Random Stuff

• Taming Firefox
• Ruby 1.9
• Resetting Dell Powerconnect Switch Passwords
• Making hme1 probe correctly on Sun Netra t1 105 servers
• hacking trac so it shows svn usernames for people without email addresses in the RSS feed

To convert asterisk gsm files to wav files it can still play:

 sox tt-weasels.gsm -r 8000 -b -c 1 -u -2 tt-weasels.wav

• Starting FORTH - online edition

Upgrading pkgsrc bootstrapped packages (bmake install-sh nawk nbsed pax tnftp bootstrap-mk-files):

bmake USE_DESTDIR=full package
rm /var/db/pkg/<pkgname>-<pkgversion>/+PRESERVE
pkg_delete "<pkgname>*"
pkg_add /usr/pkgsrc/packages/All/<pkgname>-<pkgversion>.tgz
touch /var/db/pkg/<pkgname>-<pkgversion>/+PRESERVE

• List of Operating System Defines - Handy for doing OS checking in the C preprocessor.

How to list the architecture specific preprocessor defines in gcc:

 echo | gcc -E -dM -

Taken from here.

• Reverse engineering DOS binaries

• Stian's CLI currency converter - Install the perl libwww stuff if it bitches about LWP/Simple

• awk one liners
• sed one liners

• BASH tips and tricks

• How to resize ext3 partitions with fdisk/resize2fs

• Erlang HIPE bitarrays - Undocumented mutable bitarrays/binaries for Erlang (when using HIPE)

OpenBSD key life times in ipsec.conf

Use the undocumented 'life' keyword for quick and main mode see here. NOTE: This has been found to not exactly work as (not) advertised.. ymmv.

Subnet calculations

I always forget how to do these.

The Broadcast Address is obtained doing a binary OR between an address in the subnet and the inverted Subnet Mask. You can invert the subnet mask by XORing it with the decimal representation of 255.255.255.255.

The Subnet Address is obtained by doing a binary AND between an address in the subnet and its Subnet mask.

A handy tool to convert address to/from decimal can be found here

See Also: Wikipedia IPv4 subnetting reference