/* * 清除字符串開始結尾處的空白 * 修改原字符串 * */static char* trim(char*str){  char* p1 = str,*p2 = NULL,*p3 = NULL;  int flag = 0;  while(*(p1) != '/0'){    if(isspace(*p1)){      if(p3 == NULL) p3 = p2 == NULL?p1:p2;//標記結尾空白      if(0 == flag) {//標記開頭為空白        flag = 1;        p2 = p1;      }else if(2 == flag){//中間空白        *(p2++) = *p1;      }    }else {      if(1 == flag || flag == 2){//開頭空白結束標志        *(p2++) = *p1;        flag = 2;      }else flag = -1;//開頭無空白      p3 = NULL;//清除結尾空白    }    p1++;  }  //標記結尾  if(p3 != NULL) *p3 = '/0';  else if(p2 != NULL) *p2 = '/0';  return str;}