Andrew's git / gitweb.git / config.c
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config.con commit Merge branch 'jc/cache-tree' into next (dc844aa)
   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 (space) {
  64                        if (len)
  65                                value[len++] = ' ';
  66                        space = 0;
  67                }
  68                if (c == '\\') {
  69                        c = get_next_char();
  70                        switch (c) {
  71                        case '\n':
  72                                continue;
  73                        case 't':
  74                                c = '\t';
  75                                break;
  76                        case 'b':
  77                                c = '\b';
  78                                break;
  79                        case 'n':
  80                                c = '\n';
  81                                break;
  82                        /* Some characters escape as themselves */
  83                        case '\\': case '"':
  84                                break;
  85                        /* Reject unknown escape sequences */
  86                        default:
  87                                return NULL;
  88                        }
  89                        value[len++] = c;
  90                        continue;
  91                }
  92                if (c == '"') {
  93                        quote = 1-quote;
  94                        continue;
  95                }
  96                if (!quote) {
  97                        if (c == ';' || c == '#') {
  98                                comment = 1;
  99                                continue;
 100                        }
 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_base_var(char *name)
 138{
 139        int baselen = 0;
 140
 141        for (;;) {
 142                int c = get_next_char();
 143                if (c == EOF)
 144                        return -1;
 145                if (c == ']')
 146                        return baselen;
 147                if (!isalnum(c) && c != '.')
 148                        return -1;
 149                if (baselen > MAXNAME / 2)
 150                        return -1;
 151                name[baselen++] = tolower(c);
 152        }
 153}
 154
 155static int git_parse_file(config_fn_t fn)
 156{
 157        int comment = 0;
 158        int baselen = 0;
 159        static char var[MAXNAME];
 160
 161        for (;;) {
 162                int c = get_next_char();
 163                if (c == '\n') {
 164                        /* EOF? */
 165                        if (!config_file)
 166                                return 0;
 167                        comment = 0;
 168                        continue;
 169                }
 170                if (comment || isspace(c))
 171                        continue;
 172                if (c == '#' || c == ';') {
 173                        comment = 1;
 174                        continue;
 175                }
 176                if (c == '[') {
 177                        baselen = get_base_var(var);
 178                        if (baselen <= 0)
 179                                break;
 180                        var[baselen++] = '.';
 181                        var[baselen] = 0;
 182                        continue;
 183                }
 184                if (!isalpha(c))
 185                        break;
 186                var[baselen] = tolower(c);
 187                if (get_value(fn, var, baselen+1) < 0)
 188                        break;
 189        }
 190        die("bad config file line %d in %s", config_linenr, config_file_name);
 191}
 192
 193int git_config_int(const char *name, const char *value)
 194{
 195        if (value && *value) {
 196                char *end;
 197                int val = strtol(value, &end, 0);
 198                if (!*end)
 199                        return val;
 200        }
 201        die("bad config value for '%s' in %s", name, config_file_name);
 202}
 203
 204int git_config_bool(const char *name, const char *value)
 205{
 206        if (!value)
 207                return 1;
 208        if (!*value)
 209                return 0;
 210        if (!strcasecmp(value, "true"))
 211                return 1;
 212        if (!strcasecmp(value, "false"))
 213                return 0;
 214        return git_config_int(name, value) != 0;
 215}
 216
 217int git_default_config(const char *var, const char *value)
 218{
 219        /* This needs a better name */
 220        if (!strcmp(var, "core.filemode")) {
 221                trust_executable_bit = git_config_bool(var, value);
 222                return 0;
 223        }
 224
 225        if (!strcmp(var, "core.ignorestat")) {
 226                assume_unchanged = git_config_bool(var, value);
 227                return 0;
 228        }
 229
 230        if (!strcmp(var, "core.symrefsonly")) {
 231                only_use_symrefs = git_config_bool(var, value);
 232                return 0;
 233        }
 234
 235        if (!strcmp(var, "core.warnambiguousrefs")) {
 236                warn_ambiguous_refs = git_config_bool(var, value);
 237                return 0;
 238        }
 239
 240        if (!strcmp(var, "user.name")) {
 241                strncpy(git_default_name, value, sizeof(git_default_name));
 242                return 0;
 243        }
 244
 245        if (!strcmp(var, "user.email")) {
 246                strncpy(git_default_email, value, sizeof(git_default_email));
 247                return 0;
 248        }
 249
 250        if (!strcmp(var, "i18n.commitencoding")) {
 251                strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 252                return 0;
 253        }
 254
 255        /* Add other config variables here.. */
 256        return 0;
 257}
 258
 259int git_config_from_file(config_fn_t fn, const char *filename)
 260{
 261        int ret;
 262        FILE *f = fopen(filename, "r");
 263
 264        ret = -1;
 265        if (f) {
 266                config_file = f;
 267                config_file_name = filename;
 268                config_linenr = 1;
 269                ret = git_parse_file(fn);
 270                fclose(f);
 271                config_file_name = NULL;
 272        }
 273        return ret;
 274}
 275
 276int git_config(config_fn_t fn)
 277{
 278        return git_config_from_file(fn, git_path("config"));
 279}
 280
 281/*
 282 * Find all the stuff for git_config_set() below.
 283 */
 284
 285#define MAX_MATCHES 512
 286
 287static struct {
 288        int baselen;
 289        char* key;
 290        int do_not_match;
 291        regex_t* value_regex;
 292        int multi_replace;
 293        off_t offset[MAX_MATCHES];
 294        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 295        int seen;
 296} store;
 297
 298static int matches(const char* key, const char* value)
 299{
 300        return !strcmp(key, store.key) &&
 301                (store.value_regex == NULL ||
 302                 (store.do_not_match ^
 303                  !regexec(store.value_regex, value, 0, NULL, 0)));
 304}
 305
 306static int store_aux(const char* key, const char* value)
 307{
 308        switch (store.state) {
 309        case KEY_SEEN:
 310                if (matches(key, value)) {
 311                        if (store.seen == 1 && store.multi_replace == 0) {
 312                                fprintf(stderr,
 313                                        "Warning: %s has multiple values\n",
 314                                        key);
 315                        } else if (store.seen >= MAX_MATCHES) {
 316                                fprintf(stderr, "Too many matches\n");
 317                                return 1;
 318                        }
 319
 320                        store.offset[store.seen] = ftell(config_file);
 321                        store.seen++;
 322                }
 323                break;
 324        case SECTION_SEEN:
 325                if (strncmp(key, store.key, store.baselen+1)) {
 326                        store.state = SECTION_END_SEEN;
 327                        break;
 328                } else
 329                        /* do not increment matches: this is no match */
 330                        store.offset[store.seen] = ftell(config_file);
 331                /* fallthru */
 332        case SECTION_END_SEEN:
 333        case START:
 334                if (matches(key, value)) {
 335                        store.offset[store.seen] = ftell(config_file);
 336                        store.state = KEY_SEEN;
 337                        store.seen++;
 338                } else if(!strncmp(key, store.key, store.baselen))
 339                        store.state = SECTION_SEEN;
 340        }
 341        return 0;
 342}
 343
 344static void store_write_section(int fd, const char* key)
 345{
 346        write(fd, "[", 1);
 347        write(fd, key, store.baselen);
 348        write(fd, "]\n", 2);
 349}
 350
 351static void store_write_pair(int fd, const char* key, const char* value)
 352{
 353        int i;
 354
 355        write(fd, "\t", 1);
 356        write(fd, key+store.baselen+1,
 357                strlen(key+store.baselen+1));
 358        write(fd, " = ", 3);
 359        for (i = 0; value[i]; i++)
 360                switch (value[i]) {
 361                case '\n': write(fd, "\\n", 2); break;
 362                case '\t': write(fd, "\\t", 2); break;
 363                case '"': case '\\': write(fd, "\\", 1);
 364                default: write(fd, value+i, 1);
 365        }
 366        write(fd, "\n", 1);
 367}
 368
 369static int find_beginning_of_line(const char* contents, int size,
 370        int offset_, int* found_bracket)
 371{
 372        int equal_offset = size, bracket_offset = size;
 373        int offset;
 374
 375        for (offset = offset_-2; offset > 0 
 376                        && contents[offset] != '\n'; offset--)
 377                switch (contents[offset]) {
 378                        case '=': equal_offset = offset; break;
 379                        case ']': bracket_offset = offset; break;
 380                }
 381        if (bracket_offset < equal_offset) {
 382                *found_bracket = 1;
 383                offset = bracket_offset+1;
 384        } else
 385                offset++;
 386
 387        return offset;
 388}
 389
 390int git_config_set(const char* key, const char* value)
 391{
 392        return git_config_set_multivar(key, value, NULL, 0);
 393}
 394
 395/*
 396 * If value==NULL, unset in (remove from) config,
 397 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 398 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 399 *     else all matching key/values (regardless how many) are removed,
 400 *     before the new pair is written.
 401 *
 402 * Returns 0 on success.
 403 *
 404 * This function does this:
 405 *
 406 * - it locks the config file by creating ".git/config.lock"
 407 *
 408 * - it then parses the config using store_aux() as validator to find
 409 *   the position on the key/value pair to replace. If it is to be unset,
 410 *   it must be found exactly once.
 411 *
 412 * - the config file is mmap()ed and the part before the match (if any) is
 413 *   written to the lock file, then the changed part and the rest.
 414 *
 415 * - the config file is removed and the lock file rename()d to it.
 416 *
 417 */
 418int git_config_set_multivar(const char* key, const char* value,
 419        const char* value_regex, int multi_replace)
 420{
 421        int i;
 422        int fd, in_fd;
 423        int ret;
 424        char* config_filename = strdup(git_path("config"));
 425        char* lock_file = strdup(git_path("config.lock"));
 426        const char* last_dot = strrchr(key, '.');
 427
 428        /*
 429         * Since "key" actually contains the section name and the real
 430         * key name separated by a dot, we have to know where the dot is.
 431         */
 432
 433        if (last_dot == NULL) {
 434                fprintf(stderr, "key does not contain a section: %s\n", key);
 435                ret = 2;
 436                goto out_free;
 437        }
 438        store.baselen = last_dot - key;
 439
 440        store.multi_replace = multi_replace;
 441
 442        /*
 443         * Validate the key and while at it, lower case it for matching.
 444         */
 445        store.key = (char*)malloc(strlen(key)+1);
 446        for (i = 0; key[i]; i++)
 447                if (i != store.baselen &&
 448                                ((!isalnum(key[i]) && key[i] != '.') ||
 449                                 (i == store.baselen+1 && !isalpha(key[i])))) {
 450                        fprintf(stderr, "invalid key: %s\n", key);
 451                        free(store.key);
 452                        ret = 1;
 453                        goto out_free;
 454                } else
 455                        store.key[i] = tolower(key[i]);
 456        store.key[i] = 0;
 457
 458        /*
 459         * The lock_file serves a purpose in addition to locking: the new
 460         * contents of .git/config will be written into it.
 461         */
 462        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 463        if (fd < 0) {
 464                fprintf(stderr, "could not lock config file\n");
 465                free(store.key);
 466                ret = -1;
 467                goto out_free;
 468        }
 469
 470        /*
 471         * If .git/config does not exist yet, write a minimal version.
 472         */
 473        in_fd = open(config_filename, O_RDONLY);
 474        if ( in_fd < 0 ) {
 475                free(store.key);
 476
 477                if ( ENOENT != errno ) {
 478                        error("opening %s: %s", config_filename,
 479                              strerror(errno));
 480                        close(fd);
 481                        unlink(lock_file);
 482                        ret = 3; /* same as "invalid config file" */
 483                        goto out_free;
 484                }
 485                /* if nothing to unset, error out */
 486                if (value == NULL) {
 487                        close(fd);
 488                        unlink(lock_file);
 489                        ret = 5;
 490                        goto out_free;
 491                }
 492
 493                store.key = (char*)key;
 494                store_write_section(fd, key);
 495                store_write_pair(fd, key, value);
 496        } else{
 497                struct stat st;
 498                char* contents;
 499                int i, copy_begin, copy_end, new_line = 0;
 500
 501                if (value_regex == NULL)
 502                        store.value_regex = NULL;
 503                else {
 504                        if (value_regex[0] == '!') {
 505                                store.do_not_match = 1;
 506                                value_regex++;
 507                        } else
 508                                store.do_not_match = 0;
 509
 510                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 511                        if (regcomp(store.value_regex, value_regex,
 512                                        REG_EXTENDED)) {
 513                                fprintf(stderr, "Invalid pattern: %s\n",
 514                                        value_regex);
 515                                free(store.value_regex);
 516                                ret = 6;
 517                                goto out_free;
 518                        }
 519                }
 520
 521                store.offset[0] = 0;
 522                store.state = START;
 523                store.seen = 0;
 524
 525                /*
 526                 * After this, store.offset will contain the *end* offset
 527                 * of the last match, or remain at 0 if no match was found.
 528                 * As a side effect, we make sure to transform only a valid
 529                 * existing config file.
 530                 */
 531                if (git_config(store_aux)) {
 532                        fprintf(stderr, "invalid config file\n");
 533                        free(store.key);
 534                        if (store.value_regex != NULL) {
 535                                regfree(store.value_regex);
 536                                free(store.value_regex);
 537                        }
 538                        ret = 3;
 539                        goto out_free;
 540                }
 541
 542                free(store.key);
 543                if (store.value_regex != NULL) {
 544                        regfree(store.value_regex);
 545                        free(store.value_regex);
 546                }
 547
 548                /* if nothing to unset, or too many matches, error out */
 549                if ((store.seen == 0 && value == NULL) ||
 550                                (store.seen > 1 && multi_replace == 0)) {
 551                        close(fd);
 552                        unlink(lock_file);
 553                        ret = 5;
 554                        goto out_free;
 555                }
 556
 557                fstat(in_fd, &st);
 558                contents = mmap(NULL, st.st_size, PROT_READ,
 559                        MAP_PRIVATE, in_fd, 0);
 560                close(in_fd);
 561
 562                if (store.seen == 0)
 563                        store.seen = 1;
 564
 565                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 566                        if (store.offset[i] == 0) {
 567                                store.offset[i] = copy_end = st.st_size;
 568                        } else if (store.state != KEY_SEEN) {
 569                                copy_end = store.offset[i];
 570                        } else
 571                                copy_end = find_beginning_of_line(
 572                                        contents, st.st_size,
 573                                        store.offset[i]-2, &new_line);
 574
 575                        /* write the first part of the config */
 576                        if (copy_end > copy_begin) {
 577                                write(fd, contents + copy_begin,
 578                                copy_end - copy_begin);
 579                                if (new_line)
 580                                        write(fd, "\n", 1);
 581                        }
 582                        copy_begin = store.offset[i];
 583                }
 584
 585                /* write the pair (value == NULL means unset) */
 586                if (value != NULL) {
 587                        if (store.state == START)
 588                                store_write_section(fd, key);
 589                        store_write_pair(fd, key, value);
 590                }
 591
 592                /* write the rest of the config */
 593                if (copy_begin < st.st_size)
 594                        write(fd, contents + copy_begin,
 595                                st.st_size - copy_begin);
 596
 597                munmap(contents, st.st_size);
 598                unlink(config_filename);
 599        }
 600
 601        close(fd);
 602
 603        if (rename(lock_file, config_filename) < 0) {
 604                fprintf(stderr, "Could not rename the lock file?\n");
 605                ret = 4;
 606                goto out_free;
 607        }
 608
 609        ret = 0;
 610
 611out_free:
 612        if (config_filename)
 613                free(config_filename);
 614        if (lock_file)
 615                free(lock_file);
 616        return ret;
 617}
 618
 619