off_t pagemask, off1, off2;
size_t pagesize;
if (sflag && len1 != len2)
exit(1);
if (skip1 > len1)
eofmsg(file1);
len1 -= skip1;
if (skip2 > len2)
eofmsg(file2);
len2 -= skip2;
if(sflag && len1 != len2)
exit(DIFF_EXIT);
pagesize = getpagesize();
pagemask = (off_t)pagesize - 1;