Running 32bit applications on 64bit Ubuntu

After upgrading to 64bit Ubuntu 11.04, I wasn’t able to get some applications to work and was getting a very cryptic error

nullin@null-in:/work$ p4
bash: /build/bin/p4: No such file or directory

Even though /build/bin/p4 exists, on running the command, the system was complaining that the file doesn’t exist. I soon realized these were 32 bit applications and to fix this, one just needs to install ia32-libs:

sudo apt-get install ia32-libs

After doing this, things starting working properly again:

nullin@null-in:/work$ p4
Perforce -- the Fast Software Configuration Management System.
p4 is Perforce's client tool for the command line.  Try:
...
...