device_open.c 1.3 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Utility routines.
  4. *
  5. * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  6. *
  7. * This program is free software; you can redistribute it and/or modify
  8. * it under the terms of the GNU General Public License as published by
  9. * the Free Software Foundation; either version 2 of the License, or
  10. * (at your option) any later version.
  11. *
  12. * This program is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15. * General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU General Public License
  18. * along with this program; if not, write to the Free Software
  19. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20. */
  21. #include <stdio.h>
  22. #include <fcntl.h>
  23. #include "libbb.h"
  24. /* try to open up the specified device */
  25. int device_open(const char *device, int mode)
  26. {
  27. int m, f, fd = -1;
  28. m = mode | O_NONBLOCK;
  29. /* Retry up to 5 times */
  30. for (f = 0; f < 5; f++)
  31. if ((fd = open(device, m, 0600)) >= 0)
  32. break;
  33. if (fd < 0)
  34. return fd;
  35. /* Reset original flags. */
  36. if (m != mode)
  37. fcntl(fd, F_SETFL, mode);
  38. return fd;
  39. }
  40. /* END CODE */
  41. /*
  42. Local Variables:
  43. c-file-style: "linux"
  44. c-basic-offset: 4
  45. tab-width: 4
  46. End:
  47. */