

          ctype class string
               ctype determines whether all characters in string are
               of the specified class.  It returns 1 if they are all
               of class, and 0 if they are not, or if the string is
               empty.  This command also provides another method
               (besides format and scan) of converting between an
               ASCII character and its numeric value.  The following
               ctype commands are available:

               ctype alnum string
                    Tests that all characters are alphabetic or
                    numeric characters as defined by the character
                    set.

               ctype alpha string
                    Tests that all characters are alphabetic
                    characters as defined by the character set.

               ctype ascii string
                    Tests that all characters are an ASCII character
                    (a non-negative number less than 0200).

               ctype char number
                    Converts the numeric value, string, to an ASCII
                    character.  Number must be in the range 0 through
                    255.

               ctype cntrl string
                    Tests that all characters are ``control
                    characters'' as defined by the character set.

               ctype digit string
                    Tests that all characters are valid decimal
                    digits, i.e. 0 through 9.

               ctype graph string
                    Tests that all characters within are any character
                    for which ctype print is true, except for space
                    characters.

               ctype lower string
                    Tests that all characters are lowercase letters as
                    defined by the character set.

               ctype ord character
                    Convert a character into its decimal numeric
                    value.  The string must be one character long.

               ctype space string
                    Tests that all characters are either a space,
                    horizontal-tab, carriage return, newline,
                    vertical-tab, or form-feed.

               ctype print string
                    Tests that all characters are a space or any
                    character for which ctype alnum or ctype punct is
                    true or other ``printing character'' as defined by
                    the character set.

               ctype punct string
                    Tests that all characters are made up of any of
                    the characters other than the ones for which
                    alnum, cntrl, or space is true.

               ctype upper string
                    Tests that all characters are uppercase letters as
                    defined by the character set.

               ctype xdigit string
                    Tests that all characters are valid hexadecimal
                    digits, that is 0 through 9, a through f or A
                    through F.
