Andrew's git - gitweb.git/blob

   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 */
 266static struct {
 267        int baselen;
 268        char* key;
 269        regex_t* value_regex;
 270        off_t offset;
 271        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 272        int seen;
 273} store;
 274
 275static int store_aux(const char* key, const char* value)
 276{
 277        switch (store.state) {
 278        case KEY_SEEN:
 279                if (!strcmp(key, store.key) &&
 280                                (store.value_regex == NULL ||
 281                                !regexec(store.value_regex, value, 0, NULL, 0))) {
 282                        if (store.seen == 1) {
 283                                fprintf(stderr,
 284                                        "Warning: %s has multiple values\n",
 285                                        key);
 286                        }
 287                        store.offset = ftell(config_file);
 288                        store.seen++;
 289                }
 290                break;
 291        case SECTION_SEEN:
 292                if (strncmp(key, store.key, store.baselen+1)) {
 293                        store.state = SECTION_END_SEEN;
 294                        break;
 295                } else
 296                        store.offset = ftell(config_file);
 297                /* fallthru */
 298        case SECTION_END_SEEN:
 299        case START:
 300                if (!strcmp(key, store.key) &&
 301                                (store.value_regex == NULL ||
 302                                !regexec(store.value_regex, value, 0, NULL, 0))) {
 303                        store.offset = ftell(config_file);
 304                        store.state = KEY_SEEN;
 305                        store.seen++;
 306                } else if(!strncmp(key, store.key, store.baselen))
 307                        store.state = SECTION_SEEN;
 308        }
 309        return 0;
 310}
 311
 312static void store_write_section(int fd, const char* key)
 313{
 314        write(fd, "[", 1);
 315        write(fd, key, store.baselen);
 316        write(fd, "]\n", 2);
 317}
 318
 319static void store_write_pair(int fd, const char* key, const char* value)
 320{
 321        int i;
 322
 323        write(fd, "\t", 1);
 324        write(fd, key+store.baselen+1,
 325                strlen(key+store.baselen+1));
 326        write(fd, " = ", 3);
 327        for (i = 0; value[i]; i++)
 328                switch (value[i]) {
 329                case '\n': write(fd, "\\n", 2); break;
 330                case '\t': write(fd, "\\t", 2); break;
 331                case '"': case '\\': write(fd, "\\", 1);
 332                default: write(fd, value+i, 1);
 333        }
 334        write(fd, "\n", 1);
 335}
 336
 337int git_config_set(const char* key, const char* value)
 338{
 339        return git_config_set_multivar(key, value, NULL);
 340}
 341
 342/*
 343 * If value==NULL, unset in (remove from) config,
 344 * if value_regex!=NULL, disregard key/value pairs where value does not match.
 345 *
 346 * Returns 0 on success.
 347 *
 348 * This function does this:
 349 *
 350 * - it locks the config file by creating ".git/config.lock"
 351 *
 352 * - it then parses the config using store_aux() as validator to find
 353 *   the position on the key/value pair to replace. If it is to be unset,
 354 *   it must be found exactly once.
 355 *
 356 * - the config file is mmap()ed and the part before the match (if any) is
 357 *   written to the lock file, then the changed part and the rest.
 358 *
 359 * - the config file is removed and the lock file rename()d to it.
 360 *
 361 */
 362int git_config_set_multivar(const char* key, const char* value,
 363        const char* value_regex)
 364{
 365        int i;
 366        struct stat st;
 367        int fd;
 368        char* config_file = strdup(git_path("config"));
 369        char* lock_file = strdup(git_path("config.lock"));
 370
 371        /*
 372         * Since "key" actually contains the section name and the real
 373         * key name separated by a dot, we have to know where the dot is.
 374         */
 375        for (store.baselen = 0;
 376                        key[store.baselen] != '.' && key[store.baselen];
 377                        store.baselen++);
 378        if (!key[store.baselen] || !key[store.baselen+1]) {
 379                fprintf(stderr, "key does not contain a section: %s\n", key);
 380                return 2;
 381        }
 382
 383        /*
 384         * Validate the key and while at it, lower case it for matching.
 385         */
 386        store.key = (char*)malloc(strlen(key)+1);
 387        for (i = 0; key[i]; i++)
 388                if (i != store.baselen && (!isalnum(key[i]) ||
 389                                (i == store.baselen+1 && !isalpha(key[i])))) {
 390                        fprintf(stderr, "invalid key: %s\n", key);
 391                        free(store.key);
 392                        return 1;
 393                } else
 394                        store.key[i] = tolower(key[i]);
 395
 396        /*
 397         * The lock_file serves a purpose in addition to locking: the new
 398         * contents of .git/config will be written into it.
 399         */
 400        fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 401        if (fd < 0) {
 402                fprintf(stderr, "could not lock config file\n");
 403                free(store.key);
 404                return -1;
 405        }
 406
 407        /*
 408         * If .git/config does not exist yet, write a minimal version.
 409         */
 410        if (stat(config_file, &st)) {
 411                static const char contents[] =
 412                        "#\n"
 413                        "# This is the config file\n"
 414                        "#\n"
 415                        "\n";
 416
 417                free(store.key);
 418
 419                /* if nothing to unset, error out */
 420                if (value == NULL) {
 421                        close(fd);
 422                        unlink(lock_file);
 423                        return 5;
 424                }
 425
 426                store.key = (char*)key;
 427
 428                write(fd, contents, sizeof(contents)-1);
 429                store_write_section(fd, key);
 430                store_write_pair(fd, key, value);
 431        } else{
 432                int in_fd;
 433                char* contents;
 434                int offset, new_line = 0;
 435
 436                if (value_regex == NULL)
 437                        store.value_regex = NULL;
 438                else {
 439                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 440                        if (regcomp(store.value_regex, value_regex,
 441                                        REG_EXTENDED)) {
 442                                fprintf(stderr, "Invalid pattern: %s",
 443                                        value_regex);
 444                                free(store.value_regex);
 445                                return 6;
 446                        }
 447                }
 448
 449                store.offset = 0;
 450                store.state = START;
 451                store.seen = 0;
 452
 453                /*
 454                 * After this, store.offset will contain the *end* offset
 455                 * of the last match, or remain at 0 if no match was found.
 456                 * As a side effect, we make sure to transform only a valid
 457                 * existing config file.
 458                 */
 459                if (git_config(store_aux)) {
 460                        fprintf(stderr, "invalid config file\n");
 461                        free(store.key);
 462                        if (store.value_regex != NULL) {
 463                                regfree(store.value_regex);
 464                                free(store.value_regex);
 465                        }
 466                        return 3;
 467                }
 468
 469                free(store.key);
 470                if (store.value_regex != NULL) {
 471                        regfree(store.value_regex);
 472                        free(store.value_regex);
 473                }
 474
 475                /* if nothing to unset, error out */
 476                if (store.seen == 0 && value == NULL) {
 477                        close(fd);
 478                        unlink(lock_file);
 479                        return 5;
 480                }
 481
 482                store.key = (char*)key;
 483
 484                in_fd = open(config_file, O_RDONLY, 0666);
 485                contents = mmap(NULL, st.st_size, PROT_READ,
 486                        MAP_PRIVATE, in_fd, 0);
 487                close(in_fd);
 488
 489                if (store.offset == 0) {
 490                        store.offset = offset = st.st_size;
 491                } else if (store.state != KEY_SEEN) {
 492                        offset = store.offset;
 493                } else {
 494                        int equal_offset = st.st_size,
 495                                bracket_offset = st.st_size;
 496
 497                        if (value == NULL && store.seen > 1) {
 498                                fprintf(stderr, "Cannot remove multivar (%s has %d values\n", key, store.seen);
 499                                close(fd);
 500                                unlink(lock_file);
 501                                return 7;
 502                        }
 503                        for (offset = store.offset-2; offset > 0 
 504                                        && contents[offset] != '\n'; offset--)
 505                                switch (contents[offset]) {
 506                                case '=': equal_offset = offset; break;
 507                                case ']': bracket_offset = offset; break;
 508                                }
 509                        if (bracket_offset < equal_offset) {
 510                                new_line = 1;
 511                                offset = bracket_offset+1;
 512                        } else
 513                                offset++;
 514                }
 515
 516                /* write the first part of the config */
 517                write(fd, contents, offset);
 518                if (new_line)
 519                        write(fd, "\n", 1);
 520
 521                /* write the pair (value == NULL means unset) */
 522                if (value != NULL) {
 523                        if (store.state == START)
 524                                store_write_section(fd, key);
 525                        store_write_pair(fd, key, value);
 526                }
 527
 528                /* write the rest of the config */
 529                if (store.offset < st.st_size)
 530                        write(fd, contents + store.offset,
 531                                st.st_size - store.offset);
 532
 533                munmap(contents, st.st_size);
 534                unlink(config_file);
 535        }
 536
 537        close(fd);
 538
 539        if (rename(lock_file, config_file) < 0) {
 540                fprintf(stderr, "Could not rename the lock file?\n");
 541                return 4;
 542        }
 543
 544        return 0;
 545}
 546