@Gilles - @slm - it will get you a list, but it won't work in an rc file - entry needs alias prepended. That's the problem - it's kind of simple - like for a in $(alias) ; do case "$a" in *=*) command -v "${a%%=*}" ;; esac ; done or something, but I didn't feel like writing it at the time.

@mikeserv - if you use alias | tee somefile it works

OR... can you set more than one alias in the same string like alias b='badass' \\n='hey there'?

So you get alias prepended to every entry?

@mikeserv - to append, alias | tee -a somefile

Seems to work

So - your implementation prepends alias to every entry? like alias 1=stuff alias 2=more stuff?

yeah

not just 1= and 2= but only if you pipe into a file? That's smart.

I dunno - pubs.opengroup.org/onlinepubs/9699919799/utilities/alias.html

That's what I was going off of and why I thought I was mistaken.

@slm - just bash?

dunno about other shells, but it works in bash

zsh doesn't do it.

bash does over a pipe.

yes the pipe seems to be necessary

Anyway - it was definitely a question about bash. It'll likely only alter output if it detects stdout is not a terminal.

Ok, I undeleted it again.

thanks slm.

and gilles, too. weird.

[status-complete]

Is there anyone alive out there willing to help me break something?

Hi all, I am executing dhrystone 2.1 on freescale IMX6 quad processor with 1GHz.Below are the things I tried. 1. Executed dhrystone alone first time.

2. With an application running in the background, I executed dhrystone again. In either cases I am getting DMIPS value same. I do not understand. In second case DMIPS should reduce.Please let me know

@mikeserv possibly

@user3818847 take it to Unix & Linux. thanks!

@Braiam status-complete

hey @mikeserv why does your answer say >> ./bash_aliases? did you mean >> .bash_aliases (without the /)?

@mikeserv possibly isn't this unix and linux?

ok.

Hang on...

wow, two minutes and I already have an upvote.

people here sure love their logs...

@slm I do, just for future reference.

@slm to my knowledge there is no easy way to do this unless you run an application under OS X's X11.app, aka XQuartz

does just what it sounds like: provide a rootless X11 server that draws to Quartz (Apple's native display server) windows. it's built from Xorg

Ok. this

I wrote that function and I think it can shell quote anything. But it seems... too easy? I dunno...

Apple stopped shipping it at 10.7, IIRC. but they still provide integration. the only major consumer of it I've ever seen is GIMP.

I want itto break.

@mikeserv ok, I'm looking

@mikeserv sadly that's beyond my meager knowledge of the shell.

for now. been reading Classic Shell Scripting. \o/

what does set -f do?

@strugee - actually, I just made it simpler...

@mikeserv same link?

set -f restricts the shell from expanding file globs.

Hang on...

@strugee - yeah, now it is.

@mikeserv ok

The idea is the only character you have to worry about is a single quote when using single quotes. So I set $IFS to the single quote and printf the shell array with '\'' in the format string.

I let it expand the single quotes out and replace them. I've done some very limited testing - I just got the idea before picking the boy up from school - and it wasn't long ago he fell asleep.

It should accept an argument array and return eval able strings to reproduce the same array.

Just realized that it doesn't though - I didn't separate the elements. It needs IFS between the elements for multiple. I added a space. I'd only tested it with this nonsense key-smash string:

It returns this:

Which I can eval over a pipe or whatever and arrive at the same result...

I added a space for multiple elements. i just wanna know if I'm way off base or not.

it seems pretty solid - at least foundationally.

eval "$(printf var= ; sq "'\''sine sgute in'''he
re and roundabouts here''''''")" ; echo "$var"

'\''sine sgute in'''he
re and roundabouts here''''''

That's only a single while loop iteration. Basically just printf ' ; IFS=' q "$1" ; printf %s'\'' $* ; printf '

sorry, had to step away for a bit

un petit moment

sorry, still too complex for me.

e.g. what does shift do?

@mikeserv ^^

No problem. Ok. So you do - fn arg1 arg2 arg3 - those are the positional parameters.

shift shifts one away. So "$@" now is arg2 arg3.

It's ok.

ooohhhh

hmm

That's another thing that perplexes me - I don't declare a single variable. I did it functionally - with zero effect on the shell environment and without invoking a single subshell. I'd be patting myself on the back, but someone smarter than me must have already figured out why it's a stupid idea, I'm sure.

Actually, I take that back - I do affect the environment as written - with set -f and setting, unsetting $IFS - but both things can be handled in the same way without the possibility of overwriting current environment.

I also suspect I don't need the second function at all...

yeah. it's gone now.

actually, I know one way it's really broken - it prints out that '\'' bit even if there are no ' at least once...

hmm...

I fixed that.

I think it might be good.

sq ju\'st some reg'
'ular arguments

returns:

'ju'\''st' 'some' 'reg
ular' 'arguments'

Can anyone explain more

@Gnouc - echo | tee /dev/fd/0

Why Stéphane Chazelas said that process substitution does not use named pipes?

Because it uses anonymous pipes.

really?

@Gnouc Because it's true.

as your test shows.

@Gilles: Can you clarify What is named pipe?

I read from this: en.wikipedia.org/wiki/Named_pipe

That pipe is an anonymous pipe. Try to open it.

@StéphaneChazelas - would you explain?

@Gnouc it's a file with a name (i.e. in the filesystem), where one process can write and another process can read and the reader receives the data written by the writer in a stream. (I'm simplifying.) Unlike a (non-named) pipe, which behaves in the same way but has to be created by the pipe system call and inherited as a descriptor, it has no name that would allow another process to open it independently.

It's the stuff of magic.

Thanks, got it!

Morning!

Does anyone know how to listen for data from usb device?

e.g.: having a piano connected to computer (and detected - lsusb), how can I see any logs when pressing the keys?

you need a serial terminal on it.

well, maybe not need.

it might offer some api of its own. but a sure way is a serial terminal.

@mikeserv In first instance, I just want to log any data sent by device (even it's not readable or understandable). I think there should be some very native way (C or C++?). But I don't know... Thanks for suggestion, I will try a serial terminal.

Oh, then just cat it.

Or tail -f it or something.

You probably can.

@mikeserv How to cat it?

I remember I saw cat /dev/usb/... somewhere, but it it didn't work for me.

Well, you have to get the right node and permissions and all. You might also watch uevent logs in /sys.

lsusb -v is handy on the offchance you're not already using it,

I think there's a way to get udev to notify you on device activity too. Maybe play around with udevadm. But I'm not sure about that one.

If it's an input device you'll probably also want to study up on uinput.

@mikeserv Thanks for info. I will study more about this. +20, from me ;-)

@IonicăBizău - ok, but, so you know, the serial terminal is still a very viable option. it's not so hard to get. minicom can do it for you, or even screen.

I already have screen installed, do you have any example?

@IonicăBizău - hmm. Maybe I was thinking that was easier than it actually is.

Anyway - this looks cool: linux-usb.org/tools.html

I'd write a C/C++ app if I knew how...

you and me both. but I don't think that's all there is there.

see usbfs_snoop?

Yes

...written ten years ago! :D

Yeah. 2.6 is that old already?!?

I was reading this article: linuxjournal.com/node/7582

me too

I guess this is what I need :-)

Yeah - if your thing is an input device, you can get that from uinput.

I only have one usb device connected - my keyboard/mouse - and I just did cat /dev/usb/hiddev0 and it starting outputting the scancodes for every key I typed to the terminal screen.

Well, maybe not the scancodes. I can't verify that - terminal font didn't handle whatever it was - but every time I pressed a key more nonsense appeared.

$ sudo cat /dev/usb/hiddev0
[sudo] password for ionicabizau:
cat: /dev/usb/hiddev0: No such file or directory

What am I supposed to do?

Well, sure, you need the right device node.

Start with ls /dev/usb and see what's in there.

$ ls /dev/usb
ls: cannot access /dev/usb: No such file or directory

I told you that usb directory is missing

what distro are you using? ok - step back again - do ls /dev

Ubuntu 14.04

$ ls /dev
autofs         cpu_dma_latency  input  loop6               null   ram11  ram7     sda2      snd     tty12  tty21  tty30  tty4   tty49  tty58  ttyprintk  ttyS17  ttyS26  ttyS7    usbmon4     vcs4   vcsa6
block          cuse             kmsg   loop7               nvram  ram12  ram8     sda3      sr0     tty13  tty22  tty31  tty40  tty5   tty59  ttyS0      ttyS18  ttyS27  ttyS8    v4l         vcs5   vcsa7
bsg            disk             kvm    loop-control        port   ram13  ram9     sda4      stderr  tty14  tty23  tty32  tty41  tty50  tty6   ttyS1      ttyS19  ttyS28  ttyS9    vbo…

Maybe $ sudo cat /dev/input/mouse0 ?

It doesn't output anything.

vbo..? that

vbox?

is this a vm or do you just have the modules built?

I think I found it!

usbmon4

cool

$ ls /dev/bus/usb/

oh. duh. sorry. so you should see the nodes for each device connected in there.

Yes, I see.

you also notice you have a /dev/input

lsusb outputs devices, and in /dev/bus/usb there are directories and files

look at those device node files - do stat /dev/bus/usb/*

ionicabizau@laptop:~$ lsusb
Bus 002 Device 002: ID 8087:8000 Intel Corp.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:8008 Intel Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 004: ID 0bda:0139 Realtek Semiconductor Corp. RTS5139 Card Reader Controller
Bus 003 Device 003: ID 04f2:b3fd Chicony Electronics Co., Ltd
Bus 003 Device 038: ID 13d3:3402 IMC Networks

not for me.

ionicabizau@laptop:~$ stat /dev/bus/usb/*
  File: ‘/dev/bus/usb/001’
  Size: 80        	Blocks: 0          IO Block: 4096   directory
Device: 5h/5d	Inode: 1177        Links: 2
Access: (0755/drwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2014-07-24 13:04:24.579920281 +0300
Modify: 2014-07-21 20:07:59.908002023 +0300
Change: 2014-07-21 20:07:59.908002023 +0300
 Birth: -
  File: ‘/dev/bus/usb/002’
  Size: 80        	Blocks: 0          IO Block: 4096   directory
Device: 5h/5d	Inode: 1179        Links: 2

Oh, you want to look at -verbose stuff. It's going to be mostly useless. But I'm hoping there's a major minor number in there - I can't remember.

Interesting... Learning new things everyday.

oh, well, there's only three.

unplug your keyboard or whatever and do ls again.

It will be gone

whatever it is.

but...

I don't have anything plugged in...

But I will try later

those are the hubs.

I guess I will ask a question on the site

good idea. someone a lot better than me will probably even answer. but those are the root hubs - see how they say directory?

Yes

when you plug something in maybe do ls /dev/bus/usb/00*/*

also - you may not have a dev/usb because you don't have anything plugged in. maybe udev just hasnt created it yet. i dunno for sure when that happens.

Why aren't some code blocks highlighted, like this C codeblock? unix.stackexchange.com/q/45340/72471

@polym Looks like a bug. Ask on meta.

@IonicăBizău done

@polym Upvoted

You can add that c is added to question.

Because for questions that don't have programming language tags there is no automatic highlight

Well sometimes I even see bash code like this question, which should be highlighted

shouldn't export be highlighted?

but this one has the c tag

@IonicăBizău or do you mean my meta question should have c ?

Is there any question that has code highlight on this website?

Yes, in the same thread as the path thread, see this answer

but it looks very broken to me

because sometimes

it just highlights strings

but not e.g. the alias command itself

What about questions?

I mean, highlight in question content.

I think I've seen highlighting in questions the same as answers

@IonicăBizău Did the lang : bash help in any way?

I don't see that these comments added highlighting

In my edit it doesn't, but it should...

<!--language: lang-bash -->

<!--language: lang-{{programming language}} -->

@polym - i think ir has to do with the tags when theyre not.

@IonicăBizău Why do we need to add these language comments? shouldn't it automatically highlight the codeblock?

@mikeserv when they're not added (like c) ?

@polym I tried to force highlighting, but seems not to work.

@polym - yeah, I think so.

@mikeserv well all of these questions i've tagged contain either bash or c. also then how can answers contain highlighting? :D

@polym - curious. I was just referencing this, really. I have no idea how correct it is.

the only time I ever worry about it is when it is just too glaringly ugly, so I try to find ways to mask it with comment hashes.

I don't have time to answer right now (at work and with a deadline) but c had no highlighting associated with it, I'll fix it later. The ones tagged with bash should be highlighted automatically.

@polym ^^

Oh, I had fixed it actually. It should work now.

@terdon Oded did it for you ;)

@Braiam Did he? Oh.

bash works, it was just a bad example. foo=bar is not highlighted but foo='bar' is.

@polym ^^

@terdon - will you break this?

 sq() ( set -f ; IFS=\'
    while [ $# -gt 0 ] && printf \'
    do  [ -z "${1#"${1#*\'}"}" ] ||
            printf "%s'\\\\''" ${1%\'*}
        printf "%s' " "${1##*\'}"
    shift ; done
)

@mikeserv Not today. Deadline. Work. Pressure :(

Ok. I hope you make it man.

Thanks :)

@mikeserv, are you a vampire? I always see you up all the time :D

@Ramesh - hiss

@Ramesh Vampires sleep during the daytime, supposedly.

@mikeserv what is that? Something that any sane person would have written in Perl?

@derobert - possibly, but easier for crazier folks.

@derobert

eval "$(printf var= ; sq "'\''sine sgute in'''he
re and roundabouts here''''''")" ; echo "$var"
eval set -- "$(sq ju\'st some reg'

'ular arguments '')"
for a do printf %s\\t%s\\n "Arg #$((i=i+1)):" "$a" ; done

'\''sine sgute in'''he
re and roundabouts here'''''
Arg #1: ju'st
Arg #2: some
Arg #3: reg

ular
Arg #4: arguments
Arg #5:

$ perl -MData::Dump=pp -E 'pp @ARGV' 'arg1' 'arg2' 'arg3' $'crazy \n argument "here", yep\n\nyeah!'
(
  "arg1",
  "arg2",
  "arg3",
  "crazy \n argument \"here\", yep\n\nyeah!",
)

or

$ perl -MData::Dumper -E 'say Dumper @ARGV' 'arg1' 'arg2' 'arg3' $'crazy \n argument "here", yep\n\nyeah!'
$VAR1 = 'arg1';
$VAR2 = 'arg2';
$VAR3 = 'arg3';
$VAR4 = 'crazy
 argument "here", yep

yeah!';

@mikeserv so indeed something a sane person would have done with Perl :-)

Hardly - that's a library function.

This is 6 lines that will work in any posix shell.

It's just printfs an arg list split on $IFS - it's not complicated.

sq it sh\'ell \'quotes\' its 'arg
array' for reinput to the shell

'it' 'sh'\''ell' ''\''quotes'\''' 'its' 'arg
array' 'for' 'reinput' 'to' 'the' 'shell'

No, it's not complicated per se. But I dare you to type it all from memory at 3AM when a system breaks. The perl ones, OTOH, are easy to remember.

(of course, for normal use, you can put it in a bashrc or whatever)

@derobert - that's probably true. That's why I saved it.

BTW: it has a bug, it fails to print a final newline...

anthony@Zia:~$ sq "\$foo"
'$foo' anthony@Zia:~$

@derobert - thanks - I think.

Is that a bug?

@derobert and you can put it in dashrc

@mikeserv Well, normally the default is to output the final newline. E.g, echo does (unless you tell it not to). So do almost all of the other shell utilities

I could just add an done && echo but I'm trying to remember why I didn't already...

I just added echo at the end (not even with &&), and it seems fine. Not sure why you didn't...

I know, but this is designed to produce output for eval. Still, I don't think it can hurt anything. It was important not to do it between args - so set -- can get them all. I probably just screwed up.

@derobert - agreed better that way.

Heh. Now we just need to wait for terdon to tell us how its broken. Or StéphaneChazelas to tell us how, along with a thorough (and yet somehow interesting) discussion of how the weird thing that breaks it originated from a typo dmr made back in the early 80s.

@derobert - anyway, its concept is really easy to remember: case "$var" in *\'*) printf \' ; IFS=\' ; printf "%s'\\\\''" ${var%\'*} ; printf \' "${var##*\'}";; *) printf "'%s'" "$var" ;; esac

Ok. That sounded better in my head.

but it is there.

I've only been able to find wierd --- but still correct --- output from it. E.g., sq \' gives ''\'''

Yeah - it seems like it should break - it's too easy.

It doesn't even recurse or anything.

Anyway, I like it, I'm going to have to steal it for my bashrc now :-P

It's especially useful like - set -- * ; sq "$@"

Or, just sq *, I guess.

I hardly ever use eval. I do my best to avoid it in sh, really.

Actually, looking in my vcs bin dir, the only shell scripts I have using eval is as the required part of getopt.

I do have something close though:

exec { 'script' } 'script', '-q', '-e', '-c', "mpv $arg", $fifo_name;

which is Perl calling script, and giving it a command to run.

That's a good philosophy - but it also works for { printf 'set -- ' ; sq * ; } >filelist ; . ./filelist

Yes - with fifo_name - what's in there?

@mikeserv $fifo_name contains the full path to a FIFO, the perl program reads that FIFO to see mpv's status messages.

@derobert "eval is evil"

?

@Braiam - I wholeheartedly disagree. It is dangerous. People that refuse to teach others how to use it are evil - they make it all the more dangerous.

@mikeserv that's the output-file-name argument to script. The command its running is mpv $arg, where of course $arg has already been escaped.

Cool. I'm trying to remember what mpv is. I keep coming back to music player daemon but that's just cause I'm stupid.

@mikeserv Its a fork of mplayer

@mikeserv that's not far from the truth

mpv.io

@Braiam - basically the function of this little function is the same as set or export -p.

@derobert - anything to recommend it over vlc?

BTW: bash_completion has a quote function that looks like this:

quote ()
{
    local quoted=${1//\'/\'\\\'\'};
    printf "'%s'" "$quoted"
}

@mikeserv I've always like the UI of mplayer variants greatly vs. vlc.

Yeah - that's their bash variable sed thing.

Yep. Pretty sure that's a bash-ism. Not a problem in bash-completion, of course.

And local. And a variable declare. It was important to me not to affect any state. Though I guess since I realized I did the whole thing in one sweep and put it in fn() ( subshell ) anyway I can now declare any vars I want in there.

BTW: there is already an sq command....

$ whatis sq
sq (1)               - squeeze or unsqueeze a sorted word list

But it was current shell for most of the 20 or so hours its been around.

Hmm. Ok. Then I need to _namespace it.

I shouldn't ever have much need to call on it interactively anyway.

It's purpose is kinda to be called from a function. Like saved=$(sq "$@")

Only if you have to target POSIX sh. Otherwise, just use bashisms for that.

????????????????

@ThatBrazilianGuy stat /home/user/Projetos/testecms/drupal

@derbobert - I write all of my own shell scripts with POSIX stuff and run them from dash. bash is slow - and it fucks up,

shrug, works well enough for the things I write. Of course, all my complicated stuff gets switched to Perl, so...

@derobert Oooops., just figured it out, I had inverted target and directory

I'm not as sophisticated - or educated. I stick to what I know and try to do it well.

Maybe I'll get there eventually.

@mikeserv, u r a genious

@Ramesh - perhaps. But also - and foremost - a hack.

correct?

@Ramesh ping does not operate on ports, it is an ICMP request, wheras ports are a concept of UDP and TCP

ICMP request type 8 is echo request, type 0 is echo response, which are used to implement ping

you could close all TCP and UDP ports, but if you are still configured to reply to ICMP echo requests, ping will still work.

likewise you could open all TCP and UDP ports, but disallow ICMP echo reply and ping wouldn't work but everything else would

all ping working means is that your router/firewall isn't dropping or ignoring ICMP echo requests. It tells you nothing about the availability of services running on TCP or UDP ports

(except that a positive ping reply lets you know the host is up; failure of a ping reply does not authoritatively tell you the host is down however)

In theory, ICMP is really a Layer 3 protocol

Don't mess it with TCP or UDP, which are Layer 4 protocol

meh, is probably his ISP or something that are listening on that port

^!!

@derobert though I am trying to learn the zsh way. I'm especially interested in zselect, zpty, zcurses, ztcp and friends.

I'd like to a whole screen/tmux type thing in native zsh script.

I've just gotta wrap my head around it.

@mikeserv I still haven't tried zsh.

Oh, it is a gamechanger.

But also...

I'm trying to get a line count of a set -x output just from drawing the prompt...

It's like 150 lines.

It's too smart for me though: echo | zsh -ix 2>&1 | wc -l gets no output.

@mikeserv Is it a gamechanger even if you don't use the shell very much?

@FaheemMitha - it's a shell gamechanger.

@mikeserv Ah

So... you know... one hand clapping or whatever.

Ah. It was way too smart for me - it stole the tty. All 8 times I tried it. I was just like 10 - processes deep.

sometimes zsh it too smart for its own good

i always have one of my terminals in a python virtualenv via workon research

and it will autocomplete research somehow

but then always ask me if I meant to type Research because I have a directory named that

though I can probably fix that in the zsh config... I'm too lazy to actually do it

@casey disable the ignore case for the autocoplete

@casey - I can sympathize. There are some 80 things I'd like to change in mine - but it's soo long.

@Braiam I should do that. there are other annoyances with that though. e.g. when I rename something test1 to test2 (did you mean test1?) or edit a new file closely named like that. When I get around to it i'll probably just turn it off

Especially that I hate hate hate the way it handles ! Dammit! Don't expand that 3 lines of sed into the last three lines of sed that I just fixed! It's even quoted, zsh - what the hell?

There's gotta be a simple fix. I'm almost motivated enough right now to find out how.

Hah, I've turned off !-completion in bash. !-completion is annoying.

@derobert - if you thought that sq thing was crazy, you'll love this: unix.stackexchange.com/a/145165/52934

But how did you do it?

I probably have to do it with zstyle or something.

That whole situation is intimidating.

@mikeserv Well, in .bashrc: set +H # disable evil ! completion ... but who knows about zsh

Can anyone figure out what OP wants? unix.stackexchange.com/questions/146362/… ... look at OP's comments, including the ones on the answers.

Hello

Just changed my question... hope is clearer now. unix.stackexchange.com/questions/146362/…

@derobert

Can you help me in one thing?

@Ty221 if I can, I will :)

Thank you.

I've just installed directx to wine

my os is debian'

Ihave installed eveything used winetricks

Now, dxdiag works, but GTA SA shows there is not directx

have you any idea?

@Con7e It really looks like those RFCs are what you're after, then. No idea why you first asked about how we'd explain it to a 4-year-old!

@derobert Probably I underestimated how much I understood...

@Con7e it doesn't sound like an answer explaining that the ssh client listens on port X, sends the data it gets on port X to the remote end, then the remote end makes a connection and copies the data would really be technical enough

@derobert Probably adding some wireshark output would help...

Wireshark output is pretty useless. You can't see anything interesting, since its encrypted inside the SSH connection.

Well, a before/after would be nice. I really love the picture that dude made about all the ssh options

Unfortunalty without a proper explanation they are kinda useless.

Like why did he put Localhost inside host

I looked at those pictures... and they take me a while to puzzle out what they're supposed to be showing. I think they're just not very good explanations

@Con7e that's an example of tunneling a connection to the remote machine's idea of 'localhost'

the remote machine is making a tcp connection to 127.0.0.1

which will of course mean its making a connection to itself

Oh

Well, I think that if someone replies with a thorough answer it would be good for the rest of the community

All the other answers on similar questions didn't satisfy me

I hope the bounty will bring more people

Well, the have any hope, there needs to be a clear way to answer that which is less than the 20-odd pages the RFC runs...

:)

"hey, machineB, could you send this data to machineC and tell me what it says in response? Thanks, machineA" is actually pretty close to what's technically happening

@Con7e I'm going to try another answer on it... maybe it'll turn out better...

:)

In the meanwhile I keep improving my question...

@Con7e Ok... the answer I was writing up doesn't answer the newest edit...

@derobert no pressure here :) I just want something that then can be referenced for future use. I am actually starting to collect more points so I can increase the bounty.

Hmmm... what to do with the half-written answer... hmmm... maybe save it for a blog post someday @strugee

Well, it's in blogoverflow now

do you know waht should I do?

@derobert :D Let me know the url

@Ty221 I'd say to ask the question on the site, but I'm not even sure which site you should ask that on...

@Con7e It won't have one until/if we decide to publish it. But if we do, it'll go up at unix.blogoverflow.com