莫名其妙的EOF，输出文件总是多一个字节，cmp: EOF on xxx

[Cixy]

做一个哈夫曼编码的小程序，开始用递归方法查表进行解码，正常；后来试试不用递归来写，就改了一下。。。发现。。。。结果不同，凭空多出一个字节？！用cmp比较。。。报告"cmp: EOF on ..."，怎么回事儿？？

后来输出每一个保存到文件里字节，发现两种写法的输出完全一样，字节数也一样，可是。。。费解的就是非递归方法产生的文件就是会多一个字节，而且用winhex看不到那个字节。。。。。基本上愤怒的要崩溃了。。。。求大侠指点。

相关的定义部分

typedef unsigned char  Symbol;       /* any byte is encodable */
typedef struct HuffNode *HuffTree;
struct HuffNode {
	Bool  isExt;           /* is this an external node? */
	Symbol  sym;           /* defined if isExt only */
	HuffTree  branch[2];   /* defined if !isExt only */
};

// Open bit stream for reading from fp
BitStream BitStream_OpenRead(FILE *fp);

// Open bit stream for writing to fp
BitStream BitStream_OpenWrite(FILE *fp);

// Transfer nbits (0..CHAR_BIT) from data to bs
void BitStream_Put(BitStream bs, unsigned char data, int nbits);

// Return nbits (0..CHAR_BIT) from bs
unsigned char BitStream_Get(BitStream bs, int nbits);

递归版本

static unsigned char traverse_and_decode(HuffTree t, BitStream bs){
	if (t->isExt == FALSE){
		int j = BitStream_Get(bs, 1);
		return traverse_and_decode(t->branch[j], bs);
	}
	return t->sym;
}

void HuffTree_Decode(HuffTree t, FILE *fin, FILE *fout, int num_bytes)
{
	int i;
	BitStream bsi, bso;

	bsi = BitStream_OpenRead(fin);
	bso = BitStream_OpenWrite(fout);

	for (i=0; i<num_bytes; i++)
		BitStream_Put(bso, traverse_and_decode(t, bsi) , CHAR_BIT);

	BitStream_Close(&bso);
	BitStream_Close(&bsi);
}

非递归版本

void HuffTree_Decode(HuffTree t, FILE *fin, FILE *fout, int num_bytes)
{
	int i, j;
	HuffTree tt;
	BitStream bsi, bso;

	bsi = BitStream_OpenRead(fin);
	bso = BitStream_OpenWrite(fout);

	for (i=0; i<num_bytes; i++){
		tt=t;
		while (tt->isExt==FALSE){
			j = BitStream_Get(bsi,1);
			tt=tt->branch[j];
		}

		BitStream_Put(bso, tt->sym, CHAR_BIT);
	}

	BitStream_Close(&bso);
	BitStream_Close(&bsi);
}

[jixingzhong]

楼主可以用 UE 打开文件操作试试 ～