Andrew's git / gitweb.git / config.c
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config.con commit Verify git-commit provides a reflog message. (9c7466f)
   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 <regex.h>
  10
  11#define MAXNAME (256)
  12
  13static FILE *config_file;
  14static const char *config_file_name;
  15static int config_linenr;
  16static int get_next_char(void)
  17{
  18        int c;
  19        FILE *f;
  20
  21        c = '\n';
  22        if ((f = config_file) != NULL) {
  23                c = fgetc(f);
  24                if (c == '\r') {
  25                        /* DOS like systems */
  26                        c = fgetc(f);
  27                        if (c != '\n') {
  28                                ungetc(c, f);
  29                                c = '\r';
  30                        }
  31                }
  32                if (c == '\n')
  33                        config_linenr++;
  34                if (c == EOF) {
  35                        config_file = NULL;
  36                        c = '\n';
  37                }
  38        }
  39        return c;
  40}
  41
  42static char *parse_value(void)
  43{
  44        static char value[1024];
  45        int quote = 0, comment = 0, len = 0, space = 0;
  46
  47        for (;;) {
  48                int c = get_next_char();
  49                if (len >= sizeof(value))
  50                        return NULL;
  51                if (c == '\n') {
  52                        if (quote)
  53                                return NULL;
  54                        value[len] = 0;
  55                        return value;
  56                }
  57                if (comment)
  58                        continue;
  59                if (isspace(c) && !quote) {
  60                        space = 1;
  61                        continue;
  62                }
  63                if (!quote) {
  64                        if (c == ';' || c == '#') {
  65                                comment = 1;
  66                                continue;
  67                        }
  68                }
  69                if (space) {
  70                        if (len)
  71                                value[len++] = ' ';
  72                        space = 0;
  73                }
  74                if (c == '\\') {
  75                        c = get_next_char();
  76                        switch (c) {
  77                        case '\n':
  78                                continue;
  79                        case 't':
  80                                c = '\t';
  81                                break;
  82                        case 'b':
  83                                c = '\b';
  84                                break;
  85                        case 'n':
  86                                c = '\n';
  87                                break;
  88                        /* Some characters escape as themselves */
  89                        case '\\': case '"':
  90                                break;
  91                        /* Reject unknown escape sequences */
  92                        default:
  93                                return NULL;
  94                        }
  95                        value[len++] = c;
  96                        continue;
  97                }
  98                if (c == '"') {
  99                        quote = 1-quote;
 100                        continue;
 101                }
 102                value[len++] = c;
 103        }
 104}
 105
 106static int get_value(config_fn_t fn, char *name, unsigned int len)
 107{
 108        int c;
 109        char *value;
 110
 111        /* Get the full name */
 112        for (;;) {
 113                c = get_next_char();
 114                if (c == EOF)
 115                        break;
 116                if (!isalnum(c))
 117                        break;
 118                name[len++] = tolower(c);
 119                if (len >= MAXNAME)
 120                        return -1;
 121        }
 122        name[len] = 0;
 123        while (c == ' ' || c == '\t')
 124                c = get_next_char();
 125
 126        value = NULL;
 127        if (c != '\n') {
 128                if (c != '=')
 129                        return -1;
 130                value = parse_value();
 131                if (!value)
 132                        return -1;
 133        }
 134        return fn(name, value);
 135}
 136
 137static int get_extended_base_var(char *name, int baselen, int c)
 138{
 139        do {
 140                if (c == '\n')
 141                        return -1;
 142                c = get_next_char();
 143        } while (isspace(c));
 144
 145        /* We require the format to be '[base "extension"]' */
 146        if (c != '"')
 147                return -1;
 148        name[baselen++] = '.';
 149
 150        for (;;) {
 151                int c = get_next_char();
 152                if (c == '\n')
 153                        return -1;
 154                if (c == '"')
 155                        break;
 156                if (c == '\\') {
 157                        c = get_next_char();
 158                        if (c == '\n')
 159                                return -1;
 160                }
 161                name[baselen++] = c;
 162                if (baselen > MAXNAME / 2)
 163                        return -1;
 164        }
 165
 166        /* Final ']' */
 167        if (get_next_char() != ']')
 168                return -1;
 169        return baselen;
 170}
 171
 172static int get_base_var(char *name)
 173{
 174        int baselen = 0;
 175
 176        for (;;) {
 177                int c = get_next_char();
 178                if (c == EOF)
 179                        return -1;
 180                if (c == ']')
 181                        return baselen;
 182                if (isspace(c))
 183                        return get_extended_base_var(name, baselen, c);
 184                if (!isalnum(c) && c != '.')
 185                        return -1;
 186                if (baselen > MAXNAME / 2)
 187                        return -1;
 188                name[baselen++] = tolower(c);
 189        }
 190}
 191
 192static int git_parse_file(config_fn_t fn)
 193{
 194        int comment = 0;
 195        int baselen = 0;
 196        static char var[MAXNAME];
 197
 198        for (;;) {
 199                int c = get_next_char();
 200                if (c == '\n') {
 201                        /* EOF? */
 202                        if (!config_file)
 203                                return 0;
 204                        comment = 0;
 205                        continue;
 206                }
 207                if (comment || isspace(c))
 208                        continue;
 209                if (c == '#' || c == ';') {
 210                        comment = 1;
 211                        continue;
 212                }
 213                if (c == '[') {
 214                        baselen = get_base_var(var);
 215                        if (baselen <= 0)
 216                                break;
 217                        var[baselen++] = '.';
 218                        var[baselen] = 0;
 219                        continue;
 220                }
 221                if (!isalpha(c))
 222                        break;
 223                var[baselen] = tolower(c);
 224                if (get_value(fn, var, baselen+1) < 0)
 225                        break;
 226        }
 227        die("bad config file line %d in %s", config_linenr, config_file_name);
 228}
 229
 230int git_config_int(const char *name, const char *value)
 231{
 232        if (value && *value) {
 233                char *end;
 234                int val = strtol(value, &end, 0);
 235                if (!*end)
 236                        return val;
 237        }
 238        die("bad config value for '%s' in %s", name, config_file_name);
 239}
 240
 241int git_config_bool(const char *name, const char *value)
 242{
 243        if (!value)
 244                return 1;
 245        if (!*value)
 246                return 0;
 247        if (!strcasecmp(value, "true"))
 248                return 1;
 249        if (!strcasecmp(value, "false"))
 250                return 0;
 251        return git_config_int(name, value) != 0;
 252}
 253
 254int git_default_config(const char *var, const char *value)
 255{
 256        /* This needs a better name */
 257        if (!strcmp(var, "core.filemode")) {
 258                trust_executable_bit = git_config_bool(var, value);
 259                return 0;
 260        }
 261
 262        if (!strcmp(var, "core.ignorestat")) {
 263                assume_unchanged = git_config_bool(var, value);
 264                return 0;
 265        }
 266
 267        if (!strcmp(var, "core.prefersymlinkrefs")) {
 268                prefer_symlink_refs = git_config_bool(var, value);
 269                return 0;
 270        }
 271
 272        if (!strcmp(var, "core.logallrefupdates")) {
 273                log_all_ref_updates = git_config_bool(var, value);
 274                return 0;
 275        }
 276
 277        if (!strcmp(var, "core.warnambiguousrefs")) {
 278                warn_ambiguous_refs = git_config_bool(var, value);
 279                return 0;
 280        }
 281
 282        if (!strcmp(var, "user.name")) {
 283                strncpy(git_default_name, value, sizeof(git_default_name));
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "user.email")) {
 288                strncpy(git_default_email, value, sizeof(git_default_email));
 289                return 0;
 290        }
 291
 292        if (!strcmp(var, "i18n.commitencoding")) {
 293                strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 294                return 0;
 295        }
 296
 297        /* Add other config variables here and to Documentation/config.txt. */
 298        return 0;
 299}
 300
 301int git_config_from_file(config_fn_t fn, const char *filename)
 302{
 303        int ret;
 304        FILE *f = fopen(filename, "r");
 305
 306        ret = -1;
 307        if (f) {
 308                config_file = f;
 309                config_file_name = filename;
 310                config_linenr = 1;
 311                ret = git_parse_file(fn);
 312                fclose(f);
 313                config_file_name = NULL;
 314        }
 315        return ret;
 316}
 317
 318int git_config(config_fn_t fn)
 319{
 320        return git_config_from_file(fn, git_path("config"));
 321}
 322
 323/*
 324 * Find all the stuff for git_config_set() below.
 325 */
 326
 327#define MAX_MATCHES 512
 328
 329static struct {
 330        int baselen;
 331        char* key;
 332        int do_not_match;
 333        regex_t* value_regex;
 334        int multi_replace;
 335        off_t offset[MAX_MATCHES];
 336        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 337        int seen;
 338} store;
 339
 340static int matches(const char* key, const char* value)
 341{
 342        return !strcmp(key, store.key) &&
 343                (store.value_regex == NULL ||
 344                 (store.do_not_match ^
 345                  !regexec(store.value_regex, value, 0, NULL, 0)));
 346}
 347
 348static int store_aux(const char* key, const char* value)
 349{
 350        switch (store.state) {
 351        case KEY_SEEN:
 352                if (matches(key, value)) {
 353                        if (store.seen == 1 && store.multi_replace == 0) {
 354                                fprintf(stderr,
 355                                        "Warning: %s has multiple values\n",
 356                                        key);
 357                        } else if (store.seen >= MAX_MATCHES) {
 358                                fprintf(stderr, "Too many matches\n");
 359                                return 1;
 360                        }
 361
 362                        store.offset[store.seen] = ftell(config_file);
 363                        store.seen++;
 364                }
 365                break;
 366        case SECTION_SEEN:
 367                if (strncmp(key, store.key, store.baselen+1)) {
 368                        store.state = SECTION_END_SEEN;
 369                        break;
 370                } else
 371                        /* do not increment matches: this is no match */
 372                        store.offset[store.seen] = ftell(config_file);
 373                /* fallthru */
 374        case SECTION_END_SEEN:
 375        case START:
 376                if (matches(key, value)) {
 377                        store.offset[store.seen] = ftell(config_file);
 378                        store.state = KEY_SEEN;
 379                        store.seen++;
 380                } else {
 381                        if (strrchr(key, '.') - key == store.baselen &&
 382                              !strncmp(key, store.key, store.baselen)) {
 383                                        store.state = SECTION_SEEN;
 384                                        store.offset[store.seen] = ftell(config_file);
 385                        }
 386                }
 387        }
 388        return 0;
 389}
 390
 391static void store_write_section(int fd, const char* key)
 392{
 393        const char *dot = strchr(key, '.');
 394        int len1 = store.baselen, len2 = -1;
 395
 396        dot = strchr(key, '.');
 397        if (dot) {
 398                int dotlen = dot - key;
 399                if (dotlen < len1) {
 400                        len2 = len1 - dotlen - 1;
 401                        len1 = dotlen;
 402                }
 403        }
 404
 405        write(fd, "[", 1);
 406        write(fd, key, len1);
 407        if (len2 >= 0) {
 408                write(fd, " \"", 2);
 409                while (--len2 >= 0) {
 410                        unsigned char c = *++dot;
 411                        if (c == '"')
 412                                write(fd, "\\", 1);
 413                        write(fd, &c, 1);
 414                }
 415                write(fd, "\"", 1);
 416        }
 417        write(fd, "]\n", 2);
 418}
 419
 420static void store_write_pair(int fd, const char* key, const char* value)
 421{
 422        int i;
 423
 424        write(fd, "\t", 1);
 425        write(fd, key+store.baselen+1,
 426                strlen(key+store.baselen+1));
 427        write(fd, " = ", 3);
 428        for (i = 0; value[i]; i++)
 429                switch (value[i]) {
 430                case '\n': write(fd, "\\n", 2); break;
 431                case '\t': write(fd, "\\t", 2); break;
 432                case '"': case '\\': write(fd, "\\", 1);
 433                default: write(fd, value+i, 1);
 434        }
 435        write(fd, "\n", 1);
 436}
 437
 438static int find_beginning_of_line(const char* contents, int size,
 439        int offset_, int* found_bracket)
 440{
 441        int equal_offset = size, bracket_offset = size;
 442        int offset;
 443
 444        for (offset = offset_-2; offset > 0 
 445                        && contents[offset] != '\n'; offset--)
 446                switch (contents[offset]) {
 447                        case '=': equal_offset = offset; break;
 448                        case ']': bracket_offset = offset; break;
 449                }
 450        if (bracket_offset < equal_offset) {
 451                *found_bracket = 1;
 452                offset = bracket_offset+1;
 453        } else
 454                offset++;
 455
 456        return offset;
 457}
 458
 459int git_config_set(const char* key, const char* value)
 460{
 461        return git_config_set_multivar(key, value, NULL, 0);
 462}
 463
 464/*
 465 * If value==NULL, unset in (remove from) config,
 466 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 467 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 468 *     else all matching key/values (regardless how many) are removed,
 469 *     before the new pair is written.
 470 *
 471 * Returns 0 on success.
 472 *
 473 * This function does this:
 474 *
 475 * - it locks the config file by creating ".git/config.lock"
 476 *
 477 * - it then parses the config using store_aux() as validator to find
 478 *   the position on the key/value pair to replace. If it is to be unset,
 479 *   it must be found exactly once.
 480 *
 481 * - the config file is mmap()ed and the part before the match (if any) is
 482 *   written to the lock file, then the changed part and the rest.
 483 *
 484 * - the config file is removed and the lock file rename()d to it.
 485 *
 486 */
 487int git_config_set_multivar(const char* key, const char* value,
 488        const char* value_regex, int multi_replace)
 489{
 490        int i, dot;
 491        int fd = -1, in_fd;
 492        int ret;
 493        char* config_filename = strdup(git_path("config"));
 494        char* lock_file = strdup(git_path("config.lock"));
 495        const char* last_dot = strrchr(key, '.');
 496
 497        /*
 498         * Since "key" actually contains the section name and the real
 499         * key name separated by a dot, we have to know where the dot is.
 500         */
 501
 502        if (last_dot == NULL) {
 503                fprintf(stderr, "key does not contain a section: %s\n", key);
 504                ret = 2;
 505                goto out_free;
 506        }
 507        store.baselen = last_dot - key;
 508
 509        store.multi_replace = multi_replace;
 510
 511        /*
 512         * Validate the key and while at it, lower case it for matching.
 513         */
 514        store.key = (char*)malloc(strlen(key)+1);
 515        dot = 0;
 516        for (i = 0; key[i]; i++) {
 517                unsigned char c = key[i];
 518                if (c == '.')
 519                        dot = 1;
 520                /* Leave the extended basename untouched.. */
 521                if (!dot || i > store.baselen) {
 522                        if (!isalnum(c) || (i == store.baselen+1 && !isalpha(c))) {
 523                                fprintf(stderr, "invalid key: %s\n", key);
 524                                free(store.key);
 525                                ret = 1;
 526                                goto out_free;
 527                        }
 528                        c = tolower(c);
 529                }
 530                store.key[i] = c;
 531        }
 532        store.key[i] = 0;
 533
 534        /*
 535         * The lock_file serves a purpose in addition to locking: the new
 536         * contents of .git/config will be written into it.
 537         */
 538        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 539        if (fd < 0) {
 540                fprintf(stderr, "could not lock config file\n");
 541                free(store.key);
 542                ret = -1;
 543                goto out_free;
 544        }
 545
 546        /*
 547         * If .git/config does not exist yet, write a minimal version.
 548         */
 549        in_fd = open(config_filename, O_RDONLY);
 550        if ( in_fd < 0 ) {
 551                free(store.key);
 552
 553                if ( ENOENT != errno ) {
 554                        error("opening %s: %s", config_filename,
 555                              strerror(errno));
 556                        ret = 3; /* same as "invalid config file" */
 557                        goto out_free;
 558                }
 559                /* if nothing to unset, error out */
 560                if (value == NULL) {
 561                        ret = 5;
 562                        goto out_free;
 563                }
 564
 565                store.key = (char*)key;
 566                store_write_section(fd, key);
 567                store_write_pair(fd, key, value);
 568        } else{
 569                struct stat st;
 570                char* contents;
 571                int i, copy_begin, copy_end, new_line = 0;
 572
 573                if (value_regex == NULL)
 574                        store.value_regex = NULL;
 575                else {
 576                        if (value_regex[0] == '!') {
 577                                store.do_not_match = 1;
 578                                value_regex++;
 579                        } else
 580                                store.do_not_match = 0;
 581
 582                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 583                        if (regcomp(store.value_regex, value_regex,
 584                                        REG_EXTENDED)) {
 585                                fprintf(stderr, "Invalid pattern: %s\n",
 586                                        value_regex);
 587                                free(store.value_regex);
 588                                ret = 6;
 589                                goto out_free;
 590                        }
 591                }
 592
 593                store.offset[0] = 0;
 594                store.state = START;
 595                store.seen = 0;
 596
 597                /*
 598                 * After this, store.offset will contain the *end* offset
 599                 * of the last match, or remain at 0 if no match was found.
 600                 * As a side effect, we make sure to transform only a valid
 601                 * existing config file.
 602                 */
 603                if (git_config(store_aux)) {
 604                        fprintf(stderr, "invalid config file\n");
 605                        free(store.key);
 606                        if (store.value_regex != NULL) {
 607                                regfree(store.value_regex);
 608                                free(store.value_regex);
 609                        }
 610                        ret = 3;
 611                        goto out_free;
 612                }
 613
 614                free(store.key);
 615                if (store.value_regex != NULL) {
 616                        regfree(store.value_regex);
 617                        free(store.value_regex);
 618                }
 619
 620                /* if nothing to unset, or too many matches, error out */
 621                if ((store.seen == 0 && value == NULL) ||
 622                                (store.seen > 1 && multi_replace == 0)) {
 623                        ret = 5;
 624                        goto out_free;
 625                }
 626
 627                fstat(in_fd, &st);
 628                contents = mmap(NULL, st.st_size, PROT_READ,
 629                        MAP_PRIVATE, in_fd, 0);
 630                close(in_fd);
 631
 632                if (store.seen == 0)
 633                        store.seen = 1;
 634
 635                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 636                        if (store.offset[i] == 0) {
 637                                store.offset[i] = copy_end = st.st_size;
 638                        } else if (store.state != KEY_SEEN) {
 639                                copy_end = store.offset[i];
 640                        } else
 641                                copy_end = find_beginning_of_line(
 642                                        contents, st.st_size,
 643                                        store.offset[i]-2, &new_line);
 644
 645                        /* write the first part of the config */
 646                        if (copy_end > copy_begin) {
 647                                write(fd, contents + copy_begin,
 648                                copy_end - copy_begin);
 649                                if (new_line)
 650                                        write(fd, "\n", 1);
 651                        }
 652                        copy_begin = store.offset[i];
 653                }
 654
 655                /* write the pair (value == NULL means unset) */
 656                if (value != NULL) {
 657                        if (store.state == START)
 658                                store_write_section(fd, key);
 659                        store_write_pair(fd, key, value);
 660                }
 661
 662                /* write the rest of the config */
 663                if (copy_begin < st.st_size)
 664                        write(fd, contents + copy_begin,
 665                                st.st_size - copy_begin);
 666
 667                munmap(contents, st.st_size);
 668                unlink(config_filename);
 669        }
 670
 671        if (rename(lock_file, config_filename) < 0) {
 672                fprintf(stderr, "Could not rename the lock file?\n");
 673                ret = 4;
 674                goto out_free;
 675        }
 676
 677        ret = 0;
 678
 679out_free:
 680        if (0 <= fd)
 681                close(fd);
 682        if (config_filename)
 683                free(config_filename);
 684        if (lock_file) {
 685                unlink(lock_file);
 686                free(lock_file);
 687        }
 688        return ret;
 689}
 690
 691