busybox/libbb/device_open.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
/* try to open up the specified device */
int device_open(const char *device, int mode)
{
int m, f, fd = -1;
m = mode | O_NONBLOCK;
/* Retry up to 5 times */
/* TODO: explain why it can't be considered insane */
for (f = 0; f < 5; f++)
if ((fd = open(device, m, 0600)) >= 0)
break;
if (fd < 0)
return fd;
/* Reset original flags. */
if (m != mode)
fcntl(fd, F_SETFL, mode);
return fd;
}