LXR busybox/libbb/device

   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 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8 */
   9
  10#include "libbb.h"
  11
  12/* try to open up the specified device */
  13int FAST_FUNC device_open(const char *device, int mode)
  14{
  15        int m, f, fd;
  16
  17        m = mode | O_NONBLOCK;
  18
  19        /* Retry up to 5 times */
  20        /* TODO: explain why it can't be considered insane */
  21        for (f = 0; f < 5; f++) {
  22                fd = open(device, m, 0600);
  23                if (fd >= 0)
  24                        break;
  25        }
  26        if (fd < 0)
  27                return fd;
  28        /* Reset original flags. */
  29        if (m != mode)
  30                fcntl(fd, F_SETFL, mode);
  31        return fd;
  32}
  33