Lua Basics: file opens and the colon?

[William Trenker <wtrenker@...>]

Is the following an acceptable use of the colon with io functions?

kernelinfo = io.open("/proc/version"):read()
machinetype = io.popen("uname -m"):read()

I just want to be sure that this won't leave a file handle or related
resources dangling.

Thanks,
Bill