NAME
toupper, toupper_l – lower case to upper case letter conversion
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ctype.h>
int
toupper(int c);
#include <ctype.h>
#include <xlocale.h>
int
toupper_l(int c, locale_t loc);
DESCRIPTION
The toupper() function converts a lower-case letter to the corresponding upper-case letter. The argument must be representable as an unsigned char or the value of EOF.
Although the toupper() function uses the current locale, the toupper_l() function may be passed a locale directly. See xlocale(3) for more information.
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.
COMPATIBILITY
The 4.4BSD extension of accepting arguments outside of the range of the unsigned char type in locales with large character sets is considered obsolete and may not be supported in future releases. The towupper() function should be used instead.
SEE ALSO
STANDARDS
The toupper() function conforms to ISO/IEC 9899:1990 (“ISO C90”).