Currently only text files are supported. Error can be detected by a special value being returned, and by the function error . This is more portable than the error code used by Netscape. The directory can be a File object. The default value of a File object is its path name, represented as a string.
Returns null in case of error.
Return true if successful. Write the parameters as a string to the file, return true if successful. Read a line from an input file. Return null if at eof or in case of error. An error is set if the file was not opened for reading.