Major restructuring to switch build system from old scripts to GNU Automake.

tests/General_-_--pidfile.test

@@ -0,0 +1,49 @@
+#!/bin/sh
+#
+# Check that process ID can be written to a file as described in the manual.
+
+# Dummy assignments for "shellcheck".
+testSubject="${testSubject:-false}"; workFile1="${workFile1:-.tmp1}"
+
+# Check we can run "kill -s 0".
+if ! kill -s 0 $$ >/dev/null 2>&1; then
+	echo "cannot check process existence with \`kill -s 0'"
+	exit 77
+fi
+
+dd if=/dev/zero bs=150 count=1 2>/dev/null \
+| "${testSubject}" -q -L 50 -P "${workFile1}" >/dev/null 2>/dev/null \
+&
+
+testPid="$!"
+sleep 1
+
+storedPid=$(cat "${workFile1}" 2>/dev/null)
+
+pidValid="0"
+kill -s 0 "${storedPid}" 2>/dev/null && pidValid="1"
+
+wait
+
+sleep 1
+
+if test -s "${workFile1}"; then
+	echo "PID file was not removed on exit"
+	exit 1
+fi
+
+true > "${workFile1}"
+
+if ! test "${testPid}" = "${storedPid}"; then
+	echo "stored PID [${storedPid}] did not match actual PID [${testPid}]"
+	exit 1
+fi
+
+if ! test "${pidValid}" = "1"; then
+	echo "stored PID [${storedPid}] was not reachable"
+	exit 1
+fi
+
+exit 0
+
+# EOF