added lua testlib

tests/testlib.lua

@@ -0,0 +1,47 @@
+-- common testing environment
+
+require("posix")
+
+-- escape codes to colorize output on terminal
+local c1="\027[47;34m"
+local c0="\027[0m"
+
+---
+-- writes colorized
+--
+function cwriteln(...)
+	io.write(c1, ...)
+	io.write(c0, "\n")
+end
+
+-----
+-- creates a tmp directory
+function mktempd()
+	local f = io.popen('mktemp -d', 'r')
+	local s = f:read('*a')
+	f:close()
+	s = s:gsub('[\n\r]+', ' ')
+	s = s:match("^%s*(.-)%s*$")
+	return s
+end
+
+-----
+-- spawns a subprocess.
+--
+function spawn(...)
+	local pid = posix.fork()
+	if pid < 0 then
+		cwriteln("Error, failed fork!")
+		os.exit(-1)
+	end
+	if lpid == 0 then
+		posix.exec(...)
+		-- should not return
+		cwriteln("Error, failed to spawn: ", ...)
+		os.exit(-1);
+	end
+	return pid
+end
+
+print(mktempd())
+