Get back the output of os.execute in Lua

Question

When I do an "os.execute" in Lua, a console quickly pops up, executes the command, then closes down. But is there some way of getting back the console output only using the standard Lua libraries?

Answer 1

If you have io.popen, then this is what I use:

 function os.capture(cmd, raw)   local f = assert(io.popen(cmd, 'r'))   local s = assert(f:read('*a'))   f:close()   if raw then return s end   s = string.gsub(s, '^%s+', '')   s = string.gsub(s, '%s+$', '')   s = string.gsub(s, '[\n\r]+', ' ')   return s end 

If you don't have io.popen, then presumably popen(3) is not available on your system, and you're in deep yoghurt. But all unix/mac/windows Lua ports will have io.popen.

(The gsub business strips off leading and trailing spaces and turns newlines into spaces, which is roughly what the shell does with its $(...) syntax.)

Answer 2

I think you want this http://pgl.yoyo.org/luai/i/io.popen io.popen. But it's not always compiled in.