Andrew's git / gitweb.git / config.c
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config.con commit Format tweaks for asciidoc. (b0d08a5)
   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, "user.name")) {
 236                strncpy(git_default_name, value, sizeof(git_default_name));
 237                return 0;
 238        }
 239
 240        if (!strcmp(var, "user.email")) {
 241                strncpy(git_default_email, value, sizeof(git_default_email));
 242                return 0;
 243        }
 244
 245        if (!strcmp(var, "i18n.commitencoding")) {
 246                strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 247                return 0;
 248        }
 249
 250        /* Add other config variables here.. */
 251        return 0;
 252}
 253
 254int git_config_from_file(config_fn_t fn, const char *filename)
 255{
 256        int ret;
 257        FILE *f = fopen(filename, "r");
 258
 259        ret = -1;
 260        if (f) {
 261                config_file = f;
 262                config_file_name = filename;
 263                config_linenr = 1;
 264                ret = git_parse_file(fn);
 265                fclose(f);
 266                config_file_name = NULL;
 267        }
 268        return ret;
 269}
 270
 271int git_config(config_fn_t fn)
 272{
 273        return git_config_from_file(fn, git_path("config"));
 274}
 275
 276/*
 277 * Find all the stuff for git_config_set() below.
 278 */
 279
 280#define MAX_MATCHES 512
 281
 282static struct {
 283        int baselen;
 284        char* key;
 285        int do_not_match;
 286        regex_t* value_regex;
 287        int multi_replace;
 288        off_t offset[MAX_MATCHES];
 289        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 290        int seen;
 291} store;
 292
 293static int matches(const char* key, const char* value)
 294{
 295        return !strcmp(key, store.key) &&
 296                (store.value_regex == NULL ||
 297                 (store.do_not_match ^
 298                  !regexec(store.value_regex, value, 0, NULL, 0)));
 299}
 300
 301static int store_aux(const char* key, const char* value)
 302{
 303        switch (store.state) {
 304        case KEY_SEEN:
 305                if (matches(key, value)) {
 306                        if (store.seen == 1 && store.multi_replace == 0) {
 307                                fprintf(stderr,
 308                                        "Warning: %s has multiple values\n",
 309                                        key);
 310                        } else if (store.seen >= MAX_MATCHES) {
 311                                fprintf(stderr, "Too many matches\n");
 312                                return 1;
 313                        }
 314
 315                        store.offset[store.seen] = ftell(config_file);
 316                        store.seen++;
 317                }
 318                break;
 319        case SECTION_SEEN:
 320                if (strncmp(key, store.key, store.baselen+1)) {
 321                        store.state = SECTION_END_SEEN;
 322                        break;
 323                } else
 324                        /* do not increment matches: this is no match */
 325                        store.offset[store.seen] = ftell(config_file);
 326                /* fallthru */
 327        case SECTION_END_SEEN:
 328        case START:
 329                if (matches(key, value)) {
 330                        store.offset[store.seen] = ftell(config_file);
 331                        store.state = KEY_SEEN;
 332                        store.seen++;
 333                } else if(!strncmp(key, store.key, store.baselen))
 334                        store.state = SECTION_SEEN;
 335        }
 336        return 0;
 337}
 338
 339static void store_write_section(int fd, const char* key)
 340{
 341        write(fd, "[", 1);
 342        write(fd, key, store.baselen);
 343        write(fd, "]\n", 2);
 344}
 345
 346static void store_write_pair(int fd, const char* key, const char* value)
 347{
 348        int i;
 349
 350        write(fd, "\t", 1);
 351        write(fd, key+store.baselen+1,
 352                strlen(key+store.baselen+1));
 353        write(fd, " = ", 3);
 354        for (i = 0; value[i]; i++)
 355                switch (value[i]) {
 356                case '\n': write(fd, "\\n", 2); break;
 357                case '\t': write(fd, "\\t", 2); break;
 358                case '"': case '\\': write(fd, "\\", 1);
 359                default: write(fd, value+i, 1);
 360        }
 361        write(fd, "\n", 1);
 362}
 363
 364static int find_beginning_of_line(const char* contents, int size,
 365        int offset_, int* found_bracket)
 366{
 367        int equal_offset = size, bracket_offset = size;
 368        int offset;
 369
 370        for (offset = offset_-2; offset > 0 
 371                        && contents[offset] != '\n'; offset--)
 372                switch (contents[offset]) {
 373                        case '=': equal_offset = offset; break;
 374                        case ']': bracket_offset = offset; break;
 375                }
 376        if (bracket_offset < equal_offset) {
 377                *found_bracket = 1;
 378                offset = bracket_offset+1;
 379        } else
 380                offset++;
 381
 382        return offset;
 383}
 384
 385int git_config_set(const char* key, const char* value)
 386{
 387        return git_config_set_multivar(key, value, NULL, 0);
 388}
 389
 390/*
 391 * If value==NULL, unset in (remove from) config,
 392 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 393 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 394 *     else all matching key/values (regardless how many) are removed,
 395 *     before the new pair is written.
 396 *
 397 * Returns 0 on success.
 398 *
 399 * This function does this:
 400 *
 401 * - it locks the config file by creating ".git/config.lock"
 402 *
 403 * - it then parses the config using store_aux() as validator to find
 404 *   the position on the key/value pair to replace. If it is to be unset,
 405 *   it must be found exactly once.
 406 *
 407 * - the config file is mmap()ed and the part before the match (if any) is
 408 *   written to the lock file, then the changed part and the rest.
 409 *
 410 * - the config file is removed and the lock file rename()d to it.
 411 *
 412 */
 413int git_config_set_multivar(const char* key, const char* value,
 414        const char* value_regex, int multi_replace)
 415{
 416        int i;
 417        int fd, in_fd;
 418        char* config_filename = strdup(git_path("config"));
 419        char* lock_file = strdup(git_path("config.lock"));
 420        const char* last_dot = strrchr(key, '.');
 421
 422        /*
 423         * Since "key" actually contains the section name and the real
 424         * key name separated by a dot, we have to know where the dot is.
 425         */
 426
 427        if (last_dot == NULL) { 
 428                fprintf(stderr, "key does not contain a section: %s\n", key);
 429                return 2;
 430        }
 431        store.baselen = last_dot - key;
 432
 433        store.multi_replace = multi_replace;
 434
 435        /*
 436         * Validate the key and while at it, lower case it for matching.
 437         */
 438        store.key = (char*)malloc(strlen(key)+1);
 439        for (i = 0; key[i]; i++)
 440                if (i != store.baselen &&
 441                                ((!isalnum(key[i]) && key[i] != '.') ||
 442                                 (i == store.baselen+1 && !isalpha(key[i])))) {
 443                        fprintf(stderr, "invalid key: %s\n", key);
 444                        free(store.key);
 445                        return 1;
 446                } else
 447                        store.key[i] = tolower(key[i]);
 448        store.key[i] = 0;
 449
 450        /*
 451         * The lock_file serves a purpose in addition to locking: the new
 452         * contents of .git/config will be written into it.
 453         */
 454        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 455        if (fd < 0) {
 456                fprintf(stderr, "could not lock config file\n");
 457                free(store.key);
 458                return -1;
 459        }
 460
 461        /*
 462         * If .git/config does not exist yet, write a minimal version.
 463         */
 464        in_fd = open(config_filename, O_RDONLY);
 465        if ( in_fd < 0 ) {
 466                free(store.key);
 467
 468                if ( ENOENT != errno ) {
 469                        error("opening %s: %s", config_filename,
 470                              strerror(errno));
 471                        close(fd);
 472                        unlink(lock_file);
 473                        return 3; /* same as "invalid config file" */
 474                }
 475                /* if nothing to unset, error out */
 476                if (value == NULL) {
 477                        close(fd);
 478                        unlink(lock_file);
 479                        return 5;
 480                }
 481
 482                store.key = (char*)key;
 483                store_write_section(fd, key);
 484                store_write_pair(fd, key, value);
 485        } else{
 486                struct stat st;
 487                char* contents;
 488                int i, copy_begin, copy_end, new_line = 0;
 489
 490                if (value_regex == NULL)
 491                        store.value_regex = NULL;
 492                else {
 493                        if (value_regex[0] == '!') {
 494                                store.do_not_match = 1;
 495                                value_regex++;
 496                        } else
 497                                store.do_not_match = 0;
 498
 499                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 500                        if (regcomp(store.value_regex, value_regex,
 501                                        REG_EXTENDED)) {
 502                                fprintf(stderr, "Invalid pattern: %s\n",
 503                                        value_regex);
 504                                free(store.value_regex);
 505                                return 6;
 506                        }
 507                }
 508
 509                store.offset[0] = 0;
 510                store.state = START;
 511                store.seen = 0;
 512
 513                /*
 514                 * After this, store.offset will contain the *end* offset
 515                 * of the last match, or remain at 0 if no match was found.
 516                 * As a side effect, we make sure to transform only a valid
 517                 * existing config file.
 518                 */
 519                if (git_config(store_aux)) {
 520                        fprintf(stderr, "invalid config file\n");
 521                        free(store.key);
 522                        if (store.value_regex != NULL) {
 523                                regfree(store.value_regex);
 524                                free(store.value_regex);
 525                        }
 526                        return 3;
 527                }
 528
 529                free(store.key);
 530                if (store.value_regex != NULL) {
 531                        regfree(store.value_regex);
 532                        free(store.value_regex);
 533                }
 534
 535                /* if nothing to unset, or too many matches, error out */
 536                if ((store.seen == 0 && value == NULL) ||
 537                                (store.seen > 1 && multi_replace == 0)) {
 538                        close(fd);
 539                        unlink(lock_file);
 540                        return 5;
 541                }
 542
 543                fstat(in_fd, &st);
 544                contents = mmap(NULL, st.st_size, PROT_READ,
 545                        MAP_PRIVATE, in_fd, 0);
 546                close(in_fd);
 547
 548                if (store.seen == 0)
 549                        store.seen = 1;
 550
 551                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 552                        if (store.offset[i] == 0) {
 553                                store.offset[i] = copy_end = st.st_size;
 554                        } else if (store.state != KEY_SEEN) {
 555                                copy_end = store.offset[i];
 556                        } else
 557                                copy_end = find_beginning_of_line(
 558                                        contents, st.st_size,
 559                                        store.offset[i]-2, &new_line);
 560
 561                        /* write the first part of the config */
 562                        if (copy_end > copy_begin) {
 563                                write(fd, contents + copy_begin,
 564                                copy_end - copy_begin);
 565                                if (new_line)
 566                                        write(fd, "\n", 1);
 567                        }
 568                        copy_begin = store.offset[i];
 569                }
 570
 571                /* write the pair (value == NULL means unset) */
 572                if (value != NULL) {
 573                        if (store.state == START)
 574                                store_write_section(fd, key);
 575                        store_write_pair(fd, key, value);
 576                }
 577
 578                /* write the rest of the config */
 579                if (copy_begin < st.st_size)
 580                        write(fd, contents + copy_begin,
 581                                st.st_size - copy_begin);
 582
 583                munmap(contents, st.st_size);
 584                unlink(config_filename);
 585        }
 586
 587        close(fd);
 588
 589        if (rename(lock_file, config_filename) < 0) {
 590                fprintf(stderr, "Could not rename the lock file?\n");
 591                return 4;
 592        }
 593
 594        return 0;
 595}
 596
 597