function mozexWriteFile(data, filename) {
try {
var file = Components.classes["@mozilla.org/file/local;1"].
createInstance(Components.interfaces.nsILocalFile);
file.initWithPath(filename);
try {
/* raises an error if the file already exists */
file.create(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0600);
}
catch (e) {
mozexError("cannot create temporary file '" + filename + "': " + e);
return false;
}

var uc = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"].
createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
uc.charset = "UTF-8";
var data_stream = uc.ConvertFromUnicode( data );

var stream = Components.classes["@mozilla.org/network/file-output-stream;1"].
createInstance(Components.interfaces.nsIFileOutputStream);
var PR_WRONLY = 0x02;
stream.init(file, PR_WRONLY, 0600, 0);
stream.write(data_stream, data_stream.length);
stream.flush()
stream.close();
}
catch (e) {
mozexError("cannot write to file '" + filename + "':" + e);
return false;
}
return true;
}

function mozexReadFile(filename) {
var MODE_RDONLY = 0x01;
var PERM_IRUSR = 00400;

try {
var file = Components.classes["@mozilla.org/file/local;1"].
createInstance(Components.interfaces.nsILocalFile);
file.initWithPath(filename);
if (file.exists() && file.isReadable()) {
var is = Components.classes["@mozilla.org/network/file-input-stream;1"].
createInstance(Components.interfaces.nsIFileInputStream);
is.init(file, MODE_RDONLY, PERM_IRUSR, 0);
var sis = Components.classes["@mozilla.org/scriptableinputstream;1"].
createInstance(Components.interfaces.nsIScriptableInputStream);
sis.init(is);
var data = sis.read(sis.available());
sis.close();
is.close();
var uc = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"].
createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
uc.charset = "UTF-8";
return uc.ConvertToUnicode( data );
}
else {
mozexError("temporary file '" + filename + "' does not exist or is not readable");
return null;
}
}
catch (e) {
mozexError("cannot read from temporary file '" + filename + "': " + e);
}
return null;
}