Note that ReadFile ends when it reaches a substitute character (Chr(26)).
From the Scripting Manual
function ReadFile(FileName: string): string; Parameter Info: FileName (String): File located in your Soldat Server folder. Description: This function will read a text file (FileName) located in your Soldat Server folder and return it in a String value
WriteLn(ReadFile('mapslist.txt')); //Outputs all current lines in mapslist.txt