int buf[256]; main(argc,argv) { register fi,fo,l; fi = open("../l1100",0); fo = creat("a.out",0604); l=read(fi,buf,512); buf[0]= 0410; buf[1]=buf[4]; buf[4]= buf[6]; do write(fo,buf,l); while((l=read(fi,buf,512))>0); }