nm -Dg $libc 2>/dev/null | fgrep -q inet_pton || exit 254
 
 trace_libc_inet_pton_backtrace() {
-       idx=0
-       expected[0]="ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)"
-       expected[1]=".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$"
+
+       expected=`mktemp -u /tmp/expected.XXX`
+
+       echo "ping[][0-9 \.:]+probe_libc:inet_pton: \([[:xdigit:]]+\)" > $expected
+       echo ".*inet_pton\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
        case "$(uname -m)" in
        s390x)
                eventattr='call-graph=dwarf,max-stack=4'
-               expected[2]="gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$"
-               expected[3]="(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$"
-               expected[4]="main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$"
+               echo "gaih_inet.*\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
+               echo "(__GI_)?getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc|inlined\)$" >> $expected
+               echo "main\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
                ;;
        *)
                eventattr='max-stack=3'
-               expected[2]="getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$"
-               expected[3]=".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$"
+               echo "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\($libc\)$" >> $expected
+               echo ".*\+0x[[:xdigit:]]+[[:space:]]\(.*/bin/ping.*\)$" >> $expected
                ;;
        esac
 
-       file=`mktemp -u /tmp/perf.data.XXX`
+       perf_data=`mktemp -u /tmp/perf.data.XXX`
+       perf_script=`mktemp -u /tmp/perf.script.XXX`
+       perf record -e probe_libc:inet_pton/$eventattr/ -o $perf_data ping -6 -c 1 ::1 > /dev/null 2>&1
+       perf script -i $perf_data > $perf_script
 
-       perf record -e probe_libc:inet_pton/$eventattr/ -o $file ping -6 -c 1 ::1 > /dev/null 2>&1
-       perf script -i $file | while read line ; do
+       exec 3<$perf_script
+       exec 4<$expected
+       while read line <&3 && read -r pattern <&4; do
+               [ -z "$pattern" ] && break
                echo $line
-               echo "$line" | egrep -q "${expected[$idx]}"
+               echo "$line" | egrep -q "$pattern"
                if [ $? -ne 0 ] ; then
-                       printf "FAIL: expected backtrace entry %d \"%s\" got \"%s\"\n" $idx "${expected[$idx]}" "$line"
+                       printf "FAIL: expected backtrace entry \"%s\" got \"%s\"\n" "$pattern" "$line"
                        exit 1
                fi
-               let idx+=1
-               [ -z "${expected[$idx]}" ] && break
        done
 
        # If any statements are executed from this point onwards,
 perf probe -q $libc inet_pton && \
 trace_libc_inet_pton_backtrace
 err=$?
-rm -f ${file}
+rm -f ${perf_data} ${perf_script} ${expected}
 perf probe -q -d probe_libc:inet_pton
 exit $err