As explained on ShellCheck's wiki [1], it is recommended to avoid
backquotes `...` in favour of parenthesis $(...):
> Backtick command substitution `...` is legacy syntax with several
> issues.
>
> - It has a series of undefined behaviors related to quoting in POSIX.
> - It imposes a custom escaping mode with surprising results.
> - It's exceptionally hard to nest.
>
> $(...) command substitution has none of these problems, and is
> therefore strongly encouraged.
[1] https://www.shellcheck.net/wiki/SC2006
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---
.../testing/selftests/net/mptcp/mptcp_join.sh | 66 ++++++++++---------
1 file changed, 34 insertions(+), 32 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index f5e17cd2a7df..f61c3804f5e0 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -84,7 +84,7 @@ init_partial()
# ns1eth4 ns2eth4
local i
- for i in `seq 1 4`; do
+ for i in $(seq 1 4); do
ip link add ns1eth$i netns "$ns1" type veth peer name ns2eth$i netns "$ns2"
ip -net "$ns1" addr add 10.0.$i.1/24 dev ns1eth$i
ip -net "$ns1" addr add dead:beef:$i::1/64 dev ns1eth$i nodad
@@ -103,7 +103,7 @@ init_partial()
init_shapers()
{
local i
- for i in `seq 1 4`; do
+ for i in $(seq 1 4); do
tc -n $ns1 qdisc add dev ns1eth$i root netem rate 20mbit delay 1
tc -n $ns2 qdisc add dev ns2eth$i root netem rate 20mbit delay 1
done
@@ -1014,7 +1014,7 @@ chk_csum_nr()
echo -n " "
fi
printf " %-36s %s" "$msg" "sum"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != $csum_ns1 -a $allow_multi_errors_ns1 -eq 0 ] ||
[ "$count" -lt $csum_ns1 -a $allow_multi_errors_ns1 -eq 1 ]; then
@@ -1025,7 +1025,7 @@ chk_csum_nr()
echo -n "[ ok ]"
fi
echo -n " - csum "
- count=`ip netns exec $ns2 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}'`
+ count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtDataCsumErr | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != $csum_ns2 -a $allow_multi_errors_ns2 -eq 0 ] ||
[ "$count" -lt $csum_ns2 -a $allow_multi_errors_ns2 -eq 1 ]; then
@@ -1046,7 +1046,7 @@ chk_fail_nr()
local dump_stats
printf "%-${nr_blank}s %s" " " "ftx"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPFailTx | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPFailTx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$fail_tx" ]; then
echo "[fail] got $count MP_FAIL[s] TX expected $fail_tx"
@@ -1057,7 +1057,7 @@ chk_fail_nr()
fi
echo -n " - failrx"
- count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPFailRx | awk '{print $2}'`
+ count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtMPFailRx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$fail_rx" ]; then
echo "[fail] got $count MP_FAIL[s] RX expected $fail_rx"
@@ -1199,7 +1199,7 @@ chk_join_nr()
fi
printf "%03u %-36s %s" "${TEST_COUNT}" "${title}" "syn"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$syn_nr" ]; then
echo "[fail] got $count JOIN[s] syn expected $syn_nr"
@@ -1210,8 +1210,8 @@ chk_join_nr()
fi
echo -n " - synack"
- with_cookie=`ip netns exec $ns2 sysctl -n net.ipv4.tcp_syncookies`
- count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinSynAckRx | awk '{print $2}'`
+ with_cookie=$(ip netns exec $ns2 sysctl -n net.ipv4.tcp_syncookies)
+ count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinSynAckRx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$syn_ack_nr" ]; then
# simult connections exceeding the limit with cookie enabled could go up to
@@ -1229,7 +1229,7 @@ chk_join_nr()
fi
echo -n " - ack"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinAckRx | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinAckRx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$ack_nr" ]; then
echo "[fail] got $count JOIN[s] ack expected $ack_nr"
@@ -1263,9 +1263,9 @@ chk_stale_nr()
local recover_nr
printf "%-${nr_blank}s %-18s" " " "stale"
- stale_nr=`ip netns exec $ns nstat -as | grep MPTcpExtSubflowStale | awk '{print $2}'`
+ stale_nr=$(ip netns exec $ns nstat -as | grep MPTcpExtSubflowStale | awk '{print $2}')
[ -z "$stale_nr" ] && stale_nr=0
- recover_nr=`ip netns exec $ns nstat -as | grep MPTcpExtSubflowRecover | awk '{print $2}'`
+ recover_nr=$(ip netns exec $ns nstat -as | grep MPTcpExtSubflowRecover | awk '{print $2}')
[ -z "$recover_nr" ] && recover_nr=0
if [ $stale_nr -lt $stale_min ] ||
@@ -1301,10 +1301,10 @@ chk_add_nr()
local dump_stats
local timeout
- timeout=`ip netns exec $ns1 sysctl -n net.mptcp.add_addr_timeout`
+ timeout=$(ip netns exec $ns1 sysctl -n net.mptcp.add_addr_timeout)
printf "%-${nr_blank}s %s" " " "add"
- count=`ip netns exec $ns2 nstat -as MPTcpExtAddAddr | grep MPTcpExtAddAddr | awk '{print $2}'`
+ count=$(ip netns exec $ns2 nstat -as MPTcpExtAddAddr | grep MPTcpExtAddAddr | awk '{print $2}')
[ -z "$count" ] && count=0
# if the test configured a short timeout tolerate greater then expected
@@ -1318,7 +1318,7 @@ chk_add_nr()
fi
echo -n " - echo "
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtEchoAdd | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtEchoAdd | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$echo_nr" ]; then
echo "[fail] got $count ADD_ADDR echo[s] expected $echo_nr"
@@ -1330,7 +1330,7 @@ chk_add_nr()
if [ $port_nr -gt 0 ]; then
echo -n " - pt "
- count=`ip netns exec $ns2 nstat -as | grep MPTcpExtPortAdd | awk '{print $2}'`
+ count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtPortAdd | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$port_nr" ]; then
echo "[fail] got $count ADD_ADDR[s] with a port-number expected $port_nr"
@@ -1341,8 +1341,8 @@ chk_add_nr()
fi
printf "%-${nr_blank}s %s" " " "syn"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinPortSynRx |
- awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinPortSynRx |
+ awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$syn_nr" ]; then
echo "[fail] got $count JOIN[s] syn with a different \
@@ -1354,8 +1354,8 @@ chk_add_nr()
fi
echo -n " - synack"
- count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinPortSynAckRx |
- awk '{print $2}'`
+ count=$(ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinPortSynAckRx |
+ awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$syn_ack_nr" ]; then
echo "[fail] got $count JOIN[s] synack with a different \
@@ -1367,8 +1367,8 @@ chk_add_nr()
fi
echo -n " - ack"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinPortAckRx |
- awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinPortAckRx |
+ awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$ack_nr" ]; then
echo "[fail] got $count JOIN[s] ack with a different \
@@ -1380,8 +1380,8 @@ chk_add_nr()
fi
printf "%-${nr_blank}s %s" " " "syn"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMismatchPortSynRx |
- awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMismatchPortSynRx |
+ awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$mis_syn_nr" ]; then
echo "[fail] got $count JOIN[s] syn with a mismatched \
@@ -1393,8 +1393,8 @@ chk_add_nr()
fi
echo -n " - ack "
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMismatchPortAckRx |
- awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMismatchPortAckRx |
+ awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$mis_ack_nr" ]; then
echo "[fail] got $count JOIN[s] ack with a mismatched \
@@ -1440,7 +1440,7 @@ chk_rm_nr()
fi
printf "%-${nr_blank}s %s" " " "rm "
- count=`ip netns exec $addr_ns nstat -as | grep MPTcpExtRmAddr | awk '{print $2}'`
+ count=$(ip netns exec $addr_ns nstat -as | grep MPTcpExtRmAddr | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$rm_addr_nr" ]; then
echo "[fail] got $count RM_ADDR[s] expected $rm_addr_nr"
@@ -1451,7 +1451,7 @@ chk_rm_nr()
fi
echo -n " - rmsf "
- count=`ip netns exec $subflow_ns nstat -as | grep MPTcpExtRmSubflow | awk '{print $2}'`
+ count=$(ip netns exec $subflow_ns nstat -as | grep MPTcpExtRmSubflow | awk '{print $2}')
[ -z "$count" ] && count=0
if [ -n "$simult" ]; then
local cnt=$(ip netns exec $addr_ns nstat -as | grep MPTcpExtRmSubflow | awk '{print $2}')
@@ -1493,7 +1493,7 @@ chk_prio_nr()
local dump_stats
printf "%-${nr_blank}s %s" " " "ptx"
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioTx | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioTx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$mp_prio_nr_tx" ]; then
echo "[fail] got $count MP_PRIO[s] TX expected $mp_prio_nr_tx"
@@ -1504,7 +1504,7 @@ chk_prio_nr()
fi
echo -n " - prx "
- count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioRx | awk '{print $2}'`
+ count=$(ip netns exec $ns1 nstat -as | grep MPTcpExtMPPrioRx | awk '{print $2}')
[ -z "$count" ] && count=0
if [ "$count" != "$mp_prio_nr_rx" ]; then
echo "[fail] got $count MP_PRIO[s] RX expected $mp_prio_nr_rx"
@@ -1523,8 +1523,10 @@ chk_link_usage()
local link=$2
local out=$3
local expected_rate=$4
- local tx_link=`ip netns exec $ns cat /sys/class/net/$link/statistics/tx_bytes`
- local tx_total=`ls -l $out | awk '{print $5}'`
+
+ local tx_link tx_total
+ tx_link=$(ip netns exec $ns cat /sys/class/net/$link/statistics/tx_bytes)
+ tx_total=$(ls -l $out | awk '{print $5}')
local tx_rate=$((tx_link * 100 / $tx_total))
local tolerance=5
--
2.34.1