The ReadNextInteger(file) command attempts to read an integer from file. The ReadNextInteger function skips non-numeric characters until a valid integer is found.  The integer is read from file and returned.  If no characters form a valid integer, then NULL is returned.  In this case, the file is read to the end of the file.

If file is the name of a file that has not been opened, Maple attempts to open the file before attempting to read the integer.

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