字符串的按单词逆序（带标点）

//给定一个字符串，按单词将该字符串逆序，含标点     
#include     
   
//start 和 end 之间逆序的函数  
void reverse_word(char *start, char *end)   
{    
    while(start < end)   
    {    
        *start = *start ^ *end;    
        *end = *start ^ *end;    
        *start = *start++ ^ *end--;    
    }    
}    
  
char *reverse_sentence(char *str)   
{    
    char *start = str;    
    char *end = str;    
    while(*end != '\0')   
    {    
        if(*end==' ' || *end=='!' || *end==',' || *end=='.' || *end==' ')//查到一个单词   
        {    
            if(start < end)//只有一个字母的单词不逆序  
                reverse_word(start, end-1);    
  
            while(*end==' ' || *end=='!' || *end==',' || *end=='.' || *end==' ')  
                end++; //指向下一个单词首字符     
  
            start = end;    
        }    
        else    
            end++;    
    }    
    reverse_word(str, end-1);//整个句子逆序     
    
    return str;    
}    
    
int main(int argc, char *argv[])   
{    
    char str[] = "Hello, I am glad to see you!";  
  
    printf("%s\n", str);    
    printf("%s\n", reverse_sentence(str));    
    
    return 0;    
}