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