I keep forgetting this one hence writing it up. Every so often you need to flush the local dns cache – usually you’ve made a change in some dns & you want to test it immediately etc.
dscacheutil -flushcache
It’s that simple – so simple it’s an easy one to forget 
I’ve just had this one with a pptp vpn – one network was accessible over it but another behind it wasnt so I had to add a static route.
First you need to know the remote ip address of the vpn connection:
sabrina:table peter$ ifconfig ppp0 ppp0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1444 inet 192.168.1.3 --> 192.168.1.1 netmask 0xffffff00
Here the address we want is the first one, 192.168.1.3
Now to create the route
sabrina:table peter$ sudo route add -net 192l168.2.0/24 192.168.1.3 Password: add net 192.168.2.0: gateway 192.168.1.3
Thats it, now that route will work as long as the vpn connection stays up. When you disconnect it will then be removed & you’ll have to add it again later.
Since the announcement by Apple last week about deprecating Java on OS X, there’s been a few people wanting to know how to compile OpenJDK on the Mac.
Although I’ve not done this for JDK 6, this article cover’s how to compile and use the current development version of JDK 7.0 on OS X.
First a few notes:
So as a word of warning: Don’t expect this to either work, or work well – and don’t use this in production – JDK7 isn’t due out for another 12 months or so…
Ok, first we need a bootstrap JDK6 environment. This is needed to do some of the initial java compilation during the build. For this the apple JVM can’t be used so we need to download and install the i386 Soylate binaries JDK – don’t get the amd64 version, get the i386 one…
Once you have it downloaded, copy it to /usr/local/soylatte16-i386-1.0.3 and test it:
sabrina:~ peter$ /usr/local/soylatte16-i386-1.0.3/bin/java -version java version "1.6.0_03-p3" Java(TM) SE Runtime Environment (build 1.6.0_03-p3-landonf_19_aug_2008_14_55-b00) Java HotSpot(TM) Server VM (build 1.6.0_03-p3-landonf_19_aug_2008_14_55-b00, mixed mode)
Next create a blank directory under which we will build everything. I’m using ~/dev/ojdk but you could use any directory. Under this we need to create a couple of directories and some symlinks:
sabrina:~ peter$ mkdir -p dev/ojdk sabrina:~ peter$ cd dev/ojdk sabrina:~ peter$ mkdir -p bin ALT_COMPILER_PATH sabrina:~ peter$ cd ALT_COMPILER_PATH sabrina:~ peter$ ln -s /usr/bin .SOURCE sabrina:~ peter$ ln -s .SOURCE/g++-4.0 g++ sabrina:~ peter$ ln -s .SOURCE/gcc-4.0 gcc sabrina:~ peter$ cd ../bin
Now in the bin directory you need to create two scripts. Fortunately these are readily available from http://gist.github.com/617451 – specifically update.sh and update-usr-local.sh. Copy these two files into the bin directory and ensure they are executable.
Now open update.sh in your favourite editor and find the line with ALT_COMPILER_PATH in it. Change it to hold the full path to the ALT_COMPILER_PATH directory defined above. In my case this looks like:
ALT_COMPILER_PATH=/Users/peter/dev/ojdk/ALT_COMPILER_PATH/ \
sabrina:~ peter$ cd ~/dev/ojdk sabrina:~ peter$ hg fclone http://hg.openjdk.java.net/bsd-port/bsd-port bsd
We should now be setup. The last step is to run a build. This can be done at any time. It will check for any updates, clear down and then run a full build:
sabrina:~ peter$ cd ~/dev/ojdk/bsd sabrina:~ peter$ source ../bin/update.sh
If all goes well, after about 20 minutes you should see something like the following at the end of the build:
testing build: ./build/bsd-amd64/j2sdk-image/bin/java -version openjdk version "1.7.0-internal" OpenJDK Runtime Environment (build 1.7.0-internal-peter_2010_10_25_11_19-b00) OpenJDK 64-Bit Server VM (build 19.0-b05, mixed mode)
If the build succedes the last step is to install it under /usr/local/java-1.7.0:
sabrina:~ peter$ cd ~/dev/ojdk/bsd sabrina:~ peter$ source ../bin/update-usr-local.sh
To use Java 7, you need to simply point the app to the installed application, usually by setting JAVA_HOME=/usr/local/java-1.7.0 and running $JAVA_HOME/bin/java…
sabrina:bin peter$ /usr/local/java-1.7.0/bin/java -version openjdk version "1.7.0-internal" OpenJDK Runtime Environment (build 1.7.0-internal-peter_2010_10_25_11_19-b00) OpenJDK 64-Bit Server VM (build 19.0-b05, mixed mode)
