sb, "%s\n", quote);
 717
 718        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 719        strbuf_release(&sb);
 720
 721        return success;
 722}
 723
 724static ssize_t find_beginning_of_line(const char* contents, size_t size,
 725        size_t offset_, int* found_bracket)
 726{
 727        size_t equal_offset = size, bracket_offset = size;
 728        ssize_t offset;
 729
 730contline:
 731        for (offset = offset_-2; offset > 0
 732                        && contents[offset] != '\n'; offset--)
 733                switch (contents[offset]) {
 734                        case '=': equal_offset = offset; break;
 735                        case ']': bracket_offset = offset; break;
 736                }
 737        if (offset > 0 && contents[offset-1] == '\\') {
 738                offset_ = offset;
 739                goto contline;
 740        }
 741        if (bracket_offset < equal_offset) {
 742                *found_bracket = 1;
 743                offset = bracket_offset+1;
 744        } else
 745                offset++;
 746
 747        return offset;
 748}
 749
 750int git_config_set(const char* key, const char* value)
 751{
 752        return git_config_set_multivar(key, value, NULL, 0);
 753}
 754
 755/*
 756 * If value==NULL, unset in (remove from) config,
 757 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 758 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 759 *     else all matching key/values (regardless how many) are removed,
 760 *     before the new pair is written.
 761 *
 762 * Returns 0 on success.
 763 *
 764 * This function does this:
 765 *
 766 * - it locks the config file by creating ".git/config.lock"
 767 *
 768 * - it then parses the config using store_aux() as validator to find
 769 *   the position on the key/value pair to replace. If it is to be unset,
 770 *   it must be found exactly once.
 771 *
 772 * - the config file is mmap()ed and the part before the match (if any) is
 773 *   written to the lock file, then the changed part and the rest.
 774 *
 775 * - the config file is removed and the lock file rename()d to it.
 776 *
 777 */
 778int git_config_set_multivar(const char* key, const char* value,
 779        const char* value_regex, int multi_replace)
 780{
 781        int i, dot;
 782        int fd = -1, in_fd;
 783        int ret;
 784        char* config_filename;
 785        struct lock_file *lock = NULL;
 786        const char* last_dot = strrchr(key, '.');
 787
 788        config_filename = getenv(CONFIG_ENVIRONMENT);
 789        if (!config_filename) {
 790                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 791                if (!config_filename)
 792                        config_filename  = git_path("config");
 793        }
 794        config_filename = xstrdup(config_filename);
 795
 796        /*
 797         * Since "key" actually contains the section name and the real
 798         * key name separated by a dot, we have to know where the dot is.
 799         */
 800
 801        if (last_dot == NULL) {
 802                fprintf(stderr, "key does not contain a section: %s\n", key);
 803                ret = 2;
 804                goto out_free;
 805        }
 806        store.baselen = last_dot - key;
 807
 808        store.multi_replace = multi_replace;
 809
 810        /*
 811         * Validate the key and while at it, lower case it for matching.
 812         */
 813        store.key = xmalloc(strlen(key) + 1);
 814        dot = 0;
 815        for (i = 0; key[i]; i++) {
 816                unsigned char c = key[i];
 817                if (c == '.')
 818                        dot = 1;
 819                /* Leave the extended basename untouched.. */
 820                if (!dot || i > store.baselen) {
 821                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 822                                fprintf(stderr, "invalid key: %s\n", key);
 823                                free(store.key);
 824                                ret = 1;
 825                                goto out_free;
 826                        }
 827                        c = tolower(c);
 828                } else if (c == '\n') {
 829                        fprintf(stderr, "invalid key (newline): %s\n", key);
 830                        free(store.key);
 831                        ret = 1;
 832                        goto out_free;
 833                }
 834                store.key[i] = c;
 835        }
 836        store.key[i] = 0;
 837
 838        /*
 839         * The lock serves a purpose in addition to locking: the new
 840         * contents of .git/config will be written into it.
 841         */
 842        lock = xcalloc(sizeof(struct lock_file), 1);
 843        fd = hold_lock_file_for_update(lock, config_filename, 0);
 844        if (fd < 0) {
 845                fprintf(stderr, "could not lock config file\n");
 846                free(store.key);
 847                ret = -1;
 848                goto out_free;
 849        }
 850
 851        /*
 852         * If .git/config does not exist yet, write a minimal version.
 853         */
 854        in_fd = open(config_filename, O_RDONLY);
 855        if ( in_fd < 0 ) {
 856                free(store.key);
 857
 858                if ( ENOENT != errno ) {
 859                        error("opening %s: %s", config_filename,
 860                              strerror(errno));
 861                        ret = 3; /* same as "invalid config file" */
 862                        goto out_free;
 863                }
 864                /* if nothing to unset, error out */
 865                if (value == NULL) {
 866                        ret = 5;
 867                        goto out_free;
 868                }
 869
 870                store.key = (char*)key;
 871                if (!store_write_section(fd, key) ||
 872                    !store_write_pair(fd, key, value))
 873                        goto write_err_out;
 874        } else {
 875                struct stat st;
 876                char* contents;
 877                size_t contents_sz, copy_begin, copy_end;
 878                int i, new_line = 0;
 879
 880                if (value_regex == NULL)
 881                        store.value_regex = NULL;
 882                else {
 883                        if (value_regex[0] == '!') {
 884                                store.do_not_match = 1;
 885                                value_regex++;
 886                        } else
 887                                store.do_not_match = 0;
 888
 889                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 890                        if (regcomp(store.value_regex, value_regex,
 891                                        REG_EXTENDED)) {
 892                                fprintf(stderr, "Invalid pattern: %s\n",
 893                                        value_regex);
 894                                free(store.value_regex);
 895                                ret = 6;
 896                                goto out_free;
 897                        }
 898                }
 899
 900                store.offset[0] = 0;
 901                store.state = START;
 902                store.seen = 0;
 903
 904                /*
 905                 * After this, store.offset will contain the *end* offset
 906                 * of the last match, or remain at 0 if no match was found.
 907                 * As a side effect, we make sure to transform only a valid
 908                 * existing config file.
 909                 */
 910                if (git_config_from_file(store_aux, config_filename)) {
 911                        fprintf(stderr, "invalid config file\n");
 912                        free(store.key);
 913                        if (store.value_regex != NULL) {
 914                                regfree(store.value_regex);
 915                                free(store.value_regex);
 916                        }
 917                        ret = 3;
 918                        goto out_free;
 919                }
 920
 921                free(store.key);
 922                if (store.value_regex != NULL) {
 923                        regfree(store.value_regex);
 924                        free(store.value_regex);
 925                }
 926
 927                /* if nothing to unset, or too many matches, error out */
 928                if ((store.seen == 0 && value == NULL) ||
 929                                (store.seen > 1 && multi_replace == 0)) {
 930                        ret = 5;
 931                        goto out_free;
 932                }
 933
 934                fstat(in_fd, &st);
 935                contents_sz = xsize_t(st.st_size);
 936                contents = xmmap(NULL, contents_sz, PROT_READ,
 937                        MAP_PRIVATE, in_fd, 0);
 938                close(in_fd);
 939
 940                if (store.seen == 0)
 941                        store.seen = 1;
 942
 943                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 944                        if (store.offset[i] == 0) {
 945                                store.offset[i] = copy_end = contents_sz;
 946                        } else if (store.state != KEY_SEEN) {
 947                                copy_end = store.offset[i];
 948                        } else
 949                                copy_end = find_beginning_of_line(
 950                                        contents, contents_sz,
 951                                        store.offset[i]-2, &new_line);
 952
 953                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 954                                new_line = 1;
 955
 956                        /* write the first part of the config */
 957                        if (copy_end > copy_begin) {
 958                                if (write_in_full(fd, contents + copy_begin,
 959                                                  copy_end - copy_begin) <
 960                                    copy_end - copy_begin)
 961                                        goto write_err_out;
 962                                if (new_line &&
 963                                    write_in_full(fd, "\n", 1) != 1)
 964                                        goto write_err_out;
 965                        }
 966                        copy_begin = store.offset[i];
 967                }
 968
 969                /* write the pair (value == NULL means unset) */
 970                if (value != NULL) {
 971                        if (store.state == START) {
 972                                if (!store_write_section(fd, key))
 973                                        goto write_err_out;
 974                        }
 975                        if (!store_write_pair(fd, key, value))
 976                                goto write_err_out;
 977                }
 978
 979                /* write the rest of the config */
 980                if (copy_begin < contents_sz)
 981                        if (write_in_full(fd, contents + copy_begin,
 982                                          contents_sz - copy_begin) <
 983                            contents_sz - copy_begin)
 984                                goto write_err_out;
 985
 986                munmap(contents, contents_sz);
 987        }
 988
 989        if (commit_lock_file(lock) < 0) {
 990                fprintf(stderr, "Cannot commit config file!\n");
 991                ret = 4;
 992                goto out_free;
 993        }
 994
 995        /*
 996         * lock is committed, so don't try to roll it back below.
 997         * NOTE: Since lockfile.c keeps a linked list of all created
 998         * lock_file structures, it isn't safe to free(lock).  It's
 999         * better to just leave it hanging around.
1000         */
1001        lock = NULL;
1002        ret = 0;
1003
1004out_free:
1005        if (lock)
1006                rollback_lock_file(lock);
1007        free(config_filename);
1008        return ret;
1009
1010write_err_out:
1011        ret = write_error();
1012        goto out_free;
1013
1014}
1015
1016static int section_name_match (const char *buf, const char *name)
1017{
1018        int i = 0, j = 0, dot = 0;
1019        for (; buf[i] && buf[i] != ']'; i++) {
1020                if (!dot && isspace(buf[i])) {
1021                        dot = 1;
1022                        if (name[j++] != '.')
1023                                break;
1024                        for (i++; isspace(buf[i]); i++)
1025                                ; /* do nothing */
1026                        if (buf[i] != '"')
1027                                break;
1028                        continue;
1029                }
1030                if (buf[i] == '\\' && dot)
1031                        i++;
1032                else if (buf[i] == '"' && dot) {
1033                        for (i++; isspace(buf[i]); i++)
1034                                ; /* do_nothing */
1035                        break;
1036                }
1037                if (buf[i] != name[j++])
1038                        break;
1039        }
1040        return (buf[i] == ']' && name[j] == 0);
1041}
1042
1043/* if new_name == NULL, the section is removed instead */
1044int git_config_rename_section(const char *old_name, const char *new_name)
1045{
1046        int ret = 0, remove = 0;
1047        char *config_filename;
1048        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1049        int out_fd;
1050        char buf[1024];
1051
1052        config_filename = getenv(CONFIG_ENVIRONMENT);
1053        if (!config_filename) {
1054                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1055                if (!config_filename)
1056                        config_filename  = git_path("config");
1057        }
1058        config_filename = xstrdup(config_filename);
1059        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1060        if (out_fd < 0) {
1061                ret = error("Could not lock config file!");
1062                goto out;
1063        }
1064
1065        if (!(config_file = fopen(config_filename, "rb"))) {
1066                /* no config file means nothing to rename, no error */
1067                goto unlock_and_out;
1068        }
1069
1070        while (fgets(buf, sizeof(buf), config_file)) {
1071                int i;
1072                int length;
1073                for (i = 0; buf[i] && isspace(buf[i]); i++)
1074                        ; /* do nothing */
1075                if (buf[i] == '[') {
1076                        /* it's a section */
1077                        if (section_name_match (&buf[i+1], old_name)) {
1078                                ret++;
1079                                if (new_name == NULL) {
1080                                        remove = 1;
1081                                        continue;
1082                                }
1083                                store.baselen = strlen(new_name);
1084                                if (!store_write_section(out_fd, new_name)) {
1085                                        ret = write_error();
1086                                        goto out;
1087                                }
1088                                continue;
1089                        }
1090                        remove = 0;
1091                }
1092                if (remove)
1093                        continue;
1094                length = strlen(buf);
1095                if (write_in_full(out_fd, buf, length) != length) {
1096                        ret = write_error();
1097                        goto out;
1098                }
1099        }
1100        fclose(config_file);
1101 unlock_and_out:
1102        if (commit_lock_file(lock) < 0)
1103                        ret = error("Cannot commit config file!");
1104 out:
1105        free(config_filename);
1106        return ret;
1107}
1108
1109/*
1110 * Call this to report error for your variable that should not
1111 * get a boolean value (i.e. "[my] var" means "true").
1112 */
1113int config_error_nonbool(const char *var)
1114{
1115        return error("Missing value for '%s'", var);
1116}