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On 15 August 2013 10:08, steve donovan <> wrote:
> On Thu, Aug 15, 2013 at 9:15 AM, Jakub Piotr Cłapa <> wrote:
>> What would be really nice is a wrapper around luaposix and lua-winapi modules which would work like the subprocess module in Python.
> Nice and very doable, I've been thinking about this. Generally people pick a platform and use the appropriate native API, but it _is_ useful to have cross-platform scripting that hides some implementation details.

There is already an implementation of an API allowing you to spawn processes and having a better control of the standard streams - - available for POSIX and Windows. Here is an example of "popen2", which spawns a process and creates necessary pipes for standard input and standard output. It should be easily extendable to include stderr.

-- popen2()
function popen2(...)
  local in_rd, in_wr = io.pipe()
  local out_rd, out_wr = io.pipe()
  local proc, err = os.spawn{stdin = in_rd, stdout = out_wr, ...}
  in_rd:close(); out_wr:close()
  if not proc then
    in_wr:close(); out_rd:close()
    return proc, err
  return proc, out_rd, in_wr
-- usage:
local p, i, o = assert(popen2("wc", "-w"))
o:write("Hello world"); o:close()
print(i:read"*l"); i:close()