-/* full-write.c -- an interface to write that retries after interrupts
- Copyright (C) 1993, 1994, 1997, 1998, 2000 Free Software Foundation, Inc.
+/* An interface to write() that writes all it is asked to write.
+
+ Copyright (C) 1993, 1994, 1997, 1998, 1999, 2000, 2001, 2002 Free Software
+ Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-
- Copied largely from GNU C's cccp.c.
- */
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
-#include <sys/types.h>
-
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+/* Specification. */
+#include "full-write.h"
#include <errno.h>
#ifndef errno
extern int errno;
#endif
-/* Write LEN bytes at PTR to descriptor DESC, retrying if interrupted.
- Return LEN upon success, write's (negative) error code otherwise. */
+#include "safe-write.h"
-int
-full_write (int desc, const char *ptr, size_t len)
+/* Write COUNT bytes at BUF to descriptor FD, retrying if interrupted
+ or if partial writes occur. Return the number of bytes successfully
+ written, setting errno if that is less than COUNT. */
+size_t
+full_write (int fd, const void *buf, size_t count)
{
- int total_written;
+ size_t total_written = 0;
- total_written = 0;
- while (len > 0)
+ if (count > 0)
{
- int written = write (desc, ptr, len);
- /* write on an old Slackware Linux 1.2.13 returns zero when
- I try to write more data than there is room on a floppy disk.
- This puts dd into an infinite loop. Reproduce with
- dd if=/dev/zero of=/dev/fd0. If you have this problem,
- consider upgrading to a newer kernel. */
- if (written < 0)
+ const char *ptr = buf;
+
+ do
{
-#ifdef EINTR
- if (errno == EINTR)
- continue;
-#endif
- return written;
+ size_t written = safe_write (fd, ptr, count);
+ if (written == (size_t)-1)
+ break;
+ if (written == 0)
+ {
+ /* Some buggy drivers return 0 when you fall off a device's
+ end. (Example: Linux 1.2.13 on /dev/fd0.) */
+ errno = ENOSPC;
+ break;
+ }
+ total_written += written;
+ ptr += written;
+ count -= written;
}
- total_written += written;
- ptr += written;
- len -= written;
+ while (count > 0);
}
+
return total_written;
}