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bash getopt
by samwise 21 Nov '11

21 Nov '11

Hi, Has anyone done anything with GNU enhanced getopt in bash to process incoming command line parameters? My understanding is that I have the choice of using the built-in "getopts" command within bash (on a CentOS 5.3 derivative distro), which doesn't support long options (e.g. --long-option as opposed to -l), or I can use the getopt (enhanced) 1.1.4 binary which lives in /usr/bin/getopt. I want to use long options, so I'm using the GNU getopt binary. An example script is below. Note that there is one oddity - for compatibility with some other related scripts, I need the first parameter to be something else ... so the first few lines are intended to munch $1 and pass all the remaining parameters to getopt. I don't think that should affect anything, but I've left it in as that's how I'm currently testing it. My problem is that I don't seem to be able to get the parsing to work as I expect. Specifically: # ./cmd.sh . -i -o 1 input -i is -o So the problem here is that it's quite happy to set the required parameter for -i to be -o ... when actually I was expecting it to catch that -i was missing a parameter. I think I had this working using getopts, but I need to be able to support long options now. I've messed around a bit with several different ways of writing the case script, but not managed to get it working any better. So, idle question ... has anyone got a script like this where the error checking is a bit more robust than the sample below? Cheers, Peter. #!/bin/bash paramArray=("${@}") unset paramArray[0] paramArray=("${paramArray[@]}") getopt -T if [ "$?" != "4" ]; then echo GNU enhanced getopt not detected. Quitting ... exit 1; fi # Override defaults with incoming parameters, if specified PN=`basename $0` ARGS=`getopt --name "$PN" --longoptions input:,output:,noshort:,verbose --options i:o: -- "${paramArray[@]}"` if [ $? -ne 0 ]; then echo "Invalid option specified or expected parameter argument missing. Quitting ..." exit fi eval set -- "$ARGS" while [ $# -gt 0 ]; do case "$1" in -i | --input) echo input $1 is "$2"; shift;; -o | --output) echo output $1 is "$2"; shift;; --noshort) echo noshort $1 is "$2"; shift;; -v | --verbose) VERBOSE=yes; shift;; --) shift; break;; esac shift done exit;

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Relative risks of different ports/services being open
by Chris Green 21 Nov '11

21 Nov '11

I'm wondering what are the relative risks of the different ports I have opened up on my firewall. Currently the ports I have open are:- 22 - ssh (but limited to only allowing two IP addresses to connect) 80 - http 25 - smtp 873 - rsync (not sure if I actually use this now, must check!) I'm considering what the risks of opening up port 443 (https) are to use with shellinabox and ssh. This would allow ssh from a web browser anywhere into my desktop machine (in addition to https access to the apache server of course), is this a significantly bigger risk than the limited ssh access that I have now? My thinking is that the port 443 access to ssh *is* significantly riskier than my existing ssh access, however I'm not sure if I'm being overly paranoid given that I already have open access on port 80 to my web server. What I'm really asking is whether worrying about open ssh access (with a good secure password) is a bit irrelevant given that port 80 is open to web browsers? Or is the damage that could be done if someone *does* guess my password (or it gets out by some other means, quite possible) for ssh much worse than anything using a browser/apache exploit? Any/all help appreciated, including ways that I could limit the shellinabox access to specific clients. As it is the client I'm thinking of is my Kindle but nothing at the shellinabox end can see anything to do with the Kindle because the proxying in between effectively anonymises the connection. -- Chris Green

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[ALUG Announce] 3rd Monday Monthly Ipswich Social Meeting : McGintys, Northgate Street
by samwise 21 Nov '11

21 Nov '11

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 tonight, Monday 21st November, at 20:00: P J McGinty & Sons 15 Northgate Street Ipswich Suffolk IP1 3BY Tel: 01473 251 515 Map/Directions URI: http://maps.google.co.uk/?q=IP1+3BY WWW: http://www.pjmcgintys.co.uk/ McGintys pub is in the centre of Ipswich. It's directly opposite the town's central library and has a reputation for good Irish beer. We're usually to be found in the lowest section of the bar, near the library entrance to the pub. All are welcome, novices and experienced users. Feel free to ask for further information on the Main ALUG mailing list. 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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How can I deny certain countries access to my website
by Ian Douglas 19 Nov '11

19 Nov '11

For about a month one of my websites (or rather the "Contact Us" form on that website) has been under regular, daily, attack from hackers. The attacks are consistently coming from IP Addresses in Rumania and Russia. Each time an attack occurs I use my webhost's cPanel to manually add the IP to my cPanel "IP Deny Manager" list. This is however becoming rather tedious and time consuming and seems the wrong way round to do things as I am denying IP Addresses AFTER they have tried to hack in rather than blocking them BEFORE they attempt it. Is there a way I can simply deny access to my website (or, better, just it's home-made PHP based "Contact Us" form) to all Eastern European visitors? Alternatively, since my website is primarily focused on UK customers, would there be an easier way to deny all visitors access unless they came from UK, USA Canada, Eire or Australia? I realise that this is not specifically a Linux question but any suggestions would be welcome. Ian.

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How to diagnose problem with special characters in a 'shellinabox' ssh login?
by Chris Green 19 Nov '11

19 Nov '11

I have set up shellinabox on my home system to allow me to connect from the web browser in my Amazon Kindle. I have it working OK to the extent that I can log in as a user whose password has no special characters in it, so the basic communications and connections are working. However my own password has non-alphanumeric characters in it and when I try and log in from the Kindle using shellinabox it always fails authentication. It fails if I log in directly or if I try and 'su -' from the login that I can do successfully. Logging in to shellinabox from Firefox works OK. So the Kindle->shellinabox connection is losing/changing something. When I type the non-alphanumeric characters in the working login they are echoed correctly so it's down to something in the interaction with login I think. Can anyone suggest a way of diagnosing this? -- Chris Green

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Apache2 magic
by Barry Samuels 17 Nov '11

17 Nov '11

I have set up a second virtual site on my computer so that I can use www2 instead of www because that's already used and I want to keep it separate. I have a very simple html page in www2 and this is the exact code: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  <html> <head> <title>6 Hour Live data usage</title> <meta http-equiv="refresh" content="10" > </head> <body> <img width="1250" height="800" src="/graphs/Power-6hr.png"> </body> </html> Notice the meta tag in the header which refreshes the page every 10 seconds. If I access this page with a web browser as a file i.e. file/// it works as expected, although I have to change the src= path to include / var/www2, but if I access it using http:// it doesn't update and if I use 'view/page source' I see that: <meta http-equiv="refresh" content="10" > has been replaced with: <link rev="x-refresh" href="" > Why should that happen? -- Barry Samuels http://www.beenthere-donethat.org.uk The Unofficial Guide to Great Britain

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BOINC
by Chris Walker 14 Nov '11

14 Nov '11

I've recently installed (using the app manager and not by command line) the boinc program on my Mandriva machine but it's not connecting. I'm stuck now despite looking at the help pages. The manager program fires up and tried to connect to localhost and fails. If I click on the various tabs, it shows that 0 bytes of disc space are being used because it's not connected to any projects. But all the commands under the Projects tab are greyed out. So does anybody have any ideas where I'm going wrong please and what I need to to fix it? -- __ __| |_ __ __ .----------------------------------------------. / _/ _` \ V V / | mailto:cdw_alug@the-walker-household.co.uk | \__\__,_|\_/\_/ |______________________________________________|

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Re: [ALUG] Need to add remote screen to linux box
by Mark Rogers 14 Nov '11

14 Nov '11

On 09/11/11 17:29, Tony Tibbenham wrote: > Or you could go for something like > http://www.fit-pc.com/web/fit-pc2/testimonials/ for a truly tiny PC Thanks for this, I think this one looks pretty promising: http://fit-pc.co.uk/Trim_Slice_Value--product--41.html -- 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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Re: [ALUG] Energy monitoring
by Mark Rogers 14 Nov '11

14 Nov '11

On 14/11/11 11:23, Andy Taylor wrote: > Take a look at this - > http://www.retrocomputers.eu/2011/01/11/how-much-electricity-are-you-using/ > > Software logs to a MySQL database with a web front end. My meter is > connected to my server via a serial to USB cable. Thanks, that looks like the sort of thing I'm after. I've found what I hope is a suitable meter on eBay and will have a play. -- 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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Network magic
by Barry Samuels 13 Nov '11

13 Nov '11

My computer has two network interfaces, eth0 (wired) and wlan0 (wireless), to connect to my router. The wired connection goes via a small network switch to which a laser printer is also connected. The computer normally uses the wired connection but sometimes I need to disconnect that and use the wireless so that I have a wireless connection to the router but the cable is disconnected from the router leaving my computer connected to the switch which also has a laser printer connected to it. Is there any way that I can use the laser printer via eth0 when my computer is running on wireless? -- Barry Samuels http://www.beenthere-donethat.org.uk The Unofficial Guide to Great Britain

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