Procedure

There are two primary methods of writing (and reading) files via scripted methods: a Simple Method and a Complete I/O Model:

--WRITING FILES
--Writing a File, Method 1
--The "Direct Way", Simple Model
Info = "Whatever I want\r\n"
io.output("design/MyTestFile")  --Create the file for writing to 
io.write(Info)                  --Write to the File
io.write("More stuff\r\n")        --Append more
io.close()                      --Close the file

--Writing a File, Method 2
  --The Complete I/O Model
  --use for advanced file manipulation, reading/writing to several files
Info = "A different method\r\n"
myfile = io.open ("design/MyTestFile2","w+")
  --r for Read-Only of existing file
  --w for Create/Write new file
  --a for Append Mode, this is for Writing only
  --r+ for Read/Write existing file, will overwrite existing content
  --w+, same as "w", except reading is also allowed
  --a+, same as "a", except reading is also allowed
if myfile~=nil then
 filedata = myfile:write(Info)
 filedata = myfile:write("Adding some more\r\n")
  print("File #2 has been written")
  io.close(myfile)              --Close file after use
else
  print("myfile==nil")
  --for certain argument usages a nil is returned if file does not exist
end

--The locations "design/" and "media/" are acceptable.
--The "media/" folder is generally for all media files, and the "design/" folder
--is where uncompressed design configuration files reside.
--Files in "design/" can be viewed at http://[ip of core]/designs/current_design