Use writev(2) to write history records using a single syscall.

OK deraadt@

diff --git a/bin/ksh/history.c b/bin/ksh/history.c
index be9874f..8d75212 100644 (file)
--- 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;