Andrew's git - gitweb.git/blob

0c43d7615b68cb41b60a140bdcf26559b24cc3e0
   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 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.symrefsonly")) {
 226                only_use_symrefs = git_config_bool(var, value);
 227                return 0;
 228        }
 229
 230        if (!strcmp(var, "user.name")) {
 231                strncpy(git_default_name, value, sizeof(git_default_name));
 232                return 0;
 233        }
 234
 235        if (!strcmp(var, "user.email")) {
 236                strncpy(git_default_email, value, sizeof(git_default_email));
 237                return 0;
 238        }
 239
 240        /* Add other config variables here.. */
 241        return 0;
 242}
 243
 244int git_config_from_file(config_fn_t fn, const char *filename)
 245{
 246        int ret;
 247        FILE *f = fopen(filename, "r");
 248
 249        ret = -1;
 250        if (f) {
 251                config_file = f;
 252                config_file_name = filename;
 253                config_linenr = 1;
 254                ret = git_parse_file(fn);
 255                fclose(f);
 256                config_file_name = NULL;
 257        }
 258        return ret;
 259}
 260
 261int git_config(config_fn_t fn)
 262{
 263        return git_config_from_file(fn, git_path("config"));
 264}
 265
 266/*
 267 * Find all the stuff for git_config_set() below.
 268 */
 269
 270#define MAX_MATCHES 512
 271
 272static struct {
 273        int baselen;
 274        char* key;
 275        int do_not_match;
 276        regex_t* value_regex;
 277        int multi_replace;
 278        off_t offset[MAX_MATCHES];
 279        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 280        int seen;
 281} store;
 282
 283static int matches(const char* key, const char* value)
 284{
 285        return !strcmp(key, store.key) &&
 286                (store.value_regex == NULL ||
 287                 (store.do_not_match ^
 288                  !regexec(store.value_regex, value, 0, NULL, 0)));
 289}
 290
 291static int store_aux(const char* key, const char* value)
 292{
 293        switch (store.state) {
 294        case KEY_SEEN:
 295                if (matches(key, value)) {
 296                        if (store.seen == 1 && store.multi_replace == 0) {
 297                                fprintf(stderr,
 298                                        "Warning: %s has multiple values\n",
 299                                        key);
 300                        } else if (store.seen >= MAX_MATCHES) {
 301                                fprintf(stderr, "Too many matches\n");
 302                                return 1;
 303                        }
 304
 305                        store.offset[store.seen] = ftell(config_file);
 306                        store.seen++;
 307                }
 308                break;
 309        case SECTION_SEEN:
 310                if (strncmp(key, store.key, store.baselen+1)) {
 311                        store.state = SECTION_END_SEEN;
 312                        break;
 313                } else
 314                        /* do not increment matches: this is no match */
 315                        store.offset[store.seen] = ftell(config_file);
 316                /* fallthru */
 317        case SECTION_END_SEEN:
 318        case START:
 319                if (matches(key, value)) {
 320                        store.offset[store.seen] = ftell(config_file);
 321                        store.state = KEY_SEEN;
 322                        store.seen++;
 323                } else if(!strncmp(key, store.key, store.baselen))
 324                        store.state = SECTION_SEEN;
 325        }
 326        return 0;
 327}
 328
 329static void store_write_section(int fd, const char* key)
 330{
 331        write(fd, "[", 1);
 332        write(fd, key, store.baselen);
 333        write(fd, "]\n", 2);
 334}
 335
 336static void store_write_pair(int fd, const char* key, const char* value)
 337{
 338        int i;
 339
 340        write(fd, "\t", 1);
 341        write(fd, key+store.baselen+1,
 342                strlen(key+store.baselen+1));
 343        write(fd, " = ", 3);
 344        for (i = 0; value[i]; i++)
 345                switch (value[i]) {
 346                case '\n': write(fd, "\\n", 2); break;
 347                case '\t': write(fd, "\\t", 2); break;
 348                case '"': case '\\': write(fd, "\\", 1);
 349                default: write(fd, value+i, 1);
 350        }
 351        write(fd, "\n", 1);
 352}
 353
 354static int find_beginning_of_line(const char* contents, int size,
 355        int offset_, int* found_bracket)
 356{
 357        int equal_offset = size, bracket_offset = size;
 358        int offset;
 359
 360        for (offset = offset_-2; offset > 0 
 361                        && contents[offset] != '\n'; offset--)
 362                switch (contents[offset]) {
 363                        case '=': equal_offset = offset; break;
 364                        case ']': bracket_offset = offset; break;
 365                }
 366        if (bracket_offset < equal_offset) {
 367                *found_bracket = 1;
 368                offset = bracket_offset+1;
 369        } else
 370                offset++;
 371
 372        return offset;
 373}
 374
 375int git_config_set(const char* key, const char* value)
 376{
 377        return git_config_set_multivar(key, value, NULL, 0);
 378}
 379
 380/*
 381 * If value==NULL, unset in (remove from) config,
 382 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 383 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 384 *     else all matching key/values (regardless how many) are removed,
 385 *     before the new pair is written.
 386 *
 387 * Returns 0 on success.
 388 *
 389 * This function does this:
 390 *
 391 * - it locks the config file by creating ".git/config.lock"
 392 *
 393 * - it then parses the config using store_aux() as validator to find
 394 *   the position on the key/value pair to replace. If it is to be unset,
 395 *   it must be found exactly once.
 396 *
 397 * - the config file is mmap()ed and the part before the match (if any) is
 398 *   written to the lock file, then the changed part and the rest.
 399 *
 400 * - the config file is removed and the lock file rename()d to it.
 401 *
 402 */
 403int git_config_set_multivar(const char* key, const char* value,
 404        const char* value_regex, int multi_replace)
 405{
 406        int i;
 407        struct stat st;
 408        int fd;
 409        char* config_filename = strdup(git_path("config"));
 410        char* lock_file = strdup(git_path("config.lock"));
 411        const char* last_dot = strrchr(key, '.');
 412
 413        /*
 414         * Since "key" actually contains the section name and the real
 415         * key name separated by a dot, we have to know where the dot is.
 416         */
 417
 418        if (last_dot == NULL) { 
 419                fprintf(stderr, "key does not contain a section: %s\n", key);
 420                return 2;
 421        }
 422        store.baselen = last_dot - key;
 423
 424        store.multi_replace = multi_replace;
 425
 426        /*
 427         * Validate the key and while at it, lower case it for matching.
 428         */
 429        store.key = (char*)malloc(strlen(key)+1);
 430        for (i = 0; key[i]; i++)
 431                if (i != store.baselen &&
 432                                ((!isalnum(key[i]) && key[i] != '.') ||
 433                                 (i == store.baselen+1 && !isalpha(key[i])))) {
 434                        fprintf(stderr, "invalid key: %s\n", key);
 435                        free(store.key);
 436                        return 1;
 437                } else
 438                        store.key[i] = tolower(key[i]);
 439        store.key[i] = 0;
 440
 441        /*
 442         * The lock_file serves a purpose in addition to locking: the new
 443         * contents of .git/config will be written into it.
 444         */
 445        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 446        if (fd < 0) {
 447                fprintf(stderr, "could not lock config file\n");
 448                free(store.key);
 449                return -1;
 450        }
 451
 452        /*
 453         * If .git/config does not exist yet, write a minimal version.
 454         */
 455        if (stat(config_filename, &st)) {
 456                static const char contents[] =
 457                        "#\n"
 458                        "# This is the config file\n"
 459                        "#\n"
 460                        "\n";
 461
 462                free(store.key);
 463
 464                /* if nothing to unset, error out */
 465                if (value == NULL) {
 466                        close(fd);
 467                        unlink(lock_file);
 468                        return 5;
 469                }
 470
 471                store.key = (char*)key;
 472
 473                write(fd, contents, sizeof(contents)-1);
 474                store_write_section(fd, key);
 475                store_write_pair(fd, key, value);
 476        } else{
 477                int in_fd;
 478                char* contents;
 479                int i, copy_begin, copy_end, new_line = 0;
 480
 481                if (value_regex == NULL)
 482                        store.value_regex = NULL;
 483                else {
 484                        if (value_regex[0] == '!') {
 485                                store.do_not_match = 1;
 486                                value_regex++;
 487                        } else
 488                                store.do_not_match = 0;
 489
 490                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 491                        if (regcomp(store.value_regex, value_regex,
 492                                        REG_EXTENDED)) {
 493                                fprintf(stderr, "Invalid pattern: %s",
 494                                        value_regex);
 495                                free(store.value_regex);
 496                                return 6;
 497                        }
 498                }
 499
 500                store.offset[0] = 0;
 501                store.state = START;
 502                store.seen = 0;
 503
 504                /*
 505                 * After this, store.offset will contain the *end* offset
 506                 * of the last match, or remain at 0 if no match was found.
 507                 * As a side effect, we make sure to transform only a valid
 508                 * existing config file.
 509                 */
 510                if (git_config(store_aux)) {
 511                        fprintf(stderr, "invalid config file\n");
 512                        free(store.key);
 513                        if (store.value_regex != NULL) {
 514                                regfree(store.value_regex);
 515                                free(store.value_regex);
 516                        }
 517                        return 3;
 518                }
 519
 520                free(store.key);
 521                if (store.value_regex != NULL) {
 522                        regfree(store.value_regex);
 523                        free(store.value_regex);
 524                }
 525
 526                /* if nothing to unset, or too many matches, error out */
 527                if ((store.seen == 0 && value == NULL) ||
 528                                (store.seen > 1 && multi_replace == 0)) {
 529                        close(fd);
 530                        unlink(lock_file);
 531                        return 5;
 532                }
 533
 534                in_fd = open(config_filename, O_RDONLY, 0666);
 535                contents = mmap(NULL, st.st_size, PROT_READ,
 536                        MAP_PRIVATE, in_fd, 0);
 537                close(in_fd);
 538
 539                if (store.seen == 0)
 540                        store.seen = 1;
 541
 542                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 543                        if (store.offset[i] == 0) {
 544                                store.offset[i] = copy_end = st.st_size;
 545                        } else if (store.state != KEY_SEEN) {
 546                                copy_end = store.offset[i];
 547                        } else
 548                                copy_end = find_beginning_of_line(
 549                                        contents, st.st_size,
 550                                        store.offset[i]-2, &new_line);
 551
 552                        /* write the first part of the config */
 553                        if (copy_end > copy_begin) {
 554                                write(fd, contents + copy_begin,
 555                                copy_end - copy_begin);
 556                                if (new_line)
 557                                        write(fd, "\n", 1);
 558                        }
 559                        copy_begin = store.offset[i];
 560                }
 561
 562                /* write the pair (value == NULL means unset) */
 563                if (value != NULL) {
 564                        if (store.state == START)
 565                                store_write_section(fd, key);
 566                        store_write_pair(fd, key, value);
 567                }
 568
 569                /* write the rest of the config */
 570                if (copy_begin < st.st_size)
 571                        write(fd, contents + copy_begin,
 572                                st.st_size - copy_begin);
 573
 574                munmap(contents, st.st_size);
 575                unlink(config_filename);
 576        }
 577
 578        close(fd);
 579
 580        if (rename(lock_file, config_filename) < 0) {
 581                fprintf(stderr, "Could not rename the lock file?\n");
 582                return 4;
 583        }
 584
 585        return 0;
 586}
 587
 588