Andrew's git / gitweb.git / config.c
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config.con commit Everyday: some examples. (44db136)
   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.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        if (!strcmp(var, "i18n.commitencoding")) {
 241                strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 242                return 0;
 243        }
 244
 245        /* Add other config variables here.. */
 246        return 0;
 247}
 248
 249int git_config_from_file(config_fn_t fn, const char *filename)
 250{
 251        int ret;
 252        FILE *f = fopen(filename, "r");
 253
 254        ret = -1;
 255        if (f) {
 256                config_file = f;
 257                config_file_name = filename;
 258                config_linenr = 1;
 259                ret = git_parse_file(fn);
 260                fclose(f);
 261                config_file_name = NULL;
 262        }
 263        return ret;
 264}
 265
 266int git_config(config_fn_t fn)
 267{
 268        return git_config_from_file(fn, git_path("config"));
 269}
 270
 271/*
 272 * Find all the stuff for git_config_set() below.
 273 */
 274
 275#define MAX_MATCHES 512
 276
 277static struct {
 278        int baselen;
 279        char* key;
 280        int do_not_match;
 281        regex_t* value_regex;
 282        int multi_replace;
 283        off_t offset[MAX_MATCHES];
 284        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 285        int seen;
 286} store;
 287
 288static int matches(const char* key, const char* value)
 289{
 290        return !strcmp(key, store.key) &&
 291                (store.value_regex == NULL ||
 292                 (store.do_not_match ^
 293                  !regexec(store.value_regex, value, 0, NULL, 0)));
 294}
 295
 296static int store_aux(const char* key, const char* value)
 297{
 298        switch (store.state) {
 299        case KEY_SEEN:
 300                if (matches(key, value)) {
 301                        if (store.seen == 1 && store.multi_replace == 0) {
 302                                fprintf(stderr,
 303                                        "Warning: %s has multiple values\n",
 304                                        key);
 305                        } else if (store.seen >= MAX_MATCHES) {
 306                                fprintf(stderr, "Too many matches\n");
 307                                return 1;
 308                        }
 309
 310                        store.offset[store.seen] = ftell(config_file);
 311                        store.seen++;
 312                }
 313                break;
 314        case SECTION_SEEN:
 315                if (strncmp(key, store.key, store.baselen+1)) {
 316                        store.state = SECTION_END_SEEN;
 317                        break;
 318                } else
 319                        /* do not increment matches: this is no match */
 320                        store.offset[store.seen] = ftell(config_file);
 321                /* fallthru */
 322        case SECTION_END_SEEN:
 323        case START:
 324                if (matches(key, value)) {
 325                        store.offset[store.seen] = ftell(config_file);
 326                        store.state = KEY_SEEN;
 327                        store.seen++;
 328                } else if(!strncmp(key, store.key, store.baselen))
 329                        store.state = SECTION_SEEN;
 330        }
 331        return 0;
 332}
 333
 334static void store_write_section(int fd, const char* key)
 335{
 336        write(fd, "[", 1);
 337        write(fd, key, store.baselen);
 338        write(fd, "]\n", 2);
 339}
 340
 341static void store_write_pair(int fd, const char* key, const char* value)
 342{
 343        int i;
 344
 345        write(fd, "\t", 1);
 346        write(fd, key+store.baselen+1,
 347                strlen(key+store.baselen+1));
 348        write(fd, " = ", 3);
 349        for (i = 0; value[i]; i++)
 350                switch (value[i]) {
 351                case '\n': write(fd, "\\n", 2); break;
 352                case '\t': write(fd, "\\t", 2); break;
 353                case '"': case '\\': write(fd, "\\", 1);
 354                default: write(fd, value+i, 1);
 355        }
 356        write(fd, "\n", 1);
 357}
 358
 359static int find_beginning_of_line(const char* contents, int size,
 360        int offset_, int* found_bracket)
 361{
 362        int equal_offset = size, bracket_offset = size;
 363        int offset;
 364
 365        for (offset = offset_-2; offset > 0 
 366                        && contents[offset] != '\n'; offset--)
 367                switch (contents[offset]) {
 368                        case '=': equal_offset = offset; break;
 369                        case ']': bracket_offset = offset; break;
 370                }
 371        if (bracket_offset < equal_offset) {
 372                *found_bracket = 1;
 373                offset = bracket_offset+1;
 374        } else
 375                offset++;
 376
 377        return offset;
 378}
 379
 380int git_config_set(const char* key, const char* value)
 381{
 382        return git_config_set_multivar(key, value, NULL, 0);
 383}
 384
 385/*
 386 * If value==NULL, unset in (remove from) config,
 387 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 388 * if multi_replace==0, nothing, or only one matching key/value is replaced,
 389 *     else all matching key/values (regardless how many) are removed,
 390 *     before the new pair is written.
 391 *
 392 * Returns 0 on success.
 393 *
 394 * This function does this:
 395 *
 396 * - it locks the config file by creating ".git/config.lock"
 397 *
 398 * - it then parses the config using store_aux() as validator to find
 399 *   the position on the key/value pair to replace. If it is to be unset,
 400 *   it must be found exactly once.
 401 *
 402 * - the config file is mmap()ed and the part before the match (if any) is
 403 *   written to the lock file, then the changed part and the rest.
 404 *
 405 * - the config file is removed and the lock file rename()d to it.
 406 *
 407 */
 408int git_config_set_multivar(const char* key, const char* value,
 409        const char* value_regex, int multi_replace)
 410{
 411        int i;
 412        struct stat st;
 413        int fd;
 414        char* config_filename = strdup(git_path("config"));
 415        char* lock_file = strdup(git_path("config.lock"));
 416        const char* last_dot = strrchr(key, '.');
 417
 418        /*
 419         * Since "key" actually contains the section name and the real
 420         * key name separated by a dot, we have to know where the dot is.
 421         */
 422
 423        if (last_dot == NULL) { 
 424                fprintf(stderr, "key does not contain a section: %s\n", key);
 425                return 2;
 426        }
 427        store.baselen = last_dot - key;
 428
 429        store.multi_replace = multi_replace;
 430
 431        /*
 432         * Validate the key and while at it, lower case it for matching.
 433         */
 434        store.key = (char*)malloc(strlen(key)+1);
 435        for (i = 0; key[i]; i++)
 436                if (i != store.baselen &&
 437                                ((!isalnum(key[i]) && key[i] != '.') ||
 438                                 (i == store.baselen+1 && !isalpha(key[i])))) {
 439                        fprintf(stderr, "invalid key: %s\n", key);
 440                        free(store.key);
 441                        return 1;
 442                } else
 443                        store.key[i] = tolower(key[i]);
 444        store.key[i] = 0;
 445
 446        /*
 447         * The lock_file serves a purpose in addition to locking: the new
 448         * contents of .git/config will be written into it.
 449         */
 450        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 451        if (fd < 0) {
 452                fprintf(stderr, "could not lock config file\n");
 453                free(store.key);
 454                return -1;
 455        }
 456
 457        /*
 458         * If .git/config does not exist yet, write a minimal version.
 459         */
 460        if (stat(config_filename, &st)) {
 461                free(store.key);
 462
 463                /* if nothing to unset, error out */
 464                if (value == NULL) {
 465                        close(fd);
 466                        unlink(lock_file);
 467                        return 5;
 468                }
 469
 470                store.key = (char*)key;
 471                store_write_section(fd, key);
 472                store_write_pair(fd, key, value);
 473        } else{
 474                int in_fd;
 475                char* contents;
 476                int i, copy_begin, copy_end, new_line = 0;
 477
 478                if (value_regex == NULL)
 479                        store.value_regex = NULL;
 480                else {
 481                        if (value_regex[0] == '!') {
 482                                store.do_not_match = 1;
 483                                value_regex++;
 484                        } else
 485                                store.do_not_match = 0;
 486
 487                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 488                        if (regcomp(store.value_regex, value_regex,
 489                                        REG_EXTENDED)) {
 490                                fprintf(stderr, "Invalid pattern: %s",
 491                                        value_regex);
 492                                free(store.value_regex);
 493                                return 6;
 494                        }
 495                }
 496
 497                store.offset[0] = 0;
 498                store.state = START;
 499                store.seen = 0;
 500
 501                /*
 502                 * After this, store.offset will contain the *end* offset
 503                 * of the last match, or remain at 0 if no match was found.
 504                 * As a side effect, we make sure to transform only a valid
 505                 * existing config file.
 506                 */
 507                if (git_config(store_aux)) {
 508                        fprintf(stderr, "invalid config file\n");
 509                        free(store.key);
 510                        if (store.value_regex != NULL) {
 511                                regfree(store.value_regex);
 512                                free(store.value_regex);
 513                        }
 514                        return 3;
 515                }
 516
 517                free(store.key);
 518                if (store.value_regex != NULL) {
 519                        regfree(store.value_regex);
 520                        free(store.value_regex);
 521                }
 522
 523                /* if nothing to unset, or too many matches, error out */
 524                if ((store.seen == 0 && value == NULL) ||
 525                                (store.seen > 1 && multi_replace == 0)) {
 526                        close(fd);
 527                        unlink(lock_file);
 528                        return 5;
 529                }
 530
 531                in_fd = open(config_filename, O_RDONLY, 0666);
 532                contents = mmap(NULL, st.st_size, PROT_READ,
 533                        MAP_PRIVATE, in_fd, 0);
 534                close(in_fd);
 535
 536                if (store.seen == 0)
 537                        store.seen = 1;
 538
 539                for (i = 0, copy_begin = 0; i < store.seen; i++) {
 540                        if (store.offset[i] == 0) {
 541                                store.offset[i] = copy_end = st.st_size;
 542                        } else if (store.state != KEY_SEEN) {
 543                                copy_end = store.offset[i];
 544                        } else
 545                                copy_end = find_beginning_of_line(
 546                                        contents, st.st_size,
 547                                        store.offset[i]-2, &new_line);
 548
 549                        /* write the first part of the config */
 550                        if (copy_end > copy_begin) {
 551                                write(fd, contents + copy_begin,
 552                                copy_end - copy_begin);
 553                                if (new_line)
 554                                        write(fd, "\n", 1);
 555                        }
 556                        copy_begin = store.offset[i];
 557                }
 558
 559                /* write the pair (value == NULL means unset) */
 560                if (value != NULL) {
 561                        if (store.state == START)
 562                                store_write_section(fd, key);
 563                        store_write_pair(fd, key, value);
 564                }
 565
 566                /* write the rest of the config */
 567                if (copy_begin < st.st_size)
 568                        write(fd, contents + copy_begin,
 569                                st.st_size - copy_begin);
 570
 571                munmap(contents, st.st_size);
 572                unlink(config_filename);
 573        }
 574
 575        close(fd);
 576
 577        if (rename(lock_file, config_filename) < 0) {
 578                fprintf(stderr, "Could not rename the lock file?\n");
 579                return 4;
 580        }
 581
 582        return 0;
 583}
 584
 585