compiler/stdc/memchr.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     C99 function memchr().
   6 */
   7
   8 /*****************************************************************************
   9
  10     NAME */
  11 #include <string.h>
  12
  13         void * memchr (
  14
  15 /*  SYNOPSIS */
  16         const void * mem,
  17         int          c,
  18         size_t       n)
  19
  20 /*  FUNCTION
  21         Locate the first occurence of c which is converted to an unsigned
  22         char in the first n bytes of the memory pointed to by mem.
  23
  24     INPUTS
  25         mem - pointer to memory that is searched for c
  26           c - the character to search for
  27           n - how many bytes to search through starting at mem
  28
  29     RESULT
  30         pointer to the located byte or null if c was not found
  31
  32     NOTES
  33
  34     EXAMPLE
  35
  36     BUGS
  37
  38     SEE ALSO
  39
  40     INTERNALS
  41
  42 ******************************************************************************/
  43 {
  44     /* unsigned char to compare chars > 127 */
  45     const unsigned char * ptr = (unsigned char *)mem;
  46
  47     while (n)
  48     {
  49         if (*ptr == (unsigned char)c)
  50             return ((void *)ptr);
  51
  52         n --;
  53         ptr ++;
  54     }
  55
  56     return NULL;
  57 } /* memchr */