Uninstall perl modules

perl -MExtUtils::Install -e "uninstall('/usr/lib/perl5/5.8.8/i486-linux/auto/Gaim/.packlist', 1, 1 );"
uninstall($packlist_file, $verbose, $dont_execute);
Removes the files listed in a $packlist_file.
If $verbose is true, will print out each file removed. Default is false.
If $dont_execute is true it will only print what it was going to do without actually doing it. Default is false.

Convert a Unix timestamp to a readable format

date -d '1970-01-01 1045126013 sec' +"%Y-%m-%d %T %z"
perl -e 'print scalar localtime 1045126013\n'

HEX edit in vi

vi ~/binfile
now editing in vi
[esc] :%!xxd
now editing mycat in hex
[esc] :%!xxd -r
[esc] :wq!
You can also 'pre' xxd transform the file, then edit it, then transform
it back when finished.

Extract the contents of a .rpm file

rpm2cpio rpmpackage.rpm | cpio -dmiv

Extract the contents of a .deb file

ar -x debianpackage.deb

Create an SSL key for a web-server

Make the key
openssl req -config openssl.cnf -new -out server.csr
To remove the passwd
openssl rsa -in privkey.pem -out server.key
To set the duration
openssl x509 -in server.csr -out server.crt -req -signkey server.key -days 999

allow for unattended CPAN installs

cpan> o conf build_requires_install_policy yes
cpan> o conf prerequisites_policy follow
cpan> o conf commit