Added test

tests/Modifiers_-_--line-mode.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+#
+# Check that line mode counts lines instead of bytes.
+
+# Dummy assignments for "shellcheck".
+testSubject="${testSubject:-false}"; workFile1="${workFile1:-.tmp1}"
+
+# Pass through 100 lines.
+#
+seq 1 100 \
+| "${testSubject}" -bl -i 0.2 -f -L 50 >/dev/null 2>"${workFile1}"
+
+lineCount=$(tr '\r' '\n' < "${workFile1}" | sort | uniq -u | wc -l | tr -dc '0-9')
+lastNumber=$(tr '\r' '\n' < "${workFile1}" | awk '/[0-9]/{printf "%.0f\n",$1}' | sed -n '$p')
+
+# The last number output should be the number of input lines.
+if ! test "${lastNumber}" = "100"; then
+	echo "line counter was incorrect (${lastNumber} instead of 100)"
+	tr '\r' '\n' < "${workFile1}"
+	exit 1
+fi
+
+# There should be more than 3 output lines as the counter increased.
+if ! test "${lineCount}" -gt 3; then
+	echo "fewer than 4 line counter values (${lineCount})"
+	tr '\r' '\n' < "${workFile1}"
+	exit 1
+fi
+
+exit 0
+
+# EOF