Andrew's git / gitweb.git / config.c
?
config.con commit git-p4: Clean up git-p4 submit's log message handling. (edae1e2)
   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
 475        /* Add other config variables here and to Documentation/config.txt. */
 476        return 0;
 477}
 478
 479int git_config_from_file(config_fn_t fn, const char *filename)
 480{
 481        int ret;
 482        FILE *f = fopen(filename, "r");
 483
 484        ret = -1;
 485        if (f) {
 486                config_file = f;
 487                config_file_name = filename;
 488                config_linenr = 1;
 489                config_file_eof = 0;
 490                ret = git_parse_file(fn);
 491                fclose(f);
 492                config_file_name = NULL;
 493        }
 494        return ret;
 495}
 496
 497const char *git_etc_gitconfig(void)
 498{
 499        static const char *system_wide;
 500        if (!system_wide) {
 501                system_wide = ETC_GITCONFIG;
 502                if (!is_absolute_path(system_wide)) {
 503                        /* interpret path relative to exec-dir */
 504                        struct strbuf d = STRBUF_INIT;
 505                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 506                        system_wide = strbuf_detach(&d, NULL);
 507                }
 508        }
 509        return system_wide;
 510}
 511
 512int git_env_bool(const char *k, int def)
 513{
 514        const char *v = getenv(k);
 515        return v ? git_config_bool(k, v) : def;
 516}
 517
 518int git_config_system(void)
 519{
 520        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 521}
 522
 523int git_config_global(void)
 524{
 525        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 526}
 527
 528int git_config(config_fn_t fn)
 529{
 530        int ret = 0;
 531        char *repo_config = NULL;
 532        const char *home = NULL, *filename;
 533
 534        /* $GIT_CONFIG makes git read _only_ the given config file,
 535         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 536         * global config file, the same way it would the per-repository
 537         * config file otherwise. */
 538        filename = getenv(CONFIG_ENVIRONMENT);
 539        if (!filename) {
 540                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 541                        ret += git_config_from_file(fn, git_etc_gitconfig());
 542                home = getenv("HOME");
 543                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 544                if (!filename)
 545                        filename = repo_config = xstrdup(git_path("config"));
 546        }
 547
 548        if (git_config_global() && home) {
 549                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 550                if (!access(user_config, R_OK))
 551                        ret = git_config_from_file(fn, user_config);
 552                free(user_config);
 553        }
 554
 555        ret += git_config_from_file(fn, filename);
 556        free(repo_config);
 557        return ret;
 558}
 559
 560/*
 561 * Find all the stuff for git_config_set() below.
 562 */
 563
 564#define MAX_MATCHES 512
 565
 566static struct {
 567        int baselen;
 568        char* key;
 569        int do_not_match;
 570        regex_t* value_regex;
 571        int multi_replace;
 572        size_t offset[MAX_MATCHES];
 573        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 574        int seen;
 575} store;
 576
 577static int matches(const char* key, const char* value)
 578{
 579        return !strcmp(key, store.key) &&
 580                (store.value_regex == NULL ||
 581                 (store.do_not_match ^
 582                  !regexec(store.value_regex, value, 0, NULL, 0)));
 583}
 584
 585static int store_aux(const char* key, const char* value)
 586{
 587        const char *ep;
 588        size_t section_len;
 589
 590        switch (store.state) {
 591        case KEY_SEEN:
 592                if (matches(key, value)) {
 593                        if (store.seen == 1 && store.multi_replace == 0) {
 594                                fprintf(stderr,
 595                                        "Warning: %s has multiple values\n",
 596                                        key);
 597                        } else if (store.seen >= MAX_MATCHES) {
 598                                fprintf(stderr, "Too many matches\n");
 599                                return 1;
 600                        }
 601
 602                        store.offset[store.seen] = ftell(config_file);
 603                        store.seen++;
 604                }
 605                break;
 606        case SECTION_SEEN:
 607                /*
 608                 * What we are looking for is in store.key (both
 609                 * section and var), and its section part is baselen
 610                 * long.  We found key (again, both section and var).
 611                 * We would want to know if this key is in the same
 612                 * section as what we are looking for.  We already
 613                 * know we are in the same section as what should
 614                 * hold store.key.
 615                 */
 616                ep = strrchr(key, '.');
 617                section_len = ep - key;
 618
 619                if ((section_len != store.baselen) ||
 620                    memcmp(key, store.key, section_len+1)) {
 621                        store.state = SECTION_END_SEEN;
 622                        break;
 623                }
 624
 625                /*
 626                 * Do not increment matches: this is no match, but we
 627                 * just made sure we are in the desired section.
 628                 */
 629                store.offset[store.seen] = ftell(config_file);
 630                /* fallthru */
 631        case SECTION_END_SEEN:
 632        case START:
 633                if (matches(key, value)) {
 634                        store.offset[store.seen] = ftell(config_file);
 635                        store.state = KEY_SEEN;
 636                        store.seen++;
 637                } else {
 638                        if (strrchr(key, '.') - key == store.baselen &&
 639                              !strncmp(key, store.key, store.baselen)) {
 640                                        store.state = SECTION_SEEN;
 641                                        store.offset[store.seen] = ftell(config_file);
 642                        }
 643                }
 644        }
 645        return 0;
 646}
 647
 648static int write_error(void)
 649{
 650        fprintf(stderr, "Failed to write new configuration file\n");
 651
 652        /* Same error code as "failed to rename". */
 653        return 4;
 654}
 655
 656static int store_write_section(int fd, const char* key)
 657{
 658        const char *dot;
 659        int i, success;
 660        struct strbuf sb;
 661
 662        strbuf_init(&sb, 0);
 663        dot = memchr(key, '.', store.baselen);
 664        if (dot) {
 665                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 666                for (i = dot - key + 1; i < store.baselen; i++) {
 667                        if (key[i] == '"')
 668                                strbuf_addch(&sb, '\\');
 669                        strbuf_addch(&sb, key[i]);
 670                }
 671                strbuf_addstr(&sb, "\"]\n");
 672        } else {
 673                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 674        }
 675
 676        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 677        strbuf_release(&sb);
 678
 679        return success;
 680}
 681
 682static int store_write_pair(int fd, const char* key, const char* value)
 683{
 684        int i, success;
 685        int length = strlen(key + store.baselen + 1);
 686        const char *quote = "";
 687        struct strbuf sb;
 688
 689        /*
 690         * Check to see if the value needs to be surrounded with a dq pair.
 691         * Note that problematic characters are always backslash-quoted; this
 692         * check is about not losing leading or trailing SP and strings that
 693         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 694         * configuration parser.
 695         */
 696        if (value[0] == ' ')
 697                quote = "\"";
 698        for (i = 0; value[i]; i++)
 699                if (value[i] == ';' || value[i] == '#')
 700                        quote = "\"";
 701        if (i && value[i - 1] == ' ')
 702                quote = "\"";
 703
 704        strbuf_init(&sb, 0);
 705        strbuf_addf(&sb, "\t%.*s = %s",
 706                    length, key + store.baselen + 1, quote);
 707
 708        for (i = 0; value[i]; i++)
 709                switch (value[i]) {
 710                case '\n':
 711                        strbuf_addstr(&sb, "\\n");
 712                        break;
 713                case '\t':
 714                        strbuf_addstr(&sb, "\\t");
 715                        break;
 716                case '"':
 717                case '\\':
 718                        strbuf_addch(&sb, '\\');
 719                default:
 720                        strbuf_addch(&sb, value[i]);
 721                        break;
 722                }
 723        strbuf_addf(&sb, "%s\n", quote);
 724
 725        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 726        strbuf_release(&sb);
 727
 728        return success;
 729}
 730
 731static ssize_t find_beginning_of_line(const char* contents, size_t size,
 732        size_t offset_, int* found_bracket)
 733{
 734        size_t equal_offset = size, bracket_offset = size;
 735        ssize_t offset;
 736
 737contline:
 738        for (offset = offset_-2; offset > 0
 739                        && contents[offset] != '\n'; offset--)
 740                switch (contents[offset]) {
 741                        case '=': equal_offset = offset; break;
 742                        case ']': bracket_offset = offset; break;
 743                }
 744        if (offset > 0 && contents[offset-1] == '\\') {
 745                offset_ = offset;
 746                goto contline;
 747        }
 748        if (bracket_offset < equal_offset) {
 749                *found_bracket = 1;
 750                offset = bracket_offset+1;
 751        } else
 752                offset++;
 753
 754        return offset;
 755}
 756
 757int git_config_set(const char* key, const char* value)
 758{
 759        return git_config_set_multivar(key, value, NULL, 0);
 760}
 761
 762/*
 763 * If value==NULL, unset in (remove from) config,
 764 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 765 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 766 *     else all matching key/values (regardless how many) are removed,
 767 *     before the new pair is written.
 768 *
 769 * Returns 0 on success.
 770 *
 771 * This function does this:
 772 *
 773 * - it locks the config file by creating ".git/config.lock"
 774 *
 775 * - it then parses the config using store_aux() as validator to find
 776 *   the position on the key/value pair to replace. If it is to be unset,
 777 *   it must be found exactly once.
 778 *
 779 * - the config file is mmap()ed and the part before the match (if any) is
 780 *   written to the lock file, then the changed part and the rest.
 781 *
 782 * - the config file is removed and the lock file rename()d to it.
 783 *
 784 */
 785int git_config_set_multivar(const char* key, const char* value,
 786        const char* value_regex, int multi_replace)
 787{
 788        int i, dot;
 789        int fd = -1, in_fd;
 790        int ret;
 791        char* config_filename;
 792        struct lock_file *lock = NULL;
 793        const char* last_dot = strrchr(key, '.');
 794
 795        config_filename = getenv(CONFIG_ENVIRONMENT);
 796        if (!config_filename) {
 797                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 798                if (!config_filename)
 799                        config_filename  = git_path("config");
 800        }
 801        config_filename = xstrdup(config_filename);
 802
 803        /*
 804         * Since "key" actually contains the section name and the real
 805         * key name separated by a dot, we have to know where the dot is.
 806         */
 807
 808        if (last_dot == NULL) {
 809                fprintf(stderr, "key does not contain a section: %s\n", key);
 810                ret = 2;
 811                goto out_free;
 812        }
 813        store.baselen = last_dot - key;
 814
 815        store.multi_replace = multi_replace;
 816
 817        /*
 818         * Validate the key and while at it, lower case it for matching.
 819         */
 820        store.key = xmalloc(strlen(key) + 1);
 821        dot = 0;
 822        for (i = 0; key[i]; i++) {
 823                unsigned char c = key[i];
 824                if (c == '.')
 825                        dot = 1;
 826                /* Leave the extended basename untouched.. */
 827                if (!dot || i > store.baselen) {
 828                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 829                                fprintf(stderr, "invalid key: %s\n", key);
 830                                free(store.key);
 831                                ret = 1;
 832                                goto out_free;
 833                        }
 834                        c = tolower(c);
 835                } else if (c == '\n') {
 836                        fprintf(stderr, "invalid key (newline): %s\n", key);
 837                        free(store.key);
 838                        ret = 1;
 839                        goto out_free;
 840                }
 841                store.key[i] = c;
 842        }
 843        store.key[i] = 0;
 844
 845        /*
 846         * The lock serves a purpose in addition to locking: the new
 847         * contents of .git/config will be written into it.
 848         */
 849        lock = xcalloc(sizeof(struct lock_file), 1);
 850        fd = hold_lock_file_for_update(lock, config_filename, 0);
 851        if (fd < 0) {
 852                fprintf(stderr, "could not lock config file\n");
 853                free(store.key);
 854                ret = -1;
 855                goto out_free;
 856        }
 857
 858        /*
 859         * If .git/config does not exist yet, write a minimal version.
 860         */
 861        in_fd = open(config_filename, O_RDONLY);
 862        if ( in_fd < 0 ) {
 863                free(store.key);
 864
 865                if ( ENOENT != errno ) {
 866                        error("opening %s: %s", config_filename,
 867                              strerror(errno));
 868                        ret = 3; /* same as "invalid config file" */
 869                        goto out_free;
 870                }
 871                /* if nothing to unset, error out */
 872                if (value == NULL) {
 873                        ret = 5;
 874                        goto out_free;
 875                }
 876
 877                store.key = (char*)key;
 878                if (!store_write_section(fd, key) ||
 879                    !store_write_pair(fd, key, value))
 880                        goto write_err_out;
 881        } else {
 882                struct stat st;
 883                char* contents;
 884                size_t contents_sz, copy_begin, copy_end;
 885                int i, new_line = 0;
 886
 887                if (value_regex == NULL)
 888                        store.value_regex = NULL;
 889                else {
 890                        if (value_regex[0] == '!') {
 891                                store.do_not_match = 1;
 892                                value_regex++;
 893                        } else
 894                                store.do_not_match = 0;
 895
 896                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 897                        if (regcomp(store.value_regex, value_regex,
 898                                        REG_EXTENDED)) {
 899                                fprintf(stderr, "Invalid pattern: %s\n",
 900                                        value_regex);
 901                                free(store.value_regex);
 902                                ret = 6;
 903                                goto out_free;
 904                        }
 905                }
 906
 907                store.offset[0] = 0;
 908                store.state = START;
 909                store.seen = 0;
 910
 911                /*
 912                 * After this, store.offset will contain the *end* offset
 913                 * of the last match, or remain at 0 if no match was found.
 914                 * As a side effect, we make sure to transform only a valid
 915                 * existing config file.
 916                 */
 917                if (git_config_from_file(store_aux, config_filename)) {
 918                        fprintf(stderr, "invalid config file\n");
 919                        free(store.key);
 920                        if (store.value_regex != NULL) {
 921                                regfree(store.value_regex);
 922                                free(store.value_regex);
 923                        }
 924                        ret = 3;
 925                        goto out_free;
 926                }
 927
 928                free(store.key);
 929                if (store.value_regex != NULL) {
 930                        regfree(store.value_regex);
 931                        free(store.value_regex);
 932                }
 933
 934                /* if nothing to unset, or too many matches, error out */
 935                if ((store.seen == 0 && value == NULL) ||
 936                                (store.seen > 1 && multi_replace == 0)) {
 937                        ret = 5;
 938                        goto out_free;
 939                }
 940
 941                fstat(in_fd, &st);
 942                contents_sz = xsize_t(st.st_size);
 943                contents = xmmap(NULL, contents_sz, PROT_READ,
 944                        MAP_PRIVATE, in_fd, 0);
 945                close(in_fd);
 946
 947                if (store.seen == 0)
 948                        store.seen = 1;
 949
 950                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 951                        if (store.offset[i] == 0) {
 952                                store.offset[i] = copy_end = contents_sz;
 953                        } else if (store.state != KEY_SEEN) {
 954                                copy_end = store.offset[i];
 955                        } else
 956                                copy_end = find_beginning_of_line(
 957                                        contents, contents_sz,
 958                                        store.offset[i]-2, &new_line);
 959
 960                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 961                                new_line = 1;
 962
 963                        /* write the first part of the config */
 964                        if (copy_end > copy_begin) {
 965                                if (write_in_full(fd, contents + copy_begin,
 966                                                  copy_end - copy_begin) <
 967                                    copy_end - copy_begin)
 968                                        goto write_err_out;
 969                                if (new_line &&
 970                                    write_in_full(fd, "\n", 1) != 1)
 971                                        goto write_err_out;
 972                        }
 973                        copy_begin = store.offset[i];
 974                }
 975
 976                /* write the pair (value == NULL means unset) */
 977                if (value != NULL) {
 978                        if (store.state == START) {
 979                                if (!store_write_section(fd, key))
 980                                        goto write_err_out;
 981                        }
 982                        if (!store_write_pair(fd, key, value))
 983                                goto write_err_out;
 984                }
 985
 986                /* write the rest of the config */
 987                if (copy_begin < contents_sz)
 988                        if (write_in_full(fd, contents + copy_begin,
 989                                          contents_sz - copy_begin) <
 990                            contents_sz - copy_begin)
 991                                goto write_err_out;
 992
 993                munmap(contents, contents_sz);
 994        }
 995
 996        if (commit_lock_file(lock) < 0) {
 997                fprintf(stderr, "Cannot commit config file!\n");
 998                ret = 4;
 999                goto out_free;
1000        }
1001
1002        /*
1003         * lock is committed, so don't try to roll it back below.
1004         * NOTE: Since lockfile.c keeps a linked list of all created
1005         * lock_file structures, it isn't safe to free(lock).  It's
1006         * better to just leave it hanging around.
1007         */
1008        lock = NULL;
1009        ret = 0;
1010
1011out_free:
1012        if (lock)
1013                rollback_lock_file(lock);
1014        free(config_filename);
1015        return ret;
1016
1017write_err_out:
1018        ret = write_error();
1019        goto out_free;
1020
1021}
1022
1023static int section_name_match (const char *buf, const char *name)
1024{
1025        int i = 0, j = 0, dot = 0;
1026        for (; buf[i] && buf[i] != ']'; i++) {
1027                if (!dot && isspace(buf[i])) {
1028                        dot = 1;
1029                        if (name[j++] != '.')
1030                                break;
1031                        for (i++; isspace(buf[i]); i++)
1032                                ; /* do nothing */
1033                        if (buf[i] != '"')
1034                                break;
1035                        continue;
1036                }
1037                if (buf[i] == '\\' && dot)
1038                        i++;
1039                else if (buf[i] == '"' && dot) {
1040                        for (i++; isspace(buf[i]); i++)
1041                                ; /* do_nothing */
1042                        break;
1043                }
1044                if (buf[i] != name[j++])
1045                        break;
1046        }
1047        return (buf[i] == ']' && name[j] == 0);
1048}
1049
1050/* if new_name == NULL, the section is removed instead */
1051int git_config_rename_section(const char *old_name, const char *new_name)
1052{
1053        int ret = 0, remove = 0;
1054        char *config_filename;
1055        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1056        int out_fd;
1057        char buf[1024];
1058
1059        config_filename = getenv(CONFIG_ENVIRONMENT);
1060        if (!config_filename) {
1061                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1062                if (!config_filename)
1063                        config_filename  = git_path("config");
1064        }
1065        config_filename = xstrdup(config_filename);
1066        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1067        if (out_fd < 0) {
1068                ret = error("Could not lock config file!");
1069                goto out;
1070        }
1071
1072        if (!(config_file = fopen(config_filename, "rb"))) {
1073                /* no config file means nothing to rename, no error */
1074                goto unlock_and_out;
1075        }
1076
1077        while (fgets(buf, sizeof(buf), config_file)) {
1078                int i;
1079                int length;
1080                for (i = 0; buf[i] && isspace(buf[i]); i++)
1081                        ; /* do nothing */
1082                if (buf[i] == '[') {
1083                        /* it's a section */
1084                        if (section_name_match (&buf[i+1], old_name)) {
1085                                ret++;
1086                                if (new_name == NULL) {
1087                                        remove = 1;
1088                                        continue;
1089                                }
1090                                store.baselen = strlen(new_name);
1091                                if (!store_write_section(out_fd, new_name)) {
1092                                        ret = write_error();
1093                                        goto out;
1094                                }
1095                                continue;
1096                        }
1097                        remove = 0;
1098                }
1099                if (remove)
1100                        continue;
1101                length = strlen(buf);
1102                if (write_in_full(out_fd, buf, length) != length) {
1103                        ret = write_error();
1104                        goto out;
1105                }
1106        }
1107        fclose(config_file);
1108 unlock_and_out:
1109        if (commit_lock_file(lock) < 0)
1110                        ret = error("Cannot commit config file!");
1111 out:
1112        free(config_filename);
1113        return ret;
1114}
1115
1116/*
1117 * Call this to report error for your variable that should not
1118 * get a boolean value (i.e. "[my] var" means "true").
1119 */
1120int config_error_nonbool(const char *var)
1121{
1122        return error("Missing value for '%s'", var);
1123}