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TOUPPER(3) |
Library Functions Manual |
TOUPPER(3) |
NAME
toupper — lower case to upper case letter conversion
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ctype.h>
int
toupper(int c);
DESCRIPTION
The toupper() 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.