--- /dev/null
+#/bin/bash
+
+# a simple component of unit testing which verifies that the input matches
+# the expected input.
+
+# the single parameter to the script is a file that contains the correct answer.
+
+source "$FEISTY_MEOW_SCRIPTS/core/functions.sh"
+
+answer_file="$1"; shift
+
+if [ -z "$answer_file" -o ! -f "$answer_file" ]; then
+ echo This script needs a valid file parameter that points at the correct
+ echo values for the data stream.
+ exit 1
+fi
+
+input_save_file="$(mktemp "$TMP/zz_verify_input.XXXXXX")"
+
+while read line; do
+ echo $line >>"$input_save_file"
+done
+
+diff -q "$input_save_file" "$answer_file"
+if [ $? -ne 0 ]; then
+ sep 76
+ echo "The provided text differs from the correct answer!"
+ echo -e "\nAnswer file has:\n=============="
+ cat "$answer_file"
+ echo -e "==============\nBut the data we saw has:\n=============="
+ cat "$input_save_file"
+ echo -e "=============="
+ sep 76
+ false # set bad exit value.
+fi
+
+rm "$input_save_file"
+
+exit $?
+