- Roundtable - muug.ca

MUUG Meeting, March 11, 7:30pm -- FreeNAS
by gedetil＠cs.umanitoba.ca 04 Mar '14

04 Mar '14

The Manitoba UNIX User Group (MUUG) will be holding its next monthly meeting on Tuesday, March 11. The meeting topic for this month is as follows: FreeNAS FreeNAS enables users to build network-attached-storage (NAS) on nearly any hardware platform. The FreeNAS project and software were founded in 2005 on the principle that network storage be made available to the world at no cost and unencumbered by license restrictions. FreeNAS provides a solid service platform based on FreeBSD and includes such features as replication, data protection, backups, encryption, snapshots, file sharing and a plug-in architecture. Kevin McGregor will present an overview of these features and his experiences with implementing some of them. For this month's RTFM topic, Adam Thompson will talk about quoting special characters in shell input, for example in bash(1) or tcsh(1). The group holds its general meetings at 7:30pm on the second Tuesday of every month from September to June. (There are no meetings in July and August.) Meetings are open to the general public; you don't have to be a MUUG member to attend. ***************************************************************** Please note our *NEW* meeting location for this month: Room 1L08, Lockhart Hall, University of Winnipeg, entrance on Ellice Ave. between Spence St. and Balmoral St. Parking is available on the surrounding streets and in the lots on nearby streets. Look for signage once you're at the building, or ask a security guard. ***************************************************************** For more information about MUUG, and its monthly meetings, check out their Web server: http://www.muug.mb.ca/ Help us promote this month's meeting, by putting this poster up on your workplace bulletin board or other suitable public message board: http://www.muug.mb.ca/meetings/MUUGmeeting.pdf -- Gilbert E. Detillieux E-mail: <gedetil(a)muug.mb.ca> Manitoba UNIX User Group Web: http://www.muug.mb.ca/ PO Box 130 St-Boniface Phone: (204)474-8161 Winnipeg MB CANADA R2H 3B4 Fax: (204)474-7609

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Re: [RndTbl] Ksh scripting, named pipes
by Adam Thompson 04 Mar '14

04 Mar '14

Oh, it's obvious when I think about it - the behavior of a pipe with multiple readers is well-defined as being OS and clib-dependent. Each byte is only available to one reader, ever - if the reading is interleaved, each reader will get garbage. You can use tee(1) to write to multiple FIFOs at once, or just adapt the writing script to do so manually. -Adam On Mar 1, 2014 1:35 PM, Kevin McGregor <kevin.a.mcgregor(a)gmail.com> wrote: > > The writer is: > #/bin/ksh > PIPE=/tmp/backup.pipe > [[ ! -a $PIPE ]] && mkfifo $PIPE > # Start gzip processes > /opt/cronjobs/zip1 & > /opt/cronjobs/zip2 & > > # Process files needing compression > let 'fc=0' > ls /zonebackup/*tar | while read F; do > echo $F >$PIPE > let 'fc=fc+1' > done > > echo "end of list" >$PIPE > echo "end of list" >$PIPE > exit 0 > > The readers are: > #/bin/ksh > PIPE=/tmp/backup.pipe > NAME=zip1 > if [[ ! -a $PIPE ]]; then > logger -p local0.warning "$NAME can't find $PIPE -- exiting" > exit 1 > fi > > while (( 1 )); do > read F <$PIPE > if [[ "$F" = "end of list" ]]; then > break > else > echo "$NAME: $F" > fi > done > > > > On Sat, Mar 1, 2014 at 1:29 PM, Kevin McGregor <kevin.a.mcgregor(a)gmail.com> wrote: >> >> I tried fiddling with IFS to no avail. I just changed it like this: >> IFS=' >> ' >> And now the readers show all kinds of gibberish! All lines have no whitespace, save for the newline at the end. I'm assuming it's at the end. >> >> >> On Sat, Mar 1, 2014 at 12:47 PM, Robert Keizer <robert(a)keizer.ca> wrote: >>> >>> Have you tried setting IFS ( field sep )? Also you could enable raw mode with -r. >>> >>> Can you share the script? >>> >>> Are the same lines failing repeatedly? >>> >>> Rob >>> >>> On 2014-03-01 11:55 AM, "Kevin McGregor" <kevin.a.mcgregor(a)gmail.com> wrote: >>>> >>>> I have a main script which writes to a named pipe. Before it starts writing, it starts two other scripts which read from this pipe. The reading and writing is a list of file names, one per line. How do I ensure that each script reads one complete line from the pipe at a time (no more, no less)? >>>> >>>> I have a test set up, and it usually works, but sometimes a reader will get a blank line or just a "/" (but not any other part of a line)! >>>> >>>> Kevin >>>> >>>> _______________________________________________ >>>> Roundtable mailing list >>>> Roundtable(a)muug.mb.ca >>>> http://www.muug.mb.ca/mailman/listinfo/roundtable >>>> >>> >>> _______________________________________________ >>> Roundtable mailing list >>> Roundtable(a)muug.mb.ca >>> http://www.muug.mb.ca/mailman/listinfo/roundtable >>> >> >

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Intel leaving desktop mobo business
by Trevor Cordes 03 Mar '14

03 Mar '14

This is somewhat old news, but I don't recall it being brought up via any of the MUUG channels yet. Last year Intel announced is was going to stop selling Intel branded desktop motherboards. Haswell (4th gen i-series) is its last offering. No new boards will be brought out after 2014. NOTE! This only applies to actual Intel-branded motherboards which very few people outside the channel (local resellers, not stores) will have even ever seen. This does NOT apply to any 3rd party (ie "Tawain Inc.") mobo makers like Asus, Gigabyte, etc. Intel will continue to make desktop chipsets and CPUs and provide them to Asus, Gigabyte, Dell, etc. This also does not apply to Intel server/workstation boards, which will continue to be made/sold. I don't think anyone will mourn their passing. I've had mixed results with Intel-branded desktop boards. They had just as many badcaps as everyone else. They were always just rebadged Foxconns anyways :-) (Their server boards, I should mention in contrast, are superb.)

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Re: [RndTbl] Ksh scripting, named pipes
by Trevor Cordes 01 Mar '14

01 Mar '14

Yes. The paradigm is usually one reader. You can have many writers, and I do that all the time in my scripts, but only one reader. The proper paradigm is to change your scripts around so you have one reader that can then control or start your two previous readers. You could also have an intermediate reader that then makes the decision which of two further fifos to write two, one for each of your other two previous readers. The best answer depends on what you're really trying to achieve with all this. -------- Original message -------- From: Kevin McGregor <kevin.a.mcgregor(a)gmail.com> Date:2014/03/01 16:48 (GMT-06:00) To: Continuation of Round Table discussion <roundtable(a)muug.mb.ca> Subject: Re: [RndTbl] Ksh scripting, named pipes Aw. I was afraid of that. In my 'production' script there would be a long time between most reads, so it's unlikely there would be a problem, but I still don't want rare random failures. I'll find a work-around. On Sat, Mar 1, 2014 at 2:12 PM, Adam Thompson <athompso(a)athompso.net> wrote: Oh, it's obvious when I think about it - the behavior of a pipe with multiple readers is well-defined as being OS and clib-dependent. Each byte is only available to one reader, ever - if the reading is interleaved, each reader will get garbage. You can use tee(1) to write to multiple FIFOs at once, or just adapt the writing script to do so manually. -Adam On Mar 1, 2014 1:35 PM, Kevin McGregor <kevin.a.mcgregor(a)gmail.com> wrote: > > The writer is: > #/bin/ksh > PIPE=/tmp/backup.pipe > [[ ! -a $PIPE ]] && mkfifo $PIPE > # Start gzip processes > /opt/cronjobs/zip1 & > /opt/cronjobs/zip2 & > > # Process files needing compression > let 'fc=0' > ls /zonebackup/*tar | while read F; do > echo $F >$PIPE > let 'fc=fc+1' > done > > echo "end of list" >$PIPE > echo "end of list" >$PIPE > exit 0 > > The readers are: > #/bin/ksh > PIPE=/tmp/backup.pipe > NAME=zip1 > if [[ ! -a $PIPE ]]; then > logger -p local0.warning "$NAME can't find $PIPE -- exiting" > exit 1 > fi > > while (( 1 )); do > read F <$PIPE > if [[ "$F" = "end of list" ]]; then > break > else > echo "$NAME: $F" > fi > done > > > > On Sat, Mar 1, 2014 at 1:29 PM, Kevin McGregor <kevin.a.mcgregor(a)gmail.com> wrote: >> >> I tried fiddling with IFS to no avail. I just changed it like this: >> IFS=' >> ' >> And now the readers show all kinds of gibberish! All lines have no whitespace, save for the newline at the end. I'm assuming it's at the end. >> >> >> On Sat, Mar 1, 2014 at 12:47 PM, Robert Keizer <robert(a)keizer.ca> wrote: >>> >>> Have you tried setting IFS ( field sep )? Also you could enable raw mode with -r. >>> >>> Can you share the script? >>> >>> Are the same lines failing repeatedly? >>> >>> Rob >>> >>> On 2014-03-01 11:55 AM, "Kevin McGregor" <kevin.a.mcgregor(a)gmail.com> wrote: >>>> >>>> I have a main script which writes to a named pipe. Before it starts writing, it starts two other scripts which read from this pipe. The reading and writing is a list of file names, one per line. How do I ensure that each script reads one complete line from the pipe at a time (no more, no less)? >>>> >>>> I have a test set up, and it usually works, but sometimes a reader will get a blank line or just a "/" (but not any other part of a line)! >>>> >>>> Kevin >>>> >>>> _______________________________________________ >>>> Roundtable mailing list >>>> Roundtable(a)muug.mb.ca >>>> http://www.muug.mb.ca/mailman/listinfo/roundtable >>>> >>> >>> _______________________________________________ >>> Roundtable mailing list >>> Roundtable(a)muug.mb.ca >>> http://www.muug.mb.ca/mailman/listinfo/roundtable >>> >> > _______________________________________________ Roundtable mailing list Roundtable(a)muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable

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Ksh scripting, named pipes
by Kevin McGregor 01 Mar '14

01 Mar '14

I have a main script which writes to a named pipe. Before it starts writing, it starts two other scripts which read from this pipe. The reading and writing is a list of file names, one per line. How do I ensure that each script reads one complete line from the pipe at a time (no more, no less)? I have a test set up, and it usually works, but sometimes a reader will get a blank line or just a "/" (but not any other part of a line)! Kevin

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infant game
by Trevor Cordes 28 Feb '14

28 Feb '14

Does anyone know of a Linux game for infants that would do something visual and audible on each different keypress? Like always roll a ball across the screen with a little ditty each time Z is pressed? My kid loves to sit and hit keys on the living room computer keyboard, it would be great if he can see something happening other than the complete foobar'ing of my mythtv. If not, I think this would be a great idea for pre-toddlers, and I may program something myself.

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Re: [RndTbl] Refurbished SmartUPS
by Adam Thompson 27 Feb '14

27 Feb '14

Upsforless.CA I've purchased upses and batteries from them before. Decent support, decent prices, not incredibly awesome but good enough to give them my money. -Adam On Feb 26, 2014 2:02 PM, Robert Keizer <robert(a)keizer.ca> wrote: > > Anyone know of a Canadian reseller for a refurbished SmartUPS? > > Specifically ~1500VA at ~1kw output or so. Rackmount. With smartslot. > > Normally I would go with upsforless.ca but they don't have one in stock. > > Rob

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Refurbished SmartUPS
by Robert Keizer 26 Feb '14

26 Feb '14

Anyone know of a Canadian reseller for a refurbished SmartUPS? Specifically ~1500VA at ~1kw output or so. Rackmount. With smartslot. Normally I would go with upsforless.ca but they don't have one in stock. Rob

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Solaris zone shutdown time
by Kevin McGregor 21 Feb '14

21 Feb '14

Is there any reliable way to tell from the global zone in Solaris 10+ just when a zone (now in 'installed' state) had been shut down? I can more or less tell when the last boot was, but I don't have any ideas for when it was last shut down.

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NTP DDOS Attacks
by John Lange 14 Feb '14

14 Feb '14

Does anyone know of a public site which documents the traffic associated with the recent NTP DDOS attacks? I'm trying to see if the attacks correlate to some packet loss we are seeing. -- John Lange

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