哪位大哥帮忙看下这段程序中的错误怎么改

#include <stdio.h>
#include <string.h>

char code (char ch,int key);
{ char sec;
sec=ch^ key;
return (sec);}
char decode(char ch,int key);
{int dec;
dec=ch^key;
return (dec);}

void coding (int key)
{file*fp,*fp1;
unsigned char ch;
if((fp=fopen("jj.txt","r"))==NULL)
{printf("\n cannot open file\n");
exit (0);
}
if((fp1=fopen("coded.bin","wb"))==NULL)
{printf("\n cannot open file.\n");
exit(0);}
rewind(fp);
rewind(fp1);
while(!feof (fp))
{ch=fgetc(fp);
ch=code(ch,key);
fputc=(ch,fp1);}
fclose(fp);
fclose(fp1);}

void decoding(int key)
{file*fp,*fp1;
char ch;
if((fp=fopen("coded.bin","rb"))==NULL)
{printf("\n cannot open to be coded file.\n");
exit(0);