The line termination string. Use %NULL for autodetect. Autodetection breaks on "\n", "\r\n", "\r", "\0", and the Unicode paragraph separator. Autodetection should not be used for anything other than file-based channels.
The length of the termination string. If -1 is passed, the string is assumed to be nul-terminated. This option allows termination strings with embedded nuls.
This sets the string that #GIOChannel uses to determine where in the file a line break occurs.