Andrew's git / gitweb.git / config.c
?
config.con commit Merge branch 'gp/bisect-fix' (eafa29b)
   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        if (!strcmp(var, "branch.autosetuprebase")) {
 496                if (!value)
 497                        return config_error_nonbool(var);
 498                else if (!strcmp(value, "never"))
 499                        autorebase = AUTOREBASE_NEVER;
 500                else if (!strcmp(value, "local"))
 501                        autorebase = AUTOREBASE_LOCAL;
 502                else if (!strcmp(value, "remote"))
 503                        autorebase = AUTOREBASE_REMOTE;
 504                else if (!strcmp(value, "always"))
 505                        autorebase = AUTOREBASE_ALWAYS;
 506                else
 507                        return error("Malformed value for %s", var);
 508                return 0;
 509        }
 510
 511        /* Add other config variables here and to Documentation/config.txt. */
 512        return 0;
 513}
 514
 515int git_config_from_file(config_fn_t fn, const char *filename)
 516{
 517        int ret;
 518        FILE *f = fopen(filename, "r");
 519
 520        ret = -1;
 521        if (f) {
 522                config_file = f;
 523                config_file_name = filename;
 524                config_linenr = 1;
 525                config_file_eof = 0;
 526                ret = git_parse_file(fn);
 527                fclose(f);
 528                config_file_name = NULL;
 529        }
 530        return ret;
 531}
 532
 533const char *git_etc_gitconfig(void)
 534{
 535        static const char *system_wide;
 536        if (!system_wide) {
 537                system_wide = ETC_GITCONFIG;
 538                if (!is_absolute_path(system_wide)) {
 539                        /* interpret path relative to exec-dir */
 540                        struct strbuf d = STRBUF_INIT;
 541                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 542                        system_wide = strbuf_detach(&d, NULL);
 543                }
 544        }
 545        return system_wide;
 546}
 547
 548int git_env_bool(const char *k, int def)
 549{
 550        const char *v = getenv(k);
 551        return v ? git_config_bool(k, v) : def;
 552}
 553
 554int git_config_system(void)
 555{
 556        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 557}
 558
 559int git_config_global(void)
 560{
 561        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 562}
 563
 564int git_config(config_fn_t fn)
 565{
 566        int ret = 0;
 567        char *repo_config = NULL;
 568        const char *home = NULL, *filename;
 569
 570        /* $GIT_CONFIG makes git read _only_ the given config file,
 571         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 572         * global config file, the same way it would the per-repository
 573         * config file otherwise. */
 574        filename = getenv(CONFIG_ENVIRONMENT);
 575        if (!filename) {
 576                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 577                        ret += git_config_from_file(fn, git_etc_gitconfig());
 578                home = getenv("HOME");
 579                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 580                if (!filename)
 581                        filename = repo_config = xstrdup(git_path("config"));
 582        }
 583
 584        if (git_config_global() && home) {
 585                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 586                if (!access(user_config, R_OK))
 587                        ret = git_config_from_file(fn, user_config);
 588                free(user_config);
 589        }
 590
 591        ret += git_config_from_file(fn, filename);
 592        free(repo_config);
 593        return ret;
 594}
 595
 596/*
 597 * Find all the stuff for git_config_set() below.
 598 */
 599
 600#define MAX_MATCHES 512
 601
 602static struct {
 603        int baselen;
 604        char* key;
 605        int do_not_match;
 606        regex_t* value_regex;
 607        int multi_replace;
 608        size_t offset[MAX_MATCHES];
 609        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 610        int seen;
 611} store;
 612
 613static int matches(const char* key, const char* value)
 614{
 615        return !strcmp(key, store.key) &&
 616                (store.value_regex == NULL ||
 617                 (store.do_not_match ^
 618                  !regexec(store.value_regex, value, 0, NULL, 0)));
 619}
 620
 621static int store_aux(const char* key, const char* value)
 622{
 623        const char *ep;
 624        size_t section_len;
 625
 626        switch (store.state) {
 627        case KEY_SEEN:
 628                if (matches(key, value)) {
 629                        if (store.seen == 1 && store.multi_replace == 0) {
 630                                fprintf(stderr,
 631                                        "Warning: %s has multiple values\n",
 632                                        key);
 633                        } else if (store.seen >= MAX_MATCHES) {
 634                                fprintf(stderr, "Too many matches\n");
 635                                return 1;
 636                        }
 637
 638                        store.offset[store.seen] = ftell(config_file);
 639                        store.seen++;
 640                }
 641                break;
 642        case SECTION_SEEN:
 643                /*
 644                 * What we are looking for is in store.key (both
 645                 * section and var), and its section part is baselen
 646                 * long.  We found key (again, both section and var).
 647                 * We would want to know if this key is in the same
 648                 * section as what we are looking for.  We already
 649                 * know we are in the same section as what should
 650                 * hold store.key.
 651                 */
 652                ep = strrchr(key, '.');
 653                section_len = ep - key;
 654
 655                if ((section_len != store.baselen) ||
 656                    memcmp(key, store.key, section_len+1)) {
 657                        store.state = SECTION_END_SEEN;
 658                        break;
 659                }
 660
 661                /*
 662                 * Do not increment matches: this is no match, but we
 663                 * just made sure we are in the desired section.
 664                 */
 665                store.offset[store.seen] = ftell(config_file);
 666                /* fallthru */
 667        case SECTION_END_SEEN:
 668        case START:
 669                if (matches(key, value)) {
 670                        store.offset[store.seen] = ftell(config_file);
 671                        store.state = KEY_SEEN;
 672                        store.seen++;
 673                } else {
 674                        if (strrchr(key, '.') - key == store.baselen &&
 675                              !strncmp(key, store.key, store.baselen)) {
 676                                        store.state = SECTION_SEEN;
 677                                        store.offset[store.seen] = ftell(config_file);
 678                        }
 679                }
 680        }
 681        return 0;
 682}
 683
 684static int write_error(void)
 685{
 686        fprintf(stderr, "Failed to write new configuration file\n");
 687
 688        /* Same error code as "failed to rename". */
 689        return 4;
 690}
 691
 692static int store_write_section(int fd, const char* key)
 693{
 694        const char *dot;
 695        int i, success;
 696        struct strbuf sb;
 697
 698        strbuf_init(&sb, 0);
 699        dot = memchr(key, '.', store.baselen);
 700        if (dot) {
 701                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 702                for (i = dot - key + 1; i < store.baselen; i++) {
 703                        if (key[i] == '"')
 704                                strbuf_addch(&sb, '\\');
 705                        strbuf_addch(&sb, key[i]);
 706                }
 707                strbuf_addstr(&sb, "\"]\n");
 708        } else {
 709                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 710        }
 711
 712        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 713        strbuf_release(&sb);
 714
 715        return success;
 716}
 717
 718static int store_write_pair(int fd, const char* key, const char* value)
 719{
 720        int i, success;
 721        int length = strlen(key + store.baselen + 1);
 722        const char *quote = "";
 723        struct strbuf sb;
 724
 725        /*
 726         * Check to see if the value needs to be surrounded with a dq pair.
 727         * Note that problematic characters are always backslash-quoted; this
 728         * check is about not losing leading or trailing SP and strings that
 729         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 730         * configuration parser.
 731         */
 732        if (value[0] == ' ')
 733                quote = "\"";
 734        for (i = 0; value[i]; i++)
 735                if (value[i] == ';' || value[i] == '#')
 736                        quote = "\"";
 737        if (i && value[i - 1] == ' ')
 738                quote = "\"";
 739
 740        strbuf_init(&sb, 0);
 741        strbuf_addf(&sb, "\t%.*s = %s",
 742                    length, key + store.baselen + 1, quote);
 743
 744        for (i = 0; value[i]; i++)
 745                switch (value[i]) {
 746                case '\n':
 747                        strbuf_addstr(&sb, "\\n");
 748                        break;
 749                case '\t':
 750                        strbuf_addstr(&sb, "\\t");
 751                        break;
 752                case '"':
 753                case '\\':
 754                        strbuf_addch(&sb, '\\');
 755                default:
 756                        strbuf_addch(&sb, value[i]);
 757                        break;
 758                }
 759        strbuf_addf(&sb, "%s\n", quote);
 760
 761        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 762        strbuf_release(&sb);
 763
 764        return success;
 765}
 766
 767static ssize_t find_beginning_of_line(const char* contents, size_t size,
 768        size_t offset_, int* found_bracket)
 769{
 770        size_t equal_offset = size, bracket_offset = size;
 771        ssize_t offset;
 772
 773contline:
 774        for (offset = offset_-2; offset > 0
 775                        && contents[offset] != '\n'; offset--)
 776                switch (contents[offset]) {
 777                        case '=': equal_offset = offset; break;
 778                        case ']': bracket_offset = offset; break;
 779                }
 780        if (offset > 0 && contents[offset-1] == '\\') {
 781                offset_ = offset;
 782                goto contline;
 783        }
 784        if (bracket_offset < equal_offset) {
 785                *found_bracket = 1;
 786                offset = bracket_offset+1;
 787        } else
 788                offset++;
 789
 790        return offset;
 791}
 792
 793int git_config_set(const char* key, const char* value)
 794{
 795        return git_config_set_multivar(key, value, NULL, 0);
 796}
 797
 798/*
 799 * If value==NULL, unset in (remove from) config,
 800 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 801 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 802 *     else all matching key/values (regardless how many) are removed,
 803 *     before the new pair is written.
 804 *
 805 * Returns 0 on success.
 806 *
 807 * This function does this:
 808 *
 809 * - it locks the config file by creating ".git/config.lock"
 810 *
 811 * - it then parses the config using store_aux() as validator to find
 812 *   the position on the key/value pair to replace. If it is to be unset,
 813 *   it must be found exactly once.
 814 *
 815 * - the config file is mmap()ed and the part before the match (if any) is
 816 *   written to the lock file, then the changed part and the rest.
 817 *
 818 * - the config file is removed and the lock file rename()d to it.
 819 *
 820 */
 821int git_config_set_multivar(const char* key, const char* value,
 822        const char* value_regex, int multi_replace)
 823{
 824        int i, dot;
 825        int fd = -1, in_fd;
 826        int ret;
 827        char* config_filename;
 828        struct lock_file *lock = NULL;
 829        const char* last_dot = strrchr(key, '.');
 830
 831        config_filename = getenv(CONFIG_ENVIRONMENT);
 832        if (!config_filename) {
 833                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 834                if (!config_filename)
 835                        config_filename  = git_path("config");
 836        }
 837        config_filename = xstrdup(config_filename);
 838
 839        /*
 840         * Since "key" actually contains the section name and the real
 841         * key name separated by a dot, we have to know where the dot is.
 842         */
 843
 844        if (last_dot == NULL) {
 845                fprintf(stderr, "key does not contain a section: %s\n", key);
 846                ret = 2;
 847                goto out_free;
 848        }
 849        store.baselen = last_dot - key;
 850
 851        store.multi_replace = multi_replace;
 852
 853        /*
 854         * Validate the key and while at it, lower case it for matching.
 855         */
 856        store.key = xmalloc(strlen(key) + 1);
 857        dot = 0;
 858        for (i = 0; key[i]; i++) {
 859                unsigned char c = key[i];
 860                if (c == '.')
 861                        dot = 1;
 862                /* Leave the extended basename untouched.. */
 863                if (!dot || i > store.baselen) {
 864                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 865                                fprintf(stderr, "invalid key: %s\n", key);
 866                                free(store.key);
 867                                ret = 1;
 868                                goto out_free;
 869                        }
 870                        c = tolower(c);
 871                } else if (c == '\n') {
 872                        fprintf(stderr, "invalid key (newline): %s\n", key);
 873                        free(store.key);
 874                        ret = 1;
 875                        goto out_free;
 876                }
 877                store.key[i] = c;
 878        }
 879        store.key[i] = 0;
 880
 881        /*
 882         * The lock serves a purpose in addition to locking: the new
 883         * contents of .git/config will be written into it.
 884         */
 885        lock = xcalloc(sizeof(struct lock_file), 1);
 886        fd = hold_lock_file_for_update(lock, config_filename, 0);
 887        if (fd < 0) {
 888                fprintf(stderr, "could not lock config file\n");
 889                free(store.key);
 890                ret = -1;
 891                goto out_free;
 892        }
 893
 894        /*
 895         * If .git/config does not exist yet, write a minimal version.
 896         */
 897        in_fd = open(config_filename, O_RDONLY);
 898        if ( in_fd < 0 ) {
 899                free(store.key);
 900
 901                if ( ENOENT != errno ) {
 902                        error("opening %s: %s", config_filename,
 903                              strerror(errno));
 904                        ret = 3; /* same as "invalid config file" */
 905                        goto out_free;
 906                }
 907                /* if nothing to unset, error out */
 908                if (value == NULL) {
 909                        ret = 5;
 910                        goto out_free;
 911                }
 912
 913                store.key = (char*)key;
 914                if (!store_write_section(fd, key) ||
 915                    !store_write_pair(fd, key, value))
 916                        goto write_err_out;
 917        } else {
 918                struct stat st;
 919                char* contents;
 920                size_t contents_sz, copy_begin, copy_end;
 921                int i, new_line = 0;
 922
 923                if (value_regex == NULL)
 924                        store.value_regex = NULL;
 925                else {
 926                        if (value_regex[0] == '!') {
 927                                store.do_not_match = 1;
 928                                value_regex++;
 929                        } else
 930                                store.do_not_match = 0;
 931
 932                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 933                        if (regcomp(store.value_regex, value_regex,
 934                                        REG_EXTENDED)) {
 935                                fprintf(stderr, "Invalid pattern: %s\n",
 936                                        value_regex);
 937                                free(store.value_regex);
 938                                ret = 6;
 939                                goto out_free;
 940                        }
 941                }
 942
 943                store.offset[0] = 0;
 944                store.state = START;
 945                store.seen = 0;
 946
 947                /*
 948                 * After this, store.offset will contain the *end* offset
 949                 * of the last match, or remain at 0 if no match was found.
 950                 * As a side effect, we make sure to transform only a valid
 951                 * existing config file.
 952                 */
 953                if (git_config_from_file(store_aux, config_filename)) {
 954                        fprintf(stderr, "invalid config file\n");
 955                        free(store.key);
 956                        if (store.value_regex != NULL) {
 957                                regfree(store.value_regex);
 958                                free(store.value_regex);
 959                        }
 960                        ret = 3;
 961                        goto out_free;
 962                }
 963
 964                free(store.key);
 965                if (store.value_regex != NULL) {
 966                        regfree(store.value_regex);
 967                        free(store.value_regex);
 968                }
 969
 970                /* if nothing to unset, or too many matches, error out */
 971                if ((store.seen == 0 && value == NULL) ||
 972                                (store.seen > 1 && multi_replace == 0)) {
 973                        ret = 5;
 974                        goto out_free;
 975                }
 976
 977                fstat(in_fd, &st);
 978                contents_sz = xsize_t(st.st_size);
 979                contents = xmmap(NULL, contents_sz, PROT_READ,
 980                        MAP_PRIVATE, in_fd, 0);
 981                close(in_fd);
 982
 983                if (store.seen == 0)
 984                        store.seen = 1;
 985
 986                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 987                        if (store.offset[i] == 0) {
 988                                store.offset[i] = copy_end = contents_sz;
 989                        } else if (store.state != KEY_SEEN) {
 990                                copy_end = store.offset[i];
 991                        } else
 992                                copy_end = find_beginning_of_line(
 993                                        contents, contents_sz,
 994                                        store.offset[i]-2, &new_line);
 995
 996                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 997                                new_line = 1;
 998
 999                        /* write the first part of the config */
1000                        if (copy_end > copy_begin) {
1001                                if (write_in_full(fd, contents + copy_begin,
1002                                                  copy_end - copy_begin) <
1003                                    copy_end - copy_begin)
1004                                        goto write_err_out;
1005                                if (new_line &&
1006                                    write_in_full(fd, "\n", 1) != 1)
1007                                        goto write_err_out;
1008                        }
1009                        copy_begin = store.offset[i];
1010                }
1011
1012                /* write the pair (value == NULL means unset) */
1013                if (value != NULL) {
1014                        if (store.state == START) {
1015                                if (!store_write_section(fd, key))
1016                                        goto write_err_out;
1017                        }
1018                        if (!store_write_pair(fd, key, value))
1019                                goto write_err_out;
1020                }
1021
1022                /* write the rest of the config */
1023                if (copy_begin < contents_sz)
1024                        if (write_in_full(fd, contents + copy_begin,
1025                                          contents_sz - copy_begin) <
1026                            contents_sz - copy_begin)
1027                                goto write_err_out;
1028
1029                munmap(contents, contents_sz);
1030        }
1031
1032        if (commit_lock_file(lock) < 0) {
1033                fprintf(stderr, "Cannot commit config file!\n");
1034                ret = 4;
1035                goto out_free;
1036        }
1037
1038        /*
1039         * lock is committed, so don't try to roll it back below.
1040         * NOTE: Since lockfile.c keeps a linked list of all created
1041         * lock_file structures, it isn't safe to free(lock).  It's
1042         * better to just leave it hanging around.
1043         */
1044        lock = NULL;
1045        ret = 0;
1046
1047out_free:
1048        if (lock)
1049                rollback_lock_file(lock);
1050        free(config_filename);
1051        return ret;
1052
1053write_err_out:
1054        ret = write_error();
1055        goto out_free;
1056
1057}
1058
1059static int section_name_match (const char *buf, const char *name)
1060{
1061        int i = 0, j = 0, dot = 0;
1062        for (; buf[i] && buf[i] != ']'; i++) {
1063                if (!dot && isspace(buf[i])) {
1064                        dot = 1;
1065                        if (name[j++] != '.')
1066                                break;
1067                        for (i++; isspace(buf[i]); i++)
1068                                ; /* do nothing */
1069                        if (buf[i] != '"')
1070                                break;
1071                        continue;
1072                }
1073                if (buf[i] == '\\' && dot)
1074                        i++;
1075                else if (buf[i] == '"' && dot) {
1076                        for (i++; isspace(buf[i]); i++)
1077                                ; /* do_nothing */
1078                        break;
1079                }
1080                if (buf[i] != name[j++])
1081                        break;
1082        }
1083        return (buf[i] == ']' && name[j] == 0);
1084}
1085
1086/* if new_name == NULL, the section is removed instead */
1087int git_config_rename_section(const char *old_name, const char *new_name)
1088{
1089        int ret = 0, remove = 0;
1090        char *config_filename;
1091        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1092        int out_fd;
1093        char buf[1024];
1094
1095        config_filename = getenv(CONFIG_ENVIRONMENT);
1096        if (!config_filename) {
1097                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1098                if (!config_filename)
1099                        config_filename  = git_path("config");
1100        }
1101        config_filename = xstrdup(config_filename);
1102        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1103        if (out_fd < 0) {
1104                ret = error("Could not lock config file!");
1105                goto out;
1106        }
1107
1108        if (!(config_file = fopen(config_filename, "rb"))) {
1109                /* no config file means nothing to rename, no error */
1110                goto unlock_and_out;
1111        }
1112
1113        while (fgets(buf, sizeof(buf), config_file)) {
1114                int i;
1115                int length;
1116                for (i = 0; buf[i] && isspace(buf[i]); i++)
1117                        ; /* do nothing */
1118                if (buf[i] == '[') {
1119                        /* it's a section */
1120                        if (section_name_match (&buf[i+1], old_name)) {
1121                                ret++;
1122                                if (new_name == NULL) {
1123                                        remove = 1;
1124                                        continue;
1125                                }
1126                                store.baselen = strlen(new_name);
1127                                if (!store_write_section(out_fd, new_name)) {
1128                                        ret = write_error();
1129                                        goto out;
1130                                }
1131                                continue;
1132                        }
1133                        remove = 0;
1134                }
1135                if (remove)
1136                        continue;
1137                length = strlen(buf);
1138                if (write_in_full(out_fd, buf, length) != length) {
1139                        ret = write_error();
1140                        goto out;
1141                }
1142        }
1143        fclose(config_file);
1144 unlock_and_out:
1145        if (commit_lock_file(lock) < 0)
1146                        ret = error("Cannot commit config file!");
1147 out:
1148        free(config_filename);
1149        return ret;
1150}
1151
1152/*
1153 * Call this to report error for your variable that should not
1154 * get a boolean value (i.e. "[my] var" means "true").
1155 */
1156int config_error_nonbool(const char *var)
1157{
1158        return error("Missing value for '%s'", var);
1159}