How do you construct a read-write pipe with lua?

Question

I\'d like to do the equivalent of:

foo=$(echo \"$foo\"|someprogram)

within lua -- ie, I\'ve got a variable containing a bunch of text, and

Answer 1

A not very nice solution that avoids a temporary file...

require("io")
require("posix")

x="hello\nworld"

posix.setenv("LUA_X",x)
i=popen('echo "$LUA_X" | myfilter')
x=i.read("*a")