NAME
toupper, _toupper
— lower case to upper case
letter conversion
SYNOPSIS
#include
<ctype.h>
int
toupper(int
c);
int
_toupper(int
c);
DESCRIPTION
The
toupper()
function converts a lower-case letter to the corresponding upper-case
letter. The
_toupper()
function is identical to toupper() except that
c must be a lower-case letter.
RETURN VALUES
If the argument to the toupper() function
is a lower-case letter, the corresponding upper-case letter is returned if
there is one; otherwise the argument is returned unchanged. If the argument
to the _toupper() function is a lower-case letter,
the corresponding upper-case letter is returned; otherwise the output is
undefined.
SEE ALSO
isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3), isxdigit(3), stdio(3), toascii(3), tolower(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 result is undefined.