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[ALUG Announce] ALUG Norwich Pub Meet Thursday 12th July
by Viperfang 04 Jul '12

04 Jul '12

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce ----- Hello Norwich Aluggers, Our monthly ALUG Norwich social meeting will be held this Thursday, 12th July at The Coach and Horses (82 Thorpe Road, Norwich, NR1 1BA). The meeting officially starts at 8pm, although some people may arrive earlier. More information on those people can be found on the list and the IRC channel. If you are unsure if you will recognise us then make yourself and your intent to attend known by either posting on list or visiting us on IRC so we can look out for you rather than hiding in the corner. Optionally you could ask at the bar if they know where the geeky computer weirdos are and they'll point you in the right direction (seriously!). Another possibility is look for heaps of electronics on a table that may possibly look like movie props that would used for detonating explosives. Feel free to bring electronics/laptops/gadgets to the meet, you will by no means be alone. Ben Bewick aka Viperfang NB: This mail is automated, please refer to the usual sources for more information. ALUG Contact Details: Website : http://www.alug.org.uk/ IRC : #alug on irc.alug.org.uk List : http://lists.alug.org.uk/mailman/listinfo Twitter : http://twitter.com/anglianlug Identica: TBA Facebook: http://www.facebook.com/group.php?gid=2381613902 ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce

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2600 meeting at 18:00 on Friday the 6th July.
by Viperfang 03 Jul '12

03 Jul '12

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

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Lenovo T520
by Paul Grenyer 02 Jul '12

02 Jul '12

Hi All I'm still having lots of wifi and 3G card related problems with my Lenovo T520 and Linux Mint 13 (I though it was 12, it was 13). Does anyone have a similar machine (or even the same machine) that they're successfully working with? Maybe I could pick your brains at one of the pub meets? -- Thanks Paul Paul Grenyer e: paul.grenyer(a)gmail.com b: paulgrenyer.blogspot.com t: pjgrenyer ACCU Member: License to code. (http://www.accu.org)

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2600 meeting at 18:00 on Friday the 1st June.
by Viperfang 29 Jun '12

29 Jun '12

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

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Open source alternative to full fat Adobe?
by Bev Nicolson 26 Jun '12

26 Jun '12

Evince is great for what it does, imo, but you can't extract pages with it. Does anyone round here know of a good alternative to the full-fat, all singing all dancing but not very cheap Adobe? Does such a thing exist? Bev.

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SOund unavailable on Flash Player
by Ted.Harding＠wlandres.net 24 Jun '12

24 Jun '12

Greetings All! Just now, wanting to play a YouTube video, I found that the sound on Flash Player is turned off, and I can find no way to turn it on again. The "speaker" icon in the bottom bar as an "X" beside it, indicating that it is turned off, and I can find no way to turn it back on again (e.g. clicking on the icon, or on the "X", produces not response; and looking into Settings after right-clicking on the Flash Player screen offers no help). However, everything was fine a few days ago, and I'm not aware of having done anything which might cause this problem. Also, the YouTube video is indeed the same one which I had watched a fews days ago with no problem. Can anyone offer any help with this problem? Adobe Flash Player 10 Iceweasel 3.0.6 (2009) Debian Lenny 2.6.26 ------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding(a)wlandres.net> Date: 24-Jun-2012 Time: 12:23:35 This message was sent by XFMail -------------------------------------------------

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Wierd hang(s) when using grep
by Chris Green 20 Jun '12

20 Jun '12

Over the past few months I've noticed that when I run grep it sometimes appears to hang, I had put it down to doing "grep -r" down a rather large file hierarchy but now it's happening with a perfectly simple grep:- www-data$ ls *.txt sidebar.txt start.txt www-data$ grep xxx *.txt www-data$ grep fred *.txt www-data$ grep 'CLEARFLOAT' *.txt ... and there it sits, still (like 5 minutes later). The two .txt files are only a few tens of bytes long. It's not using any processor time, it's just stuck. I have just done it again in another terminal window, quotes removed but otherwise the same:- www-data$ grep fred *.txt www-data$ grep CLEARFLOAT *.txt ^C www-data$ ... and with a different user (in the same directory):- chris$ cd /home/www-data/www/wiki/data/pages chris$ grep fred *.txt chris$ grep CLEARFLOAT *.txt ^C chris$ So, what am I missing? -- Chris Green

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Getting MAC address in a shell script
by Mark Rogers 20 Jun '12

20 Jun '12

This works: mac=$(ifconfig eth0 | grep -Eo '..:..:..:..:..:..' | sed -e 's/://g') .. but I'm sure there's a better way. Suggestions? Also, if I have something like: echotemplate="This is my MAC: (MAC)" mac=$(ifconfig eth0 | grep -Eo '..:..:..:..:..:..' | sed -e 's/://g') echo $(echo $echotemplate | sed -e "s/(MAC)/$mac/") .. is there a better way to do the substitution in the last line? I can't swap the top two lines around (one is a user-defined setting at the top of the script, the value of $mac is calculated in the body of the script), otherwise I would just use echo "This is my MAC: $mac" .. which would be nice and easy! But I'm using this as a learning exercise. -- 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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Getting round lack of suid on scripts (not to become root!)
by Chris Green 20 Jun '12

20 Jun '12

Is there any way to run a script such that it executes as another user than the person running it? Normally (well, old-fashionedly) one would have set the SUID bit in the permissions, made the script owned by the desired user and that would be it but nowadays it no longer works because SUID on scripts is disabled. Is there any reasonably simple way to work round this? All I have found searching so far is to write a short C program to do the SUID change and use that to execute the script. I could do this I suppose but I'd really prefer an easier way to do it as the C program method needs to know both the desired UID and the name of the program to run so, while hardly complex, it will need command line parameters etc. -- Chris Green

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Does anyone here know how gmail works?
by Chris Green 19 Jun '12

19 Jun '12

I am trying to sort out moving someone else's hosting. The web hosting has transferred fine along with the domain hosting but I'm a bit stuck with their E-Mail. I have their name/password for logging on to gmail but when I try and change things it just says:- Manage account information Google can't change personal information for jane(a)reshapers.org. To change the information, contact your reshapers.org administrator. Learn more ... er, but the reshapers.org administrator is now me and I haven't any idea how the E-Mail *was* getting to gmail from the old hosting account. Presumably there was some cleverness with MX settings or something but it seems a wierd way of doing things. Is there some sort of 'hidden' gmail address that a user has on gmail that I can forward mail to from the new hosting site? -- Chris Green

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svn file "sets"
by Mark Rogers 18 Jun '12

18 Jun '12

I have a library of code already in svn. I want to create subsets of it that I can either export or checkout, so that I only download the files needed for a specific job. I know about (by reading[1], not doing) sparse checkouts, eg: cd C:\path\dir svn checkout https://server/path/to/trunk/dir/dir/parent_dir--depth empty cd C:\path\dir\parent_dir svn update filename.log (Edit filename.log) svn commit -m "this is a comment." (Copy and paste from an example, hence the Windows-esque paths, although I'm only working on Linux myself.) This will do what I need, except that I'm looking for a simple way to replace "filename.log" in the example above with a name for a set of files. Depending on what I'm trying to do, I might want to export that set of files rather than do a checkout. [1] http://stackoverflow.com/questions/122107/checkout-one-file-from-subversion -- 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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[ALUG Announce] 3rd Monday Monthly Ipswich Social Meeting : The Mulberry Tree
by samwise 17 Jun '12

17 Jun '12

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce ----- The monthly "Third Monday" ALUG Ipswich Social Meeting is back this week - Monday, 18th June, at 20:00: The Mulberry Tree 5 Woodbridge Road IPSWICH IP4 2EA Tel: 01473 225776 Map/Directions URI: http://maps.google.co.uk/?q=IP4+2EA WWW: https://www.facebook.com/MULBERRYHOSPITALITY The Mulberry Tree, previously known as The Milestone Beer House, is a grade 2 listed building in the centre of Ipswich. It is located at the intersection between Woodbridge Road and the A1156, across the road from the old Odeon cinema and not far from the Regent Theatre. It re-opened on Thursday March 29th 2012 after a major refurbishment, under its original name of The Mulberry House and has already begun to regain a good reputation for its selection of beers and ales. It has a sizeable car park to the rear of the building. All are welcome, novices and experienced users. Feel free to ask for further information on the Main ALUG mailing list. Hopefully, those there last month will remember that we've reverted our regular venue to be The Mulberry Tree, which was our home a few years back, after a successful trial at May's meet. Unfortunately, I may not be able to make it this month as I have a work evening do that I'll struggle to get out of. If I can make it, I'll arrive later on in the evening. A shame as I finally have a new gadget to show off! :) Peter. ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce

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Sort of philosophical question about Web/Client/Server workings
by Chris Green 17 Jun '12

17 Jun '12

Every time I try and do some web application programming that involves forms (i.e. getting data from a user) it ends up being far more complicated than I expect (and more complicated than it should be I feel). Anywhere else that one programs something to get some data from a user it's fairly direct and simple:- Output something to ask a question Wait for user to enter response Get return with the response OK, it's a bit more complex/messier when using a GUI because there isn't necessarily a simple single thread but it still comes down to the program waiting for an event and, when the event happens, it gets handed some data. However when web programming it's nothing like this, one can't simply ask a question and get the answer. Say one has a PHP script running server side, it creates a form which is then displayed when the client requests it and the client fills in the form. The trouble is that there's no direct way for the PHP script that created the form to get the result - at least there isn't in any of the environment/frameworks that I've used. What happens is that there is *another* script which gets run (server side) when the client submits the form duly filled in. This other script has no direct connection with the script that created the form, no common environment, nothing. It's thus very difficult to write simple form driven applications as one can't simply display a form and get the data from the form in 'one place' as it were. Am I missing something obvious here? -- Chris Green

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xterm input delay and alsamixer display screwed up
by Srdjan Todorovic 16 Jun '12

16 Jun '12

Hi all, If I run KDE on the laptop and run Konsole or xterm, I can type commands immediately. Running alsamixer is also fine. Running fluxbox with xterms, input into xterm is delayed on startup by at least 10 to 30 seconds. Nothing echoed to the terminal while I type. Eventually it will show up. Running alsamixer in it caused bits of the ncurses display to screw up, last time I ran it. The volume control levels would be half-drawn etc. Any suggestions what might be the cause and how to fix? I'll try disabling xorg compositing as suggested here: http://www.linuxquestions.org/questions/slackware-14/xterm-delayed-input-fr… but I'd rather like to keep compositing alive any time I run KDE... Thanks, Srdjan

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How to get rid of "Notice: trying to get property of a non-object" errors in PHP
by Chris Green 15 Jun '12

15 Jun '12

I'm trying out a chunk of downloaded software and it's actually quite close to what I want. However it's outputting *hundreds* of "Trying to get property of non-object" errors which are somewhat distracting as there are more of them than actual data. I'm pretty sure the reason they're appearing is because the code is accessing lots of values before they're created (and presumably doing the right thing when they're null). It's not just in one place in the code so I can't very easily go and change the code at every place this is happening. Is there a way to turn of this particular warning? I'd rather not turn of all warnings and I'd rather do it just for this application rather than everywhere (I want to see warnings on code I've written!). -- Chris Green

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[ALUG Announce] ALUG Norwich Pub Meet Thursday 14th June
by Viperfang 14 Jun '12

14 Jun '12

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce ----- Hello Norwich Aluggers, Our monthly ALUG Norwich social meeting will be held this Thursday, 14th June at The Coach and Horses (82 Thorpe Road, Norwich, NR1 1BA). The meeting officially starts at 8pm, although some people may arrive earlier. More information on those people can be found on the list and the IRC channel. If you are unsure if you will recognise us then make yourself and your intent to attend known by either posting on list or visiting us on IRC so we can look out for you rather than hiding in the corner. Optionally you could ask at the bar if they know where the geeky computer weirdos are and they'll point you in the right direction (seriously!). Another possibility is look for heaps of electronics on a table that may possibly look like movie props that would used for detonating explosives. Feel free to bring electronics/laptops/gadgets to the meet, you will by no means be alone. Ben Bewick aka Viperfang NB: This mail is automated, please refer to the usual sources for more information. ALUG Contact Details: Website : http://www.alug.org.uk/ IRC : #alug on irc.alug.org.uk List : http://lists.alug.org.uk/mailman/listinfo Twitter : http://twitter.com/anglianlug Identica: TBA Facebook: http://www.facebook.com/group.php?gid=2381613902 ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via http://lists.alug.org.uk/mailman/listinfo/announce

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Linux Mint 12 Wireless Issues
by Paul Grenyer 13 Jun '12

13 Jun '12

Hi All I've a new Lenovo T520 and I've installed the latest Linux Mint on it, but the wireless is painfully slow. I can't even log into my router's admin page. If I reboot into Windows 7 the speed is fine. I haven't tried a wired connection yet. I'm hoping that the wired connection is fast and might update some drivers as part of the general update process. However, if that doesn't work, I really don't have a clue where to start. The wireless adapter in the T520 is an Intel Centrino Wireless-N 1000. Can you guys give me any pointers, please? -- Thanks Paul Paul Grenyer e: paul.grenyer(a)gmail.com b: paulgrenyer.blogspot.com t: pjgrenyer ACCU Member: License to code. (http://www.accu.org)

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Scientific Linux
by Ted.Harding＠wlandres.net 13 Jun '12

13 Jun '12

Hi All Anyone using Scientific Linux? Not that there's anything specially scientific about it in its generic form. It's basically a clone of Red Hat Enterprise Linux, and it's called "Scientific" because it was put together by FermiLabs and CERN. See: http://en.wikipedia.org/wiki/Scientific_Linux and https://www.scientificlinux.org/ I'd be interested to hear of experiences with it (especially from anyone who has installed scientific extras). Ted. ------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding(a)wlandres.net> Date: 12-Jun-2012 Time: 23:04:55 This message was sent by XFMail -------------------------------------------------

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How would the team produce a simple web page with a running balance/total on it?
by Chris Green 12 Jun '12

12 Jun '12

I've wanted to do this at several different times and places, some of my solutions are OK'ish but I've not really come up with something neat and tidy for doing it. I want a simple (for the user, and preferably for me too in creating it) web page where a user can enter an amount, probably with a date and a description, that gets added to (or subtracted from) a running total. The user can also see the list of transactions that contributes to the current total. I.e. I want something that looks like a bank statement but can be changed easily on the web page itself. So we'd have something like:- Date Descritption Credit Debit Balance 2012-01-01 Start of year 1234.00 1234.00 2012-02-14 Valentine Pres 12.34 1221.66 2012-03-01 Paid for joke 99.00 1320.66 etc. Plus either a blank line at the bottom of the table to enter new values, or some edit boxes to add new values. There's lots of online spreadsheets out there but since they all tend to be Excel lookalikes they don't do running balances very easily, you have to keep re-entering the balance calculation in the balance column, there doesn't seem to be any easy way to say a column is a calculated value that is always the same calculated value (or at least I've not found it). My implementations so far have either used a database with a very nasty complicated calculated value in the Balance column (that depends on the ordering of the date column which isn't always a good idea if there's more than one entry on the same date) or uses a plugin I have developed for my Wiki which requires the user to edit the wiki page - OK for me usually but not very good for other users. Any bright ideas anyone? Doesn't actually have to be web accessible as it will only have one or two users for each instance so could be done with a dedicated application and a shared file for example. -- Chris Green

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Email clients! - Alpine... anyone use it?
by James Freer 04 Jun '12

04 Jun '12

For a while i've just used the browser for email having found Thunderbird, Evolution and similar so slow on imap. Mutt i managed to set up but being so configurable wasn't to my liking. Alpine seems the fastest of any i've tried... easy to setup - just wondering if anyone else on here uses it. If they do any problems? jmaes

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Multi-VPN configuration
by Mark Rogers 04 Jun '12

04 Jun '12

I always get into a muddle when I try to set up VPN connections but I'm going to have another go.. What I have is lots of Linux "devices" (typically ARM boxes running Debian) which will be plugged into networks giving them Internet access. What I want to achieve is to have them auto-connect to a VPN, such that I am able to access all of them, but also that the end user can connect to their own devices but nobody elses. Ideally I'd also like other VPN capable devices, such as Draytek routers, to be able to join in the party. My starting point - which may well be wrong, is to assume that I want a server running OpenVPN somewhere on t' Internet. (Is that the right place to start?) I find the OpenVPN documentation to be very detailed but hard to narrow it down to any particular usage case unless it's a standard config (eg "road warrier"). What I don't want at my end is to *have* to connect separately to each VPN. Doing so optionally would be good (but would be possible in the same way an extra device could), but it could be I end up with dozens or hundreds of separate segregated VPNs. Furthermore, it's likely that I will want all of the VPNs to have access to certain facilities (eg databases, FTP) on other servers without having to make the other servers join multiple VPNs. -- 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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How to print stupid Royal Mail price list?
by Chris Green 01 Jun '12

01 Jun '12

The Royal Mail used to provide a neat PDF file which fitted A4 to show their postage prices. The latest version though is a 'booklet' so I can't see any way to actually print it on an A4 printer. This is the link to the PDF:- http://c435158.r58.cf3.rackcdn.com/Royal_Mail_Our_Prices.pdf Can anyone tell me how to split it up into printable pages? I've tried ImageMagick's convert but that didn't default to what I wanted, maybe I need some more options to tell it what to do. -- Chris Green

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Programming question - different approaches to classic command parsing
by Chris Green 29 May '12

29 May '12

Well my Nanode project is progressing (it's the one that has the rather idiosyncratic ethernet handling). The next question is whether to rejig the basic command handling. The Nanode software I'm maintaining/improving is basically very simple, after initialisation it waits for an ethernet UDP packet with a command code and data in it, then it acts on the command and returns (via UDP again) some sort of response. There are currently 34 commands, this will expand somewhat but is unlikely to ever be more than 100 or so. The existing code simply has a switch/case block switching on the command code with the cases handling each command. It's a bit long but is manageable. I'm wondering whether to stay with the existing structure or to go to some sort of table driven approach with an array of something like:- // // // Command table entry structure // struct command { uint32_t cmd; // the command code int (* fnc) (int addr); // the address of the function to call char * str; // the associated LCD string }; (obviously the function parameters may extend/change) A linear search of an array of these won't waste much time, speed isn't of great consequence anyway. Then each command will be a function, tidier and more modular, but will it actually win me anything (or lose anything)? In particular will it use more space, in code or RAM? In code there will be, say, 50 function calls plus a table instead of a switch statement with 50 case: blocks. In RAM there will be lots of smaller functions using a small amount of stack space instead of one big one with lots of local variables. This is using the gcc-avr compiler by the way. My gut feeling is that it probably won't make a big difference either in code space use or in RAM use but it will probably use a little bit more of both. The question then is whether the significant amount of rewriting is worth it for the more elegant (and hence easy to maintain) code. If there's another approach to managing this sort of command driven interface then I'd be interested in hearing about it. -- Chris Green

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Re: [ALUG] Ethernet programming question
by Phil Ashby 28 May '12

28 May '12

Chris Green <cl(a)isbd.net> wrote: > I'm doing some programming of a Nanode board (not far removed from > Arduino) which has an ethernet interface based on the ENC28J60. > ... > However the loop that waits for ethernet packets and deals with them > seems a bit odd to me, in psuedo-code it's something like:- > > while (not reset) > { > get a packet from ethernet > > handle DHCP message > > handle message requesting local display on LCD > > handle ARP request > > handle DNS request > > handle NTP request > > if (still something left) > { > if (ping) > { > respond to ping > } > if (UDP message for us) > { > handle our message > } > } > } > > > What I'm not clear about is whether one packet can only be one of the > above things. Hence, if a DHCP request of some sort has been received > and handled can the *same* packet contain other requests? If not then > why is the code going through all the other calls? Hi Chris - you are correct in assuming that one packet can only be one thing, since a combination of packet type fields (Ethernet frame type, IP frame type, TCP/UDP port number) determine this. > OK, it makes for simpler looking code, no conditionals and/or > switch/case but it somehow seems wrong (and a bit inefficient as each > handle function gets called even if the packet has already been > handled). Just been and looked at the code in github for the Nanode Ethershield and all I can say is yuk! https://github.com/Nanode/EtherShield/blob/master/ip_arp_udp_tcp.c I quote: "The TCP implementation uses some size optimisations which are valid only if all data can be sent in one single packet. This is however not a big limitation for a microcontroller as you will anyhow use small web-pages." Hmmn. I found the code confusing, badly structured and incomplete (eg: it doesn't work if IP options are sent and there is nothing like the full TCP state machine with various timers, backoff controls and such, only a happy path). Of course I may have been looking at different code - got a URL? Phil. PS: http://code.google.com/p/avr-uip/ looks rather better!

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Ethernet programming question
by Chris Green 28 May '12

28 May '12

I'm doing some programming of a Nanode board (not far removed from Arduino) which has an ethernet interface based on the ENC28J60. I'm only modifying the existing software rather than building from scratch but would like to tidy things as much as possible. The ethernet initialisation etc. is standard library code so is cast in stone as it were but I'm puzzling over the higher level ethernet message handling stuff a bit. The system basically handles incoming requests sent over the ethernet interface and replies with instrument data, this part of the code is pretty straightforward. However the loop that waits for ethernet packets and deals with them seems a bit odd to me, in psuedo-code it's something like:- while (not reset) { get a packet from ethernet handle DHCP message handle message requesting local display on LCD handle ARP request handle DNS request handle NTP request if (still something left) { if (ping) { respond to ping } if (UDP message for us) { handle our message } } } What I'm not clear about is whether one packet can only be one of the above things. Hence, if a DHCP request of some sort has been received and handled can the *same* packet contain other requests? If not then why is the code going through all the other calls? OK, it makes for simpler looking code, no conditionals and/or switch/case but it somehow seems wrong (and a bit inefficient as each handle function gets called even if the packet has already been handled). -- Chris Green

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