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TOUPPER(3) FreeBSD Library Functions Manual TOUPPER(3)
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);
int
toupper_l(int c, locale_t loc);
DESCRIPTION
The toupper() and toupper_l() functions convert a lower-case letter to
the corresponding upper-case letter. The argument must be representable
as an unsigned char or the value of EOF.
The toupper_l() function takes an explicit locale argument, whereas the
toupper() function uses the current global or per-thread locale.
RETURN VALUES
If the argument is a lower-case letter, the toupper() and toupper_l()
functions return 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() or
towupper_l() function should be used instead.
SEE ALSO
ctype(3), ctype_l(3), isupper(3), isupper_l(3), towupper(3),
towupper_l(3), xlocale(3)
STANDARDS
The toupper() function conforms to ISO/IEC 9899:1990 ("ISO C90").
FreeBSD 14.0-RELEASE-p11 December 19, 2022 FreeBSD 14.0-RELEASE-p11