Andrew's git / gitweb.git / config.c
?
config.con commit Git.pm: fix return value of config method (32d8050)
   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, void *data, 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, data);
 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, void *data)
 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, data, 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, void *dummy)
 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                if (git_default_email[0])
 452                        user_ident_explicitly_given = 1;
 453                return 0;
 454        }
 455
 456        if (!strcmp(var, "user.email")) {
 457                if (!value)
 458                        return config_error_nonbool(var);
 459                strlcpy(git_default_email, value, sizeof(git_default_email));
 460                if (git_default_name[0])
 461                        user_ident_explicitly_given = 1;
 462                return 0;
 463        }
 464
 465        if (!strcmp(var, "i18n.commitencoding"))
 466                return git_config_string(&git_commit_encoding, var, value);
 467
 468        if (!strcmp(var, "i18n.logoutputencoding"))
 469                return git_config_string(&git_log_output_encoding, var, value);
 470
 471        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 472                pager_use_color = git_config_bool(var,value);
 473                return 0;
 474        }
 475
 476        if (!strcmp(var, "core.pager"))
 477                return git_config_string(&pager_program, var, value);
 478
 479        if (!strcmp(var, "core.editor"))
 480                return git_config_string(&editor_program, var, value);
 481
 482        if (!strcmp(var, "core.excludesfile"))
 483                return git_config_string(&excludes_file, var, value);
 484
 485        if (!strcmp(var, "core.whitespace")) {
 486                if (!value)
 487                        return config_error_nonbool(var);
 488                whitespace_rule_cfg = parse_whitespace_rule(value);
 489                return 0;
 490        }
 491        if (!strcmp(var, "branch.autosetupmerge")) {
 492                if (value && !strcasecmp(value, "always")) {
 493                        git_branch_track = BRANCH_TRACK_ALWAYS;
 494                        return 0;
 495                }
 496                git_branch_track = git_config_bool(var, value);
 497                return 0;
 498        }
 499        if (!strcmp(var, "branch.autosetuprebase")) {
 500                if (!value)
 501                        return config_error_nonbool(var);
 502                else if (!strcmp(value, "never"))
 503                        autorebase = AUTOREBASE_NEVER;
 504                else if (!strcmp(value, "local"))
 505                        autorebase = AUTOREBASE_LOCAL;
 506                else if (!strcmp(value, "remote"))
 507                        autorebase = AUTOREBASE_REMOTE;
 508                else if (!strcmp(value, "always"))
 509                        autorebase = AUTOREBASE_ALWAYS;
 510                else
 511                        return error("Malformed value for %s", var);
 512                return 0;
 513        }
 514
 515        /* Add other config variables here and to Documentation/config.txt. */
 516        return 0;
 517}
 518
 519int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 520{
 521        int ret;
 522        FILE *f = fopen(filename, "r");
 523
 524        ret = -1;
 525        if (f) {
 526                config_file = f;
 527                config_file_name = filename;
 528                config_linenr = 1;
 529                config_file_eof = 0;
 530                ret = git_parse_file(fn, data);
 531                fclose(f);
 532                config_file_name = NULL;
 533        }
 534        return ret;
 535}
 536
 537const char *git_etc_gitconfig(void)
 538{
 539        static const char *system_wide;
 540        if (!system_wide) {
 541                system_wide = ETC_GITCONFIG;
 542                if (!is_absolute_path(system_wide)) {
 543                        /* interpret path relative to exec-dir */
 544                        struct strbuf d = STRBUF_INIT;
 545                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 546                        system_wide = strbuf_detach(&d, NULL);
 547                }
 548        }
 549        return system_wide;
 550}
 551
 552int git_env_bool(const char *k, int def)
 553{
 554        const char *v = getenv(k);
 555        return v ? git_config_bool(k, v) : def;
 556}
 557
 558int git_config_system(void)
 559{
 560        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 561}
 562
 563int git_config_global(void)
 564{
 565        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 566}
 567
 568int git_config(config_fn_t fn, void *data)
 569{
 570        int ret = 0;
 571        char *repo_config = NULL;
 572        const char *home = NULL, *filename;
 573
 574        /* $GIT_CONFIG makes git read _only_ the given config file,
 575         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 576         * global config file, the same way it would the per-repository
 577         * config file otherwise. */
 578        filename = getenv(CONFIG_ENVIRONMENT);
 579        if (!filename) {
 580                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 581                        ret += git_config_from_file(fn, git_etc_gitconfig(),
 582                                data);
 583                home = getenv("HOME");
 584                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 585                if (!filename)
 586                        filename = repo_config = xstrdup(git_path("config"));
 587        }
 588
 589        if (git_config_global() && home) {
 590                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 591                if (!access(user_config, R_OK))
 592                        ret = git_config_from_file(fn, user_config, data);
 593                free(user_config);
 594        }
 595
 596        ret += git_config_from_file(fn, filename, data);
 597        free(repo_config);
 598        return ret;
 599}
 600
 601/*
 602 * Find all the stuff for git_config_set() below.
 603 */
 604
 605#define MAX_MATCHES 512
 606
 607static struct {
 608        int baselen;
 609        char* key;
 610        int do_not_match;
 611        regex_t* value_regex;
 612        int multi_replace;
 613        size_t offset[MAX_MATCHES];
 614        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 615        int seen;
 616} store;
 617
 618static int matches(const char* key, const char* value)
 619{
 620        return !strcmp(key, store.key) &&
 621                (store.value_regex == NULL ||
 622                 (store.do_not_match ^
 623                  !regexec(store.value_regex, value, 0, NULL, 0)));
 624}
 625
 626static int store_aux(const char* key, const char* value, void *cb)
 627{
 628        const char *ep;
 629        size_t section_len;
 630
 631        switch (store.state) {
 632        case KEY_SEEN:
 633                if (matches(key, value)) {
 634                        if (store.seen == 1 && store.multi_replace == 0) {
 635                                warning("%s has multiple values", key);
 636                        } else if (store.seen >= MAX_MATCHES) {
 637                                error("too many matches for %s", key);
 638                                return 1;
 639                        }
 640
 641                        store.offset[store.seen] = ftell(config_file);
 642                        store.seen++;
 643                }
 644                break;
 645        case SECTION_SEEN:
 646                /*
 647                 * What we are looking for is in store.key (both
 648                 * section and var), and its section part is baselen
 649                 * long.  We found key (again, both section and var).
 650                 * We would want to know if this key is in the same
 651                 * section as what we are looking for.  We already
 652                 * know we are in the same section as what should
 653                 * hold store.key.
 654                 */
 655                ep = strrchr(key, '.');
 656                section_len = ep - key;
 657
 658                if ((section_len != store.baselen) ||
 659                    memcmp(key, store.key, section_len+1)) {
 660                        store.state = SECTION_END_SEEN;
 661                        break;
 662                }
 663
 664                /*
 665                 * Do not increment matches: this is no match, but we
 666                 * just made sure we are in the desired section.
 667                 */
 668                store.offset[store.seen] = ftell(config_file);
 669                /* fallthru */
 670        case SECTION_END_SEEN:
 671        case START:
 672                if (matches(key, value)) {
 673                        store.offset[store.seen] = ftell(config_file);
 674                        store.state = KEY_SEEN;
 675                        store.seen++;
 676                } else {
 677                        if (strrchr(key, '.') - key == store.baselen &&
 678                              !strncmp(key, store.key, store.baselen)) {
 679                                        store.state = SECTION_SEEN;
 680                                        store.offset[store.seen] = ftell(config_file);
 681                        }
 682                }
 683        }
 684        return 0;
 685}
 686
 687static int write_error(const char *filename)
 688{
 689        error("failed to write new configuration file %s", filename);
 690
 691        /* Same error code as "failed to rename". */
 692        return 4;
 693}
 694
 695static int store_write_section(int fd, const char* key)
 696{
 697        const char *dot;
 698        int i, success;
 699        struct strbuf sb;
 700
 701        strbuf_init(&sb, 0);
 702        dot = memchr(key, '.', store.baselen);
 703        if (dot) {
 704                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 705                for (i = dot - key + 1; i < store.baselen; i++) {
 706                        if (key[i] == '"' || key[i] == '\\')
 707                                strbuf_addch(&sb, '\\');
 708                        strbuf_addch(&sb, key[i]);
 709                }
 710                strbuf_addstr(&sb, "\"]\n");
 711        } else {
 712                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 713        }
 714
 715        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 716        strbuf_release(&sb);
 717
 718        return success;
 719}
 720
 721static int store_write_pair(int fd, const char* key, const char* value)
 722{
 723        int i, success;
 724        int length = strlen(key + store.baselen + 1);
 725        const char *quote = "";
 726        struct strbuf sb;
 727
 728        /*
 729         * Check to see if the value needs to be surrounded with a dq pair.
 730         * Note that problematic characters are always backslash-quoted; this
 731         * check is about not losing leading or trailing SP and strings that
 732         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 733         * configuration parser.
 734         */
 735        if (value[0] == ' ')
 736                quote = "\"";
 737        for (i = 0; value[i]; i++)
 738                if (value[i] == ';' || value[i] == '#')
 739                        quote = "\"";
 740        if (i && value[i - 1] == ' ')
 741                quote = "\"";
 742
 743        strbuf_init(&sb, 0);
 744        strbuf_addf(&sb, "\t%.*s = %s",
 745                    length, key + store.baselen + 1, quote);
 746
 747        for (i = 0; value[i]; i++)
 748                switch (value[i]) {
 749                case '\n':
 750                        strbuf_addstr(&sb, "\\n");
 751                        break;
 752                case '\t':
 753                        strbuf_addstr(&sb, "\\t");
 754                        break;
 755                case '"':
 756                case '\\':
 757                        strbuf_addch(&sb, '\\');
 758                default:
 759                        strbuf_addch(&sb, value[i]);
 760                        break;
 761                }
 762        strbuf_addf(&sb, "%s\n", quote);
 763
 764        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 765        strbuf_release(&sb);
 766
 767        return success;
 768}
 769
 770static ssize_t find_beginning_of_line(const char* contents, size_t size,
 771        size_t offset_, int* found_bracket)
 772{
 773        size_t equal_offset = size, bracket_offset = size;
 774        ssize_t offset;
 775
 776contline:
 777        for (offset = offset_-2; offset > 0
 778                        && contents[offset] != '\n'; offset--)
 779                switch (contents[offset]) {
 780                        case '=': equal_offset = offset; break;
 781                        case ']': bracket_offset = offset; break;
 782                }
 783        if (offset > 0 && contents[offset-1] == '\\') {
 784                offset_ = offset;
 785                goto contline;
 786        }
 787        if (bracket_offset < equal_offset) {
 788                *found_bracket = 1;
 789                offset = bracket_offset+1;
 790        } else
 791                offset++;
 792
 793        return offset;
 794}
 795
 796int git_config_set(const char* key, const char* value)
 797{
 798        return git_config_set_multivar(key, value, NULL, 0);
 799}
 800
 801/*
 802 * If value==NULL, unset in (remove from) config,
 803 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 804 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 805 *     else all matching key/values (regardless how many) are removed,
 806 *     before the new pair is written.
 807 *
 808 * Returns 0 on success.
 809 *
 810 * This function does this:
 811 *
 812 * - it locks the config file by creating ".git/config.lock"
 813 *
 814 * - it then parses the config using store_aux() as validator to find
 815 *   the position on the key/value pair to replace. If it is to be unset,
 816 *   it must be found exactly once.
 817 *
 818 * - the config file is mmap()ed and the part before the match (if any) is
 819 *   written to the lock file, then the changed part and the rest.
 820 *
 821 * - the config file is removed and the lock file rename()d to it.
 822 *
 823 */
 824int git_config_set_multivar(const char* key, const char* value,
 825        const char* value_regex, int multi_replace)
 826{
 827        int i, dot;
 828        int fd = -1, in_fd;
 829        int ret;
 830        char* config_filename;
 831        struct lock_file *lock = NULL;
 832        const char* last_dot = strrchr(key, '.');
 833
 834        config_filename = getenv(CONFIG_ENVIRONMENT);
 835        if (!config_filename) {
 836                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 837                if (!config_filename)
 838                        config_filename  = git_path("config");
 839        }
 840        config_filename = xstrdup(config_filename);
 841
 842        /*
 843         * Since "key" actually contains the section name and the real
 844         * key name separated by a dot, we have to know where the dot is.
 845         */
 846
 847        if (last_dot == NULL) {
 848                error("key does not contain a section: %s", key);
 849                ret = 2;
 850                goto out_free;
 851        }
 852        store.baselen = last_dot - key;
 853
 854        store.multi_replace = multi_replace;
 855
 856        /*
 857         * Validate the key and while at it, lower case it for matching.
 858         */
 859        store.key = xmalloc(strlen(key) + 1);
 860        dot = 0;
 861        for (i = 0; key[i]; i++) {
 862                unsigned char c = key[i];
 863                if (c == '.')
 864                        dot = 1;
 865                /* Leave the extended basename untouched.. */
 866                if (!dot || i > store.baselen) {
 867                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 868                                error("invalid key: %s", key);
 869                                free(store.key);
 870                                ret = 1;
 871                                goto out_free;
 872                        }
 873                        c = tolower(c);
 874                } else if (c == '\n') {
 875                        error("invalid key (newline): %s", key);
 876                        free(store.key);
 877                        ret = 1;
 878                        goto out_free;
 879                }
 880                store.key[i] = c;
 881        }
 882        store.key[i] = 0;
 883
 884        /*
 885         * The lock serves a purpose in addition to locking: the new
 886         * contents of .git/config will be written into it.
 887         */
 888        lock = xcalloc(sizeof(struct lock_file), 1);
 889        fd = hold_lock_file_for_update(lock, config_filename, 0);
 890        if (fd < 0) {
 891                error("could not lock config file %s", config_filename);
 892                free(store.key);
 893                ret = -1;
 894                goto out_free;
 895        }
 896
 897        /*
 898         * If .git/config does not exist yet, write a minimal version.
 899         */
 900        in_fd = open(config_filename, O_RDONLY);
 901        if ( in_fd < 0 ) {
 902                free(store.key);
 903
 904                if ( ENOENT != errno ) {
 905                        error("opening %s: %s", config_filename,
 906                              strerror(errno));
 907                        ret = 3; /* same as "invalid config file" */
 908                        goto out_free;
 909                }
 910                /* if nothing to unset, error out */
 911                if (value == NULL) {
 912                        ret = 5;
 913                        goto out_free;
 914                }
 915
 916                store.key = (char*)key;
 917                if (!store_write_section(fd, key) ||
 918                    !store_write_pair(fd, key, value))
 919                        goto write_err_out;
 920        } else {
 921                struct stat st;
 922                char* contents;
 923                size_t contents_sz, copy_begin, copy_end;
 924                int i, new_line = 0;
 925
 926                if (value_regex == NULL)
 927                        store.value_regex = NULL;
 928                else {
 929                        if (value_regex[0] == '!') {
 930                                store.do_not_match = 1;
 931                                value_regex++;
 932                        } else
 933                                store.do_not_match = 0;
 934
 935                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 936                        if (regcomp(store.value_regex, value_regex,
 937                                        REG_EXTENDED)) {
 938                                error("invalid pattern: %s", value_regex);
 939                                free(store.value_regex);
 940                                ret = 6;
 941                                goto out_free;
 942                        }
 943                }
 944
 945                store.offset[0] = 0;
 946                store.state = START;
 947                store.seen = 0;
 948
 949                /*
 950                 * After this, store.offset will contain the *end* offset
 951                 * of the last match, or remain at 0 if no match was found.
 952                 * As a side effect, we make sure to transform only a valid
 953                 * existing config file.
 954                 */
 955                if (git_config_from_file(store_aux, config_filename, NULL)) {
 956                        error("invalid config file %s", config_filename);
 957                        free(store.key);
 958                        if (store.value_regex != NULL) {
 959                                regfree(store.value_regex);
 960                                free(store.value_regex);
 961                        }
 962                        ret = 3;
 963                        goto out_free;
 964                }
 965
 966                free(store.key);
 967                if (store.value_regex != NULL) {
 968                        regfree(store.value_regex);
 969                        free(store.value_regex);
 970                }
 971
 972                /* if nothing to unset, or too many matches, error out */
 973                if ((store.seen == 0 && value == NULL) ||
 974                                (store.seen > 1 && multi_replace == 0)) {
 975                        ret = 5;
 976                        goto out_free;
 977                }
 978
 979                fstat(in_fd, &st);
 980                contents_sz = xsize_t(st.st_size);
 981                contents = xmmap(NULL, contents_sz, PROT_READ,
 982                        MAP_PRIVATE, in_fd, 0);
 983                close(in_fd);
 984
 985                if (store.seen == 0)
 986                        store.seen = 1;
 987
 988                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 989                        if (store.offset[i] == 0) {
 990                                store.offset[i] = copy_end = contents_sz;
 991                        } else if (store.state != KEY_SEEN) {
 992                                copy_end = store.offset[i];
 993                        } else
 994                                copy_end = find_beginning_of_line(
 995                                        contents, contents_sz,
 996                                        store.offset[i]-2, &new_line);
 997
 998                        if (copy_end > 0 && contents[copy_end-1] != '\n')
 999                                new_line = 1;
1000
1001                        /* write the first part of the config */
1002                        if (copy_end > copy_begin) {
1003                                if (write_in_full(fd, contents + copy_begin,
1004                                                  copy_end - copy_begin) <
1005                                    copy_end - copy_begin)
1006                                        goto write_err_out;
1007                                if (new_line &&
1008                                    write_in_full(fd, "\n", 1) != 1)
1009                                        goto write_err_out;
1010                        }
1011                        copy_begin = store.offset[i];
1012                }
1013
1014                /* write the pair (value == NULL means unset) */
1015                if (value != NULL) {
1016                        if (store.state == START) {
1017                                if (!store_write_section(fd, key))
1018                                        goto write_err_out;
1019                        }
1020                        if (!store_write_pair(fd, key, value))
1021                                goto write_err_out;
1022                }
1023
1024                /* write the rest of the config */
1025                if (copy_begin < contents_sz)
1026                        if (write_in_full(fd, contents + copy_begin,
1027                                          contents_sz - copy_begin) <
1028                            contents_sz - copy_begin)
1029                                goto write_err_out;
1030
1031                munmap(contents, contents_sz);
1032        }
1033
1034        if (commit_lock_file(lock) < 0) {
1035                error("could not commit config file %s", config_filename);
1036                ret = 4;
1037                goto out_free;
1038        }
1039
1040        /*
1041         * lock is committed, so don't try to roll it back below.
1042         * NOTE: Since lockfile.c keeps a linked list of all created
1043         * lock_file structures, it isn't safe to free(lock).  It's
1044         * better to just leave it hanging around.
1045         */
1046        lock = NULL;
1047        ret = 0;
1048
1049out_free:
1050        if (lock)
1051                rollback_lock_file(lock);
1052        free(config_filename);
1053        return ret;
1054
1055write_err_out:
1056        ret = write_error(lock->filename);
1057        goto out_free;
1058
1059}
1060
1061static int section_name_match (const char *buf, const char *name)
1062{
1063        int i = 0, j = 0, dot = 0;
1064        for (; buf[i] && buf[i] != ']'; i++) {
1065                if (!dot && isspace(buf[i])) {
1066                        dot = 1;
1067                        if (name[j++] != '.')
1068                                break;
1069                        for (i++; isspace(buf[i]); i++)
1070                                ; /* do nothing */
1071                        if (buf[i] != '"')
1072                                break;
1073                        continue;
1074                }
1075                if (buf[i] == '\\' && dot)
1076                        i++;
1077                else if (buf[i] == '"' && dot) {
1078                        for (i++; isspace(buf[i]); i++)
1079                                ; /* do_nothing */
1080                        break;
1081                }
1082                if (buf[i] != name[j++])
1083                        break;
1084        }
1085        return (buf[i] == ']' && name[j] == 0);
1086}
1087
1088/* if new_name == NULL, the section is removed instead */
1089int git_config_rename_section(const char *old_name, const char *new_name)
1090{
1091        int ret = 0, remove = 0;
1092        char *config_filename;
1093        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1094        int out_fd;
1095        char buf[1024];
1096
1097        config_filename = getenv(CONFIG_ENVIRONMENT);
1098        if (!config_filename) {
1099                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1100                if (!config_filename)
1101                        config_filename  = git_path("config");
1102        }
1103        config_filename = xstrdup(config_filename);
1104        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1105        if (out_fd < 0) {
1106                ret = error("could not lock config file %s", config_filename);
1107                goto out;
1108        }
1109
1110        if (!(config_file = fopen(config_filename, "rb"))) {
1111                /* no config file means nothing to rename, no error */
1112                goto unlock_and_out;
1113        }
1114
1115        while (fgets(buf, sizeof(buf), config_file)) {
1116                int i;
1117                int length;
1118                for (i = 0; buf[i] && isspace(buf[i]); i++)
1119                        ; /* do nothing */
1120                if (buf[i] == '[') {
1121                        /* it's a section */
1122                        if (section_name_match (&buf[i+1], old_name)) {
1123                                ret++;
1124                                if (new_name == NULL) {
1125                                        remove = 1;
1126                                        continue;
1127                                }
1128                                store.baselen = strlen(new_name);
1129                                if (!store_write_section(out_fd, new_name)) {
1130                                        ret = write_error(lock->filename);
1131                                        goto out;
1132                                }
1133                                continue;
1134                        }
1135                        remove = 0;
1136                }
1137                if (remove)
1138                        continue;
1139                length = strlen(buf);
1140                if (write_in_full(out_fd, buf, length) != length) {
1141                        ret = write_error(lock->filename);
1142                        goto out;
1143                }
1144        }
1145        fclose(config_file);
1146 unlock_and_out:
1147        if (commit_lock_file(lock) < 0)
1148                ret = error("could not commit config file %s", config_filename);
1149 out:
1150        free(config_filename);
1151        return ret;
1152}
1153
1154/*
1155 * Call this to report error for your variable that should not
1156 * get a boolean value (i.e. "[my] var" means "true").
1157 */
1158int config_error_nonbool(const char *var)
1159{
1160        return error("Missing value for '%s'", var);
1161}