src/common/file-utils.c

   1 /*
   2  * Claws Mail -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2018 Colin Leroy and the Claws Mail team
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 #  include "config.h"
  21 #include "claws-features.h"
  22 #endif
  23
  24 #include <glib.h>
  25
  26 #ifndef G_OS_WIN32
  27 #include <sys/wait.h>
  28 #else
  29 #define WEXITSTATUS(x) (x)
  30 #endif
  31
  32 #include <errno.h>
  33 #include <stdio.h>
  34 #include <unistd.h>
  35 #include <fcntl.h>
  36
  37 #include "defs.h"
  38 #include "codeconv.h"
  39 #include "timing.h"
  40 #include "file-utils.h"
  41
  42 gboolean prefs_common_get_flush_metadata(void);
  43 gboolean prefs_common_get_use_shred(void);
  44
  45 static int safe_fclose(FILE *fp)
  46 {
  47         int r;
  48         START_TIMING("");
  49
  50         if (fflush(fp) != 0) {
  51                 return EOF;
  52         }
  53         if (prefs_common_get_flush_metadata() && fsync(fileno(fp)) != 0) {
  54                 return EOF;
  55         }
  56
  57         r = fclose(fp);
  58         END_TIMING();
  59
  60         return r;
  61 }
  62
  63 /* Unlock, then safe-close a file pointer
  64  * Safe close is done using fflush + fsync
  65  * if the according preference says so.
  66  */
  67 int claws_safe_fclose(FILE *fp)
  68 {
  69 #if HAVE_FGETS_UNLOCKED
  70         funlockfile(fp);
  71 #endif
  72         return safe_fclose(fp);
  73 }
  74
  75 #if HAVE_FGETS_UNLOCKED
  76
  77 /* Open a file and locks it once
  78  * so subsequent I/O is faster
  79  */
  80 FILE *claws_fopen(const char *file, const char *mode)
  81 {
  82         FILE *fp = fopen(file, mode);
  83         if (!fp)
  84                 return NULL;
  85         flockfile(fp);
  86         return fp;
  87 }
  88
  89 FILE *claws_fdopen(int fd, const char *mode)
  90 {
  91         FILE *fp = fdopen(fd, mode);
  92         if (!fp)
  93                 return NULL;
  94         flockfile(fp);
  95         return fp;
  96 }
  97
  98 /* Unlocks and close a file pointer
  99  */
 100
 101 int claws_fclose(FILE *fp)
 102 {
 103         funlockfile(fp);
 104         return fclose(fp);
 105 }
 106 #endif
 107
 108 int claws_unlink(const char *filename)
 109 {
 110         GStatBuf s;
 111         static int found_shred = -1;
 112         static const gchar *args[4];
 113
 114         if (filename == NULL)
 115                 return 0;
 116
 117         if (prefs_common_get_use_shred()) {
 118                 if (found_shred == -1) {
 119                         /* init */
 120                         args[0] = g_find_program_in_path("shred");
 121                         debug_print("found shred: %s\n", args[0]);
 122                         found_shred = (args[0] != NULL) ? 1:0;
 123                         args[1] = "-f";
 124                         args[3] = NULL;
 125                 }
 126                 if (found_shred == 1) {
 127                         if (g_stat(filename, &s) == 0 && S_ISREG(s.st_mode)) {
 128                                 if (s.st_nlink == 1) {
 129                                         gint status=0;
 130                                         args[2] = filename;
 131                                         g_spawn_sync(NULL, (gchar **)args, NULL, 0,
 132                                          NULL, NULL, NULL, NULL, &status, NULL);
 133                                         debug_print("%s %s exited with status %d\n",
 134                                                 args[0], filename, WEXITSTATUS(status));
 135                                         if (truncate(filename, 0) < 0)
 136                                                 g_warning("couldn't truncate: %s", filename);
 137                                 }
 138                         }
 139                 }
 140         }
 141         return g_unlink(filename);
 142 }
 143
 144 gint file_strip_crs(const gchar *file)
 145 {
 146         FILE *fp = NULL, *outfp = NULL;
 147         gchar buf[4096];
 148         gchar *out = get_tmp_file();
 149         if (file == NULL)
 150                 goto freeout;
 151
 152         fp = claws_fopen(file, "rb");
 153         if (!fp)
 154                 goto freeout;
 155
 156         outfp = claws_fopen(out, "wb");
 157         if (!outfp) {
 158                 claws_fclose(fp);
 159                 goto freeout;
 160         }
 161
 162         while (claws_fgets(buf, sizeof (buf), fp) != NULL) {
 163                 strcrchomp(buf);
 164                 if (claws_fputs(buf, outfp) == EOF) {
 165                         claws_fclose(fp);
 166                         claws_fclose(outfp);
 167                         goto unlinkout;
 168                 }
 169         }
 170
 171         claws_fclose(fp);
 172         if (claws_safe_fclose(outfp) == EOF) {
 173                 goto unlinkout;
 174         }
 175
 176         if (move_file(out, file, TRUE) < 0)
 177                 goto unlinkout;
 178
 179         g_free(out);
 180         return 0;
 181 unlinkout:
 182         claws_unlink(out);
 183 freeout:
 184         g_free(out);
 185         return -1;
 186 }
 187
 188 /*
 189  * Append src file body to the tail of dest file.
 190  * Now keep_backup has no effects.
 191  */
 192 gint append_file(const gchar *src, const gchar *dest, gboolean keep_backup)
 193 {
 194         FILE *src_fp, *dest_fp;
 195         gint n_read;
 196         gchar buf[BUFSIZ];
 197
 198         gboolean err = FALSE;
 199
 200         if ((src_fp = claws_fopen(src, "rb")) == NULL) {
 201                 FILE_OP_ERROR(src, "claws_fopen");
 202                 return -1;
 203         }
 204
 205         if ((dest_fp = claws_fopen(dest, "ab")) == NULL) {
 206                 FILE_OP_ERROR(dest, "claws_fopen");
 207                 claws_fclose(src_fp);
 208                 return -1;
 209         }
 210
 211         if (change_file_mode_rw(dest_fp, dest) < 0) {
 212                 FILE_OP_ERROR(dest, "chmod");
 213                 g_warning("can't change file mode: %s", dest);
 214         }
 215
 216         while ((n_read = claws_fread(buf, sizeof(gchar), sizeof(buf), src_fp)) > 0) {
 217                 if (n_read < sizeof(buf) && claws_ferror(src_fp))
 218                         break;
 219                 if (claws_fwrite(buf, 1, n_read, dest_fp) < n_read) {
 220                         g_warning("writing to %s failed", dest);
 221                         claws_fclose(dest_fp);
 222                         claws_fclose(src_fp);
 223                         claws_unlink(dest);
 224                         return -1;
 225                 }
 226         }
 227
 228         if (claws_ferror(src_fp)) {
 229                 FILE_OP_ERROR(src, "claws_fread");
 230                 err = TRUE;
 231         }
 232         claws_fclose(src_fp);
 233         if (claws_fclose(dest_fp) == EOF) {
 234                 FILE_OP_ERROR(dest, "claws_fclose");
 235                 err = TRUE;
 236         }
 237
 238         if (err) {
 239                 claws_unlink(dest);
 240                 return -1;
 241         }
 242
 243         return 0;
 244 }
 245
 246 gint copy_file(const gchar *src, const gchar *dest, gboolean keep_backup)
 247 {
 248         FILE *src_fp, *dest_fp;
 249         gint n_read;
 250         gchar buf[BUFSIZ];
 251         gchar *dest_bak = NULL;
 252         gboolean err = FALSE;
 253
 254         if ((src_fp = claws_fopen(src, "rb")) == NULL) {
 255                 FILE_OP_ERROR(src, "claws_fopen");
 256                 return -1;
 257         }
 258         if (is_file_exist(dest)) {
 259                 dest_bak = g_strconcat(dest, ".bak", NULL);
 260                 if (rename_force(dest, dest_bak) < 0) {
 261                         FILE_OP_ERROR(dest, "rename");
 262                         claws_fclose(src_fp);
 263                         g_free(dest_bak);
 264                         return -1;
 265                 }
 266         }
 267
 268         if ((dest_fp = claws_fopen(dest, "wb")) == NULL) {
 269                 FILE_OP_ERROR(dest, "claws_fopen");
 270                 claws_fclose(src_fp);
 271                 if (dest_bak) {
 272                         if (rename_force(dest_bak, dest) < 0)
 273                                 FILE_OP_ERROR(dest_bak, "rename");
 274                         g_free(dest_bak);
 275                 }
 276                 return -1;
 277         }
 278
 279         if (change_file_mode_rw(dest_fp, dest) < 0) {
 280                 FILE_OP_ERROR(dest, "chmod");
 281                 g_warning("can't change file mode: %s", dest);
 282         }
 283
 284         while ((n_read = claws_fread(buf, sizeof(gchar), sizeof(buf), src_fp)) > 0) {
 285                 if (n_read < sizeof(buf) && claws_ferror(src_fp))
 286                         break;
 287                 if (claws_fwrite(buf, 1, n_read, dest_fp) < n_read) {
 288                         g_warning("writing to %s failed", dest);
 289                         claws_fclose(dest_fp);
 290                         claws_fclose(src_fp);
 291                         if (claws_unlink(dest) < 0)
 292                                 FILE_OP_ERROR(dest, "claws_unlink");
 293                         if (dest_bak) {
 294                                 if (rename_force(dest_bak, dest) < 0)
 295                                         FILE_OP_ERROR(dest_bak, "rename");
 296                                 g_free(dest_bak);
 297                         }
 298                         return -1;
 299                 }
 300         }
 301
 302         if (claws_ferror(src_fp)) {
 303                 FILE_OP_ERROR(src, "claws_fread");
 304                 err = TRUE;
 305         }
 306         claws_fclose(src_fp);
 307         if (claws_safe_fclose(dest_fp) == EOF) {
 308                 FILE_OP_ERROR(dest, "claws_fclose");
 309                 err = TRUE;
 310         }
 311
 312         if (err) {
 313                 if (claws_unlink(dest) < 0)
 314                         FILE_OP_ERROR(dest, "claws_unlink");
 315                 if (dest_bak) {
 316                         if (rename_force(dest_bak, dest) < 0)
 317                                 FILE_OP_ERROR(dest_bak, "rename");
 318                         g_free(dest_bak);
 319                 }
 320                 return -1;
 321         }
 322
 323         if (keep_backup == FALSE && dest_bak)
 324                 if (claws_unlink(dest_bak) < 0)
 325                         FILE_OP_ERROR(dest_bak, "claws_unlink");
 326
 327         g_free(dest_bak);
 328
 329         return 0;
 330 }
 331
 332 gint move_file(const gchar *src, const gchar *dest, gboolean overwrite)
 333 {
 334         if (overwrite == FALSE && is_file_exist(dest)) {
 335                 g_warning("move_file(): file %s already exists", dest);
 336                 return -1;
 337         }
 338
 339         if (rename_force(src, dest) == 0) return 0;
 340
 341         if (EXDEV != errno) {
 342                 FILE_OP_ERROR(src, "rename");
 343                 return -1;
 344         }
 345
 346         if (copy_file(src, dest, FALSE) < 0) return -1;
 347
 348         claws_unlink(src);
 349
 350         return 0;
 351 }
 352
 353 gint copy_file_part_to_fp(FILE *fp, off_t offset, size_t length, FILE *dest_fp)
 354 {
 355         gint n_read;
 356         gint bytes_left, to_read;
 357         gchar buf[BUFSIZ];
 358
 359         if (fseek(fp, offset, SEEK_SET) < 0) {
 360                 perror("fseek");
 361                 return -1;
 362         }
 363
 364         bytes_left = length;
 365         to_read = MIN(bytes_left, sizeof(buf));
 366
 367         while ((n_read = claws_fread(buf, sizeof(gchar), to_read, fp)) > 0) {
 368                 if (n_read < to_read && claws_ferror(fp))
 369                         break;
 370                 if (claws_fwrite(buf, 1, n_read, dest_fp) < n_read) {
 371                         return -1;
 372                 }
 373                 bytes_left -= n_read;
 374                 if (bytes_left == 0)
 375                         break;
 376                 to_read = MIN(bytes_left, sizeof(buf));
 377         }
 378
 379         if (claws_ferror(fp)) {
 380                 perror("claws_fread");
 381                 return -1;
 382         }
 383
 384         return 0;
 385 }
 386
 387 gint copy_file_part(FILE *fp, off_t offset, size_t length, const gchar *dest)
 388 {
 389         FILE *dest_fp;
 390         gboolean err = FALSE;
 391
 392         if ((dest_fp = claws_fopen(dest, "wb")) == NULL) {
 393                 FILE_OP_ERROR(dest, "claws_fopen");
 394                 return -1;
 395         }
 396
 397         if (change_file_mode_rw(dest_fp, dest) < 0) {
 398                 FILE_OP_ERROR(dest, "chmod");
 399                 g_warning("can't change file mode: %s", dest);
 400         }
 401
 402         if (copy_file_part_to_fp(fp, offset, length, dest_fp) < 0)
 403                 err = TRUE;
 404
 405         if (claws_safe_fclose(dest_fp) == EOF) {
 406                 FILE_OP_ERROR(dest, "claws_fclose");
 407                 err = TRUE;
 408         }
 409
 410         if (err) {
 411                 g_warning("writing to %s failed", dest);
 412                 claws_unlink(dest);
 413                 return -1;
 414         }
 415
 416         return 0;
 417 }
 418
 419 gint canonicalize_file(const gchar *src, const gchar *dest)
 420 {
 421         FILE *src_fp, *dest_fp;
 422         gchar buf[BUFFSIZE];
 423         gint len;
 424         gboolean err = FALSE;
 425         gboolean last_linebreak = FALSE;
 426
 427         if (src == NULL || dest == NULL)
 428                 return -1;
 429
 430         if ((src_fp = claws_fopen(src, "rb")) == NULL) {
 431                 FILE_OP_ERROR(src, "claws_fopen");
 432                 return -1;
 433         }
 434
 435         if ((dest_fp = claws_fopen(dest, "wb")) == NULL) {
 436                 FILE_OP_ERROR(dest, "claws_fopen");
 437                 claws_fclose(src_fp);
 438                 return -1;
 439         }
 440
 441         if (change_file_mode_rw(dest_fp, dest) < 0) {
 442                 FILE_OP_ERROR(dest, "chmod");
 443                 g_warning("can't change file mode: %s", dest);
 444         }
 445
 446         while (claws_fgets(buf, sizeof(buf), src_fp) != NULL) {
 447                 gint r = 0;
 448
 449                 len = strlen(buf);
 450                 if (len == 0) break;
 451                 last_linebreak = FALSE;
 452
 453                 if (buf[len - 1] != '\n') {
 454                         last_linebreak = TRUE;
 455                         r = claws_fputs(buf, dest_fp);
 456                 } else if (len > 1 && buf[len - 1] == '\n' && buf[len - 2] == '\r') {
 457                         r = claws_fputs(buf, dest_fp);
 458                 } else {
 459                         if (len > 1) {
 460                                 r = claws_fwrite(buf, 1, len - 1, dest_fp);
 461                                 if (r != (len -1))
 462                                         r = EOF;
 463                         }
 464                         if (r != EOF)
 465                                 r = claws_fputs("\r\n", dest_fp);
 466                 }
 467
 468                 if (r == EOF) {
 469                         g_warning("writing to %s failed", dest);
 470                         claws_fclose(dest_fp);
 471                         claws_fclose(src_fp);
 472                         claws_unlink(dest);
 473                         return -1;
 474                 }
 475         }
 476
 477         if (last_linebreak == TRUE) {
 478                 if (claws_fputs("\r\n", dest_fp) == EOF)
 479                         err = TRUE;
 480         }
 481
 482         if (claws_ferror(src_fp)) {
 483                 FILE_OP_ERROR(src, "claws_fgets");
 484                 err = TRUE;
 485         }
 486         claws_fclose(src_fp);
 487         if (claws_safe_fclose(dest_fp) == EOF) {
 488                 FILE_OP_ERROR(dest, "claws_fclose");
 489                 err = TRUE;
 490         }
 491
 492         if (err) {
 493                 claws_unlink(dest);
 494                 return -1;
 495         }
 496
 497         return 0;
 498 }
 499
 500 gint canonicalize_file_replace(const gchar *file)
 501 {
 502         gchar *tmp_file;
 503
 504         tmp_file = get_tmp_file();
 505
 506         if (canonicalize_file(file, tmp_file) < 0) {
 507                 g_free(tmp_file);
 508                 return -1;
 509         }
 510
 511         if (move_file(tmp_file, file, TRUE) < 0) {
 512                 g_warning("can't replace file: %s", file);
 513                 claws_unlink(tmp_file);
 514                 g_free(tmp_file);
 515                 return -1;
 516         }
 517
 518         g_free(tmp_file);
 519         return 0;
 520 }
 521
 522
 523 gint str_write_to_file(const gchar *str, const gchar *file, gboolean safe)
 524 {
 525         FILE *fp;
 526         size_t len;
 527         int r;
 528
 529         cm_return_val_if_fail(str != NULL, -1);
 530         cm_return_val_if_fail(file != NULL, -1);
 531
 532         if ((fp = claws_fopen(file, "wb")) == NULL) {
 533                 FILE_OP_ERROR(file, "claws_fopen");
 534                 return -1;
 535         }
 536
 537         len = strlen(str);
 538         if (len == 0) {
 539                 claws_fclose(fp);
 540                 return 0;
 541         }
 542
 543         if (claws_fwrite(str, 1, len, fp) != len) {
 544                 FILE_OP_ERROR(file, "claws_fwrite");
 545                 claws_fclose(fp);
 546                 claws_unlink(file);
 547                 return -1;
 548         }
 549
 550         if (safe) {
 551                 r = claws_safe_fclose(fp);
 552         } else {
 553                 r = claws_fclose(fp);
 554         }
 555
 556         if (r == EOF) {
 557                 FILE_OP_ERROR(file, "claws_fclose");
 558                 claws_unlink(file);
 559                 return -1;
 560         }
 561
 562         return 0;
 563 }
 564
 565 static gchar *file_read_stream_to_str_full(FILE *fp, gboolean recode)
 566 {
 567         GByteArray *array;
 568         guchar buf[BUFSIZ];
 569         gint n_read;
 570         gchar *str;
 571
 572         cm_return_val_if_fail(fp != NULL, NULL);
 573
 574         array = g_byte_array_new();
 575
 576         while ((n_read = claws_fread(buf, sizeof(gchar), sizeof(buf), fp)) > 0) {
 577                 if (n_read < sizeof(buf) && claws_ferror(fp))
 578                         break;
 579                 g_byte_array_append(array, buf, n_read);
 580         }
 581
 582         if (claws_ferror(fp)) {
 583                 FILE_OP_ERROR("file stream", "claws_fread");
 584                 g_byte_array_free(array, TRUE);
 585                 return NULL;
 586         }
 587
 588         buf[0] = '\0';
 589         g_byte_array_append(array, buf, 1);
 590         str = (gchar *)array->data;
 591         g_byte_array_free(array, FALSE);
 592
 593         if (recode && !g_utf8_validate(str, -1, NULL)) {
 594                 const gchar *src_codeset, *dest_codeset;
 595                 gchar *tmp = NULL;
 596                 src_codeset = conv_get_locale_charset_str();
 597                 dest_codeset = CS_UTF_8;
 598                 tmp = conv_codeset_strdup(str, src_codeset, dest_codeset);
 599                 g_free(str);
 600                 str = tmp;
 601         }
 602
 603         return str;
 604 }
 605
 606 static gchar *file_read_to_str_full(const gchar *file, gboolean recode)
 607 {
 608         FILE *fp;
 609         gchar *str;
 610         GStatBuf s;
 611 #ifndef G_OS_WIN32
 612         gint fd, err;
 613         struct timeval timeout = {1, 0};
 614         fd_set fds;
 615         int fflags = 0;
 616 #endif
 617
 618         cm_return_val_if_fail(file != NULL, NULL);
 619
 620         if (g_stat(file, &s) != 0) {
 621                 FILE_OP_ERROR(file, "stat");
 622                 return NULL;
 623         }
 624         if (S_ISDIR(s.st_mode)) {
 625                 g_warning("%s: is a directory", file);
 626                 return NULL;
 627         }
 628
 629 #ifdef G_OS_WIN32
 630         fp = claws_fopen (file, "rb");
 631         if (fp == NULL) {
 632                 FILE_OP_ERROR(file, "open");
 633                 return NULL;
 634         }
 635 #else
 636         /* test whether the file is readable without blocking */
 637         fd = g_open(file, O_RDONLY | O_NONBLOCK, 0);
 638         if (fd == -1) {
 639                 FILE_OP_ERROR(file, "open");
 640                 return NULL;
 641         }
 642
 643         FD_ZERO(&fds);
 644         FD_SET(fd, &fds);
 645
 646         /* allow for one second */
 647         err = select(fd+1, &fds, NULL, NULL, &timeout);
 648         if (err <= 0 || !FD_ISSET(fd, &fds)) {
 649                 if (err < 0) {
 650                         FILE_OP_ERROR(file, "select");
 651                 } else {
 652                         g_warning("%s: doesn't seem readable", file);
 653                 }
 654                 close(fd);
 655                 return NULL;
 656         }
 657
 658         /* Now clear O_NONBLOCK */
 659         if ((fflags = fcntl(fd, F_GETFL)) < 0) {
 660                 FILE_OP_ERROR(file, "fcntl (F_GETFL)");
 661                 close(fd);
 662                 return NULL;
 663         }
 664         if (fcntl(fd, F_SETFL, (fflags & ~O_NONBLOCK)) < 0) {
 665                 FILE_OP_ERROR(file, "fcntl (F_SETFL)");
 666                 close(fd);
 667                 return NULL;
 668         }
 669
 670         /* get the FILE pointer */
 671         fp = claws_fdopen(fd, "rb");
 672
 673         if (fp == NULL) {
 674                 FILE_OP_ERROR(file, "claws_fdopen");
 675                 close(fd); /* if fp isn't NULL, we'll use claws_fclose instead! */
 676                 return NULL;
 677         }
 678 #endif
 679
 680         str = file_read_stream_to_str_full(fp, recode);
 681
 682         claws_fclose(fp);
 683
 684         return str;
 685 }
 686
 687 gchar *file_read_to_str(const gchar *file)
 688 {
 689         return file_read_to_str_full(file, TRUE);
 690 }
 691 gchar *file_read_stream_to_str(FILE *fp)
 692 {
 693         return file_read_stream_to_str_full(fp, TRUE);
 694 }
 695
 696 gchar *file_read_to_str_no_recode(const gchar *file)
 697 {
 698         return file_read_to_str_full(file, FALSE);
 699 }
 700 gchar *file_read_stream_to_str_no_recode(FILE *fp)
 701 {
 702         return file_read_stream_to_str_full(fp, FALSE);
 703 }
 704
 705 gint rename_force(const gchar *oldpath, const gchar *newpath)
 706 {
 707 #ifndef G_OS_UNIX
 708         if (!is_file_entry_exist(oldpath)) {
 709                 errno = ENOENT;
 710                 return -1;
 711         }
 712         if (is_file_exist(newpath)) {
 713                 if (claws_unlink(newpath) < 0)
 714                         FILE_OP_ERROR(newpath, "unlink");
 715         }
 716 #endif
 717         return g_rename(oldpath, newpath);
 718 }
 719
 720 gint copy_dir(const gchar *src, const gchar *dst)
 721 {
 722         GDir *dir;
 723         const gchar *name;
 724
 725         if ((dir = g_dir_open(src, 0, NULL)) == NULL) {
 726                 g_warning("failed to open directory: %s", src);
 727                 return -1;
 728         }
 729
 730         if (make_dir(dst) < 0) {
 731                 g_dir_close(dir);
 732                 return -1;
 733         }
 734
 735         while ((name = g_dir_read_name(dir)) != NULL) {
 736                 gchar *old_file, *new_file;
 737                 gint r = 0;
 738                 old_file = g_strconcat(src, G_DIR_SEPARATOR_S, name, NULL);
 739                 new_file = g_strconcat(dst, G_DIR_SEPARATOR_S, name, NULL);
 740                 debug_print("copying: %s -> %s\n", old_file, new_file);
 741                 if (g_file_test(old_file, G_FILE_TEST_IS_REGULAR)) {
 742                         r = copy_file(old_file, new_file, TRUE);
 743                 }
 744 #ifndef G_OS_WIN32
 745                 /* Windows has no symlinks.  Or well, Vista seems to
 746                    have something like this but the semantics might be
 747                    different. Thus we don't use it under Windows. */
 748                 else if (g_file_test(old_file, G_FILE_TEST_IS_SYMLINK)) {
 749                         GError *error = NULL;
 750                         gchar *target = g_file_read_link(old_file, &error);
 751                         if (error) {
 752                                 g_warning("couldn't read link: %s", error->message);
 753                                 g_error_free(error);
 754                         }
 755                         if (target) {
 756                                 r = symlink(target, new_file);
 757                                 g_free(target);
 758                         }
 759                 }
 760 #endif /*G_OS_WIN32*/
 761                 else if (g_file_test(old_file, G_FILE_TEST_IS_DIR)) {
 762                         r = copy_dir(old_file, new_file);
 763                 }
 764                 g_free(old_file);
 765                 g_free(new_file);
 766                 if (r < 0) {
 767                         g_dir_close(dir);
 768                         return r;
 769                 }
 770         }
 771         g_dir_close(dir);
 772         return 0;
 773 }
 774
 775 gint change_file_mode_rw(FILE *fp, const gchar *file)
 776 {
 777 #if HAVE_FCHMOD
 778         return fchmod(fileno(fp), S_IRUSR|S_IWUSR);
 779 #else
 780         return g_chmod(file, S_IRUSR|S_IWUSR);
 781 #endif
 782 }
 783
 784 FILE *my_tmpfile(void)
 785 {
 786         const gchar suffix[] = ".XXXXXX";
 787         const gchar *tmpdir;
 788         guint tmplen;
 789         const gchar *progname;
 790         guint proglen;
 791         gchar *fname;
 792         gint fd;
 793         FILE *fp;
 794 #ifndef G_OS_WIN32
 795         gchar buf[2]="\0";
 796 #endif
 797
 798         tmpdir = get_tmp_dir();
 799         tmplen = strlen(tmpdir);
 800         progname = g_get_prgname();
 801         if (progname == NULL)
 802                 progname = "claws-mail";
 803         proglen = strlen(progname);
 804         Xalloca(fname, tmplen + 1 + proglen + sizeof(suffix),
 805                 return tmpfile());
 806
 807         memcpy(fname, tmpdir, tmplen);
 808         fname[tmplen] = G_DIR_SEPARATOR;
 809         memcpy(fname + tmplen + 1, progname, proglen);
 810         memcpy(fname + tmplen + 1 + proglen, suffix, sizeof(suffix));
 811
 812         fd = g_mkstemp(fname);
 813         if (fd < 0)
 814                 return tmpfile();
 815
 816 #ifndef G_OS_WIN32
 817         claws_unlink(fname);
 818
 819         /* verify that we can write in the file after unlinking */
 820         if (write(fd, buf, 1) < 0) {
 821                 close(fd);
 822                 return tmpfile();
 823         }
 824
 825 #endif
 826
 827         fp = claws_fdopen(fd, "w+b");
 828         if (!fp)
 829                 close(fd);
 830         else {
 831                 rewind(fp);
 832                 return fp;
 833         }
 834
 835         return tmpfile();
 836 }
 837
 838 FILE *get_tmpfile_in_dir(const gchar *dir, gchar **filename)
 839 {
 840         int fd;
 841         *filename = g_strdup_printf("%s%cclaws.XXXXXX", dir, G_DIR_SEPARATOR);
 842         fd = g_mkstemp(*filename);
 843         if (fd < 0)
 844                 return NULL;
 845         return claws_fdopen(fd, "w+");
 846 }
 847
 848 FILE *str_open_as_stream(const gchar *str)
 849 {
 850         FILE *fp;
 851         size_t len;
 852
 853         cm_return_val_if_fail(str != NULL, NULL);
 854
 855         len = strlen(str);
 856
 857         fp = my_tmpfile();
 858
 859         if (!fp) {
 860                 FILE_OP_ERROR("str_open_as_stream", "my_tmpfile");
 861                 return NULL;
 862         }
 863
 864         len = strlen(str);
 865         if (len == 0) return fp;
 866
 867         if (claws_fwrite(str, 1, len, fp) != len) {
 868                 FILE_OP_ERROR("str_open_as_stream", "claws_fwrite");
 869                 claws_fclose(fp);
 870                 return NULL;
 871         }
 872
 873         rewind(fp);
 874         return fp;
 875 }