Installing Linux

Security

Backing up

Applications and Utilities

Linux for Physics Majors

Printing

Linux on laptops or notebooks

General questions about Linux:
How can I ftp a large file without getting a "file too large" error?
How do I avoid getting large core files?
How do I find out the screen resolution?

Skype: microphone doesn't work

Questions:

ssh (secure shell)

General Questions:
How do I know if my password (/etc/passwd) file has been compromised?
How do I find all of the SUID and SGID files?
How can I tell if my machine has been cracked?
How can I automatically keep track of my system log files?

General Questions:
How do I set up passwordless RSA/DSA authentication with OpenSSH?

Here are the basic steps for DSA, which is relevant for ssh2 (which is what you should use!):

1. Set up a pair of keys (public and private) on one of your machines.

   ssh-keygen -t dsa

2. Copy the public key over to the any remote machines you want to access into the file ~/.ssh/authorized_keys2 (the 2 is for ssh2). (You can just append it to the end of the file.)

3. Protect the private key! IMPORTANT: You need to have the correct file protections on the ~/.ssh directory AND on the files. The ~/.ssh directory, the authorized_keys2 file, and the id_dsa file must be only accessible to you. These commands will do this:

  chmod 700 ~/.ssh
  chmod 600 ~/.ssh/id_dsa
  chmod 600 ~/.ssh/authorized_keys2

4. At this point, we still need to use the passphrase. If you check the second reference at the top, however, you'll find instructions for how to avoid typing the passphrase all the time.

2003-Apr-08 8:19am furnstahl.1@osu.edu

* the last field in a passwd entry is the shell. Nothing should have a shell except for root and any user accounts that you have set up (and possibly a database like postgres). These things have something else in that entry: sync (/bin/sync), shutdown (/sbin/shutdown), xfs (/bin/false).

* check the UID, which is the number in the third field (delimited by :'s). Only root should be UID 0.

* look for user names you don't recognize.

2000-Mar-23 9:19am furnstahl.1@osu.edu

   # find / \( -perm -004000 -o -perm -002000 \) -type f -print

* Look for /.bash_history linked to /dev/null
2000-Mar-23 9:31am furnstahl.1@osu.edu

Some steps in the installation:

  1. Change the protection of the log files so that they are
      only readable by root.

rdist

rsync

General Questions:

General Questions:

There is an rsync Faq-O-Matic (http://rsync.samba.org/cgi-bin/rsync.fom), with answers to many of your questions.

Rsync Tutorial: (http://everythinglinux.org/rsync/)

General Questions:
What is rsync?

rsync is a replacement for rcp that has many more features.

rsync uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync. It does this by sending just the differences in the files across the link, without requiring that both sets of files are present at one of the ends of the link beforehand. At first glance this may seem impossible because the calculation of diffs between two files normally requires local access to both files.
More info is available on the homepage (http://rsync.samba.org/rsync/) and the FAQ (http://rsync.samba.org/rsync/FAQ.html)

1999-Dec-27 9:03am furnstahl.1@osu.edu

Graphics

MySQL

Netscape

PDF

Printing

General Questions:

How do I synchronize my clock to a network (atomic) clock?

General Questions:
What are the available programs for making plots (graphics) in Linux?
How do I convert postscript to PDF for NSF proposals (on linux)?
How do I generate pdf output from LaTeX (including figures)?

Examples of graphs generated with xmgrace (postscript files converted to gif files):

* Diagram with shading </~ntg/examples/xmgrace/fermispheres.gif>
[input file </~ntg/examples/xmgrace/fermispheres.plot> ]

* XY plot with arrows and legend </~ntg/examples/xmgrace/fig_vt_ca40.gif>
[input file </~ntg/examples/xmgrace/fig_vt_ca40.plot> ]

* Log-log plot </~ntg/examples/xmgrace/delEoverA-CR.gif>
[input file </~ntg/examples/xmgrace/delEoverA-CR.plot> ]

2001-Sep-09 3:41pm furnstahl.1@osu.edu

  1. Make sure you have Ghostscript 6.0 or later 
        and tetex-dvips 1.0.6 or later.
  2. Make sure that any figure postscript files use Type 1 fonts only
      (I don't have a conversion plan yet if they don't!).
  3. To convert file.dvi to an appropriate file.ps:
       dvips -Ppdf -j0 -G0 -o file.ps file.dvi
  4  To convert the resulting file.ps (large!) to file.pdf:
       ps2pdf -dMaxSubsetPct=100 -dCompatibilityLevel=1.2 \ 
            -dSubsetFonts=true -dEmbedAllFonts=true file.ps file.pdf 

The general NSF instructions are: http://www.fastlane.nsf.gov/a1/pdfcreat.htm.
The Linux alternative to using Adobe Distiller on a PC is using the script ps2pdf, which runs Ghostscript to do the conversion from postscript to pdf. It seems to be essential to have up-to-date versions of ps2pdf and Ghostscript (at least 6.0) and tetex-dvips (at least 1.0.6). To check your versions (assuming they were installed from rpm's):

   rpm -q ghostscript
   rpm -q tetex-dvips

Here is what NSF has to say about Ghostscript: <http://www.fastlane.nsf.gov/a1/pdfcreat.htm#Ghostscript 6.0 or higher>
The recommended ps2pdf command is:

  ps2pdf -dMaxSubsetPct=100 -dCompatibilityLevel=1.2 \ 
      -dSubsetFonts=true -dEmbedAllFonts=true

It is important to configure dvips to use Type 1 fonts. The NSF instructions to do this are http://www.fastlane.nsf.gov/a1/pdfcreat.htm#DVIPS.
The basic trick for Linux is to use dvips -Ppdf. So to convert file.dvi to file.ps, use (the -j0 and -G0 options make sure that subsetting and character shifting are turned off):

   dvips -Ppdf -j0 -G0 -o file.ps file.dvi

I've tried this on Linux with Ghostscript 6.0 and it produces pdf readable by the Adobe acroread viewer (AND by xpdf) with what appear to be embeddable type 1 fonts (there is still a discrepancy I'm checking).

Ghostscript 6.0 rpms for Linux are available as ftp://ftp.cs.wisc.edu/ghost/aladdin/gs601/linux/ghostscript-6.01-1.i386.rpm and ftp://ftp.cs.wisc.edu/ghost/aladdin/gs601/linux/ghostscript-fonts-6.0-1.noarch.rpm (these links will no doubt be out of date by the time you read this; check http://www.cs.wisc.edu/~ghost/aladdin/ for the latest versions).

The ps2pdf page is http://www.cs.wisc.edu/~ghost/aladdin/doc/Ps2pdf.htm.

2000-Apr-21 3:25pm furnstahl.1@osu.edu

"Effective Scientific Electronic Publishing" at http://www.cl.cam.ac.uk/~mgk25/publ-tips.html

"Using LaTeX to Create Quality PDF Documents for the World Wide Web" at http://www.math.uakron.edu/~dpstory/latx2pdf.html

2000-Mar-30 8:25am furnstahl.1@osu.edu

A good discussion of options is a support page from the University of Minnesota http://www.msi.umn.edu/software/tex/help/pdf.html, which lists three possibilitiies:

 1. LaTeX -> dvips -> ps2pdf  [not recommended]
 2. LaTeX -> dvipdfm  [works with embedded eps figures]
 3. pdflatex [most reliable; requires conversion of [e]ps figures to postscript]

Find out more about dvipdfm at http://gaspra.kettering.edu/dvipdfm/. There are Linux RPM's available on this page.

2001-Oct-19 8:15am furnstahl.1@osu.edu

Answers in this category:
Where do I find documentation/tutorials for MySQL?

Of the books listed on http://www.mysql.com/portal/books/html/book-1-1.html, I can vouch for MySQL by Paul DuBois. Great book on MySQL and good details on using the database with PHP and Perl.

Of the articles listed on http://www.mysql.com/articles/index.html, I can vouch for "Building a Database-Driven Web Site Using PHP and MySQL," whic is concise yet very helpful.

2001-Sep-23 1:32pm furnstahl.1@osu.edu

General Questions:
How do I get rid of the Shop button in Netscape?
Why do apostrophes on some web pages appear as question marks in Netscape?
How do I get Netscape to automatically pop up gv (or ghostview) when I click on a postscript file?

           Netscape*toolBar.myshopping.isEnabled: false 

           Netscape*toolBar.destinations.isEnabled: false 
           Netscape*toolBar.numUserCommands: 1 
           Netscape*toolBar.userCommand1.commandName: findInObject 
           Netscape*toolBar.userCommand1.labelString: Find 
           Netscape*toolBar.userCommand1.commandIcon: Find 
           Netscape*toolBar.search.isEnabled: false 

           user_pref("browser.chrome.disableMyShopping", true); 

Answer 1:
It's people writing web pages with Windows software that uses the wrong character for apostrophes. Instead of the ' character, it uses a Windows specific character set that pretends to be iso-8859-X compatible but has characters in the "non printable control code" part of the ISO character sets. That's why you see them as question marks.

Answer 2 suggests sending a letter to the page owner:
Dear XXX:
In reading over your otherwise fascinating and useful website, I noticed documents that your web server alleges to be of content-type "text/html", but which in fact are not. The HTML standard uses the 8-bit ISO Latin-1 character set, but you include characters that are outside of that, such as those whose decimal values are in the 146-149 range. This renders your pages in an illegal, non-standard, proprietary HTML variant, and consequently illegible to millions of your readers.

I doubt your goal is to limit your audience, but this is what you have in effect done. My guess is that you are using an on-line publishing tool provided by Microsoft, or at least running on their systems. In so doing, you have unwittingly fallen prey to Microsoft's recently revealed stated goal of killing HTML by the "embrace/extend/extinguish" method. Illegal characters are just the start of these intentional incompatibilities. See http://www.fourmilab.ch/webtools/demoroniser/ for details.

2000-Mar-22 2:02pm furnstahl.1@osu.edu

  1. Under the Edit menu, select Preferences.
  2. When the Preferences window pops up, select Navigator (you need
      to click on the triangle to the left) and then Applications.
  3. You can scroll through the application list.  Find the one that 
      says "postscript document".  Click on it and push the "edit" button.
      (If there isn't one, choose "new" and fill in the info in step 4.)
  4. The information at the top should be something like:
        Description:  postscript document
        MIME Type:  application/postscript
        Suffixes:  ai, eps, ps
  5. Select "Handled by" and put 
             gv %s
      in the box (the %s passes the file to gv).
  6. Click ok until you're back to where you started!

Acrobat Reader ("acroread")

Answers in this category:
How do I read PDF files on a linux machine?

Answers in this category:
How do I set a default printer for Acrobat Reader (acroread)?
How do I make Acroread start up with a larger window?

To change your default printer to "/usr/bin/lpr -Psmith4035/duplex", which will print on the Smith4035 printer using duplex mode (this assumes you are using CUPS to print), add this line anywhere in your .Xdefaults file (which is just a text file):

  *acroread*lprCommand:/usr/bin/lpr -Psmith4035/duplex

A list of X "resources" (like *lprCommand) should have come with your Acroread installation. On my system, this file is:

  /usr/local/Acrobat5/Reader/intellinux/app-defaults/AcroRead

To adjust the default size of the window in which the text appears (which is called the "document shell", add these lines anywhere in your .Xdefaults file (which is just a text file):

   *acroread*documentShell.width:800
   *acroread*documentShell.height:950

If you're not sure what numbers to use, start up Acroread and manually resize the window to the size you want. Then, in a terminal window, type:

  xwininfo

A list of X "resources" (like *lprCommand) should have come with your Acroread installation. On my system, this file is:

  /usr/local/Acrobat5/Reader/intellinux/app-defaults/AcroRead

xpdf --- which should already be on your machine

acroread --- the official pdf viewer from Adobe.

 You can find RPM's from http://rpmfind.net/linux/rpm2html/search.php?query=acroread.

 To get acroread from Adobe and then set it up:
  1. Go to http://www.adobe.com/products/acrobat/readstep2.html 
      and choose "LINUX" as the platform under Step 1.  
      This will let you download 
      a 6MB "tarball" with a name like linux-ar-405.tar.gz.  
  2. Open the archive:
           zcat linux-ar-405.tar.gz | tar xfv -
  3. In some subdirectory like ILINXR.install you'll find an INSTALL script.
      Run it as root:
          ./INSTALL
  4. By default, acroread will be installed as
          /usr/local/Acrobat4/bin/acroread
     You will probably want to put a link in /usr/local/bin:
        ln -s /usr/local/Acrobat4/bin/acroread /usr/local/bin/acroread

General Questions:
How do I print to a remote printer?

On the machine hosting the remote printer, you need to add the names of machines allowed to print to the /etc/hosts.lpd file (you may need to create it). Just put one address (e.g., campbell.mps.ohio-state.edu) on each line.

2000-Mar-23 11:20am furnstahl.1@osu.edu

 * get a current ntp rpm (e.g., ntp-4.0.99k-4.i386.rpm)
    and install it
 * in /etc/ntp.conf, comment out the server entries and replace with
    local server ip addresses.  The lines (near the top) should be:
         #server 127.127.1.0     # local clock
         #fudge  127.127.1.0 stratum 10
         server 128.146.37.10
         server 128.146.38.12
 * make sure that /etc/rc.d/init.d/ntpd points to the correct function
    library (/etc/rc.d/init.d/functions instead of /etc/rc.d/functions).
    This may be distribution/version dependent.  Just check that it points
    to the correct place.
 * /etc/rc.d/init.d/ntpd restart   
 * check /var/log/messages to see if it is working

What is Linux?

What is Linux used for?

How Do I Use Linux?

Answers in this category:

Answers in this category:
Is Linux an application like MS Word?
What's the difference between Linux and other OS's?
What distribution of Linux do we use?
So what's the deal with all the different distributions of Linux?
How do I pronounce 'Linux'?

Answers in this category:
What's the difference between Linux and MS Windows (NT, 2000, 9x, etc.)?
What's the Difference Between Linux and Windows NT/2000

Answers in this category:
What's the Difference Between Linux and Windows 9x?

On the downside, Windows has a tendancy to crash. It does not respond quickly to users who find bugs. It often has problems with networking even when putting a 98 machine into a 2000 network.

Linux is gaining popularity and more applications are becoming available for it. There are a couple of popular GUI's (Graphical User Interfaces) available for Linux which make it similar to using Windows. Linux is considered to be more stable than Windows; it rarely crashes. Networking is one of its greatest strengths. Bug support is often found and corrected quickly by the large number of developers who form the Linux community. Also, Linux uses the entire x86 processor and many applications run faster on Linux than on other OS's.

On the other hand, Linux is best used by learning some Unix commands and using a command line interface now and then. As an OS for hackers, there may be a better turn around time for support, but it also requires a certain amount of desire to learn.

If you don't mind tinkering, exploring, and learning and are willing to put up with developing issues, Linux might be for you. On the other hand, if you would prefer a simple OS and don't mind the occasional crash or the fact that bugs will take longer to iron out, Windows might be your cup of tea.

The methods used to do these things are different in the different operating systems. It should be noted however that the stability of Linux has convinced many people to use Linux for the server of a network of Windows machines. This is often accomplished through use of a program called Samba.
Thus the network gains stability and ease of modification while the users are able to use a familiar operating system.

Answers in this category:

Quite simply, this is the result of the "open source" and "free software" movements. The Linux kernel is distributed by such companies as Debian, SuSe, and Red Hat and they sell it with a number of applications and technical support. The GNU Public License says that people are perfectly free to do this as long as they realize that other people may sell the exact same kernel for less or even nothing. In fact, it is quite easy to get the Linux kernel for free. Remember however that it will not necessarily come with any sort of guarantee or technical support like ones from major companies.

The networking aspects of Linux are especially of interest to many big businesses and scientific communities. It is easy to log in from remote machines, share files, and run remote applications. It is easy to program on Linux in a variety of languages, and text editing with the TeX language is often done using Linux.

What application should I use?

Answers in this category:

Answers in this category:
What do you have similar to MS Office?
What do you have similar to Photoshop?
What would I use to write a program?
What would I use to write a scientific paper?
What would I use to solve a mathematical problem?

There is a caveat, however. While there seems to be little to no problem reading items which were written in MS Office applications, there is a definite problem writing to a format that is readable by MS Office. Still, as long as you are not attempting to switch formats, KOffice is a very good application.

The GIMP can be used as a paint program, to edit photos, change formats of images, and batch processing among other things.

Another application used on Linux is caled ImageMagick. ImageMagick is actually a suite of tools and applications run from the command line. To run a graphical front end to ImageMagick, type the command 'display'. ImageMagick is considered to be extremely flexible by its proponents. It does, however take some time to become used to and acquainted with the many command-line options.

If on the other hand you are using the GUI, click on the start application button (it's a "K" for KDE and a foot for GNOME). From there go to Applications and select Emacs.

Mathematica is a very powerful tool which can be used to solve mathematical problems of course, but since it has mathematical symbols and notation and since it is very good at producing graphs, figures, and images, it is often used to write scientific papers. It has the entire text of the handbook in the help file so it is relatively easy to use.

LaTeX is a language whose syntax is similar to HTML. It is used to format text and can produce results of publishable quality. In fact, most papers in the serious scientific journals are produced using LaTeX or a version thereof. A good reference for LaTeX is A Guide to LaTeX 3: Document Preparation for Beginners and Advanced Users, by Helmut Kopka and Patrick W. Daly.

groff is a text processing system in the same vein as LaTeX. It is used to make the same types of documents for the most part. However, groff is better for producing documents which will be viewed online. This is because LaTeX is unable to produce plain-ASCII output while groff excels at this. Hence, groff is often used to write and to edit man pages.

You can access that application by typing 'mathematica' on your shell console screen. If you merely want to run the kernel, simply type 'math' instead of mathematica. For more information on running Mathematica, check the FAQ-O-Matic entry, go to www.wolfram.com, or read the help file in the application.

I should also let you know that there is a wonderful tutorial on Linux at www.linux.org/lessons/ which goes through many of the important functions and commands in Linux.

Later, you can explore the GUI environment which is made to be familiar to Windows and MacOS users.

Ready? Set? Here we go!

Answers in this category:
How Do I use the Command Line Interface?
How do I use the GUI (Graphical User Interface)?

You should see something to the effect of [yourname@arran ~]$. You are now at the command line.

What if I don't remember what command to use?

What is a shell and how do I use it?

How do I control printing on Linux?

What is job control?

Answers in this category:
How Do I Access My Files?
How do I change directories?
How do I copy/move/rename a file?
How do I change my password?
How do I shut down Linux?
How do I suspend/kill jobs?

Answers in this category:
What is the "man" command?
What is the "apropos" command?

The "man" command. Live it, learn it, love it!

The shell is a program that reads and executes user commands. It controls which processes get run and at what time. Much of flexibility (and the fun) of Linux comes from the ability to write programs called "shell scripts" to customize your workspace.

There are many different shells available for Linux. They include but are not limited to: C shell, the Bourne Again shell, Z shell, and the Korn shell.

Answers in this category:
Which shell should I use?
How do I change shells?

On the other hand, another popular shell is bash or the Bourne Again shell. Tcsh and bash have many similar features such as job control, command history, and filename completion. They differ in syntax and commands.

A poll of the shells of preference for the Physics Computer Facility reveals that variety is the spice of life. Each person has a different favorite. Bash, zsh, and tcsh seem to be the three favorites. Each offer similar ways to do the same jobs.

There are many good books on shells available. I recommend any published by O'Reilly. Check out http://www.oreilly.com. Also,the university offers a class on shell programming under the CIS dept.

Let's suppose that you want to learn a bit of bash. Just type 'bash' at the command prompt; you'll be in the bash shell! To switch back to your original shell, just type 'exit'. Feel free to explore shells to your heart's content!

Answers in this category:
How do I control which printer gets my print request?
How do I see which printer is the default printer?
How do I change the defaul printer selection?

     export PRINTER = name

Different shells will have different syntax so if you are unsure which command to use, check with your systems administrator or use a text shell scripting which applies to your shell.

To bring the job back to the foreground, type 'fg %1' or 'fg 10500'. Job numbers always take %. To stop the background job, you can type 'kill %1'.

A listing of the files and folders in your current directory will appear on your screen. There are several subcommands you can add to 'ls' to make it even more useful. Two of the ones I use the most are '-a' and '-l'. They stand for 'all' and 'long' respectively and the syntax would be 'ls -a' or 'ls -l'. The all command will show the hidden files in your directory. The long gives more information about the files and folders you can see. I'll get back to both of these concepts later.

What if I want to write something?

Answers in this category:

Answers in this category:
Yeah, that sounds like what I want! Tell me more about text editors!

Linux comes with several types. Emacs, vi, pico, and joe are a few of the more popular ones. Emacs and vi are the most commonly used among these four. Simply type which one you want to use and the name of the file you are writing, and you will be all set. For example, you can type 'vi bob' and you would thus commence working on a file called bob in the vi text editor.

For more information on any of the above, consult the man pages. Also, emacs has a handy tutorial available in its program. Simply type 'Ctrl-h' for the help menu then type 't' to go to the tutorial.

Desktop, public_html, and homework are directories in this case. We can go into public_html by typing 'cd public_html'. If you want to go back to your previous level, simply type 'cd ..'.

This is all nice and good if you are only going up and down one level at a time, but there will be times whem you want to make bigger leaps. If you happen to know the exact address, you can specify it. For example, you could type 'cd /net/campbell/01/your_name/homework/quantum' to take you to the quantum directory in your homework directory in your home directory. The first "/" takes you to the root directory and everything else specifies where to go from there.

Hence, if you want to simply go to the root directory, you can type 'cd /' and you'll immediately go there.

Now suppose with all of this bouncing around and changing directories, you've forgotten where you are working. This can be an important thing to know after all. All you need to do is type 'pwd' for "print working directory". It's like having your very own GPS!

Answers in this category:
How do I copy a file?
How do I move a file?
How do I rename a file?

Be careful though. If something is already at the location "filename_2", it will be overwritten without warning!

The format for the two commands are as follows:
cp filename_1 filename_2
mv filename_1 filename_2

In either case, you simply put the new name in the place of "filename_2". cp will have the result of keeping a copy of your old file while mv will move the file to the new address and delete the old copy.

For the record, you should choose a password that is a combination of lower and uppercase letters. Throwing in a few numbers is a good idea too. Don't use whole words. Not even in other languages. You never know who might try to compromise the security of a network.

Know which computer it is (the name of the Linux boxes is written on the machines beneath the CD-ROM drive. It will be either ARRAN or MULL followed by mps.ohio-state.edu). You should also be able to describe the problem precisely and be able to tell us what you were doing when whatever problem you are having occurred.

If you are using a version of Linux at home, check the documentation which came with your computer.

To suspend the job, type 'Ctrl z'. To kill it, type 'Ctrl \'.

Answers in this category:
Which GUI should I use?
How do I create a shortcut on my desktop?
Where else can I turn for help?

GNOME is part of the GNU project. It stands for GNU Network Object Model Environment. You can see more info about them at http://www.gnome.org/. It seems to aim for good looks and maximum configurability. We have experienced some crashing problems with GNOME, however, so be warned.

KDE on the other hand is more stable. KDE stands for K Desktop Environment. It is easy to use and strives to make users coming from Windows feel right at home. You can see more info on KDE at http://www.kde.org/.

The Physics Computer Facility recommends KDE for your choice of GUI. Subsequent answers will assume use of KDE.

Hence, if you wanted to create a shortcut to Mathematica on your desktop, you would type 'ln -s mathematica Desktop/Mathematica'. This would create a symbolic link called Mathematica in the Desktop folder. A graphical shortcut will appear on the desktop.

Answers in this category:
Downloading and installing CUPS

Download the latest CUPS rpm from RedHat and install it similarly to this:

  rpm -Uvh cups-1.1.9-linux-2.2-intel.rpm

(you might need the `--force' option also, if it complains of
conflicts with lpd files)

Get the local config files:

ftp://ftp.physics.ohio-state.edu/pub/linux/cups-1.1.9-config.tgz

Replace the config files to talk properly to the local server:

  cd /etc/cups
  tar zxvfp /whatever/path/cups-1.1.9-config.tgz

Edit /etc/cups/lpoptions to change the Default entry to a printer of
your choice.  This will become the default printer for anyone on this
particular host.

Make sure cupsd isn't running (you don't need it, and every daemon 
you don't run helps reduce your security vulnerability):

  /etc/rc.d/init.d/cups stop
  /sbin/chkconfig -level 0123456 cups off

That's it.  Wait 30 seconds or so, and type 

  lpstat -p

to see a list of printers.

To change the system default printer, as root type

  lpoptions -d printername

For documentation, see http://lpd.physics.ohio-state.edu:631/documentation.html

The Linux Laptop HOWTO <http://www.mobilix.org/howtos.html (which is now called the Linux-Mobile-Guide), is also worth checking out.

Answers in this category:
How do I restore my network connection after a suspend/restore?
How do I keep my laptop from freezing or otherwise screwing up when I suspend?

For example, I changed

 PCMCIARESTART="no"

 PCMCIARESTART="yes"

To start up the pcmcia card by hand, use (as root):

  /etc/rc.d/init.d/pcmcia restart

You can see and change your filesize limit and other limits. The command will depend on the shell you use.

If you use tcsh, then the "limit" command gives the info:

  ==> limit
  cputime       unlimited
  filesize      50000 kbytes
  datasize      unlimited
  stacksize     8192 kbytes
  coredumpsize  1000000 kbytes
  memoryuse     unlimited
  descriptors   1024 
  memorylocked  unlimited
  maxproc       256 
  openfiles     1024 

  ==> limit filesize 1000000

If you use bash, then the corresponding command is "ulimit -a" (the "-a" is for "all").

  [furnstah@ntg4004 furnstah]$ ulimit -a
  core file size (blocks)  1000000
  data seg size (kbytes)   unlimited
  file size (blocks)       50000
  max memory size (kbytes) unlimited
  stack size (kbytes)      8192
  cpu time (seconds)       unlimited
  max user processes       256
  pipe size (512 bytes)    8
  open files               1024
  virtual memory (kbytes)  2105343

  [furnstah@ntg4004 furnstah]$ ulimit -f 1000000

You can see and change your core file size limit and other limits. The command will depend on the shell you use.

If you use tcsh, then the "limit" command gives the info:

  ==> limit
  cputime       unlimited
  filesize      50000 kbytes
  datasize      unlimited
  stacksize     8192 kbytes
  coredumpsize  1000000 kbytes
  memoryuse     unlimited
  descriptors   1024 
  memorylocked  unlimited
  maxproc       256 
  openfiles     1024 

  ==> limit coredumpsize 0

If you use bash, then the corresponding command is "ulimit -a" (the "-a" is for "all").

  [furnstah@ntg4004 furnstah]$ ulimit -a
  core file size (blocks)  1000000
  data seg size (kbytes)   unlimited
  file size (blocks)       50000
  max memory size (kbytes) unlimited
  stack size (kbytes)      8192
  cpu time (seconds)       unlimited
  max user processes       256
  pipe size (512 bytes)    8
  open files               1024
  virtual memory (kbytes)  2105343

  [furnstah@ntg4004 furnstah]$ ulimit -c 0

  $ xdpyinfo | grep resolution

  $ xdpyinfo | grep dimensions

General Questions:

Second, run alsamixer in a terminal window. Make sure the gain for the Mic is a reasonable level, and it is set for capture (space). Also, make sure that Capture is set to a reasonable level, and is also set to capture (!). Don't see Capture? That's because it's to the right, off of the screen. Keep using right arrow until you find it.

2007-Jan-10 2:04pm bcd@pacific.mps.ohio-state.edu