Technology Tales

Ricoh Caplio GX100?

Because my digital SLR has needed to be sent away for cleaning for a while now (in the meantime I have got good at using Photoshop Elements to clean up up pictures…), I have been on the lookout for a backup camera so that I can add photos to any trip reports on my hillwalking blog without having to wait for film to be processed. Previously, my eye was on Ricoh’s GR Digital but they have now introduced the award-winning Caplio GX100. The zoom range is a very useful 24-72 mm in 35 mm film terms and that removable electronic viewfinder looks very neat. Having a 10 megapixel sensor adds to the appeal and advanced exposure modes like manual and aperture priority. The feature list has almost ensured its ousting of the GR Digital from any wish list that I might have; the only thing outstanding is seeing how it performs in a photography magazine’s full test review. A thumbs up from there might even get me onto the acquisition trail…

Uses for symbolic links

UNIX (and Linux) does a wonderful trick with its file and folder shortcuts; it effectively treats them as file and folder transporters that transfer associate a file or folder that exists in one folder hierarchy with another and it is treated as if it exists in that hierarchy too. For example, the images folder under /www/htdocs/blog can have a link under /www/htdocs/ that makes it appear that its contents exist in both places without any file duplication. For instance, the pwd command cannot tell a folder from a folder shortcut. To achieve this, I use what are called symbolic links and the following command achieves the outcome in the example:

ln -s /www/htdocs/blog/images /www/htdocs/images

The first file path is the destination for the link while the second one is that for the link itself. I had a problem with Google Reader not showing up images in its feed displays so symbolic links rode to the rescue as they did for resolve a similar conundrum that I was encountering when editing posts in my hillwalking blog.

Another Olympus E-system review

I don’t buy Amateur Photographer much these days but sight of a review of Olympus’ E-410 and E-510 SLR’s got a copy into my possession. Amateur Photographer review features are usually comprehensive and this was no exception; there was none of the vitriol directed towards the Live View feature by Practical Photography, a defining feature of what i consider a lop-sided and none too useful review. The verdict was a positive one in the main with the E-510 getting the nod over the E-410 because it fared better on the usability side of things. Image quality, my major concern, was said to be impressive with only dynamic range counting against the results. The Live View feature didn’t attract the harsh commentary devoted to it by Practical Photography. Following this review, I have to say that the E-510 does tempt me with its combination of good image quality, dust removal and image stabilisation.

ERROR: Can’t find the archive-keyring

When I recently did my usual system update for the stable version Ubuntu GNOME, there were some updates pertaining to apt and the process failed when I executed the following command:

sudo apt-get upgrade

Usefully, some messages were issued and here’s a flavour:

Setting up apt (0.9.9.1~ubuntu3.1) …
ERROR: Can’t find the archive-keyring
Is the ubuntu-keyring package installed?
dpkg: error processing apt (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
apt
E: Sub-process /usr/bin/dpkg returned an error code (1)

Some searching on the web revealed that the problem was that there were no files in /usr/share/keyring when there should have been and I had not removed them myself so I have no idea how they disappeared. Various remedies were tried and any that needed software installed were non-starters because apt was disabled by the lack of keyring files. The workaround that restored things for me was to take a copy of the files in /usr/share/keyring from an Ubuntu GNOME 14.04 installation in a VirtualBox VM and copy them in to the same location in its Ubuntu GNOME 13.10 host. For those without such resources, I have packaged them in a zip file below. Other remedies like Y PPA also were suggested where I was reading but that software package needed installing beforehand so it was little use to me when the likes of Synaptic were disabled. If there are other remedies that do not involve an operating system re-installation, I would like to know about them too as well as possible causes for the file loss in the first place and how to avoid these.

Ubuntu Keyrings

Office 2007 on test…

With its imminent launch and having had a quick at one of its beta releases, I decided to give Office 2007 a longer look after it reached its final guise. This is courtesy of the demonstration version that can be downloaded from Microsoft’s website; I snagged Office Standard which contains Word, Excel, PowerPoint and Outlook. Very generously, the trial version that I am using gives me until the end of March to come to my final decision.

And what are my impressions? Outlook, the application from the suite that I most use, has changed dramatically since Outlook 2002, the version that I have been using. Unless you open up an email in full screen mode, the ribbon interface so prevalent in other members of the Office family doesn’t make much of an appearance here. The three-paned interface taken forward from Outlook 2003 is easy to get around. I especially like the ability to collapse/expand a list of emails from a particular sender: it really cuts down on clutter. The ZoneAlarm anti-spam plug-in on my system was accepted without any complaint as were all of my PST files. One thing that needed redoing was the IMAP connection to my FastMail webmail account but that was driven more by Outlook warning messages than by necessity from a user experience point of view. I have still to get my Hotmail account going but I lost that connection when still using Outlook 2002 and after I upgraded to IE7.

What do I make of the ribbon interface? As I have said above, Outlook is not pervaded by the new interface paradigm until you open up an email. Nevertheless, I have had a short encounter with Word 2007 and am convinced that the new interface works well. It didn’t take me long to find my way around at all. In fact, I think that they have made a great job of the new main menu triggered by the Office Button (as Microsoft call it) and got all sorts of things in there; the list includes Word options, expanded options for saving files (including the new docx file format, of course, but the doc format has not been discarded either) and a publishing capability that includes popular blogs (WordPress.com, for instance) together with document management servers. Additionally, the new zoom control on the bottom right-hand corner is much nicer than the old drop down menu. As regards the “ribbon”, this is an extension of the tabbed interfaces seen in other applications like Adobe HomeSite and Adobe Dreamweaver, the difference being that the tabs are only place where any function is found because there is no menu back up. There is an Add-ins tab that captures plug-ins to things like Adobe Distiller for PDF creation. Macromedia in its pre-Adobe days offered FlashPaper for doing the same thing and this seems to function without a hitch in Word 2007. Right-clicking on any word in your document not only gives you suggested corrections to misspellings but also synonyms (no more Shift-F7 for the thesaurus, though it is still there is you need it) and enhanced on-the-spot formatting options. A miniature formatting menu even appears beside the expected context menu; I must admit that I found that a little annoying at the beginning but I suppose that I will learn to get used to it.

My use of Outlook and Word will continue, the latter’s blogging feature is very nice, but I haven’t had reason to look at Excel or PowerPoint in detail thus far. From what I have seen, the ribbon interface pervades in those applications too. Even so, my impressions the latest Office are very favourable. The interface overhaul may be radical but it does work. Their changing the file formats is a more subtle change but it does mean that users of previous Office versions will need the converter tool in order for document sharing to continue. Office 97 was the last time when we had to cope with that and it didn’t seem to cause the world to grind to a halt.

Will I upgrade? I have to say that it is very likely given what is available in Office Home and Student edition. That version misses out on having Outlook but the prices mean that even buying Outlook standalone to compliment what it offers remains a sensible financial option. Taking a look at the retail prices on dabs.com confirms the point:

Office Home and Student Edition: £94.61

Office Standard Edition: £285.50

Office Standard Edition Upgrade: £175.96

Outlook 2007: £77.98

Having full version software for the price of an upgrade sounds good to me and it is likely to be the route that I take, if I replace the Office XP Standard Edition installation that has been my mainstay over the last few years. Having been on a Windows 95 > Windows 98 > Windows 98 SE > Windows ME upgrade treadmill and endured the hell raised when reinstallation becomes unavoidable, the full product approach to getting the latest software appeals to me over the upgrade pathway. In fact, I bought Windows XP Professional as the full product in order to start afresh after moving on from Windows 9x.

Work locally, update remotely

Here’s a trick that might have its uses: using a local WordPress instance to update your online blog (yes, there are plenty of applications that promise to edit your online blog but these need file permissions to the likes of xmlrpc.php to be opened up). Along with the right database access credentials and the ability to log in remotely, adding the following two lines to wp-config.php does the trick:

define('WP_SITEURL', 'http://localhost/blog');

define('WP_HOME', 'http://localhost/blog');

These two constants override what is in the database and allow to update the online database from your own PC using WordPress running on a local web server (Apache or otherwise). One thing to remember here is that both online and offline directory structures are similar. For example, if your online WordPress files are in blog in the root of the online web server file system (typically htdocs for Linux), then they need to be contained in the same directory in the root of the offline server too. Otherwise, things could get confusing and perhaps messy. Another thing to consider is that you are modifying your online blog so the usual rules about care and attention apply, particularly with respect to using the same version of WordPress both locally and remotely. This is especially a concern if you, like me, run development versions of WordPress to see if there are any upheavals ahead of us like the overhaul that is coming in with WordPress 2.7.

An alternative use of this same trick is to keep a local copy of your online database in case of any problems while using a local WordPress instance to work with it. I used to have to edit the database backup directly (on my main Ubuntu system), first with GEdit but then using a sed command like the following:

sed -e s/www\.onlinewebsite\.com/localhost/g backup.sql > backup_l.sql

The -e switch uses regular expression substitution that follows it to edit the input with the output being directed to a new file. It’s slicker than the interactive GEdit route but has been made redundant by defining constants for a local WordPress installation as described above.

Relocating the Apache web server document root directory in Fedora 12

So as not to deface anything that is available online on the web, I have a tendency to set up an offline Apache server on a home PC to do any tinkering away from the eyes of the unsuspecting public. Though Ubuntu is my mainstay for home computing, I do have a PC with Fedora installed and I have been trying to get an Apache instance starting automatically on there without success for a few months. While I can start it by running the following command as root, I’d rather not have more manual steps than is necessary.

httpd -k start

The command used by the system when it starts is different and, even when manually run as root, it failed with messages saying that it couldn’t find the directory while the web server files are stored. Here it is:

service httpd start

The default document root location on any Linux distribution that I have seen is /var/www and all is very well with this but it isn’t a safe place to leave things if ever a re-installation is needed. Having needed to wipe /var after having it on a separate disk or partition for the sake of one installation, it doesn’t look so persistent to me. In contrast, you can safeguard /home by having it on another disk or in a dedicated partition and it can be retained even when you change the distro that you’re using. Thus, I have got into the habit of having the root of the web server document root folder in my home area and that is where I have been seeing the problem.

Because of the access message, I tried using chmod and chgrp but to no avail. The remedy has to do with reassigning the security contexts used by SELinux. In Fedora, Apache will not work with the context user_home_t that is usually associated with home directories but needs httpd_sys_content_t instead. To find out what contexts are associated with particular folders, issue the following command:

ls -Z

The final solution was to create a user account whose home directory hosts the root of the web server file system, called www in my case. Then, I executed the following command as root to get things going:

chcon -R -h -t httpd_sys_content_t /home/www

It seems that even the root of the home directory has to have an appropriate security context (/home has home_root_t so that might do the needful too). Without that, nothing will work even if all is well at the next level down. The switches for chcon command translate as follows:

-R : recursive; applies changes to all files and folders within a directory.

-h : changes apply only to symbolic links and not to where they refer in the file system.

-t : alters context type.

It took a while for all of this stuff about SELinux security contexts to percolate through to the point where I was able to solve the problem. A spot of further inspiration was needed too and even guided my search for the information that I needed. It’s well worth trying Linux Home Networking if you need more information. There are references to an earlier release of Fedora but the content still applies to later versions of Fedora right up to the current release if my experience is typical.

A NetBeans 6.1 Review

I have been thinking of sharing my thoughts on using IDE‘s such as NetBeans, Eclipse and Komodo Edit from a web developer’s point of view for a while but it has still to come. In the meantime, Java Boutique have shared their thoughts on NetBeans 6.1 and I think that they are well worth a look. In fact, I downloaded a copy for my own use off the back of this. MySQL capabilities look especially intriguing.

Amateur Photographer reviews…

Amateur Photographer seem to have had a run of reviews recently. First off were the Olympus E-410 and E-510 that they seemed to like. Then, they moved onto the Ricoh Caplio GX100 and they seemed to like that too, though they did say that quality wasn’t up to SLR standards. But then again, it is a compact and that might be expecting a bit too much. This week, Paint Shop Pro comes under the spotlight as does Epson’s V350 scanner. I have yet to read these but I have been engaging in a spot of equipment acquisition anyway. My CanoScan 5000F scanner has been usurped by Epson’s Perfection Photo 4490 and very happy I am with it too. The quality of the scans that I have been doing of prints has been good and the presence of an on/off switch is a creditable one. None of the other scanners that I have had possessed it and having to plug something in and out from the power socket is inconvenient to say the least. I have also gone and got myself a new DSLR. Seeing Pentax’s K10D going with a 18-55 mm lens for £499 at Jessop’s overrode my better reason and put paid to ideas of purchasing any other electronic goods for the rest of this year. It’s an award-winning gadget and Photography Monthly’s Will Cheung seemed to get on fine with it. Which Digital Camera said it was heavy but it has to stand up to use in the great outdoors. The sensor may be a 10 megapixel affair so this will be an upgrade to my Canon EOS 10D; that has a sensor in need of clean right now (I plan to get it done by the professionals) and every time that I want to use an image that it has made, Photoshop’s healing brush has to be pressed into service. Pentax does boast about all of the seals that it has added to the K10D, a good thing if they cut down on the dust entering the camera. And if dust does get in, the sensor cleaning feature will hopefully see it off from the photos. Image stabilisation, another value adding feature, is also there and may prove interesting. Strangely, there’s some motion picture capture as well and I hope that it doesn’t get the EU coming after me to collect retrospective camcorder duty. In any case, it’s not a feature that I really need and the Live View functions on the equivalent Olympus offerings fall into the same category anyway. It’ll be interesting to see how the K10D performs and it’s a change from the Canon/Nikon hegemony that seems to dominate digital photography these days.

Update: I have since perused the current issue of Amateur Photographer and seen that Paint Shop Pro suffered from performance issues on computers that worked fine with Photoshop. Otherwise, it compared well with Adobe’s offerings even if the interface wasn’t seen to be as slick. Epson’s V350 was well received though it was apparent that spending more got you a better scanner but that’s always the way with these things.

ASCII Codes

Having found myself looking for this from time to time, here is a table of ASCII characters and their representation in decimal, hexadecimal and octal forms together with the corresponding HTML entities. The first on the list are various non-printing characters and I have found myself using the TAB one in programming quiet often over the years. Currently, only the core ASCII characters appear but those from the extended set may be added later.