[luatex] status of io.popen() on windows

[Manuel Pégourié-Gonnard]

Hi,

According to the Lua reference manual entry for io.popen(), "This function is
system dependent and is not available on all platforms.". What's its status in
LuaTeX on windows (and other platforms, but I guess windows is the problematic
platform due to lack of fork() etc)?

Thanks,
Manuel.