| ISDIGIT(3) | Library Functions Manual | ISDIGIT(3) |
isdigit —
decimal-digit character test
#include
<ctype.h>
int
isdigit(int
c);
The
isdigit()
function tests for any decimal-digit character.
The isdigit() function returns zero if the
character tests false or non-zero if the character tests true.
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)
The isdigit() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
The isdigit() function first appeared in
Version 7 AT&T UNIX.
The argument to isdigit() must be
EOF or representable as an unsigned
char; otherwise, the result is undefined.
| July 17, 2013 | OpenBSD-6.1 |