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 15.1-STABLE-HBSD       December 19, 2022                    TOUPPER(3)