tools/perf/util/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, space = 0;
  51         size_t len = 0;
  52
  53         for (;;) {
  54                 int c = get_next_char();
  55
  56                 if (len >= sizeof(value) - 1)
  57                         return NULL;
  58                 if (c == '\n') {
  59                         if (quote)
  60                                 return NULL;
  61                         value[len] = 0;
  62                         return value;
  63                 }
  64                 if (comment)
  65                         continue;
  66                 if (isspace(c) && !quote) {
  67                         space = 1;
  68                         continue;
  69                 }
  70                 if (!quote) {
  71                         if (c == ';' || c == '#') {
  72                                 comment = 1;
  73                                 continue;
  74                         }
  75                 }
  76                 if (space) {
  77                         if (len)
  78                                 value[len++] = ' ';
  79                         space = 0;
  80                 }
  81                 if (c == '\\') {
  82                         c = get_next_char();
  83                         switch (c) {
  84                         case '\n':
  85                                 continue;
  86                         case 't':
  87                                 c = '\t';
  88                                 break;
  89                         case 'b':
  90                                 c = '\b';
  91                                 break;
  92                         case 'n':
  93                                 c = '\n';
  94                                 break;
  95                         /* Some characters escape as themselves */
  96                         case '\\': case '"':
  97                                 break;
  98                         /* Reject unknown escape sequences */
  99                         default:
 100                                 return NULL;
 101                         }
 102                         value[len++] = c;
 103                         continue;
 104                 }
 105                 if (c == '"') {
 106                         quote = 1-quote;
 107                         continue;
 108                 }
 109                 value[len++] = c;
 110         }
 111 }
 112
 113 static inline int iskeychar(int c)
 114 {
 115         return isalnum(c) || c == '-';
 116 }
 117
 118 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 119 {
 120         int c;
 121         char *value;
 122
 123         /* Get the full name */
 124         for (;;) {
 125                 c = get_next_char();
 126                 if (config_file_eof)
 127                         break;
 128                 if (!iskeychar(c))
 129                         break;
 130                 name[len++] = tolower(c);
 131                 if (len >= MAXNAME)
 132                         return -1;
 133         }
 134         name[len] = 0;
 135         while (c == ' ' || c == '\t')
 136                 c = get_next_char();
 137
 138         value = NULL;
 139         if (c != '\n') {
 140                 if (c != '=')
 141                         return -1;
 142                 value = parse_value();
 143                 if (!value)
 144                         return -1;
 145         }
 146         return fn(name, value, data);
 147 }
 148
 149 static int get_extended_base_var(char *name, int baselen, int c)
 150 {
 151         do {
 152                 if (c == '\n')
 153                         return -1;
 154                 c = get_next_char();
 155         } while (isspace(c));
 156
 157         /* We require the format to be '[base "extension"]' */
 158         if (c != '"')
 159                 return -1;
 160         name[baselen++] = '.';
 161
 162         for (;;) {
 163                 int c = get_next_char();
 164                 if (c == '\n')
 165                         return -1;
 166                 if (c == '"')
 167                         break;
 168                 if (c == '\\') {
 169                         c = get_next_char();
 170                         if (c == '\n')
 171                                 return -1;
 172                 }
 173                 name[baselen++] = c;
 174                 if (baselen > MAXNAME / 2)
 175                         return -1;
 176         }
 177
 178         /* Final ']' */
 179         if (get_next_char() != ']')
 180                 return -1;
 181         return baselen;
 182 }
 183
 184 static int get_base_var(char *name)
 185 {
 186         int baselen = 0;
 187
 188         for (;;) {
 189                 int c = get_next_char();
 190                 if (config_file_eof)
 191                         return -1;
 192                 if (c == ']')
 193                         return baselen;
 194                 if (isspace(c))
 195                         return get_extended_base_var(name, baselen, c);
 196                 if (!iskeychar(c) && c != '.')
 197                         return -1;
 198                 if (baselen > MAXNAME / 2)
 199                         return -1;
 200                 name[baselen++] = tolower(c);
 201         }
 202 }
 203
 204 static int perf_parse_file(config_fn_t fn, void *data)
 205 {
 206         int comment = 0;
 207         int baselen = 0;
 208         static char var[MAXNAME];
 209
 210         /* U+FEFF Byte Order Mark in UTF8 */
 211         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 212         const unsigned char *bomptr = utf8_bom;
 213
 214         for (;;) {
 215                 int c = get_next_char();
 216                 if (bomptr && *bomptr) {
 217                         /* We are at the file beginning; skip UTF8-encoded BOM
 218                          * if present. Sane editors won't put this in on their
 219                          * own, but e.g. Windows Notepad will do it happily. */
 220                         if ((unsigned char) c == *bomptr) {
 221                                 bomptr++;
 222                                 continue;
 223                         } else {
 224                                 /* Do not tolerate partial BOM. */
 225                                 if (bomptr != utf8_bom)
 226                                         break;
 227                                 /* No BOM at file beginning. Cool. */
 228                                 bomptr = NULL;
 229                         }
 230                 }
 231                 if (c == '\n') {
 232                         if (config_file_eof)
 233                                 return 0;
 234                         comment = 0;
 235                         continue;
 236                 }
 237                 if (comment || isspace(c))
 238                         continue;
 239                 if (c == '#' || c == ';') {
 240                         comment = 1;
 241                         continue;
 242                 }
 243                 if (c == '[') {
 244                         baselen = get_base_var(var);
 245                         if (baselen <= 0)
 246                                 break;
 247                         var[baselen++] = '.';
 248                         var[baselen] = 0;
 249                         continue;
 250                 }
 251                 if (!isalpha(c))
 252                         break;
 253                 var[baselen] = tolower(c);
 254                 if (get_value(fn, data, var, baselen+1) < 0)
 255                         break;
 256         }
 257         die("bad config file line %d in %s", config_linenr, config_file_name);
 258 }
 259
 260 static int parse_unit_factor(const char *end, unsigned long *val)
 261 {
 262         if (!*end)
 263                 return 1;
 264         else if (!strcasecmp(end, "k")) {
 265                 *val *= 1024;
 266                 return 1;
 267         }
 268         else if (!strcasecmp(end, "m")) {
 269                 *val *= 1024 * 1024;
 270                 return 1;
 271         }
 272         else if (!strcasecmp(end, "g")) {
 273                 *val *= 1024 * 1024 * 1024;
 274                 return 1;
 275         }
 276         return 0;
 277 }
 278
 279 static int perf_parse_long(const char *value, long *ret)
 280 {
 281         if (value && *value) {
 282                 char *end;
 283                 long val = strtol(value, &end, 0);
 284                 unsigned long factor = 1;
 285                 if (!parse_unit_factor(end, &factor))
 286                         return 0;
 287                 *ret = val * factor;
 288                 return 1;
 289         }
 290         return 0;
 291 }
 292
 293 int perf_parse_ulong(const char *value, unsigned long *ret)
 294 {
 295         if (value && *value) {
 296                 char *end;
 297                 unsigned long val = strtoul(value, &end, 0);
 298                 if (!parse_unit_factor(end, &val))
 299                         return 0;
 300                 *ret = val;
 301                 return 1;
 302         }
 303         return 0;
 304 }
 305
 306 static void die_bad_config(const char *name)
 307 {
 308         if (config_file_name)
 309                 die("bad config value for '%s' in %s", name, config_file_name);
 310         die("bad config value for '%s'", name);
 311 }
 312
 313 int perf_config_int(const char *name, const char *value)
 314 {
 315         long ret = 0;
 316         if (!perf_parse_long(value, &ret))
 317                 die_bad_config(name);
 318         return ret;
 319 }
 320
 321 unsigned long perf_config_ulong(const char *name, const char *value)
 322 {
 323         unsigned long ret;
 324         if (!perf_parse_ulong(value, &ret))
 325                 die_bad_config(name);
 326         return ret;
 327 }
 328
 329 int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
 330 {
 331         *is_bool = 1;
 332         if (!value)
 333                 return 1;
 334         if (!*value)
 335                 return 0;
 336         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 337                 return 1;
 338         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 339                 return 0;
 340         *is_bool = 0;
 341         return perf_config_int(name, value);
 342 }
 343
 344 int perf_config_bool(const char *name, const char *value)
 345 {
 346         int discard;
 347         return !!perf_config_bool_or_int(name, value, &discard);
 348 }
 349
 350 int perf_config_string(const char **dest, const char *var, const char *value)
 351 {
 352         if (!value)
 353                 return config_error_nonbool(var);
 354         *dest = strdup(value);
 355         return 0;
 356 }
 357
 358 static int perf_default_core_config(const char *var __used, const char *value __used)
 359 {
 360         /* Add other config variables here and to Documentation/config.txt. */
 361         return 0;
 362 }
 363
 364 int perf_default_config(const char *var, const char *value, void *dummy __used)
 365 {
 366         if (!prefixcmp(var, "core."))
 367                 return perf_default_core_config(var, value);
 368
 369         /* Add other config variables here and to Documentation/config.txt. */
 370         return 0;
 371 }
 372
 373 int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
 374 {
 375         int ret;
 376         FILE *f = fopen(filename, "r");
 377
 378         ret = -1;
 379         if (f) {
 380                 config_file = f;
 381                 config_file_name = filename;
 382                 config_linenr = 1;
 383                 config_file_eof = 0;
 384                 ret = perf_parse_file(fn, data);
 385                 fclose(f);
 386                 config_file_name = NULL;
 387         }
 388         return ret;
 389 }
 390
 391 const char *perf_etc_perfconfig(void)
 392 {
 393         static const char *system_wide;
 394         if (!system_wide)
 395                 system_wide = system_path(ETC_PERFCONFIG);
 396         return system_wide;
 397 }
 398
 399 static int perf_env_bool(const char *k, int def)
 400 {
 401         const char *v = getenv(k);
 402         return v ? perf_config_bool(k, v) : def;
 403 }
 404
 405 int perf_config_system(void)
 406 {
 407         return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
 408 }
 409
 410 int perf_config_global(void)
 411 {
 412         return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 413 }
 414
 415 int perf_config(config_fn_t fn, void *data)
 416 {
 417         int ret = 0, found = 0;
 418         char *repo_config = NULL;
 419         const char *home = NULL;
 420
 421         /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 422         if (config_exclusive_filename)
 423                 return perf_config_from_file(fn, config_exclusive_filename, data);
 424         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
 425                 ret += perf_config_from_file(fn, perf_etc_perfconfig(),
 426                                             data);
 427                 found += 1;
 428         }
 429
 430         home = getenv("HOME");
 431         if (perf_config_global() && home) {
 432                 char *user_config = strdup(mkpath("%s/.perfconfig", home));
 433                 if (!access(user_config, R_OK)) {
 434                         ret += perf_config_from_file(fn, user_config, data);
 435                         found += 1;
 436                 }
 437                 free(user_config);
 438         }
 439
 440         repo_config = perf_pathdup("config");
 441         if (!access(repo_config, R_OK)) {
 442                 ret += perf_config_from_file(fn, repo_config, data);
 443                 found += 1;
 444         }
 445         free(repo_config);
 446         if (found == 0)
 447                 return -1;
 448         return ret;
 449 }
 450
 451 /*
 452  * Find all the stuff for perf_config_set() below.
 453  */
 454
 455 #define MAX_MATCHES 512
 456
 457 static struct {
 458         int baselen;
 459         char* key;
 460         int do_not_match;
 461         regex_t* value_regex;
 462         int multi_replace;
 463         size_t offset[MAX_MATCHES];
 464         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 465         int seen;
 466 } store;
 467
 468 static int matches(const char* key, const char* value)
 469 {
 470         return !strcmp(key, store.key) &&
 471                 (store.value_regex == NULL ||
 472                  (store.do_not_match ^
 473                   !regexec(store.value_regex, value, 0, NULL, 0)));
 474 }
 475
 476 static int store_aux(const char* key, const char* value, void *cb __used)
 477 {
 478         int section_len;
 479         const char *ep;
 480
 481         switch (store.state) {
 482         case KEY_SEEN:
 483                 if (matches(key, value)) {
 484                         if (store.seen == 1 && store.multi_replace == 0) {
 485                                 warning("%s has multiple values", key);
 486                         } else if (store.seen >= MAX_MATCHES) {
 487                                 error("too many matches for %s", key);
 488                                 return 1;
 489                         }
 490
 491                         store.offset[store.seen] = ftell(config_file);
 492                         store.seen++;
 493                 }
 494                 break;
 495         case SECTION_SEEN:
 496                 /*
 497                  * What we are looking for is in store.key (both
 498                  * section and var), and its section part is baselen
 499                  * long.  We found key (again, both section and var).
 500                  * We would want to know if this key is in the same
 501                  * section as what we are looking for.  We already
 502                  * know we are in the same section as what should
 503                  * hold store.key.
 504                  */
 505                 ep = strrchr(key, '.');
 506                 section_len = ep - key;
 507
 508                 if ((section_len != store.baselen) ||
 509                     memcmp(key, store.key, section_len+1)) {
 510                         store.state = SECTION_END_SEEN;
 511                         break;
 512                 }
 513
 514                 /*
 515                  * Do not increment matches: this is no match, but we
 516                  * just made sure we are in the desired section.
 517                  */
 518                 store.offset[store.seen] = ftell(config_file);
 519                 /* fallthru */
 520         case SECTION_END_SEEN:
 521         case START:
 522                 if (matches(key, value)) {
 523                         store.offset[store.seen] = ftell(config_file);
 524                         store.state = KEY_SEEN;
 525                         store.seen++;
 526                 } else {
 527                         if (strrchr(key, '.') - key == store.baselen &&
 528                               !strncmp(key, store.key, store.baselen)) {
 529                                         store.state = SECTION_SEEN;
 530                                         store.offset[store.seen] = ftell(config_file);
 531                         }
 532                 }
 533         }
 534         return 0;
 535 }
 536
 537 static int store_write_section(int fd, const char* key)
 538 {
 539         const char *dot;
 540         int i, success;
 541         struct strbuf sb = STRBUF_INIT;
 542
 543         dot = memchr(key, '.', store.baselen);
 544         if (dot) {
 545                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 546                 for (i = dot - key + 1; i < store.baselen; i++) {
 547                         if (key[i] == '"' || key[i] == '\\')
 548                                 strbuf_addch(&sb, '\\');
 549                         strbuf_addch(&sb, key[i]);
 550                 }
 551                 strbuf_addstr(&sb, "\"]\n");
 552         } else {
 553                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 554         }
 555
 556         success = (write_in_full(fd, sb.buf, sb.len) == (ssize_t)sb.len);
 557         strbuf_release(&sb);
 558
 559         return success;
 560 }
 561
 562 static int store_write_pair(int fd, const char* key, const char* value)
 563 {
 564         int i, success;
 565         int length = strlen(key + store.baselen + 1);
 566         const char *quote = "";
 567         struct strbuf sb = STRBUF_INIT;
 568
 569         /*
 570          * Check to see if the value needs to be surrounded with a dq pair.
 571          * Note that problematic characters are always backslash-quoted; this
 572          * check is about not losing leading or trailing SP and strings that
 573          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 574          * configuration parser.
 575          */
 576         if (value[0] == ' ')
 577                 quote = "\"";
 578         for (i = 0; value[i]; i++)
 579                 if (value[i] == ';' || value[i] == '#')
 580                         quote = "\"";
 581         if (i && value[i - 1] == ' ')
 582                 quote = "\"";
 583
 584         strbuf_addf(&sb, "\t%.*s = %s",
 585                     length, key + store.baselen + 1, quote);
 586
 587         for (i = 0; value[i]; i++)
 588                 switch (value[i]) {
 589                 case '\n':
 590                         strbuf_addstr(&sb, "\\n");
 591                         break;
 592                 case '\t':
 593                         strbuf_addstr(&sb, "\\t");
 594                         break;
 595                 case '"':
 596                 case '\\':
 597                         strbuf_addch(&sb, '\\');
 598                 default:
 599                         strbuf_addch(&sb, value[i]);
 600                         break;
 601                 }
 602         strbuf_addf(&sb, "%s\n", quote);
 603
 604         success = (write_in_full(fd, sb.buf, sb.len) == (ssize_t)sb.len);
 605         strbuf_release(&sb);
 606
 607         return success;
 608 }
 609
 610 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 611         size_t offset_, int* found_bracket)
 612 {
 613         size_t equal_offset = size, bracket_offset = size;
 614         ssize_t offset;
 615
 616 contline:
 617         for (offset = offset_-2; offset > 0
 618                         && contents[offset] != '\n'; offset--)
 619                 switch (contents[offset]) {
 620                         case '=': equal_offset = offset; break;
 621                         case ']': bracket_offset = offset; break;
 622                 }
 623         if (offset > 0 && contents[offset-1] == '\\') {
 624                 offset_ = offset;
 625                 goto contline;
 626         }
 627         if (bracket_offset < equal_offset) {
 628                 *found_bracket = 1;
 629                 offset = bracket_offset+1;
 630         } else
 631                 offset++;
 632
 633         return offset;
 634 }
 635
 636 int perf_config_set(const char* key, const char* value)
 637 {
 638         return perf_config_set_multivar(key, value, NULL, 0);
 639 }
 640
 641 /*
 642  * If value==NULL, unset in (remove from) config,
 643  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 644  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 645  *     else all matching key/values (regardless how many) are removed,
 646  *     before the new pair is written.
 647  *
 648  * Returns 0 on success.
 649  *
 650  * This function does this:
 651  *
 652  * - it locks the config file by creating ".perf/config.lock"
 653  *
 654  * - it then parses the config using store_aux() as validator to find
 655  *   the position on the key/value pair to replace. If it is to be unset,
 656  *   it must be found exactly once.
 657  *
 658  * - the config file is mmap()ed and the part before the match (if any) is
 659  *   written to the lock file, then the changed part and the rest.
 660  *
 661  * - the config file is removed and the lock file rename()d to it.
 662  *
 663  */
 664 int perf_config_set_multivar(const char* key, const char* value,
 665         const char* value_regex, int multi_replace)
 666 {
 667         int i, dot;
 668         int fd = -1, in_fd;
 669         int ret = 0;
 670         char* config_filename;
 671         const char* last_dot = strrchr(key, '.');
 672
 673         if (config_exclusive_filename)
 674                 config_filename = strdup(config_exclusive_filename);
 675         else
 676                 config_filename = perf_pathdup("config");
 677
 678         /*
 679          * Since "key" actually contains the section name and the real
 680          * key name separated by a dot, we have to know where the dot is.
 681          */
 682
 683         if (last_dot == NULL) {
 684                 error("key does not contain a section: %s", key);
 685                 ret = 2;
 686                 goto out_free;
 687         }
 688         store.baselen = last_dot - key;
 689
 690         store.multi_replace = multi_replace;
 691
 692         /*
 693          * Validate the key and while at it, lower case it for matching.
 694          */
 695         store.key = malloc(strlen(key) + 1);
 696         dot = 0;
 697         for (i = 0; key[i]; i++) {
 698                 unsigned char c = key[i];
 699                 if (c == '.')
 700                         dot = 1;
 701                 /* Leave the extended basename untouched.. */
 702                 if (!dot || i > store.baselen) {
 703                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 704                                 error("invalid key: %s", key);
 705                                 free(store.key);
 706                                 ret = 1;
 707                                 goto out_free;
 708                         }
 709                         c = tolower(c);
 710                 } else if (c == '\n') {
 711                         error("invalid key (newline): %s", key);
 712                         free(store.key);
 713                         ret = 1;
 714                         goto out_free;
 715                 }
 716                 store.key[i] = c;
 717         }
 718         store.key[i] = 0;
 719
 720         /*
 721          * If .perf/config does not exist yet, write a minimal version.
 722          */
 723         in_fd = open(config_filename, O_RDONLY);
 724         if ( in_fd < 0 ) {
 725                 free(store.key);
 726
 727                 if ( ENOENT != errno ) {
 728                         error("opening %s: %s", config_filename,
 729                               strerror(errno));
 730                         ret = 3; /* same as "invalid config file" */
 731                         goto out_free;
 732                 }
 733                 /* if nothing to unset, error out */
 734                 if (value == NULL) {
 735                         ret = 5;
 736                         goto out_free;
 737                 }
 738
 739                 store.key = (char*)key;
 740                 if (!store_write_section(fd, key) ||
 741                     !store_write_pair(fd, key, value))
 742                         goto write_err_out;
 743         } else {
 744                 struct stat st;
 745                 char* contents;
 746                 ssize_t contents_sz, copy_begin, copy_end;
 747                 int i, new_line = 0;
 748
 749                 if (value_regex == NULL)
 750                         store.value_regex = NULL;
 751                 else {
 752                         if (value_regex[0] == '!') {
 753                                 store.do_not_match = 1;
 754                                 value_regex++;
 755                         } else
 756                                 store.do_not_match = 0;
 757
 758                         store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 759                         if (regcomp(store.value_regex, value_regex,
 760                                         REG_EXTENDED)) {
 761                                 error("invalid pattern: %s", value_regex);
 762                                 free(store.value_regex);
 763                                 ret = 6;
 764                                 goto out_free;
 765                         }
 766                 }
 767
 768                 store.offset[0] = 0;
 769                 store.state = START;
 770                 store.seen = 0;
 771
 772                 /*
 773                  * After this, store.offset will contain the *end* offset
 774                  * of the last match, or remain at 0 if no match was found.
 775                  * As a side effect, we make sure to transform only a valid
 776                  * existing config file.
 777                  */
 778                 if (perf_config_from_file(store_aux, config_filename, NULL)) {
 779                         error("invalid config file %s", config_filename);
 780                         free(store.key);
 781                         if (store.value_regex != NULL) {
 782                                 regfree(store.value_regex);
 783                                 free(store.value_regex);
 784                         }
 785                         ret = 3;
 786                         goto out_free;
 787                 }
 788
 789                 free(store.key);
 790                 if (store.value_regex != NULL) {
 791                         regfree(store.value_regex);
 792                         free(store.value_regex);
 793                 }
 794
 795                 /* if nothing to unset, or too many matches, error out */
 796                 if ((store.seen == 0 && value == NULL) ||
 797                                 (store.seen > 1 && multi_replace == 0)) {
 798                         ret = 5;
 799                         goto out_free;
 800                 }
 801
 802                 fstat(in_fd, &st);
 803                 contents_sz = xsize_t(st.st_size);
 804                 contents = mmap(NULL, contents_sz, PROT_READ,
 805                         MAP_PRIVATE, in_fd, 0);
 806                 close(in_fd);
 807
 808                 if (store.seen == 0)
 809                         store.seen = 1;
 810
 811                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 812                         if (store.offset[i] == 0) {
 813                                 store.offset[i] = copy_end = contents_sz;
 814                         } else if (store.state != KEY_SEEN) {
 815                                 copy_end = store.offset[i];
 816                         } else
 817                                 copy_end = find_beginning_of_line(
 818                                         contents, contents_sz,
 819                                         store.offset[i]-2, &new_line);
 820
 821                         if (copy_end > 0 && contents[copy_end-1] != '\n')
 822                                 new_line = 1;
 823
 824                         /* write the first part of the config */
 825                         if (copy_end > copy_begin) {
 826                                 if (write_in_full(fd, contents + copy_begin,
 827                                                   copy_end - copy_begin) <
 828                                     copy_end - copy_begin)
 829                                         goto write_err_out;
 830                                 if (new_line &&
 831                                     write_in_full(fd, "\n", 1) != 1)
 832                                         goto write_err_out;
 833                         }
 834                         copy_begin = store.offset[i];
 835                 }
 836
 837                 /* write the pair (value == NULL means unset) */
 838                 if (value != NULL) {
 839                         if (store.state == START) {
 840                                 if (!store_write_section(fd, key))
 841                                         goto write_err_out;
 842                         }
 843                         if (!store_write_pair(fd, key, value))
 844                                 goto write_err_out;
 845                 }
 846
 847                 /* write the rest of the config */
 848                 if (copy_begin < contents_sz)
 849                         if (write_in_full(fd, contents + copy_begin,
 850                                           contents_sz - copy_begin) <
 851                             contents_sz - copy_begin)
 852                                 goto write_err_out;
 853
 854                 munmap(contents, contents_sz);
 855         }
 856
 857         ret = 0;
 858
 859 out_free:
 860         free(config_filename);
 861         return ret;
 862
 863 write_err_out:
 864         goto out_free;
 865
 866 }
 867
 868 /*
 869  * Call this to report error for your variable that should not
 870  * get a boolean value (i.e. "[my] var" means "true").
 871  */
 872 int config_error_nonbool(const char *var)
 873 {
 874         return error("Missing value for '%s'", var);
 875 }