Initial revision

lib/full-write.c

@@ -0,0 +1,65 @@
+/* full-write.c -- an interface to write that retries after interrupts
+   Copyright (C) 1993, 1994, 1997, 1998 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
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   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.
+   */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#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.  */
+
+int
+full_write (int desc, const char *ptr, size_t len)
+{
+  int total_written;
+
+  total_written = 0;
+  while (len > 0)
+    {
+      int written = write (desc, ptr, len);
+      /* FIXME: write on my 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 (written < 0)
+	{
+#ifdef EINTR
+	  if (errno == EINTR)
+	    continue;
+#endif
+	  return written;
+	}
+      total_written += written;
+      ptr += written;
+      len -= written;
+    }
+  return total_written;
+}