4Test recognizes that it has reached the end of a file (EOF) by no longer reading that file – in other words, by receiving a null string. It does not read any special character at the EOF.
For Silk Test Classic, EOF is indicated by a FALSE bDidRead return and a null string is indicated by a TRUE bDidRead return and a null string.
This applies to FileReadLine, FileReadValue, SYS_FileReadLine, and SYS_FileReadValue.