newlib/libc/ctype/isblank.c

   1 /*
   2 FUNCTION
   3         <<isblank>>, <<isblank_l>>---blank character predicate
   4
   5 INDEX
   6         isblank
   7
   8 INDEX
   9         isblank_l
  10
  11 SYNOPSIS
  12         #include <ctype.h>
  13         int isblank(int <[c]>);
  14
  15         #include <ctype.h>
  16         int isblank_l(int <[c]>, locale_t <[locale]>);
  17
  18 DESCRIPTION
  19 <<isblank>> is a function which classifies singlebyte charset values by table
  20 lookup.  It is a predicate returning non-zero for blank characters, and 0
  21 for other characters.  It is defined only if <[c]> is representable as an
  22 unsigned char or if <[c]> is EOF.
  23
  24 <<isblank_l>> is like <<isblank>> but performs the check based on the
  25 locale specified by the locale object locale.  If <[locale]> is
  26 LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
  27
  28 RETURNS
  29 <<isblank>>, <<isblank_l>> return non-zero if <[c]> is a blank character.
  30
  31 PORTABILITY
  32 <<isblank>> is C99.
  33 <<isblank_l>> is POSIX-1.2008.
  34
  35 No supporting OS subroutines are required.
  36 */
  37
  38 #include <_ansi.h>
  39 #include <ctype.h>
  40
  41
  42
  43 #undef isblank
  44 int
  45 isblank (int c)
  46 {
  47         return ((__CTYPE_PTR[c+1] & _B) || (c == '\t'));
  48 }