June 2015 - WLUG - wlug.mailman3.com

Minecraft server security ...

by David Glaser

Folks, My grandson wants to host a minecraft server party for his boy scout troop and my daughter and I are wondering how to ensure that the existing machines on her home network are not compromised given that the members of the troop will be bringing their own machinesand ethernet switchesalthough some may be running wireless. I was wondering if you could give us some thoughts on how to set up the network. It is my understanding that the minecraft clients do need to get out to the internet to obtain a valid player name. I had thought ofsetting up a seperate Router/Lan for the party, disconnecting the existing router/lan from the wan and connecting the minecraft router/lan to the wan for the duration of the party. Any thoughts out there? -David

June 21, 2015

Re: [Wlug] ls character range wildcard oddity?

by Steve Revilak

>brett@spider /tmp/test $ \ls >apple Berry > >This is what I'd expect to see: > >brett@spider /tmp/test $ \ls [a-b]* >apple > >This makes no sense. Is this a bug?: This is probably more bash than ls. When you use `*' on a command line, the shell does filename glob expansion; the results of the glob expansion become arguments (to ls, in this case). Out of the box, I've always seen bash do case sensitive globs, but you can change this. # four files $ touch ax Ax bx Bx # all files starting with `a' $ ls a* ax # make glob expansion case insensitive $ shopt -s nocaseglob $ ls a* Ax ax # make it case sensitive again $ shopt -u nocaseglob $ ls a* ax If you actually want to see how the glob is expanded $ sh -x -c "ls [aA]*" + ls Ax ax <<< glob expansion Ax ax Steve

June 19, 2015

Re: [Wlug] ls character range wildcard oddity?

by Dennis Payne

Interesting. I see the same behavior. Near as I can tell bash decided that the alphabet is: aAbBcCdD... I wouldn't expect that to be the case but when I played around with various file name that was the behavior I saw. So [a-c] includes upercase B while [a-b] does not. 'ls [A-c]*' will show Berry but not apple. On Fri, 2015-06-19 at 09:29 -0400, Brett Russ wrote: > Can someone explain this to my evidently inadequately caffeinated > brain? I was trying to use a lower case character range wildcard to > list all files not starting with an uppercase letter and I noticed it > wasn't working as I'd expect. So I created this simple example and > still don't understand what's happening. > > Dir with two files: > > brett@spider /tmp/test $ \ls > apple Berry > > This is what I'd expect to see: > > brett@spider /tmp/test $ \ls [a-b]* > apple > > This makes no sense. Is this a bug?: > > brett@spider /tmp/test $ \ls [a-c]* > apple Berry > > From here on are just a few extra examples confirming the oddity of > the above. > > brett@spider /tmp/test $ \ls [a]* > apple > > brett@spider /tmp/test $ \ls [b]* > ls: cannot access [b]*: No such file or directory > > brett@spider /tmp/test $ \ls [c]* > ls: cannot access [c]*: No such file or directory > > brett@spider /tmp/test $ \ls a* > apple > > brett@spider /tmp/test $ \ls b* > ls: cannot access b*: No such file or directory > > brett@spider /tmp/test $ \ls c* > ls: cannot access c*: No such file or directory > > brett@spider /tmp/test $ dpkg -S `which ls` > coreutils: /bin/ls > > brett@spider /tmp/test $ dpkg -s coreutils > Package: coreutils > Essential: yes > Status: install ok installed > Priority: required > Section: utils > Installed-Size: 6020 > Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> > Architecture: amd64 > Multi-Arch: foreign > Version: 8.21-1ubuntu5.1 > [SNIP] > > > Thanks, > Brett > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug

June 19, 2015

Re: [Wlug] ls character range wildcard oddity?

by Brett Russ

Ted, Chris, Thanks for straightening me out on this! Haven't had to pay much attention to locale before. Makes sense. -Brett On Fri, Jun 19, 2015 at 10:22 AM, Chris Thompson <wolcen(a)riseup.net> wrote: > Well, this may not get you only a subset of lower-case letters, but it > does at least limit to lower case: [[:lower:]]. More details below. > > e.g.: > > ls [[:lower:]]* > > Regards, > Chris > > See also: > > http://www.tldp.org/LDP/GNU-Linux-Tools-Summar/html/x11655.htm#STANDARD-WIL… > > > man 7 glob > ---------- > > Character classes and internationalization > Of course ranges were originally meant to be ASCII ranges, so > that "[ -%]" stands for "[ !"#$%]" and "[a-z]" stands > for "any lowercase letter". Some UNIX implementations > generalized this so that a range X-Y stands for the set of > characters with code between the codes for X and for Y. > However, this requires the user to know the character cod‐ > ing in use on the local system, and moreover, is not convenient > if the collating sequence for the local alphabet > differs from the ordering of the character codes. Therefore, > POSIX extended the bracket notation greatly, both for > wildcard patterns and for regular expressions. In the above we > saw three types of items that can occur in a bracket > expression: namely (i) the negation, (ii) explicit single > characters, and (iii) ranges. POSIX specifies ranges in > an internationally more useful way and adds three more types: > > (iii) Ranges X-Y comprise all characters that fall between X and > Y (inclusive) in the current collating sequence as > defined by the LC_COLLATE category in the current locale. > > (iv) Named character classes, like > > [:alnum:] [:alpha:] [:blank:] [:cntrl:] > [:digit:] [:graph:] [:lower:] [:print:] > [:punct:] [:space:] [:upper:] [:xdigit:] > > so that one can say "[[:lower:]]" instead of "[a-z]", and have > things work in Denmark, too, where there are three > letters past 'z' in the alphabet. These character classes are > defined by the LC_CTYPE category in the current > locale. > > On 06/19/2015 09:58 AM, Theodore Ruegsegger wrote: > > It looks like a locale issue. In the old "C" locale, sorting a list > > put all cap letters before all lowercase letters. In the "en_US.UTF-8" > > locale, apparently the Ubuntu default, they're sorted as in a regular > > dictionary, regardless of caps. > > > > For example: > > > > ls > > apple berry Berry charlie > > > > Hope that's more helpful than my first response! > > Ted > > > > On Fri, Jun 19, 2015 at 9:46 AM, Theodore Ruegsegger <gruntly(a)gmail.com> > wrote: > >> Disregard last transmission. I shoulda read your post more carefully. > >> > >> Ted > >> > >> On Fri, Jun 19, 2015 at 9:44 AM, Theodore Ruegsegger <gruntly(a)gmail.com> > wrote: > >>> b != B > >>> > >>> HTH, > >>> Ted > >>> > >>> On Fri, Jun 19, 2015 at 9:29 AM, Brett Russ <bruss(a)alum.wpi.edu> > wrote: > >>>> Can someone explain this to my evidently inadequately caffeinated > brain? I > >>>> was trying to use a lower case character range wildcard to list all > files > >>>> not starting with an uppercase letter and I noticed it wasn't working > as I'd > >>>> expect. So I created this simple example and still don't understand > what's > >>>> happening. > >>>> > >>>> Dir with two files: > >>>> > >>>> brett@spider /tmp/test $ \ls > >>>> apple Berry > >>>> > >>>> This is what I'd expect to see: > >>>> > >>>> brett@spider /tmp/test $ \ls [a-b]* > >>>> apple > >>>> > >>>> This makes no sense. Is this a bug?: > >>>> > >>>> brett@spider /tmp/test $ \ls [a-c]* > >>>> apple Berry > >>>> > >>>> From here on are just a few extra examples confirming the oddity of > the > >>>> above. > >>>> > >>>> brett@spider /tmp/test $ \ls [a]* > >>>> apple > >>>> > >>>> brett@spider /tmp/test $ \ls [b]* > >>>> ls: cannot access [b]*: No such file or directory > >>>> > >>>> brett@spider /tmp/test $ \ls [c]* > >>>> ls: cannot access [c]*: No such file or directory > >>>> > >>>> brett@spider /tmp/test $ \ls a* > >>>> apple > >>>> > >>>> brett@spider /tmp/test $ \ls b* > >>>> ls: cannot access b*: No such file or directory > >>>> > >>>> brett@spider /tmp/test $ \ls c* > >>>> ls: cannot access c*: No such file or directory > >>>> > >>>> brett@spider /tmp/test $ dpkg -S `which ls` > >>>> coreutils: /bin/ls > >>>> > >>>> brett@spider /tmp/test $ dpkg -s coreutils > >>>> Package: coreutils > >>>> Essential: yes > >>>> Status: install ok installed > >>>> Priority: required > >>>> Section: utils > >>>> Installed-Size: 6020 > >>>> Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> > >>>> Architecture: amd64 > >>>> Multi-Arch: foreign > >>>> Version: 8.21-1ubuntu5.1 > >>>> [SNIP] > >>>> > >>>> > >>>> Thanks, > >>>> Brett > >>>> > >>>> _______________________________________________ > >>>> Wlug mailing list > >>>> Wlug(a)mail.wlug.org > >>>> http://mail.wlug.org/mailman/listinfo/wlug > >>>> > > _______________________________________________ > > Wlug mailing list > > Wlug(a)mail.wlug.org > > http://mail.wlug.org/mailman/listinfo/wlug > > > > > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > >

June 19, 2015

Re: [Wlug] ls character range wildcard oddity?

by Chris Thompson

Well, this may not get you only a subset of lower-case letters, but it does at least limit to lower case: [[:lower:]]. More details below. e.g.: ls [[:lower:]]* Regards, Chris See also: http://www.tldp.org/LDP/GNU-Linux-Tools-Summar/html/x11655.htm#STANDARD-WIL… man 7 glob ---------- Character classes and internationalization Of course ranges were originally meant to be ASCII ranges, so that "[ -%]" stands for "[ !"#$%]" and "[a-z]" stands for "any lowercase letter". Some UNIX implementations generalized this so that a range X-Y stands for the set of characters with code between the codes for X and for Y. However, this requires the user to know the character cod‐ ing in use on the local system, and moreover, is not convenient if the collating sequence for the local alphabet differs from the ordering of the character codes. Therefore, POSIX extended the bracket notation greatly, both for wildcard patterns and for regular expressions. In the above we saw three types of items that can occur in a bracket expression: namely (i) the negation, (ii) explicit single characters, and (iii) ranges. POSIX specifies ranges in an internationally more useful way and adds three more types: (iii) Ranges X-Y comprise all characters that fall between X and Y (inclusive) in the current collating sequence as defined by the LC_COLLATE category in the current locale. (iv) Named character classes, like [:alnum:] [:alpha:] [:blank:] [:cntrl:] [:digit:] [:graph:] [:lower:] [:print:] [:punct:] [:space:] [:upper:] [:xdigit:] so that one can say "[[:lower:]]" instead of "[a-z]", and have things work in Denmark, too, where there are three letters past 'z' in the alphabet. These character classes are defined by the LC_CTYPE category in the current locale. On 06/19/2015 09:58 AM, Theodore Ruegsegger wrote: > It looks like a locale issue. In the old "C" locale, sorting a list > put all cap letters before all lowercase letters. In the "en_US.UTF-8" > locale, apparently the Ubuntu default, they're sorted as in a regular > dictionary, regardless of caps. > > For example: > > ls > apple berry Berry charlie > > Hope that's more helpful than my first response! > Ted > > On Fri, Jun 19, 2015 at 9:46 AM, Theodore Ruegsegger <gruntly(a)gmail.com> wrote: >> Disregard last transmission. I shoulda read your post more carefully. >> >> Ted >> >> On Fri, Jun 19, 2015 at 9:44 AM, Theodore Ruegsegger <gruntly(a)gmail.com> wrote: >>> b != B >>> >>> HTH, >>> Ted >>> >>> On Fri, Jun 19, 2015 at 9:29 AM, Brett Russ <bruss(a)alum.wpi.edu> wrote: >>>> Can someone explain this to my evidently inadequately caffeinated brain? I >>>> was trying to use a lower case character range wildcard to list all files >>>> not starting with an uppercase letter and I noticed it wasn't working as I'd >>>> expect. So I created this simple example and still don't understand what's >>>> happening. >>>> >>>> Dir with two files: >>>> >>>> brett@spider /tmp/test $ \ls >>>> apple Berry >>>> >>>> This is what I'd expect to see: >>>> >>>> brett@spider /tmp/test $ \ls [a-b]* >>>> apple >>>> >>>> This makes no sense. Is this a bug?: >>>> >>>> brett@spider /tmp/test $ \ls [a-c]* >>>> apple Berry >>>> >>>> From here on are just a few extra examples confirming the oddity of the >>>> above. >>>> >>>> brett@spider /tmp/test $ \ls [a]* >>>> apple >>>> >>>> brett@spider /tmp/test $ \ls [b]* >>>> ls: cannot access [b]*: No such file or directory >>>> >>>> brett@spider /tmp/test $ \ls [c]* >>>> ls: cannot access [c]*: No such file or directory >>>> >>>> brett@spider /tmp/test $ \ls a* >>>> apple >>>> >>>> brett@spider /tmp/test $ \ls b* >>>> ls: cannot access b*: No such file or directory >>>> >>>> brett@spider /tmp/test $ \ls c* >>>> ls: cannot access c*: No such file or directory >>>> >>>> brett@spider /tmp/test $ dpkg -S `which ls` >>>> coreutils: /bin/ls >>>> >>>> brett@spider /tmp/test $ dpkg -s coreutils >>>> Package: coreutils >>>> Essential: yes >>>> Status: install ok installed >>>> Priority: required >>>> Section: utils >>>> Installed-Size: 6020 >>>> Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> >>>> Architecture: amd64 >>>> Multi-Arch: foreign >>>> Version: 8.21-1ubuntu5.1 >>>> [SNIP] >>>> >>>> >>>> Thanks, >>>> Brett >>>> >>>> _______________________________________________ >>>> Wlug mailing list >>>> Wlug(a)mail.wlug.org >>>> http://mail.wlug.org/mailman/listinfo/wlug >>>> > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug >

June 19, 2015

Re: [Wlug] ls character range wildcard oddity?

by Theodore Ruegsegger

It looks like a locale issue. In the old "C" locale, sorting a list put all cap letters before all lowercase letters. In the "en_US.UTF-8" locale, apparently the Ubuntu default, they're sorted as in a regular dictionary, regardless of caps. For example: ls apple berry Berry charlie Hope that's more helpful than my first response! Ted On Fri, Jun 19, 2015 at 9:46 AM, Theodore Ruegsegger <gruntly(a)gmail.com> wrote: > Disregard last transmission. I shoulda read your post more carefully. > > Ted > > On Fri, Jun 19, 2015 at 9:44 AM, Theodore Ruegsegger <gruntly(a)gmail.com> wrote: >> b != B >> >> HTH, >> Ted >> >> On Fri, Jun 19, 2015 at 9:29 AM, Brett Russ <bruss(a)alum.wpi.edu> wrote: >>> Can someone explain this to my evidently inadequately caffeinated brain? I >>> was trying to use a lower case character range wildcard to list all files >>> not starting with an uppercase letter and I noticed it wasn't working as I'd >>> expect. So I created this simple example and still don't understand what's >>> happening. >>> >>> Dir with two files: >>> >>> brett@spider /tmp/test $ \ls >>> apple Berry >>> >>> This is what I'd expect to see: >>> >>> brett@spider /tmp/test $ \ls [a-b]* >>> apple >>> >>> This makes no sense. Is this a bug?: >>> >>> brett@spider /tmp/test $ \ls [a-c]* >>> apple Berry >>> >>> From here on are just a few extra examples confirming the oddity of the >>> above. >>> >>> brett@spider /tmp/test $ \ls [a]* >>> apple >>> >>> brett@spider /tmp/test $ \ls [b]* >>> ls: cannot access [b]*: No such file or directory >>> >>> brett@spider /tmp/test $ \ls [c]* >>> ls: cannot access [c]*: No such file or directory >>> >>> brett@spider /tmp/test $ \ls a* >>> apple >>> >>> brett@spider /tmp/test $ \ls b* >>> ls: cannot access b*: No such file or directory >>> >>> brett@spider /tmp/test $ \ls c* >>> ls: cannot access c*: No such file or directory >>> >>> brett@spider /tmp/test $ dpkg -S `which ls` >>> coreutils: /bin/ls >>> >>> brett@spider /tmp/test $ dpkg -s coreutils >>> Package: coreutils >>> Essential: yes >>> Status: install ok installed >>> Priority: required >>> Section: utils >>> Installed-Size: 6020 >>> Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> >>> Architecture: amd64 >>> Multi-Arch: foreign >>> Version: 8.21-1ubuntu5.1 >>> [SNIP] >>> >>> >>> Thanks, >>> Brett >>> >>> _______________________________________________ >>> Wlug mailing list >>> Wlug(a)mail.wlug.org >>> http://mail.wlug.org/mailman/listinfo/wlug >>>

June 19, 2015

Re: [Wlug] ls character range wildcard oddity?

by Theodore Ruegsegger

Disregard last transmission. I shoulda read your post more carefully. Ted On Fri, Jun 19, 2015 at 9:44 AM, Theodore Ruegsegger <gruntly(a)gmail.com> wrote: > b != B > > HTH, > Ted > > On Fri, Jun 19, 2015 at 9:29 AM, Brett Russ <bruss(a)alum.wpi.edu> wrote: >> Can someone explain this to my evidently inadequately caffeinated brain? I >> was trying to use a lower case character range wildcard to list all files >> not starting with an uppercase letter and I noticed it wasn't working as I'd >> expect. So I created this simple example and still don't understand what's >> happening. >> >> Dir with two files: >> >> brett@spider /tmp/test $ \ls >> apple Berry >> >> This is what I'd expect to see: >> >> brett@spider /tmp/test $ \ls [a-b]* >> apple >> >> This makes no sense. Is this a bug?: >> >> brett@spider /tmp/test $ \ls [a-c]* >> apple Berry >> >> From here on are just a few extra examples confirming the oddity of the >> above. >> >> brett@spider /tmp/test $ \ls [a]* >> apple >> >> brett@spider /tmp/test $ \ls [b]* >> ls: cannot access [b]*: No such file or directory >> >> brett@spider /tmp/test $ \ls [c]* >> ls: cannot access [c]*: No such file or directory >> >> brett@spider /tmp/test $ \ls a* >> apple >> >> brett@spider /tmp/test $ \ls b* >> ls: cannot access b*: No such file or directory >> >> brett@spider /tmp/test $ \ls c* >> ls: cannot access c*: No such file or directory >> >> brett@spider /tmp/test $ dpkg -S `which ls` >> coreutils: /bin/ls >> >> brett@spider /tmp/test $ dpkg -s coreutils >> Package: coreutils >> Essential: yes >> Status: install ok installed >> Priority: required >> Section: utils >> Installed-Size: 6020 >> Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> >> Architecture: amd64 >> Multi-Arch: foreign >> Version: 8.21-1ubuntu5.1 >> [SNIP] >> >> >> Thanks, >> Brett >> >> _______________________________________________ >> Wlug mailing list >> Wlug(a)mail.wlug.org >> http://mail.wlug.org/mailman/listinfo/wlug >>

June 19, 2015

Re: [Wlug] ls character range wildcard oddity?

by Theodore Ruegsegger

b != B HTH, Ted On Fri, Jun 19, 2015 at 9:29 AM, Brett Russ <bruss(a)alum.wpi.edu> wrote: > Can someone explain this to my evidently inadequately caffeinated brain? I > was trying to use a lower case character range wildcard to list all files > not starting with an uppercase letter and I noticed it wasn't working as I'd > expect. So I created this simple example and still don't understand what's > happening. > > Dir with two files: > > brett@spider /tmp/test $ \ls > apple Berry > > This is what I'd expect to see: > > brett@spider /tmp/test $ \ls [a-b]* > apple > > This makes no sense. Is this a bug?: > > brett@spider /tmp/test $ \ls [a-c]* > apple Berry > > From here on are just a few extra examples confirming the oddity of the > above. > > brett@spider /tmp/test $ \ls [a]* > apple > > brett@spider /tmp/test $ \ls [b]* > ls: cannot access [b]*: No such file or directory > > brett@spider /tmp/test $ \ls [c]* > ls: cannot access [c]*: No such file or directory > > brett@spider /tmp/test $ \ls a* > apple > > brett@spider /tmp/test $ \ls b* > ls: cannot access b*: No such file or directory > > brett@spider /tmp/test $ \ls c* > ls: cannot access c*: No such file or directory > > brett@spider /tmp/test $ dpkg -S `which ls` > coreutils: /bin/ls > > brett@spider /tmp/test $ dpkg -s coreutils > Package: coreutils > Essential: yes > Status: install ok installed > Priority: required > Section: utils > Installed-Size: 6020 > Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> > Architecture: amd64 > Multi-Arch: foreign > Version: 8.21-1ubuntu5.1 > [SNIP] > > > Thanks, > Brett > > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug >

June 19, 2015

ls character range wildcard oddity?

by Brett Russ

Can someone explain this to my evidently inadequately caffeinated brain? I was trying to use a lower case character range wildcard to list all files not starting with an uppercase letter and I noticed it wasn't working as I'd expect. So I created this simple example and still don't understand what's happening. Dir with two files: brett@spider /tmp/test $ \ls apple Berry This is what I'd expect to see: brett@spider /tmp/test $ \ls [a-b]* apple This makes no sense. Is this a bug?: *brett@spider /tmp/test $ \ls [a-c]*apple Berry* >From here on are just a few extra examples confirming the oddity of the above. brett@spider /tmp/test $ \ls [a]* apple brett@spider /tmp/test $ \ls [b]* ls: cannot access [b]*: No such file or directory brett@spider /tmp/test $ \ls [c]* ls: cannot access [c]*: No such file or directory brett@spider /tmp/test $ \ls a* apple brett@spider /tmp/test $ \ls b* ls: cannot access b*: No such file or directory brett@spider /tmp/test $ \ls c* ls: cannot access c*: No such file or directory brett@spider /tmp/test $ dpkg -S `which ls` coreutils: /bin/ls brett@spider /tmp/test $ dpkg -s coreutils Package: coreutils Essential: yes Status: install ok installed Priority: required Section: utils Installed-Size: 6020 Maintainer: Ubuntu Developers <ubuntu-devel-discuss(a)lists.ubuntu.com> Architecture: amd64 Multi-Arch: foreign Version: 8.21-1ubuntu5.1 [SNIP] Thanks, Brett

June 19, 2015

Re: [Wlug] WLUG Meeting tomorrow! Jun 11th, 2015! Native ZFS on linux!

by E Johnson

Shouldn't the tagline say Please excuse my levity? But roflol, you guys. Liz J On 11 June 2015 at 17:06, Frank Sweetser <fs(a)wpi.edu> wrote: > And I was hoping to see a file system that only stored data formatted in > iambic pentameter... > ---- > Sent from my Android device with K-9 Mail. Please excuse my brevity. > > > > > See you in the future, if you're going that way. > > > > -- Keith >

June 11, 2015