Provide and suggest update-test.sh in CONTRIBUTING

Provide shell script to update the output for a single test, and suggest
using it in CONTRIBUTING.

1 files changed, 14 insertions, 0 deletions

diff --git a/update-test.sh b/update-test.sh
new file mode 100755
index 00000000..60359d48
--- /dev/null
+++ b/update-test.sh
@@ -0,0 +1,14 @@
+#!/bin/sh
+TEST="$1"
+PREFIX=tests
+MATCH=0
+while read name input output options
+do
+    [ _$name = _ ] && continue		# ignore empty lines
+    [ _${name#\#} != _$name ] && continue	# ignore comment lines
+    [ $name != "$TEST" ] && continue	# not the requested test
+    [ _$output = _ ] && continue	# ignore incomplete lines
+    MATCH=1
+    ./tcpdump -n -t -r "$PREFIX/$input" $options >"$PREFIX/$output"
+done < $PREFIX/TESTLIST
+[ $MATCH = 0 ] && echo "test $TEST not found" >&2