The ReadString(file) command reads a whitespace delimited string from file.

If file is the name of a file that has not been opened, Maple attempts to open the file before reading the character.

An error is raised if file is not a valid descriptor or if it is the name of a file that cannot be opened.

If the end of the file has been reached, ReadString returns NULL. To determine if the end of file has been reached, use AtEndOfFile.