isnumber(3) [osx man page]

ISDIGIT(3)						   BSD Library Functions Manual 						ISDIGIT(3)

NAME

     isdigit, isnumber -- decimal-digit character test

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <ctype.h>

     int
     isdigit(int c);

     int
     isnumber(int c);

DESCRIPTION

     The isdigit() function tests 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() function behaves similarly to isdigit(), but may recognize 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 isdigit() and isnumber() 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() function should be used instead.

SEE ALSO

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

STANDARDS

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

HISTORY

     The isnumber() function appeared in 4.4BSD.

BSD
								  August 21, 2004							       BSD

Check Out this Related Man Page

ISDIGIT(3)						   BSD Library Functions Manual 						ISDIGIT(3)

NAME

     isdigit -- decimal-digit character test

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <ctype.h>

     int
     isdigit(int c);

DESCRIPTION

     The isdigit() function tests for any decimal-digit character.

RETURN VALUES

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

SEE ALSO

     ctype(3), isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3),
     isxdigit(3), stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)

STANDARDS

     The isdigit() function conforms to ANSI X3.159-1989 (``ANSI C89'').

CAVEATS

     The argument to isdigit() must be EOF or representable as an unsigned char; otherwise, the behavior is undefined.	See the CAVEATS section of
     ctype(3) for more details.

BSD
								  April 17, 2008							       BSD

Linux and UNIX Man Pages

isnumber(3) [osx man page]

Check Out this Related Man Page