Author: pete

I decided to make a few changes in the blog. The first thing I did was made the comments appearable in-line. It required a few changes in the moveable type back-end.
I needed to add the ability to strip extraneous bits from the comment.cgi form. This was accomplished with a ‘raw’ parameter, that allowed it to remove code that fell within a <COOKED></COOKED> pair of tags. I also added in a ‘redir’ tag. This allows it to rediret the page somewhere other than the default redirect page – namely back to the homepage instead of back to the comments page as it is by default.
I was greedy, and wanted to add the ability to control output if there already were comments, so I added the <MTEntryIfHasComments> tag, which works quite nicely. I may need to add an inverse to this. This allows me to have entries on the main page that read Comments or Comments (<Number>)
Finally, and slightly annoyingly, I had to add a redirect to the proper hostname of my website, as the XMLHttpRequest open operator will not operate correctly cross domains (security feature for unsigned scripts). I have no intention of signing my scripts, so a simple javascript redirect is in place there.
Mozilla throws an exception if you try to cross-site execute and XMLHttpRequest, IE does a security confirmation and Konqueror (and probably safari) simply ignore the open request. annoying, but I suppose the have a point.
Things learned at this point

• XMLHttpRequest rocks!
• MT is a bit of a pain to customize
• IE caches more than it should – I can’t get the comments to reload.

Hmmm, strange one this. We have print jobs that are actually a batch of documents sent to the printer over the standard print spooling mechanism of Windows 2003. The problem is that the printers are network printers, so they can be stolen between documents by other machines feeding to the same printer.
How do we fix this?
Windows does not seem to be providing us with a way of doing this. There is no way of specifying that all the jobs need to be printed at once. Getting a lock on the printer seems impossible – they’re designed to just be dropped into the network taking the jobs as they’re being fed to it.
Potential solutions:

• Remote queues per printer – spool jobs for each printer on the single machine. This cuts down on the scalability of the system, but it’s probably the quickest fix
• Combine all the separate documents into the one print job and send that to the printer. Requires no reconfiguration of the printer queues. Means we have to concatenate all the jobs from the batch into the one file. This is ok, as weve got PDFs and there are a multitude of programs around that allow us to concatenate them.

Anyone have anything else like this happen to them and how did they solve it?

Ok,
Time for a little bit of programming trickery – this one related to makefiles and the fun of VPATH. One of the projects I was working on used the VPATH feature to build the code for each version in a subdirectory. That meant that you can have one makefile for any version, and simply include the delta makefile which contained all the conditional compilation work. The problem with this is that you need to write the makefile carefully, otherwise you can’t take advantage of this feature.
When you write a makefile rule you end up with something resembling:

target: dep1.c dep2.h
   $(CC) $(CFLAGS) -o target dep1.c

The rule itself is fine, the problem is that the build command will mess up when executed on a relative path build. The make tool cannot change the target and dep1.c entries to match the locations of the files in the build command; It’s not been given the ability to parse shell scripts. You need to use the correct variable syntax.
Firstly, we never use the absolute target name in a build – that’s really effing stupid – after all if we change the name of the target every other entry needs changing. What we use is the $@ variable – this is expanded at run time to match the target name – it means less typing, and less chance of an error.
The Second change is to replace the dep1.c with $<, this means take the first dependency of the rule, and as this is a vpath substitutable entry, this gets replaced with wherever the dep1.c is found.
I’ve been experimenting with this on a linux box and it works exactly as advertised for the gmake. I’ve not tested it recently on Solaris for svr make, I know there is a different semantic to $lt; there.