| ISDIGIT(3) | Library Functions Manual | ISDIGIT(3) |
isdigit —
decimal-digit character test
Standard C Library (libc, -lc)
#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 and returns non-zero if the character tests true.
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)
The isdigit() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
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.
| April 17, 2008 | NetBSD 11.0 |