toupper
—
lower case to upper case letter conversion
Standard C Library (libc, -lc)
#include <ctype.h>
int
toupper
(int
c);
The toupper
() function converts a lower-case letter to
the corresponding upper-case letter.
If the argument is a lower-case letter, the toupper
()
function returns the corresponding upper-case letter if there is one;
otherwise the argument is returned unchanged.
ctype(3),
isalnum(3),
isalpha(3),
isascii(3),
iscntrl(3),
isdigit(3),
isgraph(3),
islower(3),
isprint(3),
ispunct(3),
isspace(3),
isupper(3),
isxdigit(3),
stdio(3),
toascii(3),
ascii(7)
The toupper
() function conforms to ANSI
X3.159-1989 (“ANSI C89”).
The argument to toupper
() must be
EOF
or representable as an unsigned
char; otherwise, the behavior is undefined. See the
CAVEATS section of
ctype(3) for more details.