libiberty/memchr.c

   1 /*
   2
   3 @deftypefn Supplemental void* memchr (const void *@var{s}, int @var{c}, size_t @var{n})
   4
   5 This function searches memory starting at @code{*@var{s}} for the
   6 character @var{c}.  The search only ends with the first occurrence of
   7 @var{c}, or after @var{length} characters; in particular, a null
   8 character does not terminate the search.  If the character @var{c} is
   9 found within @var{length} characters of @code{*@var{s}}, a pointer
  10 to the character is returned.  If @var{c} is not found, then @code{NULL} is
  11 returned.
  12
  13 @end deftypefn
  14
  15 */
  16
  17 #include <ansidecl.h>
  18 #ifdef ANSI_PROTOTYPES
  19 #include <stddef.h>
  20 #else
  21 #define size_t unsigned long
  22 #endif
  23
  24 PTR
  25 memchr (src_void, c, length)
  26      register const PTR src_void;
  27      int c;
  28      size_t length;
  29 {
  30   const unsigned char *src = (const unsigned char *)src_void;
  31
  32   while (length-- > 0)
  33   {
  34     if (*src == c)
  35      return (PTR)src;
  36     src++;
  37   }
  38   return NULL;
  39 }