90-fseek.c 1.5 KB

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  1. /* -*-comment-start: "//";comment-end:""-*-
  2. * GNU Mes --- Maxwell Equations of Software
  3. * Copyright © 2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
  4. *
  5. * This file is part of GNU Mes.
  6. *
  7. * GNU Mes is free software; you can redistribute it and/or modify it
  8. * under the terms of the GNU General Public License as published by
  9. * the Free Software Foundation; either version 3 of the License, or (at
  10. * your option) any later version.
  11. *
  12. * GNU Mes is distributed in the hope that it will be useful, but
  13. * WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15. * GNU General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU General Public License
  18. * along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
  19. */
  20. #include <mes/lib.h>
  21. #include <unistd.h>
  22. #include <fcntl.h>
  23. #include <string.h>
  24. #include <stdio.h>
  25. int
  26. main ()
  27. {
  28. int fd = open ("../COPYING", O_RDONLY);
  29. if (fd <= 0)
  30. return 1;
  31. FILE *f = fdopen (fd, "r");
  32. int r = fseek (f, 0, SEEK_CUR);
  33. if (r != 0)
  34. return 2;
  35. int pos = ftell (f);
  36. if (pos != 0)
  37. return 3;
  38. r = fseek (f, 0, SEEK_END);
  39. if (r != 0)
  40. return 4;
  41. pos = ftell (f);
  42. eputs ("size=");
  43. eputs (itoa (pos));
  44. eputs ("\n");
  45. if (pos != 35147)
  46. return 5;
  47. r = fseek (f, 0, SEEK_SET);
  48. char buf[4096];
  49. fgets (buf, 200, f);
  50. eputs ("buf:");
  51. eputs (buf);
  52. if (strcmp (buf, " GNU GENERAL PUBLIC LICENSE\n"))
  53. return 6;
  54. return 0;
  55. }