isdigit, isnumber -- decimal-digit character test
Standard C Library (libc, -lc)
#include <ctype.h>
int
isdigit(int c);
int
isnumber(int c);
The isdigit() function tests for any decimal-digit character. For any
locale, this includes the following characters only:
``0'' ``1'' ``2'' ``3'' ``4''
``5'' ``6'' ``7'' ``8'' ``9''
For single C chars locales (see multibyte(3)) the value of the argument
is representable as an unsigned char or the value of EOF.
The isdigit() function returns zero if the character tests false and
returns non-zero if the character tests true.
Although isdigit() accepts arguments outside of the range of the unsigned
char type in locales with large character sets, this is a 4.4BSD extension
and the iswdigit() function should be used instead for maximum
portability.
ctype(3), iswdigit(3), multibyte(3), ascii(7)
The isdigit() function conforms to ISO/IEC 9899:1990 (``ISO C89'').
FreeBSD 5.2.1 October 6, 2002 FreeBSD 5.2.1 [ Back ] |