The READ X#maxlen command limits the maximum size of the input to a maximum of "maxlen" characters, where maxlen is an integer expression.

If a READ follows a READ X#maxlen command, the READ returns the remainder of the current record.

If a terminator arrives before maxlen characters are received the READ X#maxlen terminates.

For fixed format files, If WIDTH - $X is greater than len, READ X#maxlen reads maxlen characters otherwise READ reads WIDTH - $X characters. Fewer may be returned if end of file is reached.

For VARIABLE or STREAM format files, READ X#maxlen reads up to MIN(maxlen, WIDTH - $X) characters, stopping if it finds line terminator or end of file.