From 1d976324765399d96b1aeabf04b2bf7ac358b3db Mon Sep 17 00:00:00 2001
From: millert <millert@openbsd.org>
Date: Wed, 24 Aug 2016 16:09:40 +0000
Subject: [PATCH] Use writev(2) to write history records using a single
 syscall. OK deraadt@

---
 bin/ksh/history.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/bin/ksh/history.c b/bin/ksh/history.c
index be9874f0107..8d75212d106 100644
--- a/bin/ksh/history.c
+++ b/bin/ksh/history.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: history.c,v 1.57 2016/08/24 13:32:17 millert Exp $	*/
+/*	$OpenBSD: history.c,v 1.58 2016/08/24 16:09:40 millert Exp $	*/
 
 /*
  * command history
@@ -14,6 +14,7 @@
  */
 
 #include <sys/stat.h>
+#include <sys/uio.h>
 
 #include <errno.h>
 #include <fcntl.h>
@@ -901,6 +902,7 @@ writehistfile(int lno, char *cmd)
 	unsigned char	*new;
 	int	bytes;
 	unsigned char	hdr[5];
+	struct iovec	iov[2];
 
 	(void) flock(histfd, LOCK_EX);
 	sizenow = lseek(histfd, 0L, SEEK_END);
@@ -941,8 +943,11 @@ writehistfile(int lno, char *cmd)
 	hdr[2] = (lno>>16)&0xff;
 	hdr[3] = (lno>>8)&0xff;
 	hdr[4] = lno&0xff;
-	(void) write(histfd, hdr, 5);
-	(void) write(histfd, cmd, strlen(cmd)+1);
+	iov[0].iov_base = hdr;
+	iov[0].iov_len = 5;
+	iov[1].iov_base = cmd;
+	iov[1].iov_len = strlen(cmd) + 1;
+	(void) writev(histfd, iov, 2);
 	hsize = lseek(histfd, 0L, SEEK_END);
 	(void) flock(histfd, LOCK_UN);
 	return;
-- 
2.20.1