newlib/libc/ctype/isupper.c

   1 /*
   2 FUNCTION
   3         <<isupper>>, <<isupper_l>>---uppercase character predicate
   4
   5 INDEX
   6         isupper
   7
   8 INDEX
   9         isupper_l
  10
  11 SYNOPSIS
  12         #include <ctype.h>
  13         int isupper(int <[c]>);
  14
  15         #include <ctype.h>
  16         int isupper_l(int <[c]>, locale_t <[locale]>);
  17
  18 DESCRIPTION
  19 <<isupper>> is a macro which classifies singlebyte charset values by table
  20 lookup.  It is a predicate returning non-zero for uppercase letters
  21 (<<A>>--<<Z>>), and 0 for other characters.
  22
  23 <<isupper_l>> is like <<isupper>> but performs the check based on the
  24 locale specified by the locale object locale.  If <[locale]> is
  25 LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
  26
  27 You can use a compiled subroutine instead of the macro definition by
  28 undefining the macro using `<<#undef isupper>>' or `<<#undef isupper_l>>'.
  29
  30 RETURNS
  31 <<isupper>>, <<isupper_l>> return non-zero if <[c]> is an uppercase letter.
  32
  33 PORTABILITY
  34 <<isupper>> is ANSI C.
  35 <<isupper_l>> is POSIX-1.2008.
  36
  37 No supporting OS subroutines are required.
  38 */
  39 #include <_ansi.h>
  40 #include <ctype.h>
  41
  42 #undef isupper
  43 int
  44 isupper (int c)
  45 {
  46         return ((__CTYPE_PTR[c+1] & (_U|_L)) == _U);
  47 }