samples: pktgen: add trap SIGINT for printing execution result

All pktgen samples can send indefinitely num messages per thread by
setting the count option to 0(-n 0). If running sample with setting
count 0 and press Ctrl-C to stop this program, the program prints the
result of the execution so far. Currently, the samples besides
sample{3...5} don't work properly. Because Ctrl-C stops the script, not
just pktgen.

This is results of samples:

    # DEV=eth0 DEST_IP=10.1.0.1 DST_MAC=00:11:22:33:44:55 ./pktgen_sample04_many_flows.sh -n 0
    Running... ctrl^C to stop
    ^CDevice: eth0@0
    Result: OK: 569657(c569538+d118) usec, 84650 (60byte,0frags)
    148597pps 71Mb/sec (71326560bps) errors: 0

    # DEV=eth0 DEST_IP=10.1.0.1 DST_MAC=00:11:22:33:44:55 ./pktgen_sample01_simple.sh -n 0
    Running... ctrl^C to stop
    ^C

In order to solve this, this commit adds trap SIGINT. Also, this commit
changes control_c function to print_result to maintain consistency with
other samples.

Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 6 deletions

diff --git a/samples/pktgen/pktgen_sample02_multiqueue.sh b/samples/pktgen/pktgen_sample02_multiqueue.sh
index c6af3d9d5171..7fa41c84c32f 100755
--- a/samples/pktgen/pktgen_sample02_multiqueue.sh
+++ b/samples/pktgen/pktgen_sample02_multiqueue.sh
@@ -83,18 +83,25 @@ for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do
     pg_set $dev "udp_src_max $UDP_SRC_MAX"
 done
 
-if [ -z "$APPEND" ]; then
-    # start_run
-    echo "Running... ctrl^C to stop" >&2
-    pg_ctrl "start"
-    echo "Done" >&2
-
+# Run if user hits control-c
+function print_result() {
     # Print results
     for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do
         dev=${DEV}@${thread}
         echo "Device: $dev"
         cat /proc/net/pktgen/$dev | grep -A2 "Result:"
     done
+}
+# trap keyboard interrupt (Ctrl-C)
+trap true SIGINT
+
+if [ -z "$APPEND" ]; then
+    # start_run
+    echo "Running... ctrl^C to stop" >&2
+    pg_ctrl "start"
+    echo "Done" >&2
+
+    print_result
 else
     echo "Append mode: config done. Do more or use 'pg_ctrl start' to run"
 fi