| 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 | } |