iissuuppppeerr() -- ctype Function (libc)

Check if a character is an upper-case letter
#iinncclluuddee <ccttyyppee.hh>
iinntt iissuuppppeerr(_c) iinntt _c;

iissuuppppeerr() tests  whether the argument _c is an  upper-case letter (AA-ZZ).  It
returns a number other than zero  if _c is an upper-case letter, and zero if
it is not.  iissuuppppeerr() assumes that _c is an ASCII character or EEOOFF.

_E_x_a_m_p_l_e
For an example of how to use this macro, see the entry for ccttyyppee.hh.

_S_e_e _A_l_s_o
AASSCCIIII, lliibbcc
ANSI Standard, section 7.3.1.10
POSIX Standard, section 8.1
