fbobp
if (fseekp < fbobp || fseekp > feobp) {
fbobp = feobp = fseekp;
fbobp = feobp;
c = fbuf[0][fseekp - fbobp];
fseekp = fbobp = feobp = lseek(SHIN, (off_t) 0, SEEK_CUR);