Andrew's git / gitweb.git / config.c
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config.con commit Split up default "i18n" and "branch" config parsing into helper routines (1141f49)
   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
 335static int git_default_core_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, "core.pager"))
 448                return git_config_string(&pager_program, var, value);
 449
 450        if (!strcmp(var, "core.editor"))
 451                return git_config_string(&editor_program, var, value);
 452
 453        if (!strcmp(var, "core.excludesfile"))
 454                return git_config_string(&excludes_file, var, value);
 455
 456        if (!strcmp(var, "core.whitespace")) {
 457                if (!value)
 458                        return config_error_nonbool(var);
 459                whitespace_rule_cfg = parse_whitespace_rule(value);
 460                return 0;
 461        }
 462
 463        /* Add other config variables here and to Documentation/config.txt. */
 464        return 0;
 465}
 466
 467static int git_default_user_config(const char *var, const char *value)
 468{
 469        if (!strcmp(var, "user.name")) {
 470                if (!value)
 471                        return config_error_nonbool(var);
 472                strlcpy(git_default_name, value, sizeof(git_default_name));
 473                if (git_default_email[0])
 474                        user_ident_explicitly_given = 1;
 475                return 0;
 476        }
 477
 478        if (!strcmp(var, "user.email")) {
 479                if (!value)
 480                        return config_error_nonbool(var);
 481                strlcpy(git_default_email, value, sizeof(git_default_email));
 482                if (git_default_name[0])
 483                        user_ident_explicitly_given = 1;
 484                return 0;
 485        }
 486
 487        /* Add other config variables here and to Documentation/config.txt. */
 488        return 0;
 489}
 490
 491static int git_default_i18n_config(const char *var, const char *value)
 492{
 493        if (!strcmp(var, "i18n.commitencoding"))
 494                return git_config_string(&git_commit_encoding, var, value);
 495
 496        if (!strcmp(var, "i18n.logoutputencoding"))
 497                return git_config_string(&git_log_output_encoding, var, value);
 498
 499        /* Add other config variables here and to Documentation/config.txt. */
 500        return 0;
 501}
 502
 503static int git_default_branch_config(const char *var, const char *value)
 504{
 505        if (!strcmp(var, "branch.autosetupmerge")) {
 506                if (value && !strcasecmp(value, "always")) {
 507                        git_branch_track = BRANCH_TRACK_ALWAYS;
 508                        return 0;
 509                }
 510                git_branch_track = git_config_bool(var, value);
 511                return 0;
 512        }
 513        if (!strcmp(var, "branch.autosetuprebase")) {
 514                if (!value)
 515                        return config_error_nonbool(var);
 516                else if (!strcmp(value, "never"))
 517                        autorebase = AUTOREBASE_NEVER;
 518                else if (!strcmp(value, "local"))
 519                        autorebase = AUTOREBASE_LOCAL;
 520                else if (!strcmp(value, "remote"))
 521                        autorebase = AUTOREBASE_REMOTE;
 522                else if (!strcmp(value, "always"))
 523                        autorebase = AUTOREBASE_ALWAYS;
 524                else
 525                        return error("Malformed value for %s", var);
 526                return 0;
 527        }
 528
 529        /* Add other config variables here and to Documentation/config.txt. */
 530        return 0;
 531}
 532
 533int git_default_config(const char *var, const char *value, void *dummy)
 534{
 535        if (!prefixcmp(var, "core."))
 536                return git_default_core_config(var, value);
 537
 538        if (!prefixcmp(var, "user."))
 539                return git_default_user_config(var, value);
 540
 541        if (!prefixcmp(var, "i18n."))
 542                return git_default_i18n_config(var, value);
 543
 544        if (!prefixcmp(var, "branch."))
 545                return git_default_branch_config(var, value);
 546
 547        if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 548                pager_use_color = git_config_bool(var,value);
 549                return 0;
 550        }
 551
 552        /* Add other config variables here and to Documentation/config.txt. */
 553        return 0;
 554}
 555
 556int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 557{
 558        int ret;
 559        FILE *f = fopen(filename, "r");
 560
 561        ret = -1;
 562        if (f) {
 563                config_file = f;
 564                config_file_name = filename;
 565                config_linenr = 1;
 566                config_file_eof = 0;
 567                ret = git_parse_file(fn, data);
 568                fclose(f);
 569                config_file_name = NULL;
 570        }
 571        return ret;
 572}
 573
 574const char *git_etc_gitconfig(void)
 575{
 576        static const char *system_wide;
 577        if (!system_wide) {
 578                system_wide = ETC_GITCONFIG;
 579                if (!is_absolute_path(system_wide)) {
 580                        /* interpret path relative to exec-dir */
 581                        struct strbuf d = STRBUF_INIT;
 582                        strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
 583                        system_wide = strbuf_detach(&d, NULL);
 584                }
 585        }
 586        return system_wide;
 587}
 588
 589int git_env_bool(const char *k, int def)
 590{
 591        const char *v = getenv(k);
 592        return v ? git_config_bool(k, v) : def;
 593}
 594
 595int git_config_system(void)
 596{
 597        return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 598}
 599
 600int git_config_global(void)
 601{
 602        return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 603}
 604
 605int git_config(config_fn_t fn, void *data)
 606{
 607        int ret = 0;
 608        char *repo_config = NULL;
 609        const char *home = NULL, *filename;
 610
 611        /* $GIT_CONFIG makes git read _only_ the given config file,
 612         * $GIT_CONFIG_LOCAL will make it process it in addition to the
 613         * global config file, the same way it would the per-repository
 614         * config file otherwise. */
 615        filename = getenv(CONFIG_ENVIRONMENT);
 616        if (!filename) {
 617                if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 618                        ret += git_config_from_file(fn, git_etc_gitconfig(),
 619                                data);
 620                home = getenv("HOME");
 621                filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 622                if (!filename)
 623                        filename = repo_config = xstrdup(git_path("config"));
 624        }
 625
 626        if (git_config_global() && home) {
 627                char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 628                if (!access(user_config, R_OK))
 629                        ret = git_config_from_file(fn, user_config, data);
 630                free(user_config);
 631        }
 632
 633        ret += git_config_from_file(fn, filename, data);
 634        free(repo_config);
 635        return ret;
 636}
 637
 638/*
 639 * Find all the stuff for git_config_set() below.
 640 */
 641
 642#define MAX_MATCHES 512
 643
 644static struct {
 645        int baselen;
 646        char* key;
 647        int do_not_match;
 648        regex_t* value_regex;
 649        int multi_replace;
 650        size_t offset[MAX_MATCHES];
 651        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 652        int seen;
 653} store;
 654
 655static int matches(const char* key, const char* value)
 656{
 657        return !strcmp(key, store.key) &&
 658                (store.value_regex == NULL ||
 659                 (store.do_not_match ^
 660                  !regexec(store.value_regex, value, 0, NULL, 0)));
 661}
 662
 663static int store_aux(const char* key, const char* value, void *cb)
 664{
 665        const char *ep;
 666        size_t section_len;
 667
 668        switch (store.state) {
 669        case KEY_SEEN:
 670                if (matches(key, value)) {
 671                        if (store.seen == 1 && store.multi_replace == 0) {
 672                                warning("%s has multiple values", key);
 673                        } else if (store.seen >= MAX_MATCHES) {
 674                                error("too many matches for %s", key);
 675                                return 1;
 676                        }
 677
 678                        store.offset[store.seen] = ftell(config_file);
 679                        store.seen++;
 680                }
 681                break;
 682        case SECTION_SEEN:
 683                /*
 684                 * What we are looking for is in store.key (both
 685                 * section and var), and its section part is baselen
 686                 * long.  We found key (again, both section and var).
 687                 * We would want to know if this key is in the same
 688                 * section as what we are looking for.  We already
 689                 * know we are in the same section as what should
 690                 * hold store.key.
 691                 */
 692                ep = strrchr(key, '.');
 693                section_len = ep - key;
 694
 695                if ((section_len != store.baselen) ||
 696                    memcmp(key, store.key, section_len+1)) {
 697                        store.state = SECTION_END_SEEN;
 698                        break;
 699                }
 700
 701                /*
 702                 * Do not increment matches: this is no match, but we
 703                 * just made sure we are in the desired section.
 704                 */
 705                store.offset[store.seen] = ftell(config_file);
 706                /* fallthru */
 707        case SECTION_END_SEEN:
 708        case START:
 709                if (matches(key, value)) {
 710                        store.offset[store.seen] = ftell(config_file);
 711                        store.state = KEY_SEEN;
 712                        store.seen++;
 713                } else {
 714                        if (strrchr(key, '.') - key == store.baselen &&
 715                              !strncmp(key, store.key, store.baselen)) {
 716                                        store.state = SECTION_SEEN;
 717                                        store.offset[store.seen] = ftell(config_file);
 718                        }
 719                }
 720        }
 721        return 0;
 722}
 723
 724static int write_error(const char *filename)
 725{
 726        error("failed to write new configuration file %s", filename);
 727
 728        /* Same error code as "failed to rename". */
 729        return 4;
 730}
 731
 732static int store_write_section(int fd, const char* key)
 733{
 734        const char *dot;
 735        int i, success;
 736        struct strbuf sb;
 737
 738        strbuf_init(&sb, 0);
 739        dot = memchr(key, '.', store.baselen);
 740        if (dot) {
 741                strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 742                for (i = dot - key + 1; i < store.baselen; i++) {
 743                        if (key[i] == '"' || key[i] == '\\')
 744                                strbuf_addch(&sb, '\\');
 745                        strbuf_addch(&sb, key[i]);
 746                }
 747                strbuf_addstr(&sb, "\"]\n");
 748        } else {
 749                strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 750        }
 751
 752        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 753        strbuf_release(&sb);
 754
 755        return success;
 756}
 757
 758static int store_write_pair(int fd, const char* key, const char* value)
 759{
 760        int i, success;
 761        int length = strlen(key + store.baselen + 1);
 762        const char *quote = "";
 763        struct strbuf sb;
 764
 765        /*
 766         * Check to see if the value needs to be surrounded with a dq pair.
 767         * Note that problematic characters are always backslash-quoted; this
 768         * check is about not losing leading or trailing SP and strings that
 769         * follow beginning-of-comment characters (i.e. ';' and '#') by the
 770         * configuration parser.
 771         */
 772        if (value[0] == ' ')
 773                quote = "\"";
 774        for (i = 0; value[i]; i++)
 775                if (value[i] == ';' || value[i] == '#')
 776                        quote = "\"";
 777        if (i && value[i - 1] == ' ')
 778                quote = "\"";
 779
 780        strbuf_init(&sb, 0);
 781        strbuf_addf(&sb, "\t%.*s = %s",
 782                    length, key + store.baselen + 1, quote);
 783
 784        for (i = 0; value[i]; i++)
 785                switch (value[i]) {
 786                case '\n':
 787                        strbuf_addstr(&sb, "\\n");
 788                        break;
 789                case '\t':
 790                        strbuf_addstr(&sb, "\\t");
 791                        break;
 792                case '"':
 793                case '\\':
 794                        strbuf_addch(&sb, '\\');
 795                default:
 796                        strbuf_addch(&sb, value[i]);
 797                        break;
 798                }
 799        strbuf_addf(&sb, "%s\n", quote);
 800
 801        success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 802        strbuf_release(&sb);
 803
 804        return success;
 805}
 806
 807static ssize_t find_beginning_of_line(const char* contents, size_t size,
 808        size_t offset_, int* found_bracket)
 809{
 810        size_t equal_offset = size, bracket_offset = size;
 811        ssize_t offset;
 812
 813contline:
 814        for (offset = offset_-2; offset > 0
 815                        && contents[offset] != '\n'; offset--)
 816                switch (contents[offset]) {
 817                        case '=': equal_offset = offset; break;
 818                        case ']': bracket_offset = offset; break;
 819                }
 820        if (offset > 0 && contents[offset-1] == '\\') {
 821                offset_ = offset;
 822                goto contline;
 823        }
 824        if (bracket_offset < equal_offset) {
 825                *found_bracket = 1;
 826                offset = bracket_offset+1;
 827        } else
 828                offset++;
 829
 830        return offset;
 831}
 832
 833int git_config_set(const char* key, const char* value)
 834{
 835        return git_config_set_multivar(key, value, NULL, 0);
 836}
 837
 838/*
 839 * If value==NULL, unset in (remove from) config,
 840 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 841 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 842 *     else all matching key/values (regardless how many) are removed,
 843 *     before the new pair is written.
 844 *
 845 * Returns 0 on success.
 846 *
 847 * This function does this:
 848 *
 849 * - it locks the config file by creating ".git/config.lock"
 850 *
 851 * - it then parses the config using store_aux() as validator to find
 852 *   the position on the key/value pair to replace. If it is to be unset,
 853 *   it must be found exactly once.
 854 *
 855 * - the config file is mmap()ed and the part before the match (if any) is
 856 *   written to the lock file, then the changed part and the rest.
 857 *
 858 * - the config file is removed and the lock file rename()d to it.
 859 *
 860 */
 861int git_config_set_multivar(const char* key, const char* value,
 862        const char* value_regex, int multi_replace)
 863{
 864        int i, dot;
 865        int fd = -1, in_fd;
 866        int ret;
 867        char* config_filename;
 868        struct lock_file *lock = NULL;
 869        const char* last_dot = strrchr(key, '.');
 870
 871        config_filename = getenv(CONFIG_ENVIRONMENT);
 872        if (!config_filename) {
 873                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
 874                if (!config_filename)
 875                        config_filename  = git_path("config");
 876        }
 877        config_filename = xstrdup(config_filename);
 878
 879        /*
 880         * Since "key" actually contains the section name and the real
 881         * key name separated by a dot, we have to know where the dot is.
 882         */
 883
 884        if (last_dot == NULL) {
 885                error("key does not contain a section: %s", key);
 886                ret = 2;
 887                goto out_free;
 888        }
 889        store.baselen = last_dot - key;
 890
 891        store.multi_replace = multi_replace;
 892
 893        /*
 894         * Validate the key and while at it, lower case it for matching.
 895         */
 896        store.key = xmalloc(strlen(key) + 1);
 897        dot = 0;
 898        for (i = 0; key[i]; i++) {
 899                unsigned char c = key[i];
 900                if (c == '.')
 901                        dot = 1;
 902                /* Leave the extended basename untouched.. */
 903                if (!dot || i > store.baselen) {
 904                        if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 905                                error("invalid key: %s", key);
 906                                free(store.key);
 907                                ret = 1;
 908                                goto out_free;
 909                        }
 910                        c = tolower(c);
 911                } else if (c == '\n') {
 912                        error("invalid key (newline): %s", key);
 913                        free(store.key);
 914                        ret = 1;
 915                        goto out_free;
 916                }
 917                store.key[i] = c;
 918        }
 919        store.key[i] = 0;
 920
 921        /*
 922         * The lock serves a purpose in addition to locking: the new
 923         * contents of .git/config will be written into it.
 924         */
 925        lock = xcalloc(sizeof(struct lock_file), 1);
 926        fd = hold_lock_file_for_update(lock, config_filename, 0);
 927        if (fd < 0) {
 928                error("could not lock config file %s", config_filename);
 929                free(store.key);
 930                ret = -1;
 931                goto out_free;
 932        }
 933
 934        /*
 935         * If .git/config does not exist yet, write a minimal version.
 936         */
 937        in_fd = open(config_filename, O_RDONLY);
 938        if ( in_fd < 0 ) {
 939                free(store.key);
 940
 941                if ( ENOENT != errno ) {
 942                        error("opening %s: %s", config_filename,
 943                              strerror(errno));
 944                        ret = 3; /* same as "invalid config file" */
 945                        goto out_free;
 946                }
 947                /* if nothing to unset, error out */
 948                if (value == NULL) {
 949                        ret = 5;
 950                        goto out_free;
 951                }
 952
 953                store.key = (char*)key;
 954                if (!store_write_section(fd, key) ||
 955                    !store_write_pair(fd, key, value))
 956                        goto write_err_out;
 957        } else {
 958                struct stat st;
 959                char* contents;
 960                size_t contents_sz, copy_begin, copy_end;
 961                int i, new_line = 0;
 962
 963                if (value_regex == NULL)
 964                        store.value_regex = NULL;
 965                else {
 966                        if (value_regex[0] == '!') {
 967                                store.do_not_match = 1;
 968                                value_regex++;
 969                        } else
 970                                store.do_not_match = 0;
 971
 972                        store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 973                        if (regcomp(store.value_regex, value_regex,
 974                                        REG_EXTENDED)) {
 975                                error("invalid pattern: %s", value_regex);
 976                                free(store.value_regex);
 977                                ret = 6;
 978                                goto out_free;
 979                        }
 980                }
 981
 982                store.offset[0] = 0;
 983                store.state = START;
 984                store.seen = 0;
 985
 986                /*
 987                 * After this, store.offset will contain the *end* offset
 988                 * of the last match, or remain at 0 if no match was found.
 989                 * As a side effect, we make sure to transform only a valid
 990                 * existing config file.
 991                 */
 992                if (git_config_from_file(store_aux, config_filename, NULL)) {
 993                        error("invalid config file %s", config_filename);
 994                        free(store.key);
 995                        if (store.value_regex != NULL) {
 996                                regfree(store.value_regex);
 997                                free(store.value_regex);
 998                        }
 999                        ret = 3;
1000                        goto out_free;
1001                }
1002
1003                free(store.key);
1004                if (store.value_regex != NULL) {
1005                        regfree(store.value_regex);
1006                        free(store.value_regex);
1007                }
1008
1009                /* if nothing to unset, or too many matches, error out */
1010                if ((store.seen == 0 && value == NULL) ||
1011                                (store.seen > 1 && multi_replace == 0)) {
1012                        ret = 5;
1013                        goto out_free;
1014                }
1015
1016                fstat(in_fd, &st);
1017                contents_sz = xsize_t(st.st_size);
1018                contents = xmmap(NULL, contents_sz, PROT_READ,
1019                        MAP_PRIVATE, in_fd, 0);
1020                close(in_fd);
1021
1022                if (store.seen == 0)
1023                        store.seen = 1;
1024
1025                for (i = 0, copy_begin = 0; i < store.seen; i++) {
1026                        if (store.offset[i] == 0) {
1027                                store.offset[i] = copy_end = contents_sz;
1028                        } else if (store.state != KEY_SEEN) {
1029                                copy_end = store.offset[i];
1030                        } else
1031                                copy_end = find_beginning_of_line(
1032                                        contents, contents_sz,
1033                                        store.offset[i]-2, &new_line);
1034
1035                        if (copy_end > 0 && contents[copy_end-1] != '\n')
1036                                new_line = 1;
1037
1038                        /* write the first part of the config */
1039                        if (copy_end > copy_begin) {
1040                                if (write_in_full(fd, contents + copy_begin,
1041                                                  copy_end - copy_begin) <
1042                                    copy_end - copy_begin)
1043                                        goto write_err_out;
1044                                if (new_line &&
1045                                    write_in_full(fd, "\n", 1) != 1)
1046                                        goto write_err_out;
1047                        }
1048                        copy_begin = store.offset[i];
1049                }
1050
1051                /* write the pair (value == NULL means unset) */
1052                if (value != NULL) {
1053                        if (store.state == START) {
1054                                if (!store_write_section(fd, key))
1055                                        goto write_err_out;
1056                        }
1057                        if (!store_write_pair(fd, key, value))
1058                                goto write_err_out;
1059                }
1060
1061                /* write the rest of the config */
1062                if (copy_begin < contents_sz)
1063                        if (write_in_full(fd, contents + copy_begin,
1064                                          contents_sz - copy_begin) <
1065                            contents_sz - copy_begin)
1066                                goto write_err_out;
1067
1068                munmap(contents, contents_sz);
1069        }
1070
1071        if (commit_lock_file(lock) < 0) {
1072                error("could not commit config file %s", config_filename);
1073                ret = 4;
1074                goto out_free;
1075        }
1076
1077        /*
1078         * lock is committed, so don't try to roll it back below.
1079         * NOTE: Since lockfile.c keeps a linked list of all created
1080         * lock_file structures, it isn't safe to free(lock).  It's
1081         * better to just leave it hanging around.
1082         */
1083        lock = NULL;
1084        ret = 0;
1085
1086out_free:
1087        if (lock)
1088                rollback_lock_file(lock);
1089        free(config_filename);
1090        return ret;
1091
1092write_err_out:
1093        ret = write_error(lock->filename);
1094        goto out_free;
1095
1096}
1097
1098static int section_name_match (const char *buf, const char *name)
1099{
1100        int i = 0, j = 0, dot = 0;
1101        for (; buf[i] && buf[i] != ']'; i++) {
1102                if (!dot && isspace(buf[i])) {
1103                        dot = 1;
1104                        if (name[j++] != '.')
1105                                break;
1106                        for (i++; isspace(buf[i]); i++)
1107                                ; /* do nothing */
1108                        if (buf[i] != '"')
1109                                break;
1110                        continue;
1111                }
1112                if (buf[i] == '\\' && dot)
1113                        i++;
1114                else if (buf[i] == '"' && dot) {
1115                        for (i++; isspace(buf[i]); i++)
1116                                ; /* do_nothing */
1117                        break;
1118                }
1119                if (buf[i] != name[j++])
1120                        break;
1121        }
1122        return (buf[i] == ']' && name[j] == 0);
1123}
1124
1125/* if new_name == NULL, the section is removed instead */
1126int git_config_rename_section(const char *old_name, const char *new_name)
1127{
1128        int ret = 0, remove = 0;
1129        char *config_filename;
1130        struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1131        int out_fd;
1132        char buf[1024];
1133
1134        config_filename = getenv(CONFIG_ENVIRONMENT);
1135        if (!config_filename) {
1136                config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1137                if (!config_filename)
1138                        config_filename  = git_path("config");
1139        }
1140        config_filename = xstrdup(config_filename);
1141        out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1142        if (out_fd < 0) {
1143                ret = error("could not lock config file %s", config_filename);
1144                goto out;
1145        }
1146
1147        if (!(config_file = fopen(config_filename, "rb"))) {
1148                /* no config file means nothing to rename, no error */
1149                goto unlock_and_out;
1150        }
1151
1152        while (fgets(buf, sizeof(buf), config_file)) {
1153                int i;
1154                int length;
1155                for (i = 0; buf[i] && isspace(buf[i]); i++)
1156                        ; /* do nothing */
1157                if (buf[i] == '[') {
1158                        /* it's a section */
1159                        if (section_name_match (&buf[i+1], old_name)) {
1160                                ret++;
1161                                if (new_name == NULL) {
1162                                        remove = 1;
1163                                        continue;
1164                                }
1165                                store.baselen = strlen(new_name);
1166                                if (!store_write_section(out_fd, new_name)) {
1167                                        ret = write_error(lock->filename);
1168                                        goto out;
1169                                }
1170                                continue;
1171                        }
1172                        remove = 0;
1173                }
1174                if (remove)
1175                        continue;
1176                length = strlen(buf);
1177                if (write_in_full(out_fd, buf, length) != length) {
1178                        ret = write_error(lock->filename);
1179                        goto out;
1180                }
1181        }
1182        fclose(config_file);
1183 unlock_and_out:
1184        if (commit_lock_file(lock) < 0)
1185                ret = error("could not commit config file %s", config_filename);
1186 out:
1187        free(config_filename);
1188        return ret;
1189}
1190
1191/*
1192 * Call this to report error for your variable that should not
1193 * get a boolean value (i.e. "[my] var" means "true").
1194 */
1195int config_error_nonbool(const char *var)
1196{
1197        return error("Missing value for '%s'", var);
1198}