neverpanic.de » CoffeeBreak

Subversion Property Copy

written by Clemens Lang at Feb 16^th 2009, 0:03

Although there is a couple of Subversion GUIs for Macs, I usually use the CLI. I manage all source code I write during my studies using Subversion and usually add revision number and date of last checkin to the file using the svn:keywords-Property. However, I always forget the set of keywords I usually add: Author Date Id Revision URL. Unfortunately, there is no way to copy a property from one file to another in the standard subversion binary. There is, however, a little shortcut:

svn propset $propertyName "`svn propget $propertyName $fromFileName`" $toFileName

Typing this monster isn’t any userfriendly at all, though – a little .bashrc magic does the trick:

# add svn propcopy
function svn() {
    case "$1" in
        pc|propcopy)
            propName=$2
            fromFile=$3
            shift 3
            `which svn` propset $propName "`\`which svn\` propget $propName $fromFile`" $@
        ;;
        *)
            `which svn` $@
        ;;
    esac
}

Update: Thanks to Raim for the wildcard support. Using subversion auto-props is an option for files, but unfortunately, auto-props don’t work on directories yet.

Posted in Linux | 2 Comments »

A Friday 13th story

written by Clemens Lang at Feb 14^th 2009, 16:32

This site is served by my own virtual server hosted by Carrot Servers in Austria. The hardware nodes running their servers are housed in one of Germany’s largest hosting company’s datacenters. However, three of their datacenters recently suffered from a power loss because of a defunct uninterruptible power source and a series of other unfortunate problems – a little over 12,000 servers were without power for a few hours.
However, it seems my vServer’s hardware node was damaged by the power loss; one of the hard disk drives in the RAID array was replaced after the outage. Yesterday, the worst-case scenario came true: besides the hard disks, apparently the motherboard was also damaged causing the RAID controller to slowly corrupt the data on the drives. On Friday, 13^th, my provider informed me data had been lost and the server will be swapped with a new machine.
Luckily, I did remember creating backup – and it happened to be a recent one (namely from Thursday, 12^th). But as Murphy’s law states, things never work the way you expect them to work. In this case that meant that permissions were incorrect on the backup although I used rsync with the appropriate preserve-permissions option. I’ve thus been busy reinstalling the software, uploading the files and databases and fixing their permission. As of now, all data has been successfully restored (blessing in disguise) and I’m supervising the server’s functions.

Posted in Internal, Linux | No Comments »

Software on a stick?

written by Clemens Lang at Dec 4^th 2008, 13:39

Why is the software industry still using optical media to distribute software? Besides the few companies that offer software downloads everybody else ships CDs or DVDs. I occasionally wonder why they don't use USB flash drives? Flash drives are

1. small (from a hardware point of view)
   USB drives are much smaller and thus much more portable than optical media
2. large (in terms of storage capacity)
   flash memory can easily store the amount of data a DVD can and the amount will certainly grow in the future
3. robust
   try to break apart a CD, and then do the same with a flash drive
4. cheap
   I don't know the exact price per Gigabyte of a CD or DVD, but USB drives are quite cheap as well.

I'm not a business analyst, but imho thumb drives are a serious alternative to optical media especially since there will be more PCs or laptops without any optical drive (such as the MacBook Air) in the future.

Posted in | No Comments »