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diff --git a/usr.sbin/sup/lib/filecopy.c b/usr.sbin/sup/lib/filecopy.c
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+++ b/usr.sbin/sup/lib/filecopy.c
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+/*
+ * Copyright (c) 1991 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator   or   Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie the rights
+ * to redistribute these changes.
+ */
+/*  filecopy  --  copy a file from here to there
+ *
+ *  Usage:  i = filecopy (here,there);
+ *	int i, here, there;
+ *
+ *  Filecopy performs a fast copy of the file "here" to the
+ *  file "there".  Here and there are both file descriptors of
+ *  open files; here is open for input, and there for output.
+ *  Filecopy returns 0 if all is OK; -1 on error.
+ *
+ *  I have performed some tests for possible improvements to filecopy.
+ *  Using a buffer size of 10240 provides about a 1.5 times speedup
+ *  over 512 for a file of about 200,000 bytes.  Of course, other
+ *  buffer sized should also work; this is a rather arbitrary choice.
+ *  I have also tried inserting special startup code to attempt
+ *  to align either the input or the output file to lie on a
+ *  physical (512-byte) block boundary prior to the big loop,
+ *  but this presents only a small (about 5% speedup, so I've
+ *  canned that code.  The simple thing seems to be good enough.
+ *
+ *  HISTORY
+ * 20-Nov-79  Steven Shafer (sas) at Carnegie-Mellon University
+ *	Rewritten for VAX; same as "filcopy" on PDP-11.  Bigger buffer
+ *	size (20 physical blocks) seems to be a big win; aligning things
+ *	on block boundaries seems to be a negligible improvement at
+ *	considerable cost in complexity.
+ *
+ */
+
+#define BUFFERSIZE 10240
+
+int filecopy (here,there)
+int here,there;
+{
+	register int kount;
+	char buffer[BUFFERSIZE];
+	kount = 0;
+	while (kount == 0 && (kount=read(here,buffer,BUFFERSIZE)) > 0)
+		kount -= write (there,buffer,kount);
+	return (kount ? -1 : 0);
+}