NAME
toupper —
lower case to upper case letter
conversion
LIBRARY
library “libc”
SYNOPSIS
#include
<ctype.h>
int
toupper(int
c);
DESCRIPTION
Thetoupper()
function converts a lower-case letter to the corresponding upper-case letter.
RETURN VALUES
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.
SEE ALSO
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)
STANDARDS
The toupper() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
CAVEATS
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.