toolchain/gcc/newlib/libc/string/strcspn.c

   1 /*
   2 FUNCTION
   3         <<strcspn>>---count chars not in string
   4
   5 INDEX
   6         strcspn
   7
   8 ANSI_SYNOPSIS
   9         size_t strcspn(const char *<[s1]>, const char *<[s2]>);
  10
  11 TRAD_SYNOPSIS
  12         size_t strcspn(<[s1]>, <[s2]>)
  13         char *<[s1]>;
  14         char *<[s2]>;
  15
  16 DESCRIPTION
  17         This function computes the length of the initial part of
  18         the string pointed to by <[s1]> which consists entirely of
  19         characters <[NOT]> from the string pointed to by <[s2]>
  20         (excluding the terminating null character).
  21
  22 RETURNS
  23         <<strcspn>> returns the length of the substring found.
  24
  25 PORTABILITY
  26 <<strcspn>> is ANSI C.
  27
  28 <<strcspn>> requires no supporting OS subroutines.
  29  */
  30
  31 #include <string.h>
  32
  33 size_t
  34 _DEFUN (strcspn, (s1, s2),
  35         _CONST char *s1 _AND
  36         _CONST char *s2)
  37 {
  38   _CONST char *s = s1;
  39   _CONST char *c;
  40
  41   while (*s1)
  42     {
  43       for (c = s2; *c; c++)
  44         {
  45           if (*s1 == *c)
  46             break;
  47         }
  48       if (*c)
  49         break;
  50       s1++;
  51     }
  52
  53   return s1 - s;
  54 }