If you want to read a file and display that on alert screen the following code snippet will do that for you.
TBuf8<128> rcvr; TBuf<128> tDsply; RFs fSessionRd; User::LeaveIfError(fSessionRd.Connect()); RFile fileRd; TInt retRd=fileRd.Open(fSessionRd, _L("C:\\testFile.txt"), EFileRead); if(!retRd){ fileRd.Read(rcvr); tDsply.Copy(rcvr); iEikonEnv->AlertWin(tDsply); }