Adventures & experiences in contemporary technology
One of the disadvantages of my Google/Asus Nexus 7 is that it needs a Wi-Fi connection to use. Most of the time this is not a problem since I also have a Huawei mobile WiFi hub from T-Mobile and this seems to work just about anywhere in the U.K. Away from the U.K. though, it won’t work because roaming is not switched on for it and that may be no bad thing with the fees that could introduce. My HTC Desire S could deputise but I need to watch costs with that too.
There’s also the factor of download caps and those apply both to the Huawei and to the HTC. Recently, I added Anquet‘s Outdoor Map Navigator (OMN) to my Nexus 7 through the Google Play store for a fee of £7 and that allows access to any walking maps that I have bought from Anquet. However, those are large downloads so the caps start to come into play. Frugality would help but I began to look at other possibilities that make use of a laptop’s Wi-Fi functionality.
Looking on the web, I found two options for this that work on Windows 7 (8 should be OK too): Connectify Hotspot and Virtual Router Manager. The first of these is commercial software but there is a Lite edition for those wanting to try it out; that it is not a time limited demo is not something that I can confirm though that did not seem to be the case since it looked as if only features were missing from it that you’d get if you paid for the Pro variant. The second option is an open source one and is free of charge apart from an invitation to donate to the project.
Though online tutorials show the usage of either of these to be straightforward, my experiences were not all that positive at the outset. In fact, there was something that I needed to do and that is why this post has come to exist at all. That happened even after the restart that Conectify Hotspot needed as part of its installation; it runs as a system service so that’s why the restart was needed. In fact, it was Virtual Router Manager that told me what the issue was and it needed no reboot. Neither did it cause network disconnection of a laptop like the Connectify offering did on me and that was the cause of its ejection from that system; limitations in favour of its paid addition aside, it may have the snazzier interface but I’ll take effective simplicity any day.
Using Virtual Router Manager turns out to be simple enough. It needs a network name (also known as an SSID), a password to restrict who accesses the network and the internet connection to be shared. In my case, the was Local Area Connection on the drop down list. With all the required information entered, I was ready to start the router using the Start Network Router button. The text on this changes to Stop Network Router when the hub is operational or at least it should have done for me on the first time that I ran it. What I got instead was the following message:
The group or resource is not in the correct state to perform the requested operation.
The above may not say all that much but it becomes more than ample information if you enter it into the likes of Google. Behind the scenes, Virtual Router Manager is using native Windows functionality is create a WiFi hub from a PC and it appears to be the Microsoft Virtual Wi-Fi Miniport Adapter from what I have seen. When I tried setting up an adhoc Wi-Fi network from a laptop to the Nexus 7 using Windows’ own network set up capability via its Control Panel, it didn’t do what I needed so there might be something that third party software can do. So, the interesting thing about the solution to my Virtual Router Manager problem was that it needed me to delve into the innards of Windows a little.
Firstly, there’s running Command Prompt (All Programs > Accessories) from the Start Menu with Administrator privileges. It helps here if the account with which you log into Windows is in the Administrators group since all you have to do then is right click on the Start Menu entry and choose Run as administrator entry in the pop-up context menu. With a command line window now open, you then need to issue the following command:
netsh wlan set hostednetwork mode=allow ssid=[network name] key=[password] keyUsage=persistent
When that had done its thing, Virtual Router Manager worked without a hitch though it did turn itself after a while and that may be no bad thing from the security standpoint. On the Android side, it was a matter of going in Settings > Wi-Fi and choose the new network that have been creating on the laptop. This sort of thing may apply to other types of tablet (Dare I mention iPads?) so you could connect anything to the hub without needing to do any more on the Windows side.
For those wanting to know what’s going on behind the scenes on Windows, there’s a useful tutorial on Instructables that shows what third party software is saving you from having to do. Even if I never go down the more DIY route, I probably have saved myself having to buy a mobile Wi-Fi hub for any trips to Éire. For now, the Irish 3G dongle that I already have should be enough.
For quite a while now, I have offline web servers for doing a spot of tweaking and tinkering away from the gaze of web users that visit what I have on there. Therefore, one of the tests that I apply to any prospective main Linux distro is the ability to set up a web server on there. This is more straightforward for some than for others. For Ubuntu and Linux Mint, it is a matter of installing the required software and doing a small bit of configuration. My experience with Sabayon is that it needs a little more effort than this and I am sharing it here for the installation of MySQL.
The first step is too install the software using the commands that you find below. The first pops the software onto the system while second completes the set up. The --basedir option is need with the latter because it won’t find things without it. It specifies the base location on the system and it’s /usr in my case.
sudo equo install dev-db/mysql
sudo /usr/bin/mysql_install_db --basedir=/usr
With the above complete, it’s time to start the database server and set the password for the root user. That’s what the two following commands achieve. Once your root password is set, you can go about creating databases and adding other users using the MySQL command line
sudo /etc/init.d/mysql start
mysqladmin -u root password ‘password’
The last step is to set the database server to start every time you start your Sabayon system. The first command adds an entry for MySQL to the default run level so that this happens. The purpose of the second command is check that this happened before restarting your computer to discover if it really happens. This procedure also is needed for having an Apache web server behave in the same way so the commands are worth having and even may have a use for other services on your system. ProFTP is another that comes to mind, for instance.
sudo rc-update add mysql default
sudo rc-update show | grep mysql
While UNIX and Linux both have the diff command for comparing the contents of text files, the Windows counterpart was unknown to me until recently. Its name is fc and it looks as if the f is for file and c is for comparison though I cannot confirm that as of now. That command and its usage is not dissimilar to the way that things work with diff. Here is an example command:
fc file1.txt file2.txt > file3.txt
This compares file1,txt with file2.txt and sends the output to file3.txt. Any differences between the two files being compared seem to be more clearly labelled than in the diff output’s < and > labels. That verbosity could have its uses but existence of the fc command is stopping envious glances at the diff one for now, just as findstr is doing the same in comparison with grep.
To generate the package list on the GNOME version of Linux Mint, I used the Backup Tool. It simply was a matter of using the Backup Software Selection button and telling it where to put the file that it generates. Alternatively, dpkg can be used from the command line like this:
sudo dpkg --get-selections > /backup/installed-software.txt
After transferring the file to the machine with Linux Mint Debian Edition, I tried using the Backup Tool on there too. However, using the Restore Software Selection button and loading the required only produced an irrecoverable error. Therefore, I set to looking around the web and found a command line approach that did the job for me.
The first step is to load the software selection using dpkg by issuing this command (it didn’t matter that the file wasn’t made using the dpkg command though I suspect that’s what the Linux Mint Backup Tool was doing that behind the scenes):
sudo dpkg --set-selections < /backup/installed-software.txt
Then, I started dselect and chose the installation option from the menu that appeared. First time around, it fell over but trying again was enough to complete the job. Packages available to the vanilla variant of Linux Mint but not found in the LMDE repositories were overlooked as I had hoped and installation of the extra packages had no impact on system stability either.
sudo dselect
Apparently, there is an alternative to using dselect that is based on the much used apt-get command but I didn’t make use of it so cannot say more:
sudo apt-get dselect-upgrade
All that I can say is that the dpkg/dselect combination did what I wanted so I’ll keep them in mind if ever need to synchronise software selections between two Debian-based distributions in the future again. The standard edition of Linux Mint may be based on Ubuntu rather than Debian but Ubuntu is itself based on Debian so the description holds here.
Aside from permissions that can be set using the cacls command, Windows files have properties like read only, archive and hidden. Of course, these are not the same or as robust as access permissions but they may have a use in stopping accidental updates to files when you don’t have access to use of the cacls command. While you could set these attributes using the properties page of any file, executing the attrib command on the Windows command is more convenient. Here are some possible usage options:
Set the read only flag on a file:
attrib +r test.txt
Remove the read only flag from a file (found a use for this one recently):
attrib -r test.txt
Set the archive flag on a file:
attrib +a test.txt
Remove the archive flag from a file:
attrib -a test.txt
Set the hidden only flag on a file:
attrib +h test.txt
Remove the hidden flag from a file:
attrib -h test.txt
Using the /s option and wildcards processes a number of files at a time and /d applies the command to directories. They could come in handy when removing read only attributes (also called bits in places) from files copied from read only optical media such as CD’s and DVD’s.
Seeing Arch Linux running so solidly in a VirtualBox virtual box has me contemplating whether I should have it installed on a real PC. Saying that, recent announcements regarding the implementation of GNOME 3 in Linux Mint have caught my interest even if the idea of using a rolling distribution as my main home operating system still has a lot of appeal for me. Having an upheaval come my way every six months when a new version of Linux Mint is released is the main cause of that.
While remaining undecided, I continue to evaluate the idea of Arch Linux acting as my main OS for day-to-day home computing. Towards that end, I have set up a working web server instance on there using the usual combination of Apache, Perl, PHP and MySQL. Of these, it was MySQL that went the least smoothly of all because the daemon wouldn’t start for me.
It was then that I started to turn to Google for inspiration and a range of actions resulted that combined to give the result that I wanted. One problem was a lack of disk space caused by months of software upgrades. Since tools like it in other Linux distros allow you to clear some disk space of obsolete installation files, I decided to see if it was possible to do the same with pacman, the Arch Linux command line package manager. The following command, executed as root, cleared about 2 GB of cruft for me:
pacman -Sc
The S in the switch tells pacman to perform package database synchronization while the c instructs it to clear its cache of obsolete packages. In fact, using the following command as root every time an update is performed both updates software and removes redundant or outmoded packages:
pacman -Syuc
So I don’t forget the needful housekeeping, this will be what I use in future with the y being the switch for a refresh and the u triggering a system upgrade. It’s nice to have everything happen together without too much effort.
To do the required debugging that led me to the above along with other things, I issued the following command:
mysqld_safe --datadir=/var/lib/mysql/ &
This starts up the MySQL daemon in safe mode if all is working properly and it wasn’t in my case. Nevertheless, it creates a useful log file called myhost.err in /var/lib/mysql/. This gave me the messages that allowed the debugging of what was happening. It led me to installing net-tools and inettools using pacman; it was the latter of these that put hostname on my system and got the MySQL server startup a little further along. Other actions included unlocking the ibdata1 data file and removing the ib_logfile0 and ib_logfile1 files so as to gain something of a clean sheet. The kill command was used to shut down any lingering mysqld sessions too. To ensure that the ibdata1 file was unlocked, I executed the following commands:
mv ibdata1 ibdata1.bad
cp -a ibdata1.bad ibdata1
These renamed the original and then crated a new duplicate of it with the -a switch on the cp command forcing copying with greater integrity than normal. Along with the various file operations, I also created a link to my.cnf, the MySQL configuration file on Linux systems, in /etc using the following command executed by root:
ln -s /etc/mysql/ my.cnf /etc/my.cnf
While I am unsure if this made a real difference, uncommenting the lines in the same file that pertained to InnoDB tables. What directed me to these were complaints from mysqld_safe in the myhost.err log file. All I did was to uncomment the lines beginning with “innodb” and these were 116-118, 121-122 and 124-127 in my configuration file but it may be different in yours.
After all the above, the MySQL daemon ran happily and, more importantly, started when I rebooted the virtual machine. Thinking about it now, I believe that was a lack of disk space, the locking of a data file and the lack of InnoDB support that was stopping the MySQL service from running.Running commands like mysqld start weren’t yielding useful messages so a lot of digging was needed to get the result that I needed. In fact, that’s one of the reasons why I am sharing my experiences here.
In the end, creating databases and loading them with data was all that was needed for me to start see functioning websites on my (virtual) Arch Linux system. It turned out to be another step on the way to making it workable as a potential replacement for the Linux distributions that I use most often (Linux Mint, Fedora and Ubuntu).
By default in the DMS, Base SAS opens datasets from its Explorer using VIEWTABLE and with variable labels in the column headings and not variable names. Because I have been fortunate to use systems with SAS/FSP both installed and licensed, I have taken to using FSVIEW for browsing SAS datasets as a workaround and, though the interface may look old to some, it proves to be a very flexible tool that still has a few things to teach newer ones. With SAS Enterprise Guide, the dataset viewing functionality is different to both VIEWTABLE and FSVIEW but I have been to make it work for me. The SAS EG dataset viewing tool may appear like the former of these but it has a few tricks to teach its forbear.
Now that I find myself working again with the traditional SAS DMS interface and without SAS/FSP, I decided to see if there was a way to get VIEWTABLE to display variable names instead of variable labels by default. As it happened, the answer was found in an internet forum discussion. From the SAS command line, you can achieve the result issuing a command like the following:
VT SASHELP.VCOLUMN COLHEADING=NAMES
VT is the VIEWTABLE shortcut but it is the COLHEADING=NAMES option on the line that gets variable names shown in column headings. Taking it further, you can set this as the default setting for datasets opened using a mouse from Explorer panes using the following procedure:
Because the DMS looks similar across versions 8.0 through to 9.2, the above instructions should be relevant to all of those. While I have yet to get the opportunity to use SAS 9.3, I would be surprised to find that the traditional SAS interface has changed there too, even though much else has changed about SAS. In fact, the latest version of SAS has brought quite a few new interesting features for programmers so it seems that you can do more through a familiar interface, not entirely a bad thing. It looks as if this VIEWTABLE tweak could be useful for a while yet.
A little while ago, I wrote a piece on here telling of how I got GNOME 3 installed an working on Linux Mint. However, I have discovered since that there was an Achilles heel in the approach that I had taken: using the ricotz/testing PPA so that I could gain additional extensions for use with GNOME Shell. If this was just a repository of GNOME Shell extensions, that would be well and good but the maintainer(s) also has a more cutting edge of GNOME Shell in there too. Occasionally, updates from ricotz/testing have been the cause of introducing rough edges to my desktop environment that have resolved themselves within a few hours or days. However, updates came through in the last few days that broke GNOME Tweak Tool. When I tried running it from the command line, all I got was a load of output that included the message that heads this posting and no window popping up that I could use. That made me see sense so I stopped living dangerously by using that testing repository. Apparently, there is a staging variant too but a forum posting elsewhere on the web has warded me off from that too.
Until I encountered the latter posting, I had not heard of the ppa-purge tool and it came in handy for ridding my system of all packages from the ricotz repository and replacing with with alternatives from more stable ones such as that from the gnome3-team. This wasn’t installed on my computer so I added it in the usual fashion by issuing the following command:
sudo apt-get install ppa-purge
Once that was complete, I executes the following command with the ricotz/testing repository still active:
sudo ppa-purge testing ricotz
Once that was complete and everything was very nicely automated too, GNOME Tweak Tool was working again as intended and that’s the way that I intend keeping things. Another function of ppa-purge is that it has excised any mention of the ricotz/testing repos from my system too so nothing more can come from there.
While I was in the business of stabilising GNOME Shell on my system, I decided to add in UGR too. First, another repository needed to be added as follows:
sudo add-apt-repository ppa:ubuntugnometeam/ppa-gen
sudo apt-get update
The next steps were to install UGR once that was in place so these commands were issued to do the job:
sudo apt-get dist-upgrade
sudo apt-get install ugr-desktop-g3
sudo apt-get upgrade
While that had the less desirable effect of adding games that I didn’t need and have since removed, it otherwise worked well and I now have a new splash screen at starting up and shutting down times for my pains. Hopefully, it will main that any updates to GNOME Shell that come my way should be a little more polished too. All that’s needed now is for someone to set up a dedicated PPA for GNOME Shell Extensions so I could regain drop down menus in the top panel for things such as virtual desktops, places and other handy operations that perhaps should have been in GNOME Shell from the beginning. However, that’s another discussion so I’ll content myself with what I now have and see if my wish ever gets granted.
It must have been my curiosity that drove me to exploring Arch Linux a few weeks ago. Its coming on a Linux Format DVD and a few kind words about its being a cutting edge distribution were enough to set me installing it into a VirtualBox virtual machine for a spot of investigation. In spite of warnings to the contrary, I took the path of least resistance with the installation even though I did look among the packages to see if I could select a desktop environment to be added as well. Not finding anything like GNOME in there, I left everything as defaulted and ended up with a command line interface as I suspected. The next job was to use the pacman command to add the extras that were needed to set in place a fully functioning desktop.
For this, the Arch Linux wiki is a copious source of information though it didn’t stop me doing things out of sequence. That I didn’t go about perusing it in a linear manner was part of the cause of this but you have to know which place to start first as well. As a result, I have decided to draw everything together here so that it’s all in one place and in a more sensible order even if it wasn’t the one that I followed.
The first thing to do is go adding X.org using the following command:
pacman -Syu xorg-server
The -Syu switch tells pacman to update the package list, upgrade any packages that require it and add the listed package if it isn’t in place already; that’s X.org in this case. For my testing, I added xor-xinit too. This puts that startx command in place. This is the command for adding it:
pacman -S xorg-xinit
With those in place, I’d go adding the VirtualBox Guest Additions next. GNOME Shell requires 3D capability so you need to have this done while the machine is off or when setting it up in the first place. This command will add the required VirtualBox extensions:
pacman -Syu virtualbox-guest-additions
Once that’s done, you need to edit /etc/rc.conf by adding “vboxguest vboxsf vboxvideo” within the brackets on the MODULES line and adding “rc.vboxadd” within the brackets on the DAEMONS line. On restarting everything should be available to you but the modprobe command is there for any troubleshooting.
With the above pre-work done, you can set to installing GNOME and I added the basic desktop from the gnome package and the other GNOME applications from the gnome-extra one. GDM is the login screen manager so that’s needed too and the GNOME Tweak Tool is a very handy thing to have for changing settings that you otherwise couldn’t. Here are the commands that I used to add all of these:
pacman -Syu gnome
pacman -Syu gnome-extra
pacman -Syu gdm
pacman -Syu gnome-tweak-tool
With those in place, some configuration files were edited so that a GUI was on show instead of a black screen with a command prompt, as useful as that can be. The first of these was /etc/rc.conf where “dbus” was added within the brackets on the DAEMONS line and “fuse” was added between those on the MODULES one.
Creating a file named .xinitrc in the root home area with the following line in there makes running a GNOME session from issuing a startx command:
exec ck-launch-session gnome-session
With all those in place, all that was needed to get a GNOME 3 login screen was a reboot. Arch is so pared back that I could login as root, not the safest of things to be doing so I added an account for more regular use. After that, it has been a matter of tweaking the GNOME desktop environment and adding missing applications. The bare bones installation that I allowed to happen meant that there were a surprising number of them but that isn’t hard to fix using pacman.
All of this emphasises that Arch Linux is for those who want to pick what they want from an operating system rather than having that decided for you by someone else, an approach that has something going for it with some of the decisions that make their presence felt in computing environments from time to time. There’s no doubt that this isn’t for everyone but documentation is complete enough for the minimalism not to be a problem for experienced Linux users and I certainly managed to make things work for me once I got them in the right order. Another thing in its favour is that Arch also is a rolling distribution so you don’t need have to go though the whole set up routine every six months unlike some others. So far, it does seem stable enough and even has set me to wondering if I could pop it on a real computer sometime.
My early explorations of dual-booting of Windows and Linux led me into the world of disk partitioning. It also served a another use since any Windows 9x installations (that dates things a bit…) that I had didn’t have a tendency to last longer than six months at one point; putting the data on another partition meant that a fresh Windows installation didn’t jeopardise any data that I had should a mishap occur.
Then, Partition Magic was the favoured tool and it wasn’t free of charge, though it wasn’t extortionately priced either. For those operations that couldn’t be done with Windows running, you could create bootable floppy disks to get the system going in order to perform those. Thinking about it now, it all worked well enough and the usual caveats about taking care with your data applied as much then as they do now.
For the last few years, many Linux distributions have coming in the form of CD’s or DVD’s from which you can boot into a full operating system session, complete with near enough the same GUI that an installed version. When a PC is poorly, this is a godsend and makes me wonder how we managed without; having that visual way of saving data sounds all too necessary now. For me, the answer to that is that I misspent too many hours blundering blindly using the very limited Windows command line to get myself out of a crux. Looking back on it now, it all feels very dark compared to today.
Another good aspect to these Live Distribution Disks is that they come with hard disk partitioning tools such as the effective GParted. They are needed to configure hard drives during the actual installation process but they serve another process too: they can be used in place of the old proprietary software disks that were in use not so long ago. Being able to deal with the hard disk sizes available today is a very good thing as is coping with NTFS partitions along with the usual Linux options. The operations may be time consuming but they have seemed reliable so far and I hope that it stays that way in spite of any warning that get issued but you make any changes. Last weekend, I got to see a lot of what that means and I setting up my Toshiba Equium laptop for Windows/Ubuntu dual booting.
With the capability that is available both free of charge and free of limitations, you cannot justify paying for disk partitioning software nowadays and that’s handy when you consider the state of the economy. It also shows how things have changed over the last decade. Being able to load up a complete operating system from a DVD also serves to calm any nerves when a system goes down on you, especially when you surf the web to find a solution for the malady that’s causing the downtime.