How do I apply a patch or a di ?
You need the patch program. You should probably duplicate the entire directory structure before applying the patch. For example, if you are upgrading from squid-1.1.10 to 1.1.11, you would run these commands: cd squid-2.5.STABLE3 mkdir ../squid-2.5.STABLE4 find . -depth -print | cpio -pdv ../squid-1.1.11 cd ../squid-1.1.11 patch -p1 < /tmp/squid-2.5.STABLE3-STABLE4.diff or alternatively cp -rl squid-2.5.STABLE3 squid-2.5.STABLE4 cd squid-2.5.STABLE4 zcat /tmp/squid-2.5.STABLE3-STABLE4.diff.gz | patch -p1 After the patch has been applied, you must rebuild Squid from the very beginning, i.e.: make distclean ./configure ... make make install If your patch program seems to complain or refuses to work, you should get a more recent version, from the GNU FTP site ftp://ftp.gnu.ai.mit.edu/pub/gnu/ , for example. 2.7 con gure options The con gure script can take numerous options. The most useful is prefix to install it in a di erent directory.