diff --git a/contrib/pjdfstest/tests/ftruncate/12.t b/contrib/pjdfstest/tests/ftruncate/12.t
index 98f3daeaf461..022f2cdae47a 100644
--- a/contrib/pjdfstest/tests/ftruncate/12.t
+++ b/contrib/pjdfstest/tests/ftruncate/12.t
@@ -1,28 +1,28 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/truncate/12.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="truncate returns EFBIG or EINVAL if the length argument was greater than the maximum file size"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 echo "1..3"
 
 n0=`namegen`
 
 expect 0 create ${n0} 0644
 r=`${fstest} truncate ${n0} 999999999999999 2>/dev/null`
 case "${r}" in
 EFBIG|EINVAL)
 	expect 0 stat ${n0} size
 	;;
 0)
 	expect 999999999999999 stat ${n0} size
 	;;
 *)
 	echo "not ok ${ntest}"
-	ntest=`expr ${ntest} + 1`
+	ntest=$((ntest + 1))
 	;;
 esac
 expect 0 unlink ${n0}
diff --git a/contrib/pjdfstest/tests/link/05.t b/contrib/pjdfstest/tests/link/05.t
index e6a7d1cc8201..4641e3605efb 100644
--- a/contrib/pjdfstest/tests/link/05.t
+++ b/contrib/pjdfstest/tests/link/05.t
@@ -1,38 +1,38 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/link/05.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="link returns EMLINK if the link count of the file named by name1 would exceed {PC_LINK_MAX}"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 [ "${os}:${fs}" = "FreeBSD:UFS" ] || quick_exit
 
 echo "1..5"
 
 n0=`namegen`
 n1=`namegen`
 n2=`namegen`
 
 expect 0 mkdir ${n0} 0755
 n=`mdconfig -a -n -t malloc -s 2m` || exit
 newfs -i 1 /dev/md${n} >/dev/null || exit
 mount /dev/md${n} ${n0} || exit
 link_max=`${fstest} pathconf ${n0} _PC_LINK_MAX`
 expect 0 create ${n0}/${n1} 0644
 i=1
 while [ ${i} -le ${link_max} ]; do
 	link ${n0}/${n1} ${n0}/${i} >/dev/null 2>&1
 	if [ $? -ne 0 ]; then
 		break
 	fi
-	i=`expr $i + 1`
+	i=$((i + 1))
 done
 test_check $i -eq ${link_max}
 
 expect EMLINK link ${n0}/${n1} ${n0}/${n2}
 
 umount /dev/md${n}
 mdconfig -d -u ${n} || exit
 expect 0 rmdir ${n0}
diff --git a/contrib/pjdfstest/tests/link/15.t b/contrib/pjdfstest/tests/link/15.t
index cb41ad503370..0dc7648df5cb 100644
--- a/contrib/pjdfstest/tests/link/15.t
+++ b/contrib/pjdfstest/tests/link/15.t
@@ -1,34 +1,34 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/link/15.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="link returns ENOSPC if the directory in which the entry for the new link is being placed cannot be extended because there is no space left on the file system containing the directory"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 [ "${os}:${fs}" = "FreeBSD:UFS" ] || quick_exit
 
 echo "1..4"
 
 n0=`namegen`
 n1=`namegen`
 n2=`namegen`
 
 expect 0 mkdir ${n0} 0755
 n=`mdconfig -a -n -t malloc -s 512k` || exit
 newfs /dev/md${n} >/dev/null || exit
 mount /dev/md${n} ${n0} || exit
 expect 0 create ${n0}/${n1} 0644
 i=0
 while :; do
 	link ${n0}/${n1} ${n0}/${i} >/dev/null 2>&1
 	if [ $? -ne 0 ]; then
 		break
 	fi
-	i=`expr $i + 1`
+	i=$((i + 1))
 done
 expect ENOSPC link ${n0}/${n1} ${n0}/${n2}
 umount /dev/md${n}
 mdconfig -d -u ${n} || exit
 expect 0 rmdir ${n0}
diff --git a/contrib/pjdfstest/tests/mkdir/11.t b/contrib/pjdfstest/tests/mkdir/11.t
index 118ca3af8896..f162f6d4eb86 100644
--- a/contrib/pjdfstest/tests/mkdir/11.t
+++ b/contrib/pjdfstest/tests/mkdir/11.t
@@ -1,32 +1,32 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/mkdir/11.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="mkdir returns ENOSPC if there are no free inodes on the file system on which the directory is being created"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 [ "${os}:${fs}" = "FreeBSD:UFS" ] || quick_exit
 
 echo "1..3"
 
 n0=`namegen`
 n1=`namegen`
 
 expect 0 mkdir ${n0} 0755
 n=`mdconfig -a -n -t malloc -s 512k` || exit
 newfs /dev/md${n} >/dev/null || exit
 mount /dev/md${n} ${n0} || exit
 i=0
 while :; do
 	mkdir ${n0}/${i} >/dev/null 2>&1
 	if [ $? -ne 0 ]; then
 		break
 	fi
-	i=`expr $i + 1`
+	i=$((i + 1))
 done
 expect ENOSPC mkdir ${n0}/${n1} 0755
 umount /dev/md${n}
 mdconfig -d -u ${n} || exit
 expect 0 rmdir ${n0}
diff --git a/contrib/pjdfstest/tests/mkfifo/11.t b/contrib/pjdfstest/tests/mkfifo/11.t
index 39cfea4e40f7..73d4a5d09f30 100644
--- a/contrib/pjdfstest/tests/mkfifo/11.t
+++ b/contrib/pjdfstest/tests/mkfifo/11.t
@@ -1,32 +1,32 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/mkfifo/11.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="mkfifo returns ENOSPC if there are no free inodes on the file system on which the file is being created"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 [ "${os}:${fs}" = "FreeBSD:UFS" ] || quick_exit
 
 echo "1..3"
 
 n0=`namegen`
 n1=`namegen`
 
 expect 0 mkdir ${n0} 0755
 n=`mdconfig -a -n -t malloc -s 512k` || exit
 newfs /dev/md${n} >/dev/null || exit
 mount /dev/md${n} ${n0} || exit
 i=0
 while :; do
 	mkfifo ${n0}/${i} >/dev/null 2>&1
 	if [ $? -ne 0 ]; then
 		break
 	fi
-	i=`expr $i + 1`
+	i=$((i + 1))
 done
 expect ENOSPC mkfifo ${n0}/${n1} 0644
 umount /dev/md${n}
 mdconfig -d -u ${n} || exit
 expect 0 rmdir ${n0}
diff --git a/contrib/pjdfstest/tests/open/19.t b/contrib/pjdfstest/tests/open/19.t
index 4bc2df2a4313..e3c5b35fd96b 100644
--- a/contrib/pjdfstest/tests/open/19.t
+++ b/contrib/pjdfstest/tests/open/19.t
@@ -1,32 +1,32 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/open/19.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="open returns ENOSPC when O_CREAT is specified, the file does not exist, and there are no free inodes on the file system on which the file is being created"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 [ "${os}:${fs}" = "FreeBSD:UFS" ] || quick_exit
 
 echo "1..3"
 
 n0=`namegen`
 n1=`namegen`
 
 expect 0 mkdir ${n0} 0755
 n=`mdconfig -a -n -t malloc -s 512k` || exit
 newfs /dev/md${n} >/dev/null || exit
 mount /dev/md${n} ${n0} || exit
 i=0
 while :; do
 	touch ${n0}/${i} >/dev/null 2>&1
 	if [ $? -ne 0 ]; then
 		break
 	fi
-	i=`expr $i + 1`
+	i=$((i + 1))
 done
 expect ENOSPC open ${n0}/${i} O_RDONLY,O_CREAT 0644
 umount /dev/md${n}
 mdconfig -d -u ${n} || exit
 expect 0 rmdir ${n0}
diff --git a/contrib/pjdfstest/tests/symlink/11.t b/contrib/pjdfstest/tests/symlink/11.t
index b1be674370ad..5d5e864674d6 100644
--- a/contrib/pjdfstest/tests/symlink/11.t
+++ b/contrib/pjdfstest/tests/symlink/11.t
@@ -1,32 +1,32 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/symlink/11.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="symlink returns ENOSPC if there are no free inodes on the file system on which the symbolic link is being created"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 [ "${os}:${fs}" = "FreeBSD:UFS" ] || quick_exit
 
 echo "1..3"
 
 n0=`namegen`
 n1=`namegen`
 
 expect 0 mkdir ${n0} 0755
 n=`mdconfig -a -n -t malloc -s 512k` || exit
 newfs /dev/md${n} >/dev/null || exit
 mount /dev/md${n} ${n0} || exit
 i=0
 while :; do
 	ln -s test ${n0}/${i} >/dev/null 2>&1
 	if [ $? -ne 0 ]; then
 		break
 	fi
-	i=`expr $i + 1`
+	i=$((i + 1))
 done
 expect ENOSPC symlink test ${n0}/${n1}
 umount /dev/md${n}
 mdconfig -d -u ${n} || exit
 expect 0 rmdir ${n0}
diff --git a/contrib/pjdfstest/tests/truncate/12.t b/contrib/pjdfstest/tests/truncate/12.t
index 98f3daeaf461..022f2cdae47a 100644
--- a/contrib/pjdfstest/tests/truncate/12.t
+++ b/contrib/pjdfstest/tests/truncate/12.t
@@ -1,28 +1,28 @@
 #!/bin/sh
 # vim: filetype=sh noexpandtab ts=8 sw=8
 # $FreeBSD: head/tools/regression/pjdfstest/tests/truncate/12.t 211352 2010-08-15 21:24:17Z pjd $
 
 desc="truncate returns EFBIG or EINVAL if the length argument was greater than the maximum file size"
 
 dir=`dirname $0`
 . ${dir}/../misc.sh
 
 echo "1..3"
 
 n0=`namegen`
 
 expect 0 create ${n0} 0644
 r=`${fstest} truncate ${n0} 999999999999999 2>/dev/null`
 case "${r}" in
 EFBIG|EINVAL)
 	expect 0 stat ${n0} size
 	;;
 0)
 	expect 999999999999999 stat ${n0} size
 	;;
 *)
 	echo "not ok ${ntest}"
-	ntest=`expr ${ntest} + 1`
+	ntest=$((ntest + 1))
 	;;
 esac
 expect 0 unlink ${n0}