memchr.c revision 130562 
1/*
2
3@deftypefn Supplemental void* memchr (const void *@var{s}, int @var{c}, size_t @var{n})
4
5This function searches memory starting at @code{*@var{s}} for the
6character @var{c}.  The search only ends with the first occurrence of
7@var{c}, or after @var{length} characters; in particular, a null
8character does not terminate the search.  If the character @var{c} is
9found within @var{length} characters of @code{*@var{s}}, a pointer
10to the character is returned.  If @var{c} is not found, then @code{NULL} is
11returned.
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
24PTR
25memchr (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}
40