SYNOPSIS

     #include <ctype.h>

     int
     isxdigit(int c);

     int
     ishexnumber(int c);

DESCRIPTION

     The isxdigit() function tests for any hexadecimal-digit character.
     Regardless of locale, this includes the following characters only:

     ``0''         ``1''         ``2''         ``3''         ``4''
     ``5''         ``6''         ``7''         ``8''         ``9''
     ``A''         ``B''         ``C''         ``D''         ``E''
     ``F''         ``a''         ``b''         ``c''         ``d''
     ``e''         ``f''

     The ishexnumber() function behaves similarly to isxdigit(), but may rec-
     ognize additional characters, depending on the current locale setting.

     For single C chars locales (see multibyte(3)) the value of the argument
     is representable as an unsigned char or the value of EOF.

RETURN VALUES

     The isxdigit() function returns zero if the character tests false and
     returns non-zero if the character tests true.

COMPATIBILITY

     The 4.4BSD extension of accepting arguments outside of the range of the
     unsigned char type in locales with large character sets is considered
     obsolete and may not be supported in future releases.  The iswxdigit()
     function should be used instead.

SEE ALSO

     ctype(3), iswxdigit(3), multibyte(3), ascii(7), isalnum_l

STANDARDS

     The isxdigit() function conforms to ISO/IEC 9899:1990 (``ISO C90'').

HISTORY

     The ishexnumber() function appeared in 4.4BSD.

BSD                             August 21, 2004                            BSD