Available since: Gideros 2011.6
Class: io


This function opens a file in the specified mode. The function returns a new file handle, or nil plus an error message.

(file) =, mode)

The mode string can be any of the following:

  • "r": read mode (the default)
  • "w": write mode
  • "a": append mode
  • "r+": update mode, all previous data is preserved
  • "w+": update mode, all previous data is erased
  • "a+": append update mode, previous data is preserved, writing is only allowed at the end of file

The mode string can also have a 'b' at the end, which is needed in some systems to open the file in binary mode.

This string is exactly what is used in the standard C function fopen.


filename: (string) filename to open
mode: (string) mode in which to open the file optional (default = "r")

Return values

Returns (file) file object