字符串中字符查找函数:strchr,wcschr 及strrchr, wcsrchr函数

（1）

   char *strchr( const char *string, int c );
   wchar_t *wcschr( const wchar_t *string, wchar_t c );
   Find a character in a string. 查找一个字符串中首次出现的指定字符。

  Return Value:Each of these functions returns a pointer to the first occurrence of c in string(address), or NULL if c is not found.

（2）
  char *strrchr( const char *string, int c);
   char *wcsrchr( const wchar_t *string, int c );

Scan a string for the last occurrence of a character.:查找一个字符串中最后出现的指定字符。

Return Value:Each of these functions returns a pointer to the last occurrence of c in string(address), or NULL if c is not found.
找出字符串中最后一个出现查找字符的地址，然后将该字符出现的地址返回。

附上源代码:

wchar_t *  _DEFUN (wcsrchr, (s, c),  _CONST wchar_t * s _AND   wchar_t c)  
{  
   _CONST wchar_t *p;  
   p = s;  
  

   while (*p)   

   p++;  
   while (s <= p)  
    {  
     if (*p == c)  

      {  
   	  /** LINTED interface specification */ 
   	   return (wchar_t *) p;  
      }  
       p--;  
    }  
  return NULL;  
}