Andrew's git - gitweb.git/blob

e78520ba07035fbd11b56fbf016ec4affe0dd9ac
   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))
 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        if (!strcmp(var, "diff.renamelimit")) {
 240                diff_rename_limit_default = git_config_int(var, value);
 241                return 0;
 242        }
 243
 244        /* Add other config variables here.. */
 245        return 0;
 246}
 247
 248int git_config(config_fn_t fn)
 249{
 250        int ret;
 251        FILE *f = fopen(git_path("config"), "r");
 252
 253        ret = -1;
 254        if (f) {
 255                config_file = f;
 256                config_linenr = 1;
 257                ret = git_parse_file(fn);
 258                fclose(f);
 259        }
 260        return ret;
 261}
 262
 263/*
 264 * Find all the stuff for git_config_set() below.
 265 */
 266
 267#define MAX_MATCHES 512
 268
 269static struct {
 270        int baselen;
 271        char* key;
 272        int do_not_match;
 273        regex_t* value_regex;
 274        int multi_replace;
 275        off_t offset[MAX_MATCHES];
 276        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 277        int seen;
 278} store;
 279
 280static int matches(const char* key, const char* value)
 281{
 282        return !strcmp(key, store.key) &&
 283                (store.value_regex == NULL ||
 284                 (store.do_not_match ^
 285                  !regexec(store.value_regex, value, 0, NULL, 0)));
 286}
 287
 288static int store_aux(const char* key, const char* value)
 289{
 290        switch (store.state) {
 291        case KEY_SEEN:
 292                if (matches(key, value)) {
 293                        if (store.seen == 1 && store.multi_replace == 0) {
 294                                fprintf(stderr,
 295                                        "Warning: %s has multiple values\n",
 296                                        key);
 297                        } else if (store.seen >= MAX_MATCHES) {
 298                                fprintf(stderr, "Too many matches\n");
 299                                return 1;
 300                        }
 301
 302                        store.offset[store.seen] = ftell(config_file);
 303                        store.seen++;
 304                }
 305                break;
 306        case SECTION_SEEN:
 307                if (strncmp(key, store.key, store.baselen+1)) {
 308                        store.state = SECTION_END_SEEN;
 309                        break;
 310                } else
 311                        /* do not increment matches: this is no match */
 312                        store.offset[store.seen] = ftell(config_file);
 313                /* fallthru */
 314        case SECTION_END_SEEN:
 315        case START:
 316                if (matches(key, value)) {
 317                        store.offset[store.seen] = ftell(config_file);
 318                        store.state = KEY_SEEN;
 319                        store.seen++;
 320                } else if(!strncmp(key, store.key, store.baselen))
 321                        store.state = SECTION_SEEN;
 322        }
 323        return 0;
 324}
 325
 326static void store_write_section(int fd, const char* key)
 327{
 328        write(fd, "[", 1);
 329        write(fd, key, store.baselen);
 330        write(fd, "]\n", 2);
 331}
 332
 333static void store_write_pair(int fd, const char* key, const char* value)
 334{
 335        int i;
 336
 337        write(fd, "\t", 1);
 338        write(fd, key+store.baselen+1,
 339                strlen(key+store.baselen+1));
 340        write(fd, " = ", 3);
 341        for (i = 0; value[i]; i++)
 342                switch (value[i]) {
 343                case '\n': write(fd, "\\n", 2); break;
 344                case '\t': write(fd, "\\t", 2); break;
 345                case '"': case '\\': write(fd, "\\", 1);
 346                default: write(fd, value+i, 1);
 347        }
 348        write(fd, "\n", 1);
 349}
 350
 351static int find_beginning_of_line(const char* contents, int size,
 352        int offset_, int* found_bracket)
 353{
 354        int equal_offset = size, bracket_offset = size;
 355        int offset;
 356
 357        for (offset = offset_-2; offset > 0 
 358                        && contents[offset] != '\n'; offset--)
 359                switch (contents[offset]) {
 360                        case '=': equal_offset = offset; break;
 361                        case ']': bracket_offset = offset; break;
 362                }
 363        if (bracket_offset < equal_offset) {
 364                *found_bracket = 1;
 365                offset = bracket_offset+1;
 366        } else
 367                offset++;
 368
 369        return offset;
 370}
 371
 372int git_config_set(const char* key, const char* value)
 373{
 374        return git_config_set_multivar(key, value, NULL, 0);
 375}
 376
 377/*
 378 * If value==NULL, unset in (remove from) config,
 379 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 380 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 381 *     else all matching key/values (regardless how many) are removed,
 382 *     before the new pair is written.
 383 *
 384 * Returns 0 on success.
 385 *
 386 * This function does this:
 387 *
 388 * - it locks the config file by creating ".git/config.lock"
 389 *
 390 * - it then parses the config using store_aux() as validator to find
 391 *   the position on the key/value pair to replace. If it is to be unset,
 392 *   it must be found exactly once.
 393 *
 394 * - the config file is mmap()ed and the part before the match (if any) is
 395 *   written to the lock file, then the changed part and the rest.
 396 *
 397 * - the config file is removed and the lock file rename()d to it.
 398 *
 399 */
 400int git_config_set_multivar(const char* key, const char* value,
 401        const char* value_regex, int multi_replace)
 402{
 403        int i;
 404        struct stat st;
 405        int fd;
 406        char* config_file = strdup(git_path("config"));
 407        char* lock_file = strdup(git_path("config.lock"));
 408
 409        store.multi_replace = multi_replace;
 410
 411        /*
 412         * Since "key" actually contains the section name and the real
 413         * key name separated by a dot, we have to know where the dot is.
 414         */
 415        for (store.baselen = 0;
 416                        key[store.baselen] != '.' && key[store.baselen];
 417                        store.baselen++);
 418        if (!key[store.baselen] || !key[store.baselen+1]) {
 419                fprintf(stderr, "key does not contain a section: %s\n", key);
 420                return 2;
 421        }
 422
 423        /*
 424         * Validate the key and while at it, lower case it for matching.
 425         */
 426        store.key = (char*)malloc(strlen(key)+1);
 427        for (i = 0; key[i]; i++)
 428                if (i != store.baselen && (!isalnum(key[i]) ||
 429                                (i == store.baselen+1 && !isalpha(key[i])))) {
 430                        fprintf(stderr, "invalid key: %s\n", key);
 431                        free(store.key);
 432                        return 1;
 433                } else
 434                        store.key[i] = tolower(key[i]);
 435        store.key[i] = 0;
 436
 437        /*
 438         * The lock_file serves a purpose in addition to locking: the new
 439         * contents of .git/config will be written into it.
 440         */
 441        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 442        if (fd < 0) {
 443                fprintf(stderr, "could not lock config file\n");
 444                free(store.key);
 445                return -1;
 446        }
 447
 448        /*
 449         * If .git/config does not exist yet, write a minimal version.
 450         */
 451        if (stat(config_file, &st)) {
 452                static const char contents[] =
 453                        "#\n"
 454                        "# This is the config file\n"
 455                        "#\n"
 456                        "\n";
 457
 458                free(store.key);
 459
 460                /* if nothing to unset, error out */
 461                if (value == NULL) {
 462                        close(fd);
 463                        unlink(lock_file);
 464                        return 5;
 465                }
 466
 467                store.key = (char*)key;
 468
 469                write(fd, contents, sizeof(contents)-1);
 470                store_write_section(fd, key);
 471                store_write_pair(fd, key, value);
 472        } else{
 473                int in_fd;
 474                char* contents;
 475                int i, copy_begin, copy_end, new_line = 0;
 476
 477                if (value_regex == NULL)
 478                        store.value_regex = NULL;
 479                else {
 480                        if (value_regex[0] == '!') {
 481                                store.do_not_match = 1;
 482                                value_regex++;
 483                        } else
 484                                store.do_not_match = 0;
 485
 486                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 487                        if (regcomp(store.value_regex, value_regex,
 488                                        REG_EXTENDED)) {
 489                                fprintf(stderr, "Invalid pattern: %s",
 490                                        value_regex);
 491                                free(store.value_regex);
 492                                return 6;
 493                        }
 494                }
 495
 496                store.offset[0] = 0;
 497                store.state = START;
 498                store.seen = 0;
 499
 500                /*
 501                 * After this, store.offset will contain the *end* offset
 502                 * of the last match, or remain at 0 if no match was found.
 503                 * As a side effect, we make sure to transform only a valid
 504                 * existing config file.
 505                 */
 506                if (git_config(store_aux)) {
 507                        fprintf(stderr, "invalid config file\n");
 508                        free(store.key);
 509                        if (store.value_regex != NULL) {
 510                                regfree(store.value_regex);
 511                                free(store.value_regex);
 512                        }
 513                        return 3;
 514                }
 515
 516                free(store.key);
 517                if (store.value_regex != NULL) {
 518                        regfree(store.value_regex);
 519                        free(store.value_regex);
 520                }
 521
 522                /* if nothing to unset, or too many matches, error out */
 523                if ((store.seen == 0 && value == NULL) ||
 524                                (store.seen > 1 && multi_replace == 0)) {
 525                        close(fd);
 526                        unlink(lock_file);
 527                        return 5;
 528                }
 529
 530                in_fd = open(config_file, O_RDONLY, 0666);
 531                contents = mmap(NULL, st.st_size, PROT_READ,
 532                        MAP_PRIVATE, in_fd, 0);
 533                close(in_fd);
 534
 535                if (store.seen == 0)
 536                        store.seen = 1;
 537
 538                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 539                        if (store.offset[i] == 0) {
 540                                store.offset[i] = copy_end = st.st_size;
 541                        } else if (store.state != KEY_SEEN) {
 542                                copy_end = store.offset[i];
 543                        } else
 544                                copy_end = find_beginning_of_line(
 545                                        contents, st.st_size,
 546                                        store.offset[i]-2, &new_line);
 547
 548                        /* write the first part of the config */
 549                        if (copy_end > copy_begin) {
 550                                write(fd, contents + copy_begin,
 551                                copy_end - copy_begin);
 552                                if (new_line)
 553                                        write(fd, "\n", 1);
 554                        }
 555                        copy_begin = store.offset[i];
 556                }
 557
 558                /* write the pair (value == NULL means unset) */
 559                if (value != NULL) {
 560                        if (store.state == START)
 561                                store_write_section(fd, key);
 562                        store_write_pair(fd, key, value);
 563                }
 564
 565                /* write the rest of the config */
 566                if (copy_begin < st.st_size)
 567                        write(fd, contents + copy_begin,
 568                                st.st_size - copy_begin);
 569
 570                munmap(contents, st.st_size);
 571                unlink(config_file);
 572        }
 573
 574        close(fd);
 575
 576        if (rename(lock_file, config_file) < 0) {
 577                fprintf(stderr, "Could not rename the lock file?\n");
 578                return 4;
 579        }
 580
 581        return 0;
 582}
 583
 584