编程一个程序，实现解压缩的目的
我编了一个程序，解压缩都可以运行，但是为什么把文件压缩之后，压缩包打不开，到底是哪里的问题？#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <windows.h>
typedef struct node
{
long w;
short p,l,r;
}htnode,*htnp;
typedef struct huffman_code
{
unsigned char len;
unsigned char *codestr;
}hufcode;
typedef char **huffmancode;
int initial_files(char *source_filename,FILE **inp,char *obj_filename,FILE **outp);
char *create_filename(char *source_filename,char* obj_filename);
int compress(char *source_filename,char *obj_filename);
long frequency_data(FILE *in,long fre[]);
int search_set(htnp ht,int n,int *s1, int *s2);
int create_hftree(long w[],int n,htnode ht[]);
int encode_hftree(htnp htp,int n,hufcode hc[]);
unsigned char chars_to_bits(const unsigned char chars[8]);
int write_compress_file(FILE *in,FILE *out,htnp ht,hufcode hc[],char* source_filename,long source_filesize);
int decompress(char *source_filename,char *obj_filename);
void get_mini_huffmantree(FILE* in,short mini_ht[][2]);
int write_decompress_file(FILE *in,FILE* out,short mini_ht[][2],long bits_pos,long obj_filesize);
int d_initial_files(char *source_filename,FILE **inp,char *obj_filename,FILE **outp);
main()
{
int s;
char filename[10];
printf("1.压缩\n");
printf("2.解压缩\n");
printf("3.退出\n");
scanf("%d",&s);
while(s!=0)
{
getchar();
switch(s)
{
case 1:
puts("请输入待压缩文件路径：");
gets(filename);
compress(filename,NULL);
break;
case 2:
puts("请输入待解压文件路径：");
gets(filename);
decompress(filename,NULL);
break;
default :
printf("指令错误！请重新输入指令：\n");
}
puts(" ");
printf("1.压缩\n");
printf("2.解压缩\n");
printf("3.退出\n");
scanf("%d",&s);
}
}
int initial_files(char *source_filename,FILE **inp,char *obj_filename,FILE **outp)
{
if(fopen(source_filename,"rb")==NULL)
{
return -1;
}
if(obj_filename==NULL)
{
if((obj_filename=(char*)malloc(256*sizeof(char)))==NULL)
{
return -1;
}
create_filename(source_filename,obj_filename);
}
if(strcmp(source_filename,obj_filename)==0)
{
return -1;
}
printf("待压缩文件:%s,压缩文件:%s\n",source_filename,obj_filename);
if((*outp=fopen(obj_filename,"wb"))==NULL)
{
return -1;
}
if((*inp=fopen(source_filename,"rb"))==NULL)
{
return -1;
}
free(obj_filename);
return 0;
}
char *create_filename(char *source_filename,char* obj_filename)
{
char *temp;
if((temp=strrchr(source_filename,'.'))==NULL)
{
strcpy(obj_filename,source_filename);
strcat(obj_filename,".zip");
}
else
{
strncpy(obj_filename,source_filename,temp-source_filename);
obj_filename[temp-source_filename]='\0';
strcat(obj_filename,".zip");
}
return obj_filename;
}
int compress(char *source_filename,char *obj_filename)
{
FILE *in,*out;
char ch;
int error_code,i,j;
float compress_rate;
hufcode hc[256];
htnode ht[256*2-1];
long frequency[256],source_filesize,obj_filesize=0;
error_code=initial_files(source_filename,&in,obj_filename,&out);
if(error_code!=0)
{
puts("文件打开失败！请重新输入文件路径：");
return error_code;
}
source_filesize=frequency_data(in,frequency);
printf("文件大小 %ld 字节\n",source_filesize);
error_code=create_hftree(frequency,256,ht);
if(error_code!=0)
{
puts("建立哈夫曼树失败！");
return error_code;
}
error_code=encode_hftree(ht,256,hc);
if(error_code!=0)
{
puts("建立哈夫曼编码失败！");
return error_code;
}
for(i=0;i<256;i++)
obj_filesize+=frequency[i]*hc[i].len;
obj_filesize=obj_filesize%8==0?obj_filesize/8:obj_filesize/8+1;
for(i=0;i<256-1;i++)
obj_filesize+=2*sizeof(short);
obj_filesize+=strlen(source_filename)+1;
obj_filesize+=sizeof(long);
obj_filesize+=sizeof(unsigned int);
compress_rate=(float)obj_filesize/source_filesize;
printf("压缩文件大小:%ld字节,压缩比例:%.2lf%%\n",obj_filesize,compress_rate*100);
error_code=write_compress_file(in,out,ht,hc,source_filename,source_filesize);
if(error_code!=0)
{
puts("写入文件失败！");
return error_code;
}
puts("压缩完成!");
do{
scanf("%s",&ch);
switch(ch)
{
case 'Y':
puts("以下是哈夫曼树：");
for(i=256;i<256*2-2;i++)
{
if(ht[i].w>0)
printf("%-10d%-10d%-10d%-10d%-10d\n",i,ht[i].w,ht[i].p,ht[i].l,ht[i].r);
}
puts("以下是哈夫曼编码：");
for(i=0;i<256;i++)
{
if(frequency[i]==0)
i++;
else
{
printf("%d\t",frequency[i]);
for(j=0;j<hc[i].len;j++)
printf(" %d",hc[i].codestr[j]);
printf("\n");
}
}
break;
case 'N': break;
default :
printf("指令错误！请重新输入指令：\n");
}
}while(ch!='Y'&&ch!='N');
fclose(in);
fclose(out);
for(i=0;i<256;i++)
{
free(hc[i].codestr);
}
return 0;
}
long frequency_data(FILE *in,long frequency[])
{
int i,read_len;
unsigned char buf[256];
long filesize;
for(i=0;i<256;i++)
{
frequency[i]=0;
}
fseek(in,0L,SEEK_SET);
read_len=256;
while(read_len==256)
{
read_len=fread(buf,1,256,in);
for(i=0;i<read_len;i++)
{
frequency[*(buf+i)]++;
}
}
for(i=0,filesize=0;i<256;i++)
{
filesize+=frequency[i];
}
return filesize;
}
int search_set(htnp ht,int n,int *s1, int *s2)
{
int i,x;
long minValue = 1000000,min = 0;
for(x=0;x<n;x++)
{
if(ht[x].p==-1) break;
}
for(i=0;i<n;i++)
{
if(ht[i].p==-1 && ht[i].w < minValue)
{
minValue = ht[i].w;
min=i;
}
}
*s1 = min;
minValue = 1000000,min = 0;
for(i=0;i<n;i++)
{
if(ht[i].p==-1 && ht[i].w < minValue && i != *s1)
{
minValue = ht[i].w;
min=i;
}
}
*s2 = min;
return 1;
}
int create_hftree(long w[],int n,htnode ht[])
{
int m,i,s1,s2;
if (n<1) return -1;
m=2*n-1;
if (ht==NULL) return -1;
for(i=0;i<n;i++)
{
ht[i].w=w[i];
ht[i].p=ht[i].l=ht[i].r=-1;
}
for(;i<m;i++)
{
ht[i].w=ht[i].p=ht[i].l=ht[i].r=-1;
}
for(i=n;i<m;i++)
{
search_set(ht,i,&s1,&s2);
ht[s1].p = ht[s2].p = i;
ht[i].l = s1;
ht[i].r = s2;
ht[i].w = ht[s1].w + ht[s2].w;
}
return 0;
}
int encode_hftree(htnp htp,int n,hufcode hc[])
{
int i,j,p,codelen;
unsigned char *code=(unsigned char*)malloc(n*sizeof(unsigned char));
if (code==NULL) return -1;
for(i=0;i<n;i++)
{
for(p=i,codelen=0;p!=2*n-2;p=htp[p].p,codelen++)
{
code[codelen]=(htp[htp[p].p].l==p?0:1);
}
if((hc[i].codestr=(unsigned char *)malloc((codelen)*sizeof(unsigned char)))==NULL)
{
return -1;
}
hc[i].len=codelen;
for(j=0;j<codelen;j++)
{
hc[i].codestr[j]=code[codelen-j-1];
}
}
free(code);
return 0;
}
unsigned char chars_to_bits(const unsigned char chars[8])
{
int i;
unsigned char bits=0;
bits|=chars[0];
for(i=1;i<8;++i)
{
bits<<=1;
bits|=chars[i];
}
return bits;
}
int write_compress_file(FILE *in,FILE *out,htnp ht,hufcode hc[],char* source_filename,long source_filesize)
{
unsigned int i,read_counter,write_counter,zip_head=0xFFFFFFFF;
unsigned char write_char_counter,code_char_counter,copy_char_counter,
read_buf[256],write_buf[256],write_chars[8],filename_size=strlen(source_filename);
hufcode *cur_hufcode;
fseek(in,0L,SEEK_SET);
fseek(out,0L,SEEK_SET);
fwrite(&zip_head,sizeof(unsigned int),1,out);
fwrite(&filename_size,sizeof(unsigned char),1,out);
fwrite(source_filename,sizeof(char),filename_size,out);
fwrite(&source_filesize,sizeof(long),1,out);
for(i=256;i<256*2-1;i++)
{
fwrite(&(ht[i].l),sizeof(ht[i].l),1,out);
fwrite(&(ht[i].r),sizeof(ht[i].r),1,out);
}
write_counter=write_char_counter=0;
read_counter=256;
while(read_counter==256)
{
read_counter=fread(read_buf,1,256,in);
for(i=0;i<read_counter;i++)
{
cur_hufcode=&hc[read_buf[i]];
code_char_counter=0;
while(code_char_counter!=cur_hufcode->len)
{
copy_char_counter= (8-write_char_counter > cur_hufcode->len-code_char_counter ?
cur_hufcode->len-code_char_counter : 8-write_char_counter);
memcpy(write_chars+write_char_counter,cur_hufcode->codestr+code_char_counter,copy_char_counter);
write_char_counter+=copy_char_counter;
code_char_counter+=copy_char_counter;
if(write_char_counter==8)
{
write_char_counter=0;
write_buf[write_counter++]=chars_to_bits(write_chars);
if(write_counter==256)
{
fwrite(write_buf,1,256,out);
write_counter=0;
}
}
}
}
}
fwrite(write_buf,1,write_counter,out);
if(write_char_counter!=0)
{
write_char_counter=chars_to_bits(write_chars);
fwrite(&write_char_counter,1,1,out);
}
return 0;
}
void get_mini_huffmantree(FILE* in,short mini_ht[][2])
{
int i;
for(i=0;i<256;i++)
{
mini_ht[i][0]=mini_ht[i][1]=-1;
}
fread(mini_ht[i],sizeof(short),2*(256-1),in);
}
int write_decompress_file(FILE *in,FILE* out,short mini_ht[][2],long bits_pos,long obj_filesize)
{
long cur_size;
unsigned char read_buf[256],write_buf[256],convert_bit;
unsigned int read_counter,write_counter,cur_pos;
fseek(in,bits_pos,SEEK_SET);
fseek(out,0L,SEEK_SET);
read_counter=256-1;
cur_size=write_counter=0;
cur_pos=256*2-2;
while(cur_size!=obj_filesize)
{
if(++read_counter==256)
{
fread(read_buf,1,256,in);
read_counter=0;
}
for(convert_bit=128;convert_bit!=0;convert_bit>>=1)
{
cur_pos=((read_buf[read_counter]&convert_bit)==0?mini_ht[cur_pos][0]:mini_ht[cur_pos][1]);
if(cur_pos<256)
{
write_buf[write_counter]=(unsigned char)cur_pos;
if(++write_counter==256)
{
fwrite(write_buf,1,256,out);
write_counter=0;
}
cur_pos=256*2-2;
if(++cur_size==obj_filesize)
{
break;
}
}
}
}
fwrite(write_buf,1,write_counter,out);
return 0;
}
int decompress(char *source_filename,char *obj_filename)
{
int error_code;
FILE *in,*out;
short mini_ht[256*2-1][2];
long obj_filesize;
error_code=d_initial_files(source_filename,&in,obj_filename,&out);
if(error_code!=0)
{
puts("打开文件失败！请重新输入文件路径：");
return error_code;
}
fread(&obj_filesize,sizeof(long),1,in);
printf("解压文件大小:%ld字节\n",obj_filesize);
get_mini_huffmantree(in,mini_ht);
error_code=write_decompress_file(in,out,mini_ht,ftell(in),obj_filesize);
if(error_code!=0)
{
puts("解压缩失败！");
return error_code;
}
puts("解压缩完成!");
fclose(in);
fclose(out);
return 0;
}
int d_initial_files(char *source_filename,FILE **inp,char *obj_filename,FILE **outp)
{
unsigned int zip_head;
unsigned char filename_size;
if ((*inp=fopen(source_filename,"rb"))==NULL)
{
return -1;
}
printf("待解压缩文件:%s,",source_filename);
fread(&zip_head,sizeof(unsigned int),1,*inp);
if(zip_head!=0xFFFFFFFF)
{
return -1;
}
if(obj_filename==NULL)
{
if((obj_filename=(char*)malloc(256*sizeof(char)))==NULL)
{
return -1;
}
fread(&filename_size,sizeof(unsigned char),1,*inp);
fread(obj_filename,sizeof(char),filename_size,*inp);
obj_filename[filename_size]='\0';
}
else
{
fread(&filename_size,sizeof(unsigned char),1,*inp);
fseek(*inp,filename_size,SEEK_CUR);
}
printf("解压缩文件:%s\n",obj_filename);
if((*outp=fopen(obj_filename,"wb"))==NULL)
{
return -1;
}
free(obj_filename);
return 0;
}
