Archive for Scripting

A waiting game

Having been away every weekend in July, I was looking forward to a quiet one at home to start August. However, there was a problem with one of my websites hosted by Fasthosts that was set to occupy me for the weekend and a few weekday evenings afterwards.

The issue appeared to be slow site response so I followed advice given to me by second line support when this website displayed the same type of behaviour: upgrade from Apache 1.3 to 2.2 using the control panel. Unfortunately for me, that didn’t work smoothly at all and there seemed to be serious file loss as a result. Raising a ticket with the support desk only got me the answer that I had to wait for completion and I now have come to the conclusion that the migration process may have got stuck somewhere along the way. Maybe another ticket is in order.

There were a number of causes of the waiting that gave rise to the title of this post. Firstly, support for low costing isn’t exactly timely and I do wonder if it’s any better for more prominent websites. Restoration of websites by FTP is another activity that takes up plenty of time as does rebuilding databases and populating them with data. Lastly, there’s changing the DNS details for a website. In hindsight, there may be ways of reducing the time demands of these. For instance, contacting a support team by telephone may be quicker unless there is a massive queue awaiting attention and there was a wait of several hours one night when a security changeover affected a multitude of Fasthosts users. Of course, it is not a panacea at the best of times as we have known since all those stories began to do the rounds in the middle of the 1990′s. Doing regular backups would help the second though the ones that I was using for the restoration weren’t too bad at all. Nevertheless, they weren’t complete so there was unfinished business that required resolution later. The last of these is helped along by more regular PC restarts so that unexpected discovery will remain a lesson for the future though I don’t plan on moving websites around for a while. After all, getting DNS details propagated more quickly really is a big help.

While awaiting a response from Fasthosts, I began to ponder the idea of using an alternative provider. Perusal of the latest digital edition of .Net (I now subscribe to the non-paper edition so as to cut down on the clutter caused by having paper copies about the place) ensued before I decided to investigate the option of using Webfusion. Having decided to stick with shared hosting, I gave their Unlimited Linux option a go. For someone accustomed to monthly billing, it was unusual to see annual biannual and triannual payment schemes too. The first of these appears to be the default option so a little care and attention is needed if you want something else. In order to encourage you to stay with Webfusion longer, the per month is on sliding scale: the longer the period you buy, the lower the cost of a month’s hosting.

Once the account was set up, I added a database and set to the long process of uploading files from my local development site using FileZilla. Having got a MySQL backup from the Fasthosts site, I used the provided PHPMyAdmin interface to upload the data in pieces not exceeding the 8 MB file size limitation. It isn’t possible to connect remotely to the MySQL server using the likes of MySQL Administrator so I bear with this not so smooth process. SSH is another connection option that isn’t available but I never use it much on Fasthosts sites anyway. There were some questions to the support people along and the first of these got a timely answer though later ones took longer before I got an answer. Still, getting advice on the address of the test website was a big help while I was sorting out the DNS changeover.

Speaking of the latter, it took a little doing and not little poking around Webfusion’s FAQ’s before I made it happen. First, I tried using name servers that I found listed in one of the articles but this didn’t seem to achieve the end that I needed. Mind you, I would have seen the effects of this change a little earlier if I had rebooted my PC earlier than I did than I did but it didn’t occur to me at the time. In the end, I switched to using my domain provider’s name servers and added the required information to them to get things going. It was then that my website was back online in some fashion so I could any outstanding loose ends.

With the site essentially operating again, it was time to iron out the rough edges. The biggest of these was that MOD_REWRITE doesn’t seem to work the same on the Webfusion server like it does on the Fasthosts ones. This meant that I needed to use the SCRIPT_URI CGI variable instead of PATH_INFO in order to keep using clean URL’s for a PHP-powered photo gallery that I have. It took me a while to figure that out and I felt much better when I managed to get the results that I needed. However, I also took the chance to tidy up site addresses with redirections in my .htaccess file in an attempt to ensure that I lost no regular readers, something that I seem to have achieved with some success because one such visitor later commented on a new entry in the outdoors blog.

Once any remaining missing images were instated or references to them removed, it was then time to do a full backup for sake of safety. The first of these activities was yet another consumer while the second didn’t take so long and I need to do this more often in case anything happens. Hopefully though, the relocated site’s performance continues to be as solid as it is now.

The question as to what to do with the Fasthosts webspace remains outstanding. Currently, they are offering free upgrades to existing hosting packages so long as you commit for a year. After my recent experience, I cannot say that I’m so sure about doing that kind of thing. In fact, the observation leaves me wondering if instating that very extension was the cause of breaking my site. In fact, it appears that the migration from Apache 1.3 to 2.2 seems to have got stuck for whatever reason. Maybe another ticket should be raised but I am not decided on that yet. All in all, what happened to that Fasthosts website wasn’t the greatest of experiences but the service offered by Webfusion is rock solid thus far. While wondering if the service from Fasthosts wasn’t as good as it once was, I’ll keep an open mind and wait to see if my impressions changes over time.

Moving from Ubuntu 10.10 to Linux Mint 10

With a long Easter weekend available to me and with thoughts of forthcoming changes in the world of Ubuntu, I got to wondering about the merits of moving my main home PC to Linux Mint instead. Though there is a rolling variant based on Debian, I went for the more usual one based on Ubuntu that uses GNOME. For the record, Linux Mint isn’t just about the GNOME desktop but you also can have it with Xfce, LXDE and KDE desktops as well. While I have been known to use Lubuntu and like its LXDE implementation, I stuck with the option of which I have most experience.

Once I selected the right disk for the boot loader, the main installation of Mint went smoothly. By default, Ubuntu seems to take care of this but Mint leaves it to you. When you have your operating system files on sdc, installation on the default of sda isn’t going to produce a booting system. Instead, I ended up with GRUB errors and, while I suppose that I could have resolved these, the lazier option of repeating the install with the right boot loader location was the one that I chose. It produced the result that I wanted: a working and loading operating system.

However, there was not something not right about the way that the windows were displayed on the desktop with title bars and window management not working as they should. Creating a new account showed that it was the settings that were carried over from Ubuntu in my home area that were the cause. Again, I opted for a less strenuous option and moved things from the old account to the new one. One outcome of that decisions was that there was a lot of use of the chown command in order to get file and folder permissions set for the new account. In order to make this all happen, the new account needed to be made into an Administrator just like its predecessor; by default, more restrictive desktop accounts are created using the Users and Groups application from the Administration submenu. Once I was happy that the migration was complete, I backed up any remaining files from the old user folder and removed it from the system. Some of the old configuration files were to find a new life with Linux Mint.

In the middle of the above, I also got to customising my desktop to get the feel that is amenable. For example, I do like a panel at the top and another at the bottom. By default, Linux Mint only comes with the latter. The main menu was moved to the top because I have become used to having there and switchers for windows and desktops were added at the bottom. They were only a few from what has turned out not to be a short list of things that I fancied having: clock, bin, clearance of desktop, application launchers, clock, broken application killer, user switcher, off button for PC, run command and notification area. It all was gentle tinkering but still is the sort of thing that you wouldn’t want to have to do over and over again. Let’s hope that is the case for Linux Mint upgrades in the future. That the configuration files for all of these are stored in home area hopefully should make life easier, especially when an in-situ upgrade like that for Ubuntu isn’t recommended by the Mint team.

With the desktop arranged to my liking, the longer job of adding to the collection of software on there while pruning a few unwanted items too was next. Having had Apache, PHP and MySQL on the system before I popped in that Linux Format magazine cover disk for the installation, I wanted to restore them. To get the off-line websites back, I had made copies of the old Apache settings that simply were copied over the defaults in /etc/apache (in fact, I simply overwrote the apache directory in /etc but the effect was the same). MySQL Administrator had been used to take a backup of the old database too. In the interests of spring cleaning, I only migrated a few of the old databases from the old system to the new one. In fact, there was an element of such tidying in my mind when I decided to change Linux distribution in the first place; Ubuntu hadn’t been installed from afresh onto the system for a while anyway and some undesirable messages were appearing at update time though they were far from being critical errors.

The web server reinstatement was only part of the software configuration that I was doing and there was a lot of use of apt-get while this was in progress. A rather diverse selection was added: Emacs, NEdit, ClamAV, Shotwell (just make sure that your permissions are sorted first before getting this to use older settings because anything inaccessible just gets cleared out; F-Spot was never there is the first place in my case but it may differ for you), UFRaw, Chrome, Evolution (never have been a user of Mozilla Thunderbird, the default email client on Mint), Dropbox, FileZilla, MySQL Administrator, MySQL Query Browser, NetBeans, POEdit, Banshee (Rhythmbox is what comes with Mint but I replaced it with this), VirtualBox and GParted. This is quite a list and while I maybe should have engaged the services of dpkg to help automate things, I didn’t on this occasion though Mint seems to have a front end for it that does the same sort of thing. Given that the community favour clean installations, it’s little that something like this is on offer in the suite of tools in the standard installation. This is the type of rigmarole that one would not draw on themselves too often.

With desktop tinkering and software installations complete, it was time to do a little more configuration. In order to get my HP laser printer going, I ran hp-setup to download the (proprietary, RMS will not be happy…) driver for it because it otherwise wouldn’t work for me. Fortune was removed from the terminal sessions because I like them to be without such things. To accomplish this, I edited /etc/bash.bashrc and commented out the /usr/games/fortune line before using apt-get to clear the software from my system. Being able to migrate my old Firefox and Evolution profiles, albeit manually, has become another boon. Without doubt, there are more adjustments that I could be making but I am happy to do these as and when I get to them. So far, I have a more than usable system, even if I engaged in more customisation than many users would go doing.

It probably is useful to finish this by sharing my impressions of Linux Mint. What goes without saying is that some things are done differently and that is to be expected. Distribution upgrades are just one example but there are tools available to make clean installations that little bit easier. To my eyes, the desktop looks very clean and fond display is carried over from Ubuntu, not at all a bad thing. That may sound a small matter but it does appear to me that Fedora and openSUSE could learn a thing or too about how to display fonts on screen on their systems. It is the sort of thing that adds the spot of polish that leaves a much better impression. So far, it hasn’t been any hardship to find my way around and I can make the system fit my wants and needs. That it looks set to stay that way is another bonus. We have a lot of change coming in the Linux world with GNOME 3 on the way and Ubuntu’s decision to use Unity as their main desktop environment. While watching both of these developments mature, it looks as if I’ll be happily using Mint. Change can refresh but a bit of stability is good too.

Making a custom button to hide or display the Google Toolbar in Firefox

Adding more toolbars to Firefox is all very fine but they can take up space on the screen. Even with the big screens that many of us have these days, it’s still nice to be able to see more of what we use web browsers to visit: web pages. For the Web Developer extension’s toolbar, there is the Toggle Web Developer Toolbar plugin for showing and hiding the thing when so desired. As it happens, I keep it hidden until I need it and I fancied doing exactly the same thing with the Google Toolbar but found none. Instead, I happened on a tutorial that used the Custom Buttons plugin to define a custom button. That gives you an entry named Add new button… to the context menu that appears when you right-click on the main menu bar near the top of the Firefox window. When you select the that extra entry in the menu, you get the dialogue box that you see below.

In there, that are some form fields that need filling. Button URL is an option without which you can do but I entered “Toggle Google Toolbar” into the Name field while also sourcing an image to be used on the button instead of the default (a Google logo, naturally…). The last step is to add the code below underneath the /*CODE*/ comment line, leaving the latter in place.

const toolbar = document.getElementById(“gtbToolbar”);
toolbar.collapsed = !toolbar.collapsed;

With all that completed, clicking on the OK button is all that’s needed to finish off the button definition. With that done, the next step is to add the button where you want it by right clicking on the top menu bar again and selecting the Customise… entry. From the list of buttons that appears, just pick the new one and drag it to where you want it to go. Then, you’re done with what might sound a roundabout away of putting in place a space saver but I can live with that.

Turning off the admin bar in WordPress 3.1

Work on WordPress 3.1 is in full swing at the moment though I initially though that they were taking a little break after 3.0. From what I can see, many refinements are being made to the multi-blog functionality and behind-the-scenes work is ongoing on the administration screens too.

Another under-the-bonnet change has been to make WordPress less tied to MySQL since the possibility of dropping in support for an alternative such as PostgreSQL is now a reality even if it isn’t part of the default package. For now, it looks as if this is going to be plugin territory rather than default multi-database support though that may become a sensible development in the light of Oracle’s acquisition of MySQL and its sabre rattling with regard to Java patents. So far, the change to WordPress has affected my use of its database engine to power an offline version of my online photo gallery but a quick spot of code editing sorted that issue.

One more obvious alteration is going to be the addition of a WordPress.com style administration bar to the top of all content and administration screens for a user who is logged into the system. It is going to be turned on by default but there will be the option of turning it off for those among who prefer things that way. All that will be needed for this is to add the following line near the top of wp-config.php:

define( “WP_SHOW_ADMIN_BAR”, false);

The chance to see new additions like those above and be ready for is my main reason for following WordPress development. It’s best to be ready than surprised though it has to be said that the blogging or CMS platform is a very polished one these days.

A look at Emacs

It’s amazing what work can bring your way in terms of technology. For me, (GNU) Emacs Has proved to be such a thing recently. It may have been around since 1975, long before my adventures in computing ever started in fact, but I am asking myself why I never really have used it much. There are vague recollections of my being aware of its existence in the early days of my using UNIX over a decade ago. Was it a shortcut card with loads of seemingly esoteric keyboard shortcuts and commands that put me off it back then? The truth may have been that I got bedazzled with the world of Microsoft Windows instead and so began a distraction that lingered until very recently. As unlikely as it looks now, Word and Office would have been part of the allure of what some consider as the dark side these days. O how OpenOffice.org and their ilk have changed that state of affairs…

The unfortunate part of the Emacs story might be that its innovations were never taken up as conventions by mainstream computing. If its counterparts elsewhere used the same keyboard shortcuts, it would feel like learning such an unfamiliar tool. Still, it’s not as if there isn’t logic behind it because it will work both in a terminal session (where I may have met it for the first time) and a desktop application GUI. The latter is the easier to learn and the menus list equivalent keyboard shortcuts for many of their entries too. For a fuller experience though, I can recommend the online manual and you can buy it in paper form too if you prefer.

One thing that I discovered recently is that external factors can sour the impressions of a piece of software.For instance, I was using a UNIX session where the keyboard mapping weren’t optimal. There’s nothing like unfamiliar behaviour for throwing you off track because you felt your usual habits were being obstructed. For instance, finding that a Backspace key is behaving like a Delete one is such an obstruction. It wasn’t the fault of Emacs and I have found that using Ctrl+K (C-k in the documentation) to delete whole lines is invaluable.

Apart from keyboard mapping niggles, Emacs has to be respected as a powerful piece of software in its own right. It may not have the syntax highlighting capabilities of some, like gedit or NEdit for instance, but I have a hunch that a spot of Lisp programming would address that need. What you get instead is support for version control systems like RCS or CVS along with integration with GDB for debugging programs written in a number of languages. Then, there are features like file management, email handling, newsgroup browsing, a calendar and calculator that make you wonder if they tried to turn a text editor into something like an operating system. With Google trying to use Chrome as the basis of one, it almost feels as is Emacs was ahead of its time though that may have been more due to its needing work within a UNIX shell in those far-off pre-GUI days. It really is saying something that it has stood the test of time when so much has fallen by the wayside. Like Vi, it looks as if the esteemable piece of software is showing no signs of going away just yet. Maybe it was well designed in the beginning and the thing certainly seems more than a text editor with its extras. Well, it has offer a good reason for making its way into Linux too…

Basic string searching in MySQL table columns

Last weekend, I ended up doing a spot of file structure reorganisation on the web server for www.johnhennessy.co.uk and needed to correct some file pointers in entries on my outdoors blog. Rather than grabbing a plugin from somewhere, I decided to edit the posts table directly. First, I needed to select the affected observations and this is where I needed to pick out the affected rows and edit them in MySQL Query Browser. To do that, I needed basic string searching so I opened up my MySQL eBook from Apress and constructed something like the following:

select * from posts_table where post_text like ‘%some_text%’;

The % wildcard characters are needed to pick out a search string in any part of a piece of text. There may be more sophisticated method but this did what I needed in a quick and dirty manner without further ado. Well, it was what I needed.

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