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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.

     The value of the argument must be 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 ob-
     solete and	may not	be supported in	future releases.  The iswdigit() func-
     tion should be used instead.

SEE ALSO
     ctype(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				  May 4, 2007				   BSD
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | COMPATIBILITY | SEE ALSO | STANDARDS | HISTORY

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