1  /*
       2  
       3  @deftypefn Supplemental void* memchr (const void *@var{s}, int @var{c}, @
       4    size_t @var{n})
       5  
       6  This function searches memory starting at @code{*@var{s}} for the
       7  character @var{c}.  The search only ends with the first occurrence of
       8  @var{c}, or after @var{length} characters; in particular, a null
       9  character does not terminate the search.  If the character @var{c} is
      10  found within @var{length} characters of @code{*@var{s}}, a pointer
      11  to the character is returned.  If @var{c} is not found, then @code{NULL} is
      12  returned.
      13  
      14  @end deftypefn
      15  
      16  */
      17  
      18  #include <ansidecl.h>
      19  #include <stddef.h>
      20  
      21  void *
      22  memchr (register const void *src_void, int c, size_t length)
      23  {
      24    const unsigned char *src = (const unsigned char *)src_void;
      25    
      26    while (length-- > 0)
      27    {
      28      if (*src == c)
      29       return (void *)src;
      30      src++;
      31    }
      32    return NULL;
      33  }