March 2016 - main

Starting a web server on demand - sensible, easy?
by Chris Green 06 May '16

06 May '16

I want to run a Javascript/PHP application on my laptop which will at times be unable to get to the internet. Thus I need to run a web server of some sort on it to serve the PHP side of things. If the laptop is at home on the home LAN I want to be able to run the same Javascript/PHP application on my desktop machine so I can use the bigger screen etc. This will work fine of course with the web server on the laptop, as long as the web server is running. What's the neatest/easiest way to fire up the web server on demand? I don't really want to run it all the time. Ideally also I'd prefer not to run Apache as it's total overkill for what I'm doing. I tried PHP's built-in web server ("php -S localhost:80") and it works fine for me, the home LAN can't be accessed from outside so security should be OK. I suppose the modern equivalent of inetd would do what I want but I'm a bit worried about how easy it might be (or not). -- Chris Green

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Re: [ALUG] 2600 meeting at 18:00 on Friday the 1st April.
by Chris Walker 02 Apr '16

02 Apr '16

On Tue, 29 Mar 2016 03:00:42 +0100 Viperfang <viperfang(a)gmail.com> wrote: > Quick heads up about this months Norwich 2600 meeting, > more info at http://www.norwich2600.co.uk Notice that this domain name has expired! -- __ __| |_ __ __ .----------------------------------------------. / _/ _` \ V V / | mailto:alug_cdw@the-walker-household.co.uk | \__\__,_|\_/\_/ |______________________________________________|

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2600 meeting at 18:00 on Friday the 1st April.
by Viperfang 29 Mar '16

29 Mar '16

Quick heads up about this months Norwich 2600 meeting, more info at http://www.norwich2600.co.uk

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get_iplayer help
by Chris Walker 24 Mar '16

24 Mar '16

Perhaps somebody can point me in the right direction here as I'm failing to achieve what I want. On Radio 4 is a new series by Hal Cruttenden called simply Hal. But if I say get_iplayer --type=radio "Hal" I end up with several Asian programmes along with Hancock's Half Hour and so on. Also listed though is Hal - Career, BBC Radio 4 so my question is, how can I differentiate between those unwanted programmes and the one sole programme I do want? My first thought was that I could simply put a space in the name but then I don't get Hal Cruttenden, just the Asian programmes. I then tried to add stuff like "--fields comedy" but that didn't find anything so I'm stuck! I assume other people have overcome similar problems so how did they solve it? Any help appreciated. -- __ __| |_ __ __ .----------------------------------------------. / _/ _` \ V V / | mailto:alug_cdw@the-walker-household.co.uk | \__\__,_|\_/\_/ |______________________________________________|

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How to debug a bit of javascript?
by Chris Green 23 Mar '16

23 Mar '16

I am using a thing called editablegrid which is mostly javascript. I've got it working pretty well displaying my data in an editable grid but there's a couple of niggles that are driving me mad. One is that the setting for the number of lines to be displayed in the grid doesn't work. I can set the number of lines in the code but I can't select it with the displayed selector. The HTML has:- <label for="pagecontrol">Rows per page: </label> <select id="pagesize" name="pagesize"> <option value="5">5</option> <option value="10">10</option> <option value="15">15</option> <option value="20">20</option> <option value="25">25</option> <option value="30">30</option> <option value="40">40</option> <option value="50">50</option> </select> Which displays the numbers one can select OK. Then, in the javascript is the following:- $("#pagesize").val(pageSize).change(function() { editableGrid.setPageSize($("#pagesize").val()); }); In the demo it works perfectly, in my copy it doesn't work at all. One can select a value but nothing changes. How can I debug this? There are no errors in the Browser Console (firefox) nor in the apache log. It's as if the hooks are not being set but other hook functions in the initialisation are working OK. Can I set a break point or something on the select and see what gets called? -- Chris Green

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DNS go bye-bye
by Bill Hill 18 Mar '16

18 Mar '16

This is the third time I've been unable to log out; the problem: $ cat /etc/resolv.conf # Generated by NetworkManager $ Any ideas why? (NB, this is a really complex setup consisting of an archaic item of technology termed a "network cable" and a very non-standard configuration of a "fixed IP address".) Once is an accident. Twice is coincidence. Three times is an enemy action. $ sudo apt-get purge network-manager

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Customising a Pi image
by Mark Rogers 17 Mar '16

17 Mar '16

This is really just a sanity check! Background: The current standard Pi Rasbian image is 3.8GB in size. If I write that to (say) an 8GB card it'll only give me access to that 3.8Gb until I resize the partition (for which Raspbian includes scripts). Assume I *don't* do that resize. I set things up the way I want on the Pi, and I then want to create a new image of the SD card to restore to another card (possibly a different size). "dd" will get me an 8GB image by default (since it's an 8GB card) but am I correct that I can safely limit the image to the exact size of the original Rasbian image? The objective here is that (a) writing a 3.8GB image to a new card is much faster than writing an 8GB image, and (b) that it will safely write to any 4GB/8GB/16GB/etc card (where an 8GB image might not fit on a different model of 8GB card). The third benefit (c) of a smaller image is less of a concern as I can compress it anyway and unused space should pretty much disappear that way. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Automatically selecting the best wifi adapter
by Mark Rogers 17 Mar '16

17 Mar '16

The new Pi 3 has built in Wifi, great! But it'll never be as good as a USB adapter with proper antenna, although it might often be sufficient. Out of the box, if I connect it to wifi using the onboard adapter and then add a second USB adapter is connects the second one in tandem (ie both connect to the same network and get distinct IP addresses via DHCP). This is a waste of DHCP allocation resources and (correct me if I'm wrong) could cause routing issues? What I'd like is to have the Pi use the built in adapter if that's the only one present but switch to the added adapter if one is present (and working[1]), switching back to the on-board one otherwise. None of this is Pi-specific of-course, the same would apply to any laptop with built in adapter where an additional dongle might be used periodically. However my Googling has so far only thrown up more permanent solutions, and not automatic switching between them. [1] Ideally it would fail over to the onboard adapter if the USB one wasn't reliable, but I'd settle for it always using USB if present, and onboard otherwise. I'm guessing I should be able to detect the arrival/departure of wlan1 and use it to enable/disable wlan0? -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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DNS Provider
by Karl Foley 14 Mar '16

14 Mar '16

I have a simple .co.uk domain that I currently have with Daily Internet that is due for renewal shortly. This domain is just for home use and just hosts a single A record pointing to my home server, a few TXT records for SPF and DKIM, MX records and a few CNAMEs for my Google Apps account along with a few other CNAMEs for some simple locally hosted sites, and a redirect to a Blogger site. I'm quite happy to renew with Daily, though they, like Free Parking before them seem to have pushed their prices up quite a bit. So I would be prepared to transfer. Does the list have any recommendation for DNS providers please? ATB, Karl.

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Running code on startup
by Mark Rogers 11 Mar '16

11 Mar '16

Simple question: Is there anywhere I can dump a script file that will cause it to get run on startup? System is Debian (actually Raspbian although it could apply to other Debian derivatives). On this occasion it has a GUI but I'm looking for something that would work in a GUI-less environment. Caveats: What I want to do is just copy a file there (eg dropping files onto the SD card of a Pi). I'm trying to keep things simple so ideally I don't want to edit any files, which means appending to rc.local is out, for example. I tried creating /etc/cron.d/mystuff with @reboot root /root/mystuff.sh .. which works fine on reboot but doesn't run from any other startup, so not what I need. I'm thinking about creating a script for /etc/rc.d and also creating all the symlinks manually that would otherwise be created by update-rc.d, but that's messy. It seems odd that there isn't a /etc/rc.local.d directory (or similar) which automatically runs all scripts present at the end of rc.local, but unless I'm missing something there isn't any such approach. (Background: I want a simple way to configure a Pi (or similar) by writing the latest Raspbian image to a disk then extracting a tar file of my changes over the top. I want to supplement existing files rather than replace any that could obviously change between Raspbian versions.) -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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