# More 2¢ Tips!

Send Linux Tips and Tricks to linux-questions-only@ssc.com

- Tweaking the wily interface
- Clipping URLs
- w3m to access CUPS configuration utility
- Imagem linux_logo.h na Inicializacao do linux
- partial answer to euro-symbol question
- PPP
- Mouse control in X
- Re LG 77: More on NET4
- partition overlap = bad juju
- Re LG 77, wanted #1: private email
- RPMs
- Re LG 77, wanted #5: serial programming: toys.
- Re LG 77, wanted #5: serial programming: a guide.
- subsystem sftp
- some email related problems
- Linux Red Hat 6.2 Unistallation
- Make sure sshd is "always" there for you
- LJWNN tech tips
  - Python recursion limit
  - Ssh2 client to ssh1 server
  - Making executables smaller
  - Headphone volume control
  - subscribe to Linux Journal's Weekly News Notes

### Tweaking the wily interface

Thu, 11 Apr 2002 00:39:48 -0400
Ben Okopnik (The Answer Gang)

Well, I found a solution - but that solution is part of a package that's interesting for more reasons than one. AccessControl, a package of useful tweaks designed to help folks with disabilities, had what I needed and more, along with a control panel that pulled it all together (of course, the individual utilities could still be used as stand-alone programs.) It's available at <http://cmos-eng.rehab.uiuc.edu/accessx/>.

Interestingly enough, Dan Linder (the author) says that a similar panel has been incorporated into X11R6.6 - a Very Good Thing, in my opinion. However, for those of us who'd like (or need) a bit more control over our keyboards, mice, display, etc. and are not willing to chase the bleeding edge, this package can be a useful tool in the sometimes confusing "battle of the interfaces".

### Clipping URLs

Mon, 8 Apr 2002 13:02:20 -0400
Ben Okopnik (The Answer Gang)

After going back to my tried-and-true "icewm" (KDE was just too bloated for my 366MHz/64MB laptop), I gave a bit of thought to "URL clipping", which - if not over-automated - could be a handy feature indeed. Then, I remembered the "xclip" utility.

See attached `clipurl.bash.txt`

All that was left was tying "clipurl" to a key sequence in "icewm". To do that, I simply added the following line to my "~/.icewm/keys" file:

>     key "Alt+Ctrl+u" clipurl

Now, when I select a URL and want to launch it, I press "Alt-Ctrl-u", and - presto! A new Netscape window pops up (if Netscape is already running, it spawns a new one). It also works for files in your home directory, or "clips" that contain the entire path as well as the filename.

One of these days, I might write a little "chooser" for "ftp://", etc. URIs... but so far, it hasn't been a problem.

### w3m to access CUPS configuration utility

Thu, 18 Apr 2002 00:34:16 -0700
Steven R. Robertson (srobert from anv.net)

My tip concerns the CUPS configuration utility that is accessed through the webbrowser at http://localhost:631/

My default browser, galeon, takes awhile to start on my machine. If all I want to do is run the CUPS interface to change a printer parameter, then it's much quicker to call it up with the w3m webbrowser in an xterm. Though text based, w3m even supports inline images. I put a "printer" button on my gnome panel that launches the following command when pressed:

>     "xterm -title CUPS -bg black -fg white -geometry 110x46+240+50  -fn 7x14 -e w3m http://localhost:631/printers"

Steve Robertson

### Imagem linux_logo.h na Inicializacao do linux

Wed, 17 Apr 2002 10:40:44 +0100
Heather Stern (LG Technical Editor)
Translated by Pedro Medas (editor from gazetadolinux.com)
Question from Alfredo Guimaraes Neto (alfredogn from bol.com.br)

Hi,

I'm the editor of the 'Gazeta do Linux', the portuguese version of Linux Gazette. We received the attached email with a question for you from Alfredo Guimaraes Neto.

Cheers, Pedro Medas

Ola,
Gostaria de saber se voces teem um tutorial de como mudar a imagem de inicializacao do linux, aquele pinguinzinho com um copo de cerveja, pois tentei varias vezes e estou com dificuldades, quando mando compilar o kernel, da sempre erro nesse arquivo.

Grato, Alfredo

Hi,

I would like to know if you have a HOWTO to change the boot image of linux, that penguin with a beer cup, I tried several times and I'm having difficulties, when I try to compile the kernel, it reports always the same error.

Greetings,
Alfredo

Thank you Pedro. I have an answer for him. If you would be kind enough to translate it back I think he'd appreciate it. -- Heather

Hi Heather,
Thanks for the answer to the 'Two Centavos Tip'. I will translate it for him.

If you need any more info or help feel free to say so.

bests,
Pedro

> Not precisely a HOWTO, but actually useful instructions, are at the Linux Kernel Logo Patch Project: http://www.arnor.net/linuxlogo/download.html

> Apparently you are not the only one in the world who is inclined to change the boot logo, but finds it hard to figure out where you would tweak the kernel code to use your own. So these people have a patch that makes it easy for everybody, not just kernel-hackers, to put in a new image.

> I think they're looking for help on getting the non-intel platform logos right.

> For my own part, I like it, I think I'll be using it soon myself!

### partial answer to euro-symbol question

Mon, 1 Apr 2002 15:38:48 +0200 (MEST)
rene.leeuwen (rene from wxs.nl)

Hi Mailgang,

Concerning the question of Donal Rogers (rogers from clubi.ie) in the Mailbag of LG76 I found the following in: http://users.pandora.be/sim/euro/112/kde/kbdandbdf.html http://www.interface-ag.com/%7Ejsf/europunx_en.html

So: you may start a new xterminal screen with the Euro-enabled font:

>     xterm -fn -misc-fixed-medium-r-normal--13-120-75-75-C-70-ISO8859-15 &

In this terminal you can use the Euro-symbol (eg. echo -e "\244"). The question I cannot answer is: how do you force all of your applications to use this font (if indeed that is the best solution). But I hope it gives you something to start working with.

-- groeten,
Rene van Leeuwen

### PPP

Sun, 7 Apr 2002 23:40:06 -0400
Ben Okopnik (The Answer Gang)
Question from cka74 (cka74 from yahoo.com)

Hi,

Please kindly advise me on PPP.

I'm using RedHat 7.2, somehow I having difficulties in getting the modem setup and recognized.

I compiled the new kernel with PPP add-on: Network Device Support -> (Y) PPP Support -> (Y) PPP Support for async serial ports

1. My external modem was connected to com1, so when I echo > `/dev/ttyS0`, my TR on modem get lighted.

2. I set; setserial -g `/dev/ttyS0`, it shows: `/dev/ttyS0`, UART: 16550A, Port: 0x03f8, IRQ: 4

> OK - those numbers look fine, and the above test says that you're definitely on the right port.

I ensured that IRQ 4 is not used by other program by cat `/proc/interrupts`

3. When I performed; wvdialconf `/etc/wvdial.conf`, the results show ttyS0 modem was not found.

I tested out on 2 external modems, same problem arise. but of course my both modems (one of them was MERZ 566) were in working condition.

Where did I went wrong?

> As far I can tell, you didn't; "wvdialconf" does not guarantee to detect all modems. Try using "minicom" to test it: do the serial port setup (it's pretty self-explanatory) and see if the modem will respond to simple commands like "AT" (it should come back with "OK"), "AT&V" (show the profiles), "ATDT5555555" (dial those numbers), etc. If it responds, just use those values in your "`/etc/wvdial.conf`", and everything will be fine.

### Mouse control in X

Tue, 9 Apr 2002 03:40:43 -0400
Ben Okopnik (The Answer Gang)

>     xmodmap -e "pointer = 1 3 2 4 5"

If that works for you, you can place the expression (the part between the double quotes) in a ".Xmodmap" file in your home directory - or launch it directly by specifying the entire command line in your "~/.xinitrc" or "~/.xsession" file, depending on how you start your X session.

### More on NET4 (from LG 77, 2 cent tips)

Wed, 3 Apr 2002 07:07:38 -0600
Brian Finn (brian from nacmsw.com)
replying to Chris Gianakopoulos' previous Tip

Hi,

In the 2 cent tips from LG 77, Chris Gianakopoulos writes:

> "It is my belief that Net4, although it may be influenced by other protocol suites, was written from scratch (other han being derived from NET3.)"

I read recently in Linus Torvalds' "Just for Fun" (and again in in Glyn Moody's "Rebel Code") that the TCP/IP implementation in Linux was written from scratch in order to avoid being hassled by AT&T, who owned UNIX at the time. I suppose AT&T was using their legion of lawyers to go after other UNIX implementors for royalties.

Thanks,
Brian Finn

> Hi Brian,
> That makes sense. I've read somewhere that the book, "The Design of the Unix Operating System" by Maurice Bach, influenced Linus Torvalds with respect to his Linux stuff. The book described the algorithms of System V Release 2. Of course, other stuff influenced him also. Thanks for that info, Brian.

> Regards,
> Chris G.

### partition overlap = bad juju

Fri, 12 Apr 2002 01:30:51 -0400
Frank Brand (fbrand from uq.net.au)
replying to the Gang's previous Thread

Hi there Ben,

I am responding to you as you were first on the list of answer people:-

I refer to "ntfs clobbered my ext3fs!!" in Linux Gazette 77 in which the questioner asks about a partition overlap.

I have encountered this twice. Both times it has been with a mixed Windows/Linux drive and using automated partitioning (ie Disk Druid or DiskDrake). Your questioner has exactly this scenario.

Now, I never use automated partitioning and I partition the drive using parted before I start the installation. I use primary partitions where possible and avoid mixed Windows/Linux disk setup.

I have experienced the overlapping partition syndrome and have found it very difficult to overcome. I have not been able to sort it out using fdisk as either Linux or Windows fdisk can not do anything to such corrupted partitions. I have only been able to recover using disk manager software and this was a destructive recovery.

Regards
Frank Brand

### Re: [LG 77] help wanted #1 private email

Wed, 3 Apr 2002 09:00:37 +0100
Neil Youngman (n.youngman from ntlworld.com)

Hi there

I would like to know how to set up my email on my home network with win98 outlook express and Linux.

I would like to set it up so that I can email anybody else in the house on the network and email via the internet when needed.

Thank You
Cheryl

> There are a couple of linuxWorld articles describing Nicholas Petreley's setup, which may be suitable for you requirements.

> http://www.linuxworld.com/site-stories/2002/0318.ldap1.html
> http://www.linuxworld.com/site-stories/2002/0401.ldap2.html

### RPMs

Thu, 25 Apr 2002 07:06:04 +0100
Neil Youngman (n.youngman from ntlworld.com)
Question from Lord of Wolves (Lord0Wolves from aol.com)

Simple question: What is a ".RPM" and how do I use them. I assume they are a type of compression file, but what do I need to use them.

> RPMs are RedHat Package manager files. They contain the necessary files for a package, including setup scripts to be run pre- and post-install. They also have a list of dependencies, so they can determine whether you have installed the other packages on which this one depends.

> Simple usage

>     rpm -Uvh pkg.rpm	# install package from pkg.rpm
>     rpm -Fvh pkg.rpm	# freshen (update) package from pkg.rpm

> In both the above examples v is verbose and h is using a hash mark progress indicator.

> For examples of other usages see
>   http://www.getlinuxonline.com/omp/distro/RedHat/rpm.htm

> Neil Youngman
> P.S. If you're asking questions of this list, please turn off MIME and HTML.

### Re: [LG 77] help wanted #5 serial programming

Wed, 03 Apr 2002 22:54:48 -0500
Gary J. Wozniak (gjwoz from 110.net)

Hi,

Check out www.linuxtoys.com. This site has some great examples of how to read/write form serial ports in linux.

The

Radio Shack DVM with RS-232 <http://www.linuxtoys.com/dvm/dvm.html>;

article was of particular use for me.

Good luck,
G Wozniak

### Re: [LG 77] help wanted #5 serial programming

Wed, 10 Apr 2002 14:35:24 +0200
Matthias Prinke (matthias.prinke from sci-worx.com)

Hi,

check out the Serial Programming Guide for POSIX Compliant Operating Systems at http://www.easysw.com/~mike/serial You can find the answer in chapter 4.

Best regards,
Matthias

### subsystem sftp

Mon, 8 Apr 2002 18:27:59 -0400
Ben Okopnik (The Answer Gang)
QUestion from Francoise Guilbault (guilbaultf from em.agr.ca)

Why when starting SSH client does a subset of sftp open up in the background by default?

> Take a look at the last line of your "`/etc/ssh/sshd_config`":

>     Subsystem	sftp	/usr/lib/sftp-server

> Also, from "man sshd":

>     Subsystem
>        Configures an external subsystem (e.g., file transfer daemon).
>        Arguments should be a subsystem name and a command to execute
>        upon subsystem request.  The command sftp-server(8) implements
>        the "sftp" file transfer subsystem.  By default no subsystems
>        are defined.  Note that this option applies to protocol version 2
>        only.

> I find the next-to-the-last sentence very interesting... on Solaris, for example, it's defined but commented out. On Debian Linux, it's defined and enabled by default. I suppose you could turn it off by commenting out the line, but I'd make absolutely certain that I didn't have any need for it first.

### some email related problems

Wed, 3 Apr 2002 18:40:17 +0100
Neil Youngman (n.youngman from ntlworld.com)
Question from amitava maity (amaity from vsnl.net)

Hello everybody,

I have emails with a MS-TNEF file and a humor.mp3.scr file as attachments waiting in my inbox. How do I view/listen to these attachments?

> You really don't want to open humor.mp3.scr. That's the Badtrans virus! Fortunately, as a linux user you're immune

> See http://vil.nai.com/vil/content/v_99069.htm for more info.

> Neil Youngman

> As a general point, anything which has two whole three letter extensions (.jpg.pdf, .mp3.scr, and so on) especially when the second is one that may be reasonable to auto-view, you should be immediately suspicious that it's probably a virus. The same goes for MIME types which represent auto-view type files but which do not match the extensions given on the attachment (e.g. audio/wav but the attachment says .jpg).
> However, there are 4 or 5 different small utilities that will deal with a true "TNEF" attachment, easily found at freshmeat.net -- Heather

### Linux Red Hat 6.2 Unistallation

Fri, 12 Apr 2002 01:46:11 -0400
Ben Okopnik (The Answer Gang)
Question from Alok Garg (aalugarg from yahoo.com)

On Fri, Apr 12, 2002 at 06:02:39AM +0100, Alok Garg wrote:

Hello Sir,
I have 2 HDD of 20 Gig each, on the Primary drive I have WinNT and on the secondary I have Linux RH 6.2 I wanted to uninstall Linux from the system without effecting my data on Win NT. I wanted to move my secondary drive to other machine.

I'm sorry, but that's impossible. Removing Linux from your machine would utterly destroy (beyond any hope of recovery) the data on every WinNT machine in a 60-mile radius of where you are. Note that everybody will know exactly who is responsible: you'll be left in the center of a large charred circle. Even if you removed the HD with Linux and carried it off, as soon as you erased it, your NT would know.

It all happens magically, really.

(HINT: There's no magic. NT may be evil, but it does not watch your Linux drive and explode if anything changes.)

See <http://www.linuxgazette.com/tag/kb.html#uninstall> for tips on uninstalling Linux.

### Make sure sshd is "always" there for you

Mon, 29 Apr 2002 19:16:33 -0700
James T. Dennis (The Answer Gang)

Make sure sshd is "always" there for you.

Using OpenSSH (circa 2.95 or later?) you can configure the sshd to run directly from your `/etc/inittab` under a "respawn" directive by adding the -D (don't detach) option like so:

>     # excerpt from /etc/inittab, near end
>     ss:12345:respawn:/usr/sbin/sshd -D

This will ensure that an ssh daemon process is always kept running even if the system experiences extreme conditions (such as OOM, out of memory, overcommitted memory) or a careless sysadmin's killall which kills the running daemon. So long as init can function it will keep an sshd running (just as it does with your existing getty processes).

This is particularly handy for systems that are co-located and which don't have (reliable) serial port console connections. It just might save that drive across town or that frustrating, time consuming and embarassing call to the colo staff, etc.

### Linux Journal Weekly News Notes tech tips

####
Python recursion limit

If Python's built-in recursion limit keeps your incredibly cool recursive function from working, you can temporarily set a different recursion limit with the sys module.

>     oldlimit = sys.getrecursionlimit()
>     sys.setrecursionlimit(len(big_hairy_list))
>     incredibly_cool_recursive_function(big_hairy_list)
>     sys.setrecursionlimit(oldlimit)

####
Ssh2 client to ssh1 server

If you have an account on a system where only your ssh1 key is installed in your authorized_keys file, you can force your ssh connection to use version 1 of the protocol with ssh -1 example.com.

Then you can use scp with the -1 option to transfer your ssh2 key there, so that you can use version 2 to connect from now on. Paranoid sysadmins are turning off version 1 access, so you should be using version 2 everywhere by now to be on the safe side.

####
Making executables smaller

To make executables smaller, try running strip(1) with the options -R Comment -R Note. This removes "comment" and "note" sections that the compiler and linker may have added during the build process.

(source: MontaVista Software's MontaVista Zone customer support site.)

####
Headphone volume control

If you're running your headphones straight out of your sound card's "Line out" jack, you might notice there's no volume control. Instead of trashing your ears or firing up a audio mixer every time you need to set the volume, just bind the commands

> `
> aumix -v+4 # crank up the volume!`

and

> `
> aumix -v-4 # turn that crap down!`

to two spare function keys. (In Sawfish, this is under the "Bindings" menu in the sawfish-ui program.) Presto--free and easy volume control straight from the keyboard.

There are also nifty little volume control applets for the KDE and GNOME taskbars, but why spend pixels on a common task when you have all those keys just sitting there?

##### This page edited and maintained by the Editors of Linux Gazette Copyright © 2002
Published in issue 78 of Linux Gazette May 2002

###### HTML script maintained by Heather Stern of Starshine Technical Services, http://www.starshine.org/