Merging in Subversion

Merging in subversion doesn't work like you'd think it'd work. You don't say "take this branch and apply all the changes to trunk". No... you say "calculate the differences between this branch and and older revision then apply these changes to trunk". That's very different. Because of this you need to note the revision at which you're branch was made and use this when merging. Here's a quick example:

Make a branch:

svn copy trunk ./branches/nw3

NOTE THE REVISION NUMBER (basenum) AND LEAVE A USEFUL LOG COMMENT. OK, now make edits commit them etc on the branch. At some point you want to merge the changes in to trunk (run this while in the trunk directory):

svn merge -r basenum:currentrev https://swiftng.svn.sourceforge.net/svnroot/swiftng/trunk

Where basenum is the revision number at which the branch was made and currentrev is the current revision.

Beagleboard GPIO Input (driverless)

This blog post has moved HERE

Disk space usage

My VM keeps getting filled up, and then crashing cos the programs that write logs are not being correctly handled by the underlying FS. So I am interested in generating useful infos on the disk to find out where all the disk space is at. The command du is a big help here. But I frequently just want to know in which directories the most space is being used.

du -h --max-depth=1

That command will give you a listing of which directories under the current dir are using all the space. So in the home dir or at the usr dir run this and find out where all the unneccessary crap is.

Giving me in the /usr dir the following output:

1.1G    ./share
40K     ./games
1.4G    ./local
7.1M    ./sbin
125M    ./src
36K     ./X11R6
136M    ./bin
14M     ./include
1.6G    ./lib
4.3G    .

And this tells me that I ought to tidy up the /usr/local dir. If you ran the above command without the max-depth option then the resulting output will probably overrun your cache/history in your bash shell and besides the output would be impossible to make sense of.