In a previous entry, I mused over a move from Windows to Linux, a suggestion being that Fedora Core Linux would be my base operating system with Windows installed in a Xen virtual machine. That of course led me to wonder how I would swap my current situation about: Linux in VM, Windows as host. Meantime, I discovered something that makes the whole process a little easier: VMware Convertor. The Starter version can be downloaded free of charge while the Enterprise edition comes with VirtualCenter Management Server for corporate use. What it does is to make a virtual version of a real computer, a process that takes drive imaging much, much further. I have given it a whirl and the conversion seems to go well; the only thing left is for me to fire it up in VMware Workstation – I believe that Player and Server will also run the VM that is created and, like Convertor Starter, they also can be downloaded free of charge; Workstation does everything for me so I haven’t looked beyond it, even though it did cost me money all those moons ago – and get through licence activation issues without leaving me with no authorised Windows installation.
Archive for February 9th, 2007
From real to virtual…
Octals in UNIX shell scripting
I have just discovered that if you have a number with a leading zero, such as 08, it is assumed to be an octal number, that is, one of base 8. The upshot of this is that you get errors when you have numbers like 08 and 09 in your arithmetical expressions; they are illegal in octal: 08 should be 10 and 09 should be 11. Og course, as luck would have it, you get exactly these expressions when date/time processing. Luckily you can forced things to be base 10 by having something like 10#08 or, when extracting the minute from a date-time value, 10#$(date +%M). Strange as it might appear, this behaviour is all by design. It is dictated in the POSIX standard that governs UNIX. That said, I’d rather it if 08 was interpreted as an 8 and 09 as a 9 rather than triggering the errors that we see but that could have been seen as muddying the simplicity of the standard.