Documentation/perf_counter/config.c

   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 "util.h"
   9 #include "cache.h"
  10 #include "exec_cmd.h"
  11
  12 #define MAXNAME (256)
  13
  14 static FILE *config_file;
  15 static const char *config_file_name;
  16 static int config_linenr;
  17 static int config_file_eof;
  18
  19 const char *config_exclusive_filename = NULL;
  20
  21 static int get_next_char(void)
  22 {
  23         int c;
  24         FILE *f;
  25
  26         c = '\n';
  27         if ((f = config_file) != NULL) {
  28                 c = fgetc(f);
  29                 if (c == '\r') {
  30                         /* DOS like systems */
  31                         c = fgetc(f);
  32                         if (c != '\n') {
  33                                 ungetc(c, f);
  34                                 c = '\r';
  35                         }
  36                 }
  37                 if (c == '\n')
  38                         config_linenr++;
  39                 if (c == EOF) {
  40                         config_file_eof = 1;
  41                         c = '\n';
  42                 }
  43         }
  44         return c;
  45 }
  46
  47 static char *parse_value(void)
  48 {
  49         static char value[1024];
  50         int quote = 0, comment = 0, len = 0, space = 0;
  51
  52         for (;;) {
  53                 int c = get_next_char();
  54                 if (len >= sizeof(value) - 1)
  55                         return NULL;
  56                 if (c == '\n') {
  57                         if (quote)
  58                                 return NULL;
  59                         value[len] = 0;
  60                         return value;
  61                 }
  62                 if (comment)
  63                         continue;
  64                 if (isspace(c) && !quote) {
  65                         space = 1;
  66                         continue;
  67                 }
  68                 if (!quote) {
  69                         if (c == ';' || c == '#') {
  70                                 comment = 1;
  71                                 continue;
  72                         }
  73                 }
  74                 if (space) {
  75                         if (len)
  76                                 value[len++] = ' ';
  77                         space = 0;
  78                 }
  79                 if (c == '\\') {
  80                         c = get_next_char();
  81                         switch (c) {
  82                         case '\n':
  83                                 continue;
  84                         case 't':
  85                                 c = '\t';
  86                                 break;
  87                         case 'b':
  88                                 c = '\b';
  89                                 break;
  90                         case 'n':
  91                                 c = '\n';
  92                                 break;
  93                         /* Some characters escape as themselves */
  94                         case '\\': case '"':
  95                                 break;
  96                         /* Reject unknown escape sequences */
  97                         default:
  98                                 return NULL;
  99                         }
 100                         value[len++] = c;
 101                         continue;
 102                 }
 103                 if (c == '"') {
 104                         quote = 1-quote;
 105                         continue;
 106                 }
 107                 value[len++] = c;
 108         }
 109 }
 110
 111 static inline int iskeychar(int c)
 112 {
 113         return isalnum(c) || c == '-';
 114 }
 115
 116 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 117 {
 118         int c;
 119         char *value;
 120
 121         /* Get the full name */
 122         for (;;) {
 123                 c = get_next_char();
 124                 if (config_file_eof)
 125                         break;
 126                 if (!iskeychar(c))
 127                         break;
 128                 name[len++] = tolower(c);
 129                 if (len >= MAXNAME)
 130                         return -1;
 131         }
 132         name[len] = 0;
 133         while (c == ' ' || c == '\t')
 134                 c = get_next_char();
 135
 136         value = NULL;
 137         if (c != '\n') {
 138                 if (c != '=')
 139                         return -1;
 140                 value = parse_value();
 141                 if (!value)
 142                         return -1;
 143         }
 144         return fn(name, value, data);
 145 }
 146
 147 static int get_extended_base_var(char *name, int baselen, int c)
 148 {
 149         do {
 150                 if (c == '\n')
 151                         return -1;
 152                 c = get_next_char();
 153         } while (isspace(c));
 154
 155         /* We require the format to be '[base "extension"]' */
 156         if (c != '"')
 157                 return -1;
 158         name[baselen++] = '.';
 159
 160         for (;;) {
 161                 int c = get_next_char();
 162                 if (c == '\n')
 163                         return -1;
 164                 if (c == '"')
 165                         break;
 166                 if (c == '\\') {
 167                         c = get_next_char();
 168                         if (c == '\n')
 169                                 return -1;
 170                 }
 171                 name[baselen++] = c;
 172                 if (baselen > MAXNAME / 2)
 173                         return -1;
 174         }
 175
 176         /* Final ']' */
 177         if (get_next_char() != ']')
 178                 return -1;
 179         return baselen;
 180 }
 181
 182 static int get_base_var(char *name)
 183 {
 184         int baselen = 0;
 185
 186         for (;;) {
 187                 int c = get_next_char();
 188                 if (config_file_eof)
 189                         return -1;
 190                 if (c == ']')
 191                         return baselen;
 192                 if (isspace(c))
 193                         return get_extended_base_var(name, baselen, c);
 194                 if (!iskeychar(c) && c != '.')
 195                         return -1;
 196                 if (baselen > MAXNAME / 2)
 197                         return -1;
 198                 name[baselen++] = tolower(c);
 199         }
 200 }
 201
 202 static int perf_parse_file(config_fn_t fn, void *data)
 203 {
 204         int comment = 0;
 205         int baselen = 0;
 206         static char var[MAXNAME];
 207
 208         /* U+FEFF Byte Order Mark in UTF8 */
 209         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 210         const unsigned char *bomptr = utf8_bom;
 211
 212         for (;;) {
 213                 int c = get_next_char();
 214                 if (bomptr && *bomptr) {
 215                         /* We are at the file beginning; skip UTF8-encoded BOM
 216                          * if present. Sane editors won't put this in on their
 217                          * own, but e.g. Windows Notepad will do it happily. */
 218                         if ((unsigned char) c == *bomptr) {
 219                                 bomptr++;
 220                                 continue;
 221                         } else {
 222                                 /* Do not tolerate partial BOM. */
 223                                 if (bomptr != utf8_bom)
 224                                         break;
 225                                 /* No BOM at file beginning. Cool. */
 226                                 bomptr = NULL;
 227                         }
 228                 }
 229                 if (c == '\n') {
 230                         if (config_file_eof)
 231                                 return 0;
 232                         comment = 0;
 233                         continue;
 234                 }
 235                 if (comment || isspace(c))
 236                         continue;
 237                 if (c == '#' || c == ';') {
 238                         comment = 1;
 239                         continue;
 240                 }
 241                 if (c == '[') {
 242                         baselen = get_base_var(var);
 243                         if (baselen <= 0)
 244                                 break;
 245                         var[baselen++] = '.';
 246                         var[baselen] = 0;
 247                         continue;
 248                 }
 249                 if (!isalpha(c))
 250                         break;
 251                 var[baselen] = tolower(c);
 252                 if (get_value(fn, data, var, baselen+1) < 0)
 253                         break;
 254         }
 255         die("bad config file line %d in %s", config_linenr, config_file_name);
 256 }
 257
 258 static int parse_unit_factor(const char *end, unsigned long *val)
 259 {
 260         if (!*end)
 261                 return 1;
 262         else if (!strcasecmp(end, "k")) {
 263                 *val *= 1024;
 264                 return 1;
 265         }
 266         else if (!strcasecmp(end, "m")) {
 267                 *val *= 1024 * 1024;
 268                 return 1;
 269         }
 270         else if (!strcasecmp(end, "g")) {
 271                 *val *= 1024 * 1024 * 1024;
 272                 return 1;
 273         }
 274         return 0;
 275 }
 276
 277 static int perf_parse_long(const char *value, long *ret)
 278 {
 279         if (value && *value) {
 280                 char *end;
 281                 long val = strtol(value, &end, 0);
 282                 unsigned long factor = 1;
 283                 if (!parse_unit_factor(end, &factor))
 284                         return 0;
 285                 *ret = val * factor;
 286                 return 1;
 287         }
 288         return 0;
 289 }
 290
 291 int perf_parse_ulong(const char *value, unsigned long *ret)
 292 {
 293         if (value && *value) {
 294                 char *end;
 295                 unsigned long val = strtoul(value, &end, 0);
 296                 if (!parse_unit_factor(end, &val))
 297                         return 0;
 298                 *ret = val;
 299                 return 1;
 300         }
 301         return 0;
 302 }
 303
 304 static void die_bad_config(const char *name)
 305 {
 306         if (config_file_name)
 307                 die("bad config value for '%s' in %s", name, config_file_name);
 308         die("bad config value for '%s'", name);
 309 }
 310
 311 int perf_config_int(const char *name, const char *value)
 312 {
 313         long ret = 0;
 314         if (!perf_parse_long(value, &ret))
 315                 die_bad_config(name);
 316         return ret;
 317 }
 318
 319 unsigned long perf_config_ulong(const char *name, const char *value)
 320 {
 321         unsigned long ret;
 322         if (!perf_parse_ulong(value, &ret))
 323                 die_bad_config(name);
 324         return ret;
 325 }
 326
 327 int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
 328 {
 329         *is_bool = 1;
 330         if (!value)
 331                 return 1;
 332         if (!*value)
 333                 return 0;
 334         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 335                 return 1;
 336         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 337                 return 0;
 338         *is_bool = 0;
 339         return perf_config_int(name, value);
 340 }
 341
 342 int perf_config_bool(const char *name, const char *value)
 343 {
 344         int discard;
 345         return !!perf_config_bool_or_int(name, value, &discard);
 346 }
 347
 348 int perf_config_string(const char **dest, const char *var, const char *value)
 349 {
 350         if (!value)
 351                 return config_error_nonbool(var);
 352         *dest = strdup(value);
 353         return 0;
 354 }
 355
 356 static int perf_default_core_config(const char *var, const char *value)
 357 {
 358         /* Add other config variables here and to Documentation/config.txt. */
 359         return 0;
 360 }
 361
 362 int perf_default_config(const char *var, const char *value, void *dummy)
 363 {
 364         if (!prefixcmp(var, "core."))
 365                 return perf_default_core_config(var, value);
 366
 367         /* Add other config variables here and to Documentation/config.txt. */
 368         return 0;
 369 }
 370
 371 int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
 372 {
 373         int ret;
 374         FILE *f = fopen(filename, "r");
 375
 376         ret = -1;
 377         if (f) {
 378                 config_file = f;
 379                 config_file_name = filename;
 380                 config_linenr = 1;
 381                 config_file_eof = 0;
 382                 ret = perf_parse_file(fn, data);
 383                 fclose(f);
 384                 config_file_name = NULL;
 385         }
 386         return ret;
 387 }
 388
 389 const char *perf_etc_perfconfig(void)
 390 {
 391         static const char *system_wide;
 392         if (!system_wide)
 393                 system_wide = system_path(ETC_PERFCONFIG);
 394         return system_wide;
 395 }
 396
 397 static int perf_env_bool(const char *k, int def)
 398 {
 399         const char *v = getenv(k);
 400         return v ? perf_config_bool(k, v) : def;
 401 }
 402
 403 int perf_config_system(void)
 404 {
 405         return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
 406 }
 407
 408 int perf_config_global(void)
 409 {
 410         return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 411 }
 412
 413 int perf_config(config_fn_t fn, void *data)
 414 {
 415         int ret = 0, found = 0;
 416         char *repo_config = NULL;
 417         const char *home = NULL;
 418
 419         /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 420         if (config_exclusive_filename)
 421                 return perf_config_from_file(fn, config_exclusive_filename, data);
 422         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
 423                 ret += perf_config_from_file(fn, perf_etc_perfconfig(),
 424                                             data);
 425                 found += 1;
 426         }
 427
 428         home = getenv("HOME");
 429         if (perf_config_global() && home) {
 430                 char *user_config = strdup(mkpath("%s/.perfconfig", home));
 431                 if (!access(user_config, R_OK)) {
 432                         ret += perf_config_from_file(fn, user_config, data);
 433                         found += 1;
 434                 }
 435                 free(user_config);
 436         }
 437
 438         repo_config = perf_pathdup("config");
 439         if (!access(repo_config, R_OK)) {
 440                 ret += perf_config_from_file(fn, repo_config, data);
 441                 found += 1;
 442         }
 443         free(repo_config);
 444         if (found == 0)
 445                 return -1;
 446         return ret;
 447 }
 448
 449 /*
 450  * Find all the stuff for perf_config_set() below.
 451  */
 452
 453 #define MAX_MATCHES 512
 454
 455 static struct {
 456         int baselen;
 457         char* key;
 458         int do_not_match;
 459         regex_t* value_regex;
 460         int multi_replace;
 461         size_t offset[MAX_MATCHES];
 462         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 463         int seen;
 464 } store;
 465
 466 static int matches(const char* key, const char* value)
 467 {
 468         return !strcmp(key, store.key) &&
 469                 (store.value_regex == NULL ||
 470                  (store.do_not_match ^
 471                   !regexec(store.value_regex, value, 0, NULL, 0)));
 472 }
 473
 474 static int store_aux(const char* key, const char* value, void *cb)
 475 {
 476         const char *ep;
 477         size_t section_len;
 478
 479         switch (store.state) {
 480         case KEY_SEEN:
 481                 if (matches(key, value)) {
 482                         if (store.seen == 1 && store.multi_replace == 0) {
 483                                 warning("%s has multiple values", key);
 484                         } else if (store.seen >= MAX_MATCHES) {
 485                                 error("too many matches for %s", key);
 486                                 return 1;
 487                         }
 488
 489                         store.offset[store.seen] = ftell(config_file);
 490                         store.seen++;
 491                 }
 492                 break;
 493         case SECTION_SEEN:
 494                 /*
 495                  * What we are looking for is in store.key (both
 496                  * section and var), and its section part is baselen
 497                  * long.  We found key (again, both section and var).
 498                  * We would want to know if this key is in the same
 499                  * section as what we are looking for.  We already
 500                  * know we are in the same section as what should
 501                  * hold store.key.
 502                  */
 503                 ep = strrchr(key, '.');
 504                 section_len = ep - key;
 505
 506                 if ((section_len != store.baselen) ||
 507                     memcmp(key, store.key, section_len+1)) {
 508                         store.state = SECTION_END_SEEN;
 509                         break;
 510                 }
 511
 512                 /*
 513                  * Do not increment matches: this is no match, but we
 514                  * just made sure we are in the desired section.
 515                  */
 516                 store.offset[store.seen] = ftell(config_file);
 517                 /* fallthru */
 518         case SECTION_END_SEEN:
 519         case START:
 520                 if (matches(key, value)) {
 521                         store.offset[store.seen] = ftell(config_file);
 522                         store.state = KEY_SEEN;
 523                         store.seen++;
 524                 } else {
 525                         if (strrchr(key, '.') - key == store.baselen &&
 526                               !strncmp(key, store.key, store.baselen)) {
 527                                         store.state = SECTION_SEEN;
 528                                         store.offset[store.seen] = ftell(config_file);
 529                         }
 530                 }
 531         }
 532         return 0;
 533 }
 534
 535 static int store_write_section(int fd, const char* key)
 536 {
 537         const char *dot;
 538         int i, success;
 539         struct strbuf sb = STRBUF_INIT;
 540
 541         dot = memchr(key, '.', store.baselen);
 542         if (dot) {
 543                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 544                 for (i = dot - key + 1; i < store.baselen; i++) {
 545                         if (key[i] == '"' || key[i] == '\\')
 546                                 strbuf_addch(&sb, '\\');
 547                         strbuf_addch(&sb, key[i]);
 548                 }
 549                 strbuf_addstr(&sb, "\"]\n");
 550         } else {
 551                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 552         }
 553
 554         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 555         strbuf_release(&sb);
 556
 557         return success;
 558 }
 559
 560 static int store_write_pair(int fd, const char* key, const char* value)
 561 {
 562         int i, success;
 563         int length = strlen(key + store.baselen + 1);
 564         const char *quote = "";
 565         struct strbuf sb = STRBUF_INIT;
 566
 567         /*
 568          * Check to see if the value needs to be surrounded with a dq pair.
 569          * Note that problematic characters are always backslash-quoted; this
 570          * check is about not losing leading or trailing SP and strings that
 571          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 572          * configuration parser.
 573          */
 574         if (value[0] == ' ')
 575                 quote = "\"";
 576         for (i = 0; value[i]; i++)
 577                 if (value[i] == ';' || value[i] == '#')
 578                         quote = "\"";
 579         if (i && value[i - 1] == ' ')
 580                 quote = "\"";
 581
 582         strbuf_addf(&sb, "\t%.*s = %s",
 583                     length, key + store.baselen + 1, quote);
 584
 585         for (i = 0; value[i]; i++)
 586                 switch (value[i]) {
 587                 case '\n':
 588                         strbuf_addstr(&sb, "\\n");
 589                         break;
 590                 case '\t':
 591                         strbuf_addstr(&sb, "\\t");
 592                         break;
 593                 case '"':
 594                 case '\\':
 595                         strbuf_addch(&sb, '\\');
 596                 default:
 597                         strbuf_addch(&sb, value[i]);
 598                         break;
 599                 }
 600         strbuf_addf(&sb, "%s\n", quote);
 601
 602         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 603         strbuf_release(&sb);
 604
 605         return success;
 606 }
 607
 608 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 609         size_t offset_, int* found_bracket)
 610 {
 611         size_t equal_offset = size, bracket_offset = size;
 612         ssize_t offset;
 613
 614 contline:
 615         for (offset = offset_-2; offset > 0
 616                         && contents[offset] != '\n'; offset--)
 617                 switch (contents[offset]) {
 618                         case '=': equal_offset = offset; break;
 619                         case ']': bracket_offset = offset; break;
 620                 }
 621         if (offset > 0 && contents[offset-1] == '\\') {
 622                 offset_ = offset;
 623                 goto contline;
 624         }
 625         if (bracket_offset < equal_offset) {
 626                 *found_bracket = 1;
 627                 offset = bracket_offset+1;
 628         } else
 629                 offset++;
 630
 631         return offset;
 632 }
 633
 634 int perf_config_set(const char* key, const char* value)
 635 {
 636         return perf_config_set_multivar(key, value, NULL, 0);
 637 }
 638
 639 /*
 640  * If value==NULL, unset in (remove from) config,
 641  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 642  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 643  *     else all matching key/values (regardless how many) are removed,
 644  *     before the new pair is written.
 645  *
 646  * Returns 0 on success.
 647  *
 648  * This function does this:
 649  *
 650  * - it locks the config file by creating ".perf/config.lock"
 651  *
 652  * - it then parses the config using store_aux() as validator to find
 653  *   the position on the key/value pair to replace. If it is to be unset,
 654  *   it must be found exactly once.
 655  *
 656  * - the config file is mmap()ed and the part before the match (if any) is
 657  *   written to the lock file, then the changed part and the rest.
 658  *
 659  * - the config file is removed and the lock file rename()d to it.
 660  *
 661  */
 662 int perf_config_set_multivar(const char* key, const char* value,
 663         const char* value_regex, int multi_replace)
 664 {
 665         int i, dot;
 666         int fd = -1, in_fd;
 667         int ret = 0;
 668         char* config_filename;
 669         const char* last_dot = strrchr(key, '.');
 670
 671         if (config_exclusive_filename)
 672                 config_filename = strdup(config_exclusive_filename);
 673         else
 674                 config_filename = perf_pathdup("config");
 675
 676         /*
 677          * Since "key" actually contains the section name and the real
 678          * key name separated by a dot, we have to know where the dot is.
 679          */
 680
 681         if (last_dot == NULL) {
 682                 error("key does not contain a section: %s", key);
 683                 ret = 2;
 684                 goto out_free;
 685         }
 686         store.baselen = last_dot - key;
 687
 688         store.multi_replace = multi_replace;
 689
 690         /*
 691          * Validate the key and while at it, lower case it for matching.
 692          */
 693         store.key = malloc(strlen(key) + 1);
 694         dot = 0;
 695         for (i = 0; key[i]; i++) {
 696                 unsigned char c = key[i];
 697                 if (c == '.')
 698                         dot = 1;
 699                 /* Leave the extended basename untouched.. */
 700                 if (!dot || i > store.baselen) {
 701                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 702                                 error("invalid key: %s", key);
 703                                 free(store.key);
 704                                 ret = 1;
 705                                 goto out_free;
 706                         }
 707                         c = tolower(c);
 708                 } else if (c == '\n') {
 709                         error("invalid key (newline): %s", key);
 710                         free(store.key);
 711                         ret = 1;
 712                         goto out_free;
 713                 }
 714                 store.key[i] = c;
 715         }
 716         store.key[i] = 0;
 717
 718         /*
 719          * If .perf/config does not exist yet, write a minimal version.
 720          */
 721         in_fd = open(config_filename, O_RDONLY);
 722         if ( in_fd < 0 ) {
 723                 free(store.key);
 724
 725                 if ( ENOENT != errno ) {
 726                         error("opening %s: %s", config_filename,
 727                               strerror(errno));
 728                         ret = 3; /* same as "invalid config file" */
 729                         goto out_free;
 730                 }
 731                 /* if nothing to unset, error out */
 732                 if (value == NULL) {
 733                         ret = 5;
 734                         goto out_free;
 735                 }
 736
 737                 store.key = (char*)key;
 738                 if (!store_write_section(fd, key) ||
 739                     !store_write_pair(fd, key, value))
 740                         goto write_err_out;
 741         } else {
 742                 struct stat st;
 743                 char* contents;
 744                 size_t contents_sz, copy_begin, copy_end;
 745                 int i, new_line = 0;
 746
 747                 if (value_regex == NULL)
 748                         store.value_regex = NULL;
 749                 else {
 750                         if (value_regex[0] == '!') {
 751                                 store.do_not_match = 1;
 752                                 value_regex++;
 753                         } else
 754                                 store.do_not_match = 0;
 755
 756                         store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 757                         if (regcomp(store.value_regex, value_regex,
 758                                         REG_EXTENDED)) {
 759                                 error("invalid pattern: %s", value_regex);
 760                                 free(store.value_regex);
 761                                 ret = 6;
 762                                 goto out_free;
 763                         }
 764                 }
 765
 766                 store.offset[0] = 0;
 767                 store.state = START;
 768                 store.seen = 0;
 769
 770                 /*
 771                  * After this, store.offset will contain the *end* offset
 772                  * of the last match, or remain at 0 if no match was found.
 773                  * As a side effect, we make sure to transform only a valid
 774                  * existing config file.
 775                  */
 776                 if (perf_config_from_file(store_aux, config_filename, NULL)) {
 777                         error("invalid config file %s", config_filename);
 778                         free(store.key);
 779                         if (store.value_regex != NULL) {
 780                                 regfree(store.value_regex);
 781                                 free(store.value_regex);
 782                         }
 783                         ret = 3;
 784                         goto out_free;
 785                 }
 786
 787                 free(store.key);
 788                 if (store.value_regex != NULL) {
 789                         regfree(store.value_regex);
 790                         free(store.value_regex);
 791                 }
 792
 793                 /* if nothing to unset, or too many matches, error out */
 794                 if ((store.seen == 0 && value == NULL) ||
 795                                 (store.seen > 1 && multi_replace == 0)) {
 796                         ret = 5;
 797                         goto out_free;
 798                 }
 799
 800                 fstat(in_fd, &st);
 801                 contents_sz = xsize_t(st.st_size);
 802                 contents = mmap(NULL, contents_sz, PROT_READ,
 803                         MAP_PRIVATE, in_fd, 0);
 804                 close(in_fd);
 805
 806                 if (store.seen == 0)
 807                         store.seen = 1;
 808
 809                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 810                         if (store.offset[i] == 0) {
 811                                 store.offset[i] = copy_end = contents_sz;
 812                         } else if (store.state != KEY_SEEN) {
 813                                 copy_end = store.offset[i];
 814                         } else
 815                                 copy_end = find_beginning_of_line(
 816                                         contents, contents_sz,
 817                                         store.offset[i]-2, &new_line);
 818
 819                         if (copy_end > 0 && contents[copy_end-1] != '\n')
 820                                 new_line = 1;
 821
 822                         /* write the first part of the config */
 823                         if (copy_end > copy_begin) {
 824                                 if (write_in_full(fd, contents + copy_begin,
 825                                                   copy_end - copy_begin) <
 826                                     copy_end - copy_begin)
 827                                         goto write_err_out;
 828                                 if (new_line &&
 829                                     write_in_full(fd, "\n", 1) != 1)
 830                                         goto write_err_out;
 831                         }
 832                         copy_begin = store.offset[i];
 833                 }
 834
 835                 /* write the pair (value == NULL means unset) */
 836                 if (value != NULL) {
 837                         if (store.state == START) {
 838                                 if (!store_write_section(fd, key))
 839                                         goto write_err_out;
 840                         }
 841                         if (!store_write_pair(fd, key, value))
 842                                 goto write_err_out;
 843                 }
 844
 845                 /* write the rest of the config */
 846                 if (copy_begin < contents_sz)
 847                         if (write_in_full(fd, contents + copy_begin,
 848                                           contents_sz - copy_begin) <
 849                             contents_sz - copy_begin)
 850                                 goto write_err_out;
 851
 852                 munmap(contents, contents_sz);
 853         }
 854
 855         ret = 0;
 856
 857 out_free:
 858         free(config_filename);
 859         return ret;
 860
 861 write_err_out:
 862         goto out_free;
 863
 864 }
 865
 866 /*
 867  * Call this to report error for your variable that should not
 868  * get a boolean value (i.e. "[my] var" means "true").
 869  */
 870 int config_error_nonbool(const char *var)
 871 {
 872         return error("Missing value for '%s'", var);
 873 }