DragonFly On-Line Manual Pages

ISDIGIT(3)            DragonFly Library Functions Manual            ISDIGIT(3)

NAME
     isdigit, isdigit_l, isnumber, isnumber_l -- decimal-digit character test

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <ctype.h>

     int
     isdigit(int c);

     int
     isnumber(int c);

     int
     isdigit_l(int c, locale_t locale);

     #include <xlocale.h>

     int
     isnumber_l(int c, locale_t locale);

DESCRIPTION
     The isdigit() and isdigit_l() functions test for a decimal digit
     character.  Regardless of locale, this includes the following characters
     only:

     ``0''         ``1''         ``2''         ``3''         ``4''
     ``5''         ``6''         ``7''         ``8''         ``9''

     The isnumber() and isnumber_l() functions behave similarly to isdigit()
     and isdigit_l(), but may recognize additional characters, depending on
     the current locale setting.

     The value of the argument must be representable as an unsigned char or
     the value of EOF.

     The _l-suffixed versions take an explicit locale argument, whereas the
     non-suffixed versions use the current global or per-thread locale.

RETURN VALUES
     The isdigit(), isdigit_l(), isnumber(), and isnumber_l() functions return
     zero if the character tests false and return 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 iswdigit(),
     iswdigit_l(), iswnumber(), and iswnumber_l() functions should be used
     instead.

SEE ALSO
     ctype(3), ctype_l(3), iswdigit(3), iswdigit_l(3), multibyte(3),
     xlocale(3), ascii(7)

STANDARDS
     The isdigit() function conforms to ISO/IEC 9899:1990 (``ISO C90'').  The
     isdigit_l() function conforms to IEEE Std 1003.1-2008 (``POSIX.1'').

HISTORY
     The isnumber() function appeared in 4.4BSD.

DragonFly 4.3                  December 25, 2013                 DragonFly 4.3