strlen()实现

   1:  /*
   2:   计算字符串长度。
   3:  */
   4:
   5:  #include <stdlib.h>
   6:
   7:  size_t strlen(char *string)
   8:  {
   9:      int length = 0;
  10:
  11:      while (*string++ != '\0')
  12:          length++;
  13:
  14:      return length;
  15:  }