config.con commit Merge branch 'jc/xsha1' (b9895c0)
   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_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.prefersymlinkrefs")) {
 231                prefer_symlink_refs = 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 and to Documentation/config.txt. */
 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 (strrchr(key, '.') - key == store.baselen &&
 339                              !strncmp(key, store.key, store.baselen)) {
 340                                        store.state = SECTION_SEEN;
 341                                        store.offset[store.seen] = ftell(config_file);
 342                }
 343        }
 344        return 0;
 345}
 346
 347static void store_write_section(int fd, const char* key)
 348{
 349        write(fd, "[", 1);
 350        write(fd, key, store.baselen);
 351        write(fd, "]\n", 2);
 352}
 353
 354static void store_write_pair(int fd, const char* key, const char* value)
 355{
 356        int i;
 357
 358        write(fd, "\t", 1);
 359        write(fd, key+store.baselen+1,
 360                strlen(key+store.baselen+1));
 361        write(fd, " = ", 3);
 362        for (i = 0; value[i]; i++)
 363                switch (value[i]) {
 364                case '\n': write(fd, "\\n", 2); break;
 365                case '\t': write(fd, "\\t", 2); break;
 366                case '"': case '\\': write(fd, "\\", 1);
 367                default: write(fd, value+i, 1);
 368        }
 369        write(fd, "\n", 1);
 370}
 371
 372static int find_beginning_of_line(const char* contents, int size,
 373        int offset_, int* found_bracket)
 374{
 375        int equal_offset = size, bracket_offset = size;
 376        int offset;
 377
 378        for (offset = offset_-2; offset > 0 
 379                        && contents[offset] != '\n'; offset--)
 380                switch (contents[offset]) {
 381                        case '=': equal_offset = offset; break;
 382                        case ']': bracket_offset = offset; break;
 383                }
 384        if (bracket_offset < equal_offset) {
 385                *found_bracket = 1;
 386                offset = bracket_offset+1;
 387        } else
 388                offset++;
 389
 390        return offset;
 391}
 392
 393int git_config_set(const char* key, const char* value)
 394{
 395        return git_config_set_multivar(key, value, NULL, 0);
 396}
 397
 398/*
 399 * If value==NULL, unset in (remove from) config,
 400 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 401 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 402 *     else all matching key/values (regardless how many) are removed,
 403 *     before the new pair is written.
 404 *
 405 * Returns 0 on success.
 406 *
 407 * This function does this:
 408 *
 409 * - it locks the config file by creating ".git/config.lock"
 410 *
 411 * - it then parses the config using store_aux() as validator to find
 412 *   the position on the key/value pair to replace. If it is to be unset,
 413 *   it must be found exactly once.
 414 *
 415 * - the config file is mmap()ed and the part before the match (if any) is
 416 *   written to the lock file, then the changed part and the rest.
 417 *
 418 * - the config file is removed and the lock file rename()d to it.
 419 *
 420 */
 421int git_config_set_multivar(const char* key, const char* value,
 422        const char* value_regex, int multi_replace)
 423{
 424        int i;
 425        int fd = -1, in_fd;
 426        int ret;
 427        char* config_filename = strdup(git_path("config"));
 428        char* lock_file = strdup(git_path("config.lock"));
 429        const char* last_dot = strrchr(key, '.');
 430
 431        /*
 432         * Since "key" actually contains the section name and the real
 433         * key name separated by a dot, we have to know where the dot is.
 434         */
 435
 436        if (last_dot == NULL) {
 437                fprintf(stderr, "key does not contain a section: %s\n", key);
 438                ret = 2;
 439                goto out_free;
 440        }
 441        store.baselen = last_dot - key;
 442
 443        store.multi_replace = multi_replace;
 444
 445        /*
 446         * Validate the key and while at it, lower case it for matching.
 447         */
 448        store.key = (char*)malloc(strlen(key)+1);
 449        for (i = 0; key[i]; i++)
 450                if (i != store.baselen &&
 451                                ((!isalnum(key[i]) && key[i] != '.') ||
 452                                 (i == store.baselen+1 && !isalpha(key[i])))) {
 453                        fprintf(stderr, "invalid key: %s\n", key);
 454                        free(store.key);
 455                        ret = 1;
 456                        goto out_free;
 457                } else
 458                        store.key[i] = tolower(key[i]);
 459        store.key[i] = 0;
 460
 461        /*
 462         * The lock_file serves a purpose in addition to locking: the new
 463         * contents of .git/config will be written into it.
 464         */
 465        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 466        if (fd < 0) {
 467                fprintf(stderr, "could not lock config file\n");
 468                free(store.key);
 469                ret = -1;
 470                goto out_free;
 471        }
 472
 473        /*
 474         * If .git/config does not exist yet, write a minimal version.
 475         */
 476        in_fd = open(config_filename, O_RDONLY);
 477        if ( in_fd < 0 ) {
 478                free(store.key);
 479
 480                if ( ENOENT != errno ) {
 481                        error("opening %s: %s", config_filename,
 482                              strerror(errno));
 483                        ret = 3; /* same as "invalid config file" */
 484                        goto out_free;
 485                }
 486                /* if nothing to unset, error out */
 487                if (value == NULL) {
 488                        ret = 5;
 489                        goto out_free;
 490                }
 491
 492                store.key = (char*)key;
 493                store_write_section(fd, key);
 494                store_write_pair(fd, key, value);
 495        } else{
 496                struct stat st;
 497                char* contents;
 498                int i, copy_begin, copy_end, new_line = 0;
 499
 500                if (value_regex == NULL)
 501                        store.value_regex = NULL;
 502                else {
 503                        if (value_regex[0] == '!') {
 504                                store.do_not_match = 1;
 505                                value_regex++;
 506                        } else
 507                                store.do_not_match = 0;
 508
 509                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 510                        if (regcomp(store.value_regex, value_regex,
 511                                        REG_EXTENDED)) {
 512                                fprintf(stderr, "Invalid pattern: %s\n",
 513                                        value_regex);
 514                                free(store.value_regex);
 515                                ret = 6;
 516                                goto out_free;
 517                        }
 518                }
 519
 520                store.offset[0] = 0;
 521                store.state = START;
 522                store.seen = 0;
 523
 524                /*
 525                 * After this, store.offset will contain the *end* offset
 526                 * of the last match, or remain at 0 if no match was found.
 527                 * As a side effect, we make sure to transform only a valid
 528                 * existing config file.
 529                 */
 530                if (git_config(store_aux)) {
 531                        fprintf(stderr, "invalid config file\n");
 532                        free(store.key);
 533                        if (store.value_regex != NULL) {
 534                                regfree(store.value_regex);
 535                                free(store.value_regex);
 536                        }
 537                        ret = 3;
 538                        goto out_free;
 539                }
 540
 541                free(store.key);
 542                if (store.value_regex != NULL) {
 543                        regfree(store.value_regex);
 544                        free(store.value_regex);
 545                }
 546
 547                /* if nothing to unset, or too many matches, error out */
 548                if ((store.seen == 0 && value == NULL) ||
 549                                (store.seen > 1 && multi_replace == 0)) {
 550                        ret = 5;
 551                        goto out_free;
 552                }
 553
 554                fstat(in_fd, &st);
 555                contents = mmap(NULL, st.st_size, PROT_READ,
 556                        MAP_PRIVATE, in_fd, 0);
 557                close(in_fd);
 558
 559                if (store.seen == 0)
 560                        store.seen = 1;
 561
 562                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 563                        if (store.offset[i] == 0) {
 564                                store.offset[i] = copy_end = st.st_size;
 565                        } else if (store.state != KEY_SEEN) {
 566                                copy_end = store.offset[i];
 567                        } else
 568                                copy_end = find_beginning_of_line(
 569                                        contents, st.st_size,
 570                                        store.offset[i]-2, &new_line);
 571
 572                        /* write the first part of the config */
 573                        if (copy_end > copy_begin) {
 574                                write(fd, contents + copy_begin,
 575                                copy_end - copy_begin);
 576                                if (new_line)
 577                                        write(fd, "\n", 1);
 578                        }
 579                        copy_begin = store.offset[i];
 580                }
 581
 582                /* write the pair (value == NULL means unset) */
 583                if (value != NULL) {
 584                        if (store.state == START)
 585                                store_write_section(fd, key);
 586                        store_write_pair(fd, key, value);
 587                }
 588
 589                /* write the rest of the config */
 590                if (copy_begin < st.st_size)
 591                        write(fd, contents + copy_begin,
 592                                st.st_size - copy_begin);
 593
 594                munmap(contents, st.st_size);
 595                unlink(config_filename);
 596        }
 597
 598        if (rename(lock_file, config_filename) < 0) {
 599                fprintf(stderr, "Could not rename the lock file?\n");
 600                ret = 4;
 601                goto out_free;
 602        }
 603
 604        ret = 0;
 605
 606out_free:
 607        if (0 <= fd)
 608                close(fd);
 609        if (config_filename)
 610                free(config_filename);
 611        if (lock_file) {
 612                unlink(lock_file);
 613                free(lock_file);
 614        }
 615        return ret;
 616}
 617
 618