Dos Copy command

I am trying to make a c programe which will work like dos copy command.
I am able to copy the one txt file but this programe is not working with other extension file.

Void main()
{
FILE *fp,*fp1;
char c;

fp=fopen("source","r");
fp1=fopen(" destination","w");

while((c=getc(fp))!=EOF)
putc(c,fp1);
fclose(fp1);
fclose(fp);
}