  Configuration HOWTO
  By Guido Gonzato,  <guido ``at'' ibogeo.df.unibo.it>
  v1.3.7, 6 September 1999

  This HOWTO aims at making the fine--tuning of your newly installed
  Linux box quicker and easier. Here you will find a set of configura-
  tions for the most common applications and services.
  ______________________________________________________________________

  Table of Contents
























































  1. Introduction

     1.1 Why This HOWTO
     1.2 What We Will Be Configuring

  2. General System Setup

     2.1 A Few Words About Security
     2.2 Start the Logbook!
     2.3 Keyboard
     2.4 Boot and Rescue Floppy
     2.5 Kernel Matters
     2.6 Sendmail Lock
     2.7 Hard Disk Performance
     2.8 Parallel Port Zip Drive
     2.9 Device Drivers
     2.10 Sound Card
     2.11 Login Messages
     2.12 Hostname
     2.13 Mouse
     2.14 Mount Points
     2.15 lilo(8) and LOADLIN.EXE
        2.15.1 Security Tip
     2.16 Mail Capabilities
     2.17 Printer Configuration
     2.18 SVGATextMode

  3. Common Administration Tasks

     3.1 Network configuration
     3.2 Sharing the Internet
     3.3 Restricting Network Access
     3.4 NFS Exports
     3.5 Name Server

  4. Software Configuration

     4.1 bash(1)
     4.2 ls(1)
     4.3 less(1)
     4.4 emacs(1)
     4.5 joe(1)
     4.6 jed(1)
     4.7 pine(1)
     4.8 minicom(1)
     4.9 efax(1)
     4.10 Ghostscript
     4.11 TeX and Friends
     4.12 Avoid PPProblems!
        4.12.1 A Quick Start with eznet
        4.12.2 A Quick Start with wvdial
     4.13 POP Client
     4.14 X Window System (XFree86)
        4.14.1 Setting Up the X Server
        4.14.2 Keypad
        4.14.3 Graphical Login with xdm
        4.14.4 Window Manager
        4.14.5 Defaults for X11 Apps
     4.15 Users' Configurations
     4.16 Making .rpms
     4.17 Upgrading

  5. Configuration Software

  6. The End

     6.1 Copyright
     6.2 Feedback
     6.3 Disclaimer


  ______________________________________________________________________

  1.  Introduction



  1.1.  Why This HOWTO


  I have installed Linux on many PCs and noted that current
  distributions are terrific but, annoyingly, lack some basic
  configuration. Most applications will work out of the box, but others
  won't. Moreover, I have noted that the same questions crop up on
  c.o.l.setup over and over again. To try and remedy this situation, and
  for my own convenience, I wrote a to--do list that eventually became
  this HOWTO. Here you will find configuration tips and examples for the
  most common applications, programs, and services, which should save
  you a fair amount of time and work.

  A few of the examples outlined in this HOWTO depend somehow on the
  distribution. Currently, I only have access to Red Hat 5.2 machines,
  kernel 2.0.36; so don't take any of my tips as gospel if you have
  other distributions. It shouldn't be hard to adapt my tips to other
  distros, though.

  This HOWTO can't, and is not meant to, replace others. Reading docs
  and HOWTOs always pays, so you're strongly advised to do so if you
  want to know more. Also, no spoon--feeding here: if you realise you
  don't understand something, please refer to the relevant HOWTO. Let me
  remind you that the right place for seeking help with Linux
  configuration is Usenet, i.e.  <news:comp.os.linux.setup>. Please,
  don't seek help from me because I'm quite overloaded.

  The official place for this document, including some translations, is
  available at  <http://metalab.unc.edu/mdw/HOWTO>. Here you will also
  find all other HOWTOs I refer to. The very latest version is available
  at  <http://ibogeo.df.unibo.it/guido/Configuration>.



  1.2.  What We Will Be Configuring


  There can be endless hardware configurations for a PC, but in my
  experience one is quite common: a PC fitted with a large HD split into
  three partitions (one for DOS/Windows, one for Linux, one for the
  swap), sound card, modem, CD--ROM drive, printer, mouse. A parallel
  port Zip Drive is also very common. This machine is possibly part of a
  mixed Windows-Linux network, where it acts as server.

  This is the hardware I'll assume you want to configure, but it's easy
  to adapt the following tips to different configurations. It's
  implicitly assumed that you'll be root when editing/fixing/hacking.

  And now, lads, sleeves up.






  2.  General System Setup




  2.1.  A Few Words About Security


  Even before your system boots, you should decide what level of
  security you want to implement. To begin with, don't connect your
  machine to the network until you have decided what to do.

  Security is a vast subject that goes beyond the scope of this HOWTO;
  two good starting points are the Linux Security Administrator's Guide
  at <http://www.seifried.org/lasg> and the Linux Security Guide at
  <http://nic.com/~dave/Security>. You should consider at least the
  following steps: using shadow passwords (Shadow Password HOWTO),
  restricting network access to the machine (Section ``Restricting
  Network Access''), using the Secure Shell (
  <http://www.cs.hut.fi/ssh/>) or the Secure Remote Password (
  <http://srp.stanford.edu/srp/>). Good luck.



  2.2.  Start the Logbook!


  To keep your installation in shape, it's essential that you know
  exactly what happened to your machine, which packages you installed
  that day, what you removed or modified, and so on. So, the first thing
  you'll do before you tamper with your machine is start a ``logbook''.
  Therein you'll take note of every move you make as root; in my own
  logbook I also keep a section where I list all modified system files,
  additional .rpms, and .tar.gz I installed. Optimally, backtracking
  your moves you should be able to re-obtain a pristine installation.

  Make a backup copy of the system files you touch. Better still, use
  RCS; you'll be able to backtrack all changes. Never work as root
  without logging your moves!



  2.3.  Keyboard


  If you missed this step during installation or have changed your
  keyboard, you'll have to:


  o  find a suitable key table starting from /usr/lib/kbd/keymaps/; for
     example, it.map selects the Italian keyboard;

  o  edit the file /etc/sysconfig/keyboard so as it reads:
     KEYTABLE="it";

  o  to set up the keyboard repeat rate and delay time, add this line to
     /etc/rc.d/rc.sysinit (Red Hat) or /etc/rc.d/rc.boot (Caldera) or
     /etc/rc.d/boot (S.u.S.E.):



       /sbin/kbdrate -s -r 16 -d 500  # or whatever you like




  To load the key table, issue /etc/rc.d/init.d/keytable start.  Other
  special keys will be considered in the following sections.

  To enable NumLock on by default, add these lines to
  /etc/rc.d/rc.sysinit:



       for tty in /dev/tty[1-9]*; do
         setleds -D +num < $tty
       done






  2.4.  Boot and Rescue Floppy


  Make a couple of boot floppies for your newly installed system. Your
  distribution may include a command for creating such a floppy; if not,
  these commands will do:



       #~ dd if=/boot/vmlinuz-2.0.36-0.7 of=/dev/fd0  # use your kernel image
       #~ rdev /dev/fd0 /dev/hda2                     # your Linux partition




  Also, have at least a couple of rescue disks ready. There's a wide
  choice of rescue disks at
  <ftp://metalab.unc.edu/pub/Linux/system/recovery>; if you don't know
  which one to choose, I suggest you try out Tomsbtrt.



  2.5.  Kernel Matters


  IMHO, the first thing to do next is build a kernel that best suits
  your system. It's very simple to do but, in any case, refer to the
  README file in /usr/src/linux/ or the Kernel HOWTO. Hints:


  o  consider carefully your needs. Choosing a kernel configuration,
     applying the patches, and compiling it once and for all is more
     productive than reconfiguring and recompiling each month; this is
     especially true if your Linux box is a server. Don't forget to
     include support for all the hardware you might likely add in the
     future (e.g. SCSI, Zip, network cards, etc); using modules is
     usually the best choice;

  o  if your PC is based on a Cyrix CPU that is not properly recognised
     as such by the kernel, apply appropriate patches to improve its
     performance. Information on
     <http://www.linuxhq.com/patch/20-p0591.html>;

  o  notebook users will want to improve their LCD screen legibility. I
     once suggested that a kernel patch should be applied, but
     SVGATextMode (see Section ``SVGATextMode'') is probably the best
     solution. Anyway, the Big Cursor kernel patch is on
     <http://www.linuxhq.com/patch/20-p0239.html>;

  o  again for notebook users, if you plan to use a PCMCIA modem/fax
     don't compile serial support as a module; compile it in the kernel,
     otherwise your PCMCIA modem won't work;

  o  if you use PCMCIA cards, remember to compile those modules as well;
     also, don't forget to edit /etc/pcmcia/network.opts if you use a
     PCMCIA network card;

  o  if you get those pesky messages from modprobe indicating that some
     modules can't be located, that means that your /etc/conf.modules
     needs mending. For instance, if you don't use the ipx and appletalk
     modules, add these lines:



       alias net-pf-4 off
       alias net-pf-5 off





  o  to save time the next time you reconfigure and recompile the
     kernel, it's a good idea to save your configuration on a file and
     keep it in a safe place. Beware: if you upgrade your kernel this
     config file is bound to be useless, because it doesn't contain the
     features of the new kernel.



  2.6.  Sendmail Lock


  On some systems, sendmail hangs the machine for a couple of minutes at
  boot time. There are two cases: 1) the machine is not directly
  connected to the Internet, 2) the machine is connected, and has a
  permanent IP address.

  Quick fix for the first case: make sure your /etc/hosts contains a
  line that reads



       127.0.0.1   localhost




  For the second case: the lock is caused by /etc/hosts containing a
  line like



       127.0.0.1   localhost   your_host_name




  which you will split this way:



       127.0.0.1    localhost
       w.x.y.z      your_host_name


  See also Section ``Hostname''.



  2.7.  Hard Disk Performance


  Your (E)IDE hard disk's performance can be greatly enhanced by
  carefully using hdparm(8). If your Linux distribution doesn't include
  it, you'll find on <ftp://metalab.unc.edu/pub/Linux/system/hardware>;
  look for a file called hdparm-X.Y.tar.gz.

  Since many details depend on your hard disk and HD controller, I can't
  give you a general recipe. You risk to toast your filesystem, so read
  the man page carefully before using some of the options. At its
  simplest, you could add the following line to /etc/rc.d/rc.sysinit:



       /sbin/hdparm -c1 /dev/hda  # first IDE drive assumed




  which enables (E)IDE 32-bit I/O support. As for the `-m' option, this
  is what hdparm author Mark Lord emailed me:


       (...) if your system uses components from the past couple of
       years [< 1997], it will be fine. Older than that, there
       *may* be a problem (unlikely). The really buggy chips were
       the CMD0646 and RZ1000 chips, used *extensively* on 486 and
       (early) 586 motherboards about 2-3 years ago.


  For recent machines, these settings should work fine:



       /sbin/hdparm -c1 -A1 -m16 -d1 /dev/hda






  2.8.  Parallel Port Zip Drive


  To use the parallel port version of the Zip drive you can use the
  default driver that comes with recent (2.x.x) kernels. During kernel
  configuration, make sure that SCSI support and SCSI disk support are
  enabled. Remember, there can be conflicts between the printer and the
  Zip drive on the same parallel port, so you will want to use kernel
  modules. There's an alternative ppa driver at
  <http://www.torque.net/~campbell>.

  Zip disks are sold preformatted on partition /dev/sda4. To enable the
  Zip, append this to /etc/rc.d/rc.sysinit:



       # Enable the Zip drive
       /sbin/modprobe ppa


  Zip disks can be mounted via /etc/fstab as shown below, or via Mtools
  adding this line to your /etc/mtools.conf:



       drive z: file="/dev/sda4" exclusive




  besides, the command mzip allows you to eject, query the status, write
  and password protect Zip disks; man mzip for details.  The Mtools home
  page is at <http://linux.wauug.org/pub/knaff/mtools>.



  2.9.  Device Drivers


  Devices in /dev (or better, links to the actual device drivers) may be
  missing. Check what devices your mouse, modem, and CD--ROM drive
  correspond to, then do what follows:



       ~# cd /dev
       /dev# ln -s ttyS0 mouse; ln -s ttyS1 modem; ln -s hdb cdrom; ln -s sda4 zip




  In most notebooks the mouse device is /dev/psaux: take this into
  account when configuring X11.

  If you want, do chmod 666 to these devices to make them fully
  accessible by every user.




  2.10.  Sound Card


  All I own is an old Sound Blaster 16; even if you've got something
  different, you may take what follows as guidelines.

  I compiled the sound card support as a module (sb.o).  Then I put this
  in /etc/conf.modules:



       options sb io=0x220 irq=5 dma=1 dma16=5 mpu_io=0x330
       alias sound sb




  To enable the sound, make sure that modprobe sound is invoked in
  /etc/rc.d/rc.sysinit. Alternatively, get the tool sndconfig from the
  RedHat site.






  2.11.  Login Messages


  If you wish to customise the login messages, check whether your
  /etc/rc.d/rc.local overwrites /etc/issue and /etc/motd. (RedHat does.)
  If so, get on with your editor.

  If you'd like a colourised login message, you may adapt your rc.local
  inserting lines like these:



       # put a real escape character instead of ^[. To do this:
       # emacs: ^Q ESC   vi: ^V ESC   joe:  ` 0 2 7   jed: ` ESC
       ESC="^["  # a real escape character
       BLUE="$ESC[44;37m"
       NORMAL="$ESC[40;37m"
       CLEAR="$ESC[H$ESC[J"

       > /etc/issue
       echo "$CLEAR" >> /etc/issue
       echo "$BLUE   Welcome to MyServer (192.168.1.1)   " >> /etc/issue
       echo "$NORMAL " >> /etc/issue
       echo "" >> /etc/issue






  2.12.  Hostname


  Issuing the command hostname new_host_name may not be enough. To avoid
  the dreaded sendmail lock, follow these steps (only valid for a
  stand--alone machine):


  o  edit /etc/sysconfig/network and change the hostname therein (e.g.
     new_host_name.localdomain);

  o  edit /etc/HOSTNAME appropriately;

  o  append the new hostname in the line in /etc/hosts:


       127.0.0.1       localhost  new_host_name.locadomain







  2.13.  Mouse


  gpm mouse services are useful to perform cut and paste in tty mode,
  and to use the mouse in some applications. For Red Hat, check that you
  have a file called /etc/sysconfig/mouse and that it reads:



       MOUSETYPE="Microsoft"
       XEMU3=yes

  Moreover, you must have a file /etc/rc.d/init.d/gpm, where you'll put
  additional command line parameters. Mine reads:



       ...
              daemon gpm -t $MOUSETYPE -d 2 -a 5 -B 132 # two-button mouse
       ...




  Obviously, make sure this configuration is right for your mouse type.
  In most notebooks, MOUSETYPE is ``PS/2''.

  For Caldera, all you have to do is append this line to
  /etc/rc.d/rc.boot:



       /usr/bin/gpm




  On S.u.S.E., gpm options go in /etc/rc.config; on Debian, you'll edit
  /etc/gpm.conf.

  If you like to use menus in console with Ctrl-button, then configure
  gpm-root. Edit the default menu in /etc/gpm-root.conf, then launch
  gpm-root from /etc/rc.d/rc.local.



  2.14.  Mount Points


  It's handy to have mount points for the floppy, other devices and NFS-
  exported directories. For example, you can do the following:



       ~# cd /mnt
       /mnt# mkdir floppy; mkdir cdrom; mkdir win; mkdir zip; mkdir server




  This creates mount points for a DOS/Win floppy, an ext2 floppy, the
  CD--ROM, the Windows partition, the parallel port Zip drive, and a NFS
  directory.

  Now edit the file /etc/fstab and add the following entries:



       /dev/fd0        /mnt/floppy     auto            user,noauto 0 1
       /dev/cdrom      /mnt/cdrom      iso9660         ro,user,noauto 0 1
       /dev/zip        /mnt/zip        vfat            user,noauto,exec 0 1
       /dev/hda1       /mnt/win        vfat            user,noauto 0 1
       server:/export  /mnt/server     nfs             defaults





  Obviously, you must use the correct device in the first field. Recent
  kernels support fat32 partitions natively; for older ones, there's a
  kernel patch at <http://bmrc.berkeley.edu/people/chaffee/fat32.html>.
  man mount for further information.

  Note the ``auto'' filesystem type in the first line; it allows you to
  mount both ext2 and vfat (DOS/Windows) floppies. You may find mtools
  more convenient.



  2.15.  lilo(8) and LOADLIN.EXE


  Many users run both Linux and DOS/Windows on their PC, and want to
  choose at boot time which os to use; this should be done at install
  time, but in case, do what follows. Let's suppose that /dev/hda1
  contains DOS/Windows and that /dev/hda2 contains Linux.



       ~# fdisk
       Using /dev/hda as default device!

       Command (m for help):a
       Partition number (1-4): 2

       Command (m for help):w
       ~#




  This makes the Linux partition bootable. Then write this basic
  /etc/lilo.conf file:



       boot = /dev/hda2
       compact                # may conflict with "linear"
       delay = 100            # 10 seconds
       linear                 # gets rid of the "1024 cylinder" problem
       # message = /boot/bootmesg.txt  # write your own, if you will
       root = current
       image = /boot/vmlinuz  # boot linux by default as this entry comes first
         label = linux
         read-only
       #  append="mem=128M"   # to see more memory than 64M
       other = /dev/hda1
         table = /dev/hda
         label = dos




  Now issue /sbin/lilo and you're done. Being lilo a crucial part of
  your installation, you're strongly advised to read its documentation
  anyway.

  To boot Linux from DOS/Windows without resetting, put LOADLIN.EXE in a
  directory (in the DOS partition!) included in the DOS path; then copy
  your kernel to, say, C:\TEMP\VMLINUZ. The following simple .BAT file
  will boot Linux:



  rem   linux.bat
  smartdrv /C
  loadlin c:\temp\vmlinuz root=/dev/hda2 ro




  If you use Windows 9x, set the properties of this .BAT so as it starts
  in MS--DOS mode.



  2.15.1.  Security Tip


  Making a backup copy of your MBR before installing Linux is a safe
  move.  Use restorrb (included in the FIPS package) before
  installation, or a Linux rescue floppy to issue this command:



       rescue:~# dd if=/dev/hda of=MBR bs=512 count=1




  then make at least two copies of the file MBR on floppies. Should
  disaster strike, you'll be able to restore your old MBR by issuing:



       rescue:~# dd if=/mnt/MBR of=/dev/hda bs=446 count=1




  assuming that a floppy containing MBR is mounted under /mnt.
  Alternatively, use a DOS rescue floppy to issue FDISK /MBR.



  2.16.  Mail Capabilities


  You will want to be able to read mail messages written in HTML or
  containing exotic file formats. Make sure you have two files:
  /etc/mime.types and /etc/mailcap. The first one lists file types and
  related extensions, like:



       application/postscript          ps eps
       image/jpeg                      jpe jpeg jpg
       text/html                       html




  while the second one tells the mail client how to display that file
  type.

  You may receive mail from people who use Microsoft Outlook, whose
  messages are in multi--part MIME format. These two lines, put in
  etc/mailcap, should let you read those messages:


       text/plain; less %s; needsterminal
       text/html; lynx -force_html %s; needsterminal






  2.17.  Printer Configuration


  All distributions I know have a configuration tool for setting up the
  printer (printtool, yast, or magicfilter); if you don't have it, this
  is a basic manual configuration.

  Let's suppose you have a non--PostScript (non ``Windows-only'' too!)
  printer you want to use to print raw text (e.g., C source files) and
  PostScript files via Ghostscript, which is assumed to be already
  installed.

  Setting up the printer involves a few steps:


  o  find out which one the parallel print device is: try



       ~# echo "hello, world" > /dev/lp0
       ~# echo "hello, world" > /dev/lp1





  and take note which one works.

  o  make two spool directories:



       ~# cd /var/spool/lpd
       /var/spool/lpd/# mkdir raw; mkdir postscript





  o  if your printer exibits the ``staircase effect'' (most inkjets do),
     you'll need a filter. Try to print two lines with



       ~# echo "first line" > /dev/lp1 ; echo "second line" > /dev/lp1





  if the output is like this:



       first line
                 second line


  then save this script as /var/spool/lpd/raw/filter:



       #!/bin/sh
       # This filter eliminates the "staircase effect"
       awk '{print $0, "\r"}'





  and make it executable with chmod 755 /var/spool/lpd/raw/filter.

  o  make a filter for PostScript emulation. Write the following filter
     as /var/spool/lpd/postscript/filter:



       #!/bin/sh

       DEVICE=djet500
       RESOLUTION=300x300
       PAPERSIZE=a4
       SENDEOF=

       nenscript -TUS -ZB -p- |
       if [ "$DEVICE" = "PostScript" ]; then
               cat -
       else
               gs -q -sDEVICE=$DEVICE \
                       -r$RESOLUTION \
                       -sPAPERSIZE=$PAPERSIZE \
                       -dNOPAUSE \
                       -dSAFER \
                       -sOutputFile=- -
       fi

       if [ "$SENDEOF" != "" ]; then
               printf "\004"
       fi





  (in this example an HP DeskJet printer is assumed. Fix it to suit your
  printer).

  o  finally, add the following entries in /etc/printcap:
















  # /etc/printcap
  lp|ps|PS|PostScript|djps:\
          :sd=/var/spool/lpd/postscript:\
          :mx#0:\
          :lp=/dev/lp1:\
          :if=/var/spool/lpd/postscript/filter:\
          :sh:
  raw:\
          :sd=/var/spool/lpd/raw:\
          :mx#0:\
          :lp=/dev/lp1:\
          :if=/var/spool/lpd/raw/filter:\
          :sh:





  For more complex or exotic printing configurations, the Printing-HOWTO
  awaits you.

  If you use printtool, be aware that the GSDEVICE chosen by Printtool
  will work, but not necessarily at its best for your printer. You may
  consider fiddling a bit with the file postscript.cfg; for instance, I
  changed GSDEVICE from cdj500 to djet500 and now my prints come out
  much quicker.



  2.18.  SVGATextMode


  This utility, available on
  <ftp://tsx-11.mit.edu/pub/linux/sources/sbin>, is useful for changing
  the console screen resolution, font, and cursor shape. Users whose
  language include accented characters will be able to use them in
  console applications, while notebook users may change the cursor shape
  to make it more visible.

  Edit /etc/TextConfig or /etc/TextMode, starting with the default VGA
  definition. Europeans should be happy with this ``LoadFont'' section:



       Option "LoadFont"
       FontProg "/usr/bin/setfont"
       FontPath "/usr/lib/kbd/consolefonts"
       FontSelect "lat1u-16.psf"   8x16 9x16 8x15 9x15
       FontSelect "lat1u-14.psf"   8x14 9x14 8x13 9x13
       FontSelect "lat1u-12.psf"   8x12 9x12 8x11 9x11
       FontSelect "lat1u-08.psf"   8x8  9x8  8x7  9x7




  Once you're done, try your configuration with a command like
  SVGATextMode "80x34x9", and if everything appears to be working fine,
  remove the warnings from /etc/TextMode and include this line in
  etc/rc.d/rc.sysinit:



       # SVGATextMode
       /usr/sbin/SVGATextMode "80x34x9"


  Please note that the block cursor only works with some modes; on my
  notebook, "80x32x9".



  3.  Common Administration Tasks


  So many things to do, so little time! Here is where the fun begins.
  This section is rather network-centric, though many other tasks await
  you.

  Networking is a vast subject which cannot be fully covered here. The
  reference is the NET-3 HOWTO, and most distributions provide
  documentation on setting up network services. Only a few points will
  be recalled here.

  A quick to-do list for the services you may want to install: cron and
  timed tasks like calendar or reminder, Http, Samba, telnet/ssh access,
  anonymous ftp, POP/IMAP server, NFS services...



  3.1.  Network configuration


  Although the actual method of starting network services of your
  distribution may be much more complex, the following script should be
  enough to get you started:



       #!/bin/sh

       # net-up.sh: set up network access

       DEVICE=eth0
       IPADDR=192.168.1.100
       NETMASK=255.255.255.0
       NETWORK=192.168.1.0
       GATEWAY=192.168.1.1

       ifconfig $DEVICE $IPADDR netmask $NETMASK up
       route add -net $NETWORK netmask $NETMASK $DEVICE
       route add default gw $GATEWAY




  This script is handy for enabling network access when you use a rescue
  disk.  Obviously, this lets you only ping, ftp and telnet to the
  outside.



  3.2.  Sharing the Internet


  One of the most useful tasks for a Linux server. Currently, most stock
  kernels come with IP firewalling, masquerading and forwarding enabled
  by default; if in doubt, consult the IP-Masquerade mini-HOWTO to learn
  how to enable them. Then install ipfwadm (kernels 2.0.x;
  <http://www.xos.nl/linux/ipfwadm/>) or ipchains (kernels 2.2.x;
  <http://www.adelaide.net.au/~rustcorp/ipfwchains/ipfwchains.html>).
  Remember to enable kernel modules for the services you need, e.g. for
  ftp you'll add this line to /etc/rc.d/rc.sysconfig:
       /sbin/modprobe ip_masq_ftp




  Other modules are usually found in /lib/modules/KERNEL-VERSION/ipv4.

  Enabling IP masquerading for other machines in your local network is
  very simple. First, check the network initialisation scripts
  (/etc/sysconfig/network should be the right place) to see if they
  contain a line that reads FORWARD_IPV4=true. It's used to set
  /proc/sys/net/ipv4/ip_forward to 1 when the network subsystem comes
  up.

  Add these lines to /etc/rc.d/rc.sysinit:



       # default: packets cannot go reach the outside
       /sbin/ipfwadm -F -p deny
       # allow all machines on the local network to reach the Internet
       /sbin/ipfwadm -F -a m -S 192.168.1.0/24 -D 0.0.0.0/0
       # alternatively, allow only these two machines
       # /sbin/ipfwadm -F -a m -S 192.168.1.100/24 -D 0.0.0.0/0
       # /sbin/ipfwadm -F -a m -S 192.168.1.101/24 -D 0.0.0.0/0




  If you use a kernel of the 2.2.x series, use ipfwadm-wrapper instead
  of ipfwadm to get started quickly.

  Now you'll want something to let client machines dial the ISP; I use
  Mserver ( <http://cpwright.villagenet.com/mserver/>). Edit
  etc/mserver.conf; the only entries that you should modify are
  ``checkhost'', ``shadow'', and ``cname''. Then define your
  connection(s).  Obviously, install one of the available clients on the
  client machines.




  3.3.  Restricting Network Access


  Let's suppose you connect to the Internet via PPP. Once you're
  connected, your machine may become vulnerable to attacks. Insert this
  in /etc/hosts.allow:



       # only allow access to localhost
       ALL: 127.




  and this in /etc/hosts.deny:



       # deny access to everyone
       ALL: ALL



  If you belong to a network with direct Internet access, you had better
  disable finger, telnet, and possibly other services for security
  reasons; use ssh instead of telnet. The file to edit is
  /etc/inet.conf. Alternatively, you can restrict network access putting
  this in /etc/hosts.allow:



       in.telnetd: 192.168.1., .another.trusted.network
       in.ftpd: 192.168.1., .another.trusted.network




  and this in /etc/hosts.deny:



       in.telnetd: ALL
       in.ftpd: ALL






  3.4.  NFS Exports


  It is common to export the home directories on the server; a problem
  arises if a user's UID and GID are not consistent across different
  machines.  If user guido has UID/GID equal to 500 on server and
  UID/GID equal to 512 on client, a convenient configuration is this:



       # /etc/exports
       /tmp            my.client.machine(rw)
       /home/guido     my.client.machine(rw,map_static=/etc/nfs/client.map)




  In /etc/nfs/client.map you'll put this:



       # /etc/nfs/client.map
       # NFS mapping for client
       #       remote          local
       uid     512             500
       gid     512             500







  3.5.  Name Server


  Not written yet.



  4.  Software Configuration


  These are the the configuration files we are going to custimise:
  /etc/profile /etc/bashrc .bashrc .bashrc .bash_profile .bash_logout
  .inputrc .less .lessrc .xinitrc .fvwmrc .fvwm2rc95 .Xmodmap
  .Xmodmap.num .Xdefaults .jedrc .abbrevs.sl .joerc .emacs .  Don't add
  users until you have completed your system configuration; you'll put
  the dot files in /etc/skel.



  4.1.  bash(1)


  Arguably, the most important piece of software after the kernel. To
  tailor the behaviour of bash, these are the main files to edit:


  o  /etc/bashrc contains system wide aliases and functions;

  o  /etc/profile contains system wide environment stuff and startup
     programs;

  o  $HOME/.bashrc contains user aliases and functions;

  o  $HOME/.bash_profile contains user environment stuff and startup
     programs;

  o  $HOME/.inputrc contains key bindings and other bits.

  Examples of these files are shown below. First, the most important:
  /etc/profile. It's used to configure a lot of features in your Linux
  box, as you will see in the following sections. Please look out for
  reverse quotes!































  ______________________________________________________________________
  # /etc/profile

  # System wide environment and startup programs
  # Functions and aliases go in /etc/bashrc

  # This file sets up the following features and programs:
  #
  #   o path
  #   o prompts
  #   o a few environment variables
  #   o colour ls
  #   o less
  #   o rxvt
  #
  # Users can override these settings and/or add others in their
  # $HOME/.bash_profile

  # set a decent path
  PATH="$PATH:/usr/X11R6/bin:$HOME/bin:."

  # notify the user: login or non-login shell. If login, the prompt is
  # coloured in blue; otherwise in magenta. Root's prompt is red.
  # See the Colour-ls mini HOWTO for an explanation of the escape codes.
  USER=`whoami`
  if [ $LOGNAME = $USER ] ; then
    COLOUR=44  # blue
  else
    COLOUR=45  # magenta
  fi

  if [ $USER = 'root' ] ; then
    COLOUR=41  # red
    PATH="$PATH:/usr/local/bin"
  fi

  ESC="\033"
  PROMPT='\h'    # hostname
  STYLE=';1m'    # bold
  # PROMPT='\u'  # username
  # STYLE='m'    # plain
  PS1="\[$ESC[$COLOUR;37$STYLE\]$PROMPT:\[$ESC[37;40$STYLE\]\w\\$ "
  PS2="> "

  # no core dumps, please
  ulimit -c 0

  # set umask
  if [ `id -gn` = `id -un` -a `id -u` -gt 14 ]; then
    umask 002
  else
    umask 022
  fi

  # a few variables
  USER=`id -un`
  LOGNAME=$USER
  MAIL="/var/spool/mail/$USER"  # sendmail, postfix, smail
  # MAIL="$HOME/Mailbox"        # qmail
  NNTPSERVER=news.myisp.it      # put your own here
  VISUAL=jed
  EDITOR=jed
  HOSTNAME=`/bin/hostname`
  HISTSIZE=1000
  HISTFILESIZE=1000
  export PATH PS1 PS2 USER LOGNAME MAIL NNTPSERVER
  export VISUAL EDITOR HOSTNAME HISTSIZE HISTFILESIZE

  # enable colour ls
  eval `dircolors /etc/DIR_COLORS -b`
  export LS_OPTIONS='-s -F -T 0 --color=yes'

  # customize less
  LESS='-M-Q'
  LESSEDIT="%E ?lt+%lt. %f"
  LESSOPEN="| lesspipe.sh %s"
  LESSCHARDEF=8bcccbcc13b.4b95.33b. # show colours in ls -l | less
  # LESSCHARSET=latin1
  PAGER=less
  export LESS LESSEDIT LESSOPEN VISUAL LESSCHARDEF

  # fix the backspace key in rxvt/xterm
  CTRL_H="\010"
  NULL_STRING=" $CTRL_H" # space + backspace
  if [ "$NULL_STRING" != "" ] ; then
    stty erase ^?
  else
    stty erase ^H
  fi

  # set xterm title: full path
  case $TERM in
    xterm*)
      PROMPT_COMMAND='echo -ne "\033]0;${USER}@${HOSTNAME}: ${PWD}\007"'
      ;;
  esac

  for i in /etc/profile.d/*.sh ; do
    if [ -x $i ]; then
      . $i # beware - variables and aliases might get overridden!
    fi
  done

  # call fortune, if available
  if [ -x /usr/games/fortune ] ; then
    echo ; /usr/games/fortune ; echo
  fi
  ______________________________________________________________________



  This is a sample /etc/bashrc:




















  ______________________________________________________________________
  # /etc/bashrc

  # System wide functions and aliases
  # Environment stuff goes in /etc/profile
  # Insert PS1 definitions here if you experience problems.

  export CDPATH="$CDPATH:~"

  # common aliases
  alias cp='cp -i'
  alias l=less
  alias ls="ls $LS_OPTIONS"
  alias mv='mv -i'
  alias rm='rm -i'
  alias rmbk='/bin/rm -f .*~ *~ *aux *bak *log *tmp 2> /dev/null'
  alias u='cd ..'
  alias which="type -path"
  alias x=startx

  # A few useful functions
  c ()    # cd to the new directory and list its contents
  {
    cd $1 ; ls
  }

  inst()  # Install a .tar.gz archive in current directory
  {
    if [ $# != 0 ]; then tar zxvf $1; fi
  }

  cz()    # List the contents of a .zip archive
  {
    if [ $# != 0 ]; then unzip -l $*; fi
  }

  ctgz()  # List the contents of a .tar.gz archive
  {
    for file in $* ; do
      tar ztf ${file}
    done
  }

  tgz()   # Create a .tgz archive a la zip.
  {
    if [ $# != 0 ]; then
      name=$1.tar; shift; tar -rvf ${name} $* ; gzip -9 ${name}
    fi
  }

  crpm()  # list information on an .rpm file
  {
    if [ $# != 0 ]; then rpm -qil $1 | less; fi
  }
  ______________________________________________________________________



  This is a sample .bashrc:







  ______________________________________________________________________
  # $HOME/.bashrc
  # Source global definitions

  if [ -f /etc/bashrc ]; then
    . /etc/bashrc
  fi

  # this is needed to notify the user that they are in non-login shell
  if [ "$GET_PS1" = "" ] ; then
    COLOUR=45; ESC="\033"; STYLE=';1m';  # STYLE='m'
    USER=`whoami`
    export PS1="\[$ESC[$COLOUR;37$STYLE\]$USER:\[$ESC[37;40$STYLE\]\w\\$ "
  fi

  # personal aliases
  alias backup='tar -Mcvf /dev/fd0'
  alias dial='eznet up myisp'
  alias f='cd ~/fortran'
  alias hangup='eznet down'
  alias lyx='lyx -width 580 -height 450'
  alias restore='tar -M -xpvf /dev/fd0'

  # personal functions
  xj()    # Launch xjed and a file in background
  {
    xjed $1 &
  }
  ______________________________________________________________________



  This is a sample .bash_profile:


  ______________________________________________________________________
  # $HOME/.bash_profile

  # User specific environment and startup programs
  # This file contains user-defined settings that override
  # those in /etc/profile

  # Get user aliases and functions
  if [ -f ~/.bashrc ]; then
    GET_PS1="NO"  # don't change the prompt colour
    . ~/.bashrc
  fi

  # set a few `default' directories
  export CDPATH="$CDPATH:$HOME:$HOME/text:$HOME/text/geology"
  ______________________________________________________________________



  This is a sample .inputrc:











  ______________________________________________________________________
  # $HOME/.inputrc

  # key bindings
  "\e[1~": beginning-of-line
  "\e[3~": delete-char
  "\e[4~": end-of-line
  # (F1 .. F5) are "\e[[A" ... "\e[[E"
  "\e[[A": "info \C-m"

  set bell-style visible          # please don't beep
  set meta-flag On                # allow 8-bit input (i.e, accented letters)
  set convert-meta Off            # don't strip 8-bit characters
  set output-meta On              # display 8-bit characters correctly
  set horizontal-scroll-mode On   # scroll long command lines
  set show-all-if-ambiguous On    # after TAB is pressed
  ______________________________________________________________________



  To make the backspace and delete keys work correctly in xterm and
  other X11 applications, the following is also needed:


  o  put this in your .xinitrc:



       usermodmap=$HOME/.Xmodmap
       xmodmap $usermodmap





  o  then your .Xmodmap will contain:



       keycode 22 = BackSpace
       keycode 107 = Delete





  this fixes the console. To fix xterm:

  o  put this in your .Xdefaults:



       xterm*VT100.Translations: #override <Key>BackSpace: string(0x7F)\n\
               <Key>Delete:        string(0x1b) string("[3~")\n\
               <Key>Home:          string(0x1b) string("[1~")\n\
               <Key>End:           string(0x1b) string("[4~")\n\
               Ctrl<Key>Prior:     string(0x1b) string("[40~")\n\
               Ctrl<Key>Next:      string(0x1b) string("[41~")

       nxterm*VT100.Translations: #override <Key>BackSpace: string(0x7F)\n\
               <Key>Delete:        string(0x1b) string("[3~")\n\
               <Key>Home:          string(0x1b) string("[1~")\n\
               <Key>End:           string(0x1b) string("[4~")\n\
               Ctrl<Key>Prior:     string(0x1b) string("[40~")\n\
               Ctrl<Key>Next:      string(0x1b) string("[41~")

  rxvt is a wee bit more complicated, as some compile--time options
  influence its behaviour. See the above /etc/profile.

  More info in bash(1) and readline(3) man pages.

  Don't expect every application to work correctly! If you run joe in
  xterm, for instance, some keys won't work; the same holds for some
  versions of rxvt.



  4.2.  ls(1)


  ls can display directory listings using colours to highlight different
  file types. To enable this feature, you just need a couple of lines in
  /etc/profile as seen above. However, this won't work with some
  versions of rxvt; use some flavour of xterm instead. It looks like
  some old rxvts have a bug that prevents them from inheriting the
  environment correctly in some circumstances.

  Caldera's ls doesn't have colours, but there's an equivalent color-ls.
  Add this in /etc/bashrc:



       alias ls="color-ls $LS_OPTIONS"






  4.3.  less(1)


  With this excellent pager you can browse not only plain text files,
  but also gzip compressed, tar and zip archives, man pages, and what
  have you. Its configuration involves a few steps:


  o  to use it with the movement keys, have this plain ASCII file
     .lesskey in your home directory:



       ^[[A   back-line
       ^[[B   forw-line
       ^[[C   right-scroll
       ^[[D   left-scroll
       ^[OA   back-line
       ^[OB   forw-line
       ^[OC   right-scroll
       ^[OD   left-scroll
       ^[[6~  forw-scroll
       ^[[5~  back-scroll
       ^[[1~  goto-line
       ^[[4~  goto-end
       ^[[7~  goto-line
       ^[[8~  goto-end





  then run the command lesskey. (These are escape sequences for
  vt100-like terminals.) This creates a binary file .less containing the
  key bindings.


  o  write the following file as /usr/local/bin/lesspipe.sh:


     ___________________________________________________________________
     #!/bin/sh
     # This is a preprocessor for 'less'.  It is used when this environment
     # variable is set:   LESSOPEN="|lesspipe.sh %s"

     lesspipe() {
       case "$1" in
       *.tar) tar tf $1 2>/dev/null ;; # View contents of .tar and .tgz files
       *.tgz|*.tar.gz|*.tar.Z|*.tar.z) tar ztf $1 2>/dev/null ;;
       *.Z|*.z|*.gz) gzip -dc $1  2>/dev/null ;; # View compressed files correctly
       *.zip) unzip -l $1 2>/dev/null ;; # View archives
       *.arj) unarj -l $1 2>/dev/null ;;
       *.rpm) rpm -qpil $1 2>/dev/null ;;
       *.cpio) cpio --list -F $1 2>/dev/null ;;
       *.1|*.2|*.3|*.4|*.5|*.6|*.7|*.8|*.9|*.n|*.l|*.man) FILE=`file -L $1`
         FILE=`echo $FILE | cut -d ' ' -f 2`
         if [ "$FILE" = "troff" ]; then
           groff -s -p -t -e -Tascii -mandoc $1
         fi ;;
       *) file $1 | grep text > /dev/null ;
         if [ $? = 1 ] ; then # it's not some kind of text
           strings $1
         fi ;;
       esac
     }

     lesspipe $1
     ___________________________________________________________________



  then make it executable with chmod 755 lesspipe.sh.

  o  put the necessary variables in /etc/profile as seen above.




  4.4.  emacs(1)


  I rarely use emacs, so I have only a couple of tips for you.  Some
  emacs distributions don't come preconfigured for colours and syntax
  highlighting. Put this in your .emacs:



       (global-font-lock-mode t)
       (setq font-lock-maximum-decoration t)




  This only works in X11. Moreover, to enable accented characters you'll
  add this line:




  (standard-display-european 1)




  I'll leave it to you to peruse all of emacs' documentation to find out
  how to tailor it to your needs---potentially, it can take months of
  hacking.  The Dotfile generator (Section ``Configuration Software'')
  is a good helping hand.



  4.5.  joe(1)


  Some versions of joe don't work with colours in console, and some
  special keys don't work either. A quick and dirty (and inelegant)
  solution to the former problem is this:



       ~$ export TERM=vt100
       ~$ joe myfile
          (edit your file)
       ~$ export TERM=linux




  To make the special keys work, all you have to do is edit .joerc,
  .jstarrc or your favourite emulation; you can start from the system-
  wide config files in /usr/lib/joe. Look for the fourth section (key
  bindings). This enables Home and End:



       bol ^[ [ 1 ~    Go to beginning of line
       eol ^[ [ 4 ~    Go to end of line




  Find out the desired ESC sequences typing cat followed by the special
  keys.



  4.6.  jed(1)


  This is my favourite editor: it does what I need, it's lighter and
  easier to configure than emacs, and emulates other editors quite well.
  Many users at my university use jed to emulate EDT, VMS' system
  editor.

  jed's configuration files are .jedrc and /usr/lib/jed/lib/*; the
  former can be adapted from jed.rc in the latter directory.


  o  to make jed use the special keys correctly, write the file
     /usr/lib/jed/lib/defaults.sl whose only line reads:



       () = evalfile("linux");

  o  if xjed apparently doesn't recognise the DEL key, add these lines
     to your .jedrc:



       #ifdef XWINDOWS
         x_set_keysym (0xFFFF, 0, "\e[3~");
         setkey (``delete_char_cmd'', "\e[3~");
       #endif





  o  edit /usr/lib/jed/lib/linux.sl to specify Info_Directory =
     "/usr/info"; and /bin/mail after /UCB_Mailer = "/bin/mail";;

  o  to make jed emulate EDT (or other editors) all you have to do is
     edit a couple of lines in .jedrc. If you want the numeric keypad
     `+' to delete words instead of a single character, add this in
     .jedrc:



       unsetkey("\eOl");
       unsetkey("\eOP\eOl");
       setkey("edt_wdel", "\eOl");
       setkey("edt_uwdel", "\eOP\eOl");





  after the line that reads () = evalfile("edt") (or similar);

  o  to make xjed use the numeric keypad for EDT emulation, insert the
     following in .Xmodmap:



       keycode 77  = KP_F1
       keycode 112 = KP_F2
       keycode 63  = KP_F3
       keycode 82  = KP_F4
       keycode 86  = KP_Separator





  o  colour customization for xjed is done adding lines like these in
     .Xdefaults:



       xjed*Geometry: 80x32+150+50
       xjed*font: 10x20
       xjed*background: midnight blue
       # and so on...





  o  the ``abbreviation'' feature is an invaluable timesaver. Write a
     file like the following as $HOME/.abbrevs.sl (you can change this
     name by inserting variable Abbrev_File = "/usr/lib/jed/abbrev.sl";
     in .jedrc):



       create_abbrev_table ("Global", "0-9A-Za-z");
       define_abbrev ("Global", "GG", "Guido Gonzato");
       create_abbrev_table ("TeX", "\\A-Za-z0-9");
       define_abbrev ("TeX", "\\beq", "\\begin{equation}");
       define_abbrev ("TeX", "\\eeq", "\\end{equation}");
       % and so on...





  and type ESC x abbrev_mode to enable it. To have the abbreviation
  enabled by default, add entries like these to your .jedrc:



       define text_mode_hook ()
       {
         set_abbrev_mode (1);
       }
       %
       define fortran_hook ()
       {
         set_abbrev_mode (1);
         use_abbrev_table ("Fortran");
       }
       % and so on...







  4.7.  pine(1)


  Edit the global configuration in /usr/lib/pine.conf, taking care at
  least of the following fields: user-domain, smtp-server, and nntp-
  server. Note that inbox-path depends on your MTA: if you use sendmail
  or postfix, that'll be var/spool/mail/$USER; with Qmail,
  /home/$USER/Mailbox (but root will use /var/qmail/alias/Mailbox.



  4.8.  minicom(1)


  Users can't use minicom unless a global configuration has been made by
  root. Remember to make it.



  4.9.  efax(1)


  This package is probably the most convenient for simple
  sending/receiving of faxes. You'll have to tailor the script
  /usr/bin/fax; easy job, but a couple of quirks caused me quite a
  headache:

  o  to find out whether your modem is class 1, 2, or 2.0, use minicom
     or similar program to issue the command at+fclass=?. The reply may
     be like 0,1,2; 1 and 2 are the classes supported by your modem;

  o  DIALPREFIX: chances are that simply putting `T' or `P' won't work
     in some countries (in Italy, at least). Put `ATDT' or `ATDP'
     instead;

  o  INIT and RESET: these strings contain the initialisers `-i' and
     `-k', needed by efax. If you want to add an AT command, add it to
     the appropriate string leaving out `AT' and preceding the rest with
     either `-i' or `-k'. Example: to add the `ATX3' command to INIT,
     you'll append `-iX3'.

  That done, there are a few permissions to fix to enable non-root users
  to send and receive faxes. The directories /var/lock and
  /var/spool/fax must be writable. To do so, create the group faxusers,
  add users to it, then type:



       ~# chown root.faxusers /var/lock
       ~# mkdir /var/spool/fax
       ~# chown root.faxusers /var/spool/fax; chmod g+w /var/spool/fax






  4.10.  Ghostscript


  This essential tool suffers from a small snag. Owing to to the well-
  known export regulations in the USA, the utility pdf2ps doesn't work
  on encrypted .pdf files. Never mind: turn your browser to
  <http://www.ozemail.com.au/~geoffk/pdfencrypt>, download the file
  pdf_sec.ps and put it in place of the file with the same name that
  comes with the distribution of Ghostscript.



  4.11.  TeX and Friends


  I'll assume you have the teTeX distribution.


  o  download additional LaTeX packages from your nearest CTAN mirror
     site, e.g.  <ftp://ftp.dante.de/pub/tex>. Add the files under
     /usr/share/texmf/tex/latex, then run the command texhash so that
     teTeX recognises the new package;

  o  to configure the hyphenation pattern for your language, edit the
     file /usr/share/texmf/tex/generic/config/language.dat, then do:



       ~# texconfig init ; texconfig hyphen





  o  to tailor dvips, the file to edit is
     /usr/share/texmf/dvips/config/config.ps. Be aware that the fields
     regarding the default resolution also affect xdvi's behaviour; if
     you experience annoying attempts to create fonts each time you run
     it, put the line



       XDvi*mfmode:





  in .Xdefault. This should help.

  o  to include PostScript figures that reside in subdirectories, you
     can expand TeX's search path to include subdirectories. Put this
     command in your .bash_profile:



       export TEXINPUTS="$HOME/figures::./figures"





  which makes TeX search in $HOME/figures before the default directo-
  ries, and ./figures after the default directories.



  4.12.  Avoid PPProblems!


  I'll take it for granted that your kernel has PPP + TCP/IP support
  compiled in, that loopback is enabled, and that you already have the
  pppd package correctly installed and, if you will, suid root.
  Obviously, your ISP must support PPP.

  There are now two ways to get PPP to work: a) manual configuration,
  and b) a configuration program that automagically sees to it.
  Whichever option you choose, have the following information on hand:


  o  your ISP's telephone number;

  o  your ISP's name, mail and news server address;

  o  your ISP's domain;

  o  your username and password.

  Manual configuration is a drudgery. It's about editing files and
  writing scripts; not too much work, but it's easy to make mistakes and
  newcomers are often intimidated. The PPP HOWTO is there for you.
  Alternatively, there are tools that ask for the information above and
  do all the work.

  Gnome and KDE include, respectively, gnome-ppp and kppp which are easy
  enough to set up. Alternatively, I suggest that you have a look at a
  couple of tty--based tools, wvdial and eznet.  You feed them your
  ISP's phone number, your username, your password, and you're in
  business. Their home pages are at
  <http://www.worldvisions.ca/wvdial> and
  <http://www.hwaci.com/sw/eznet>. Both are great, but I prefer the
  latter.
  4.12.1.  A Quick Start with eznet


  First of all, create an /etc/resolv.conf like this:



       nameserver w.x.y.z




  where you'll insert the address of your ISP's nameserver. To create an
  account with eznet, issue the following command:



       #~ eznet add service=YOUR_ISP user=NAME password=PASSWORD phone=PHONE




  which creates the file /var/eznet/eznet.conf, owned by root.root with
  permissions 600; chmod it to 666 if you want it to be world readable.
  Now dial your ISP with eznet up YOUR_ISP. If the modem keeps waiting
  for the dial tone and won't connect, then try this command:



       #~ eznet change YOUR_ISP init0=atx3




  To hang up, the command is eznet down. That's all!



  4.12.2.  A Quick Start with wvdial


  wvdial's setup is even shorter. Type wvdialconf /etc/wvdial.conf, then
  edit the resulting file to include your username, password, and phone
  number. Try it out with wvdial, and keep your fingers crossed. To hang
  up, stop it with Ctrl-C.



  4.13.  POP Client


  To retrieve your mail from a POP3 server, you use a POP client like
  fetchpop or fetchmail; the latter is more advanced, but requires that
  you run sendmail. This is a bit of an overkill on low-spec machines.
  They're available on
  <ftp://metalab.unc.edu/pub/Linux/system/mail/pop>.

  To configure these clients:


  o  fetchpop: the first time you run it, you'll be prompted for some
     information. Answer the questions and you're set. fetchpop must be
     used with the -r switch if your ISP's POP3 server doesn't implement
     the command LAST properly.


  o  fetchmail: adapt this sample .fetchmailrc:



       # $HOME/.fetchmailrc
       poll mbox.myisp.com with protocol pop3;
         user john there with password _Loo%ny is john here





  One user reported that adding ``smtphost localhost'' to the second
  line improved performance dramatically.

  You must set the permissions to this file with the command chmod 600
  .fetchmailrc, otherwise fetchmail will rightly refuse to start. This
  example is very basic; there are endless possibilities of configura-
  tion. Check out at  <http://www.ccil.org/~esr/fetchmail>.



  4.14.  X Window System (XFree86)



  4.14.1.  Setting Up the X Server


  Come on, it's not difficult as it used to be... All major
  distributions include a tool for setting up X11 (e.g.  XConfigurator,
  sax, XF86Setup, or at least xf86config). X configuration is virtually
  automatic these days, but a few video cards may refuse to work. Each
  time I experience problems setting up X on a system, I resort to a
  simple method that has always worked:


  o  make sure that the plain VGA server is installed;

  o  go to <ftp://ftp.XFree86.org/pub/XFree86/current/binaries>, cd to
     the proper Linux subdirectory, and download the archives
     X_version_bin.tgz, X_version_set.tgz, and all the servers.  Amongst
     other programs, the first archive contains the most up-to-date
     SuperProbe;

  o  unpack X_version_bin.tgz to a temporary directory, cd to it, and
     run ./SuperProbe. If your video card is recognised, chances are
     that you'll be able to set it up. Otherwise, hard luck;

  o  install the servers and X_version_set.tgz from /usr/X11R6/, then
     run XF86Setup.

  This has always worked for me, but your mileage may vary. Please note
  that most times X11 won't start because the specs you choose for your
  monitor were too high! Start with conservative settings, i.e. 800x600
  and 256 colours, then pump it up. Warning: these operations are
  dangerous and your monitor might be damaged!



  4.14.2.  Keypad


  We have seen above how to make a few special keys work. The sample
  file .Xmodmap works well if you want to use Xjed, but it makes the
  keypad unusable. You'll then need another config file, which we'll
  call .Xmodmap.num:



       ! Definitions can be found in <X11/keysymdef.h>

       keycode 77  = Num_Lock
       keycode 112 = KP_Divide
       keycode 63  = KP_Multiply
       keycode 82  = KP_Subtract
       keycode 86  = KP_Add
       keycode 79  = KP_7
       keycode 80  = KP_8
       keycode 81  = KP_9
       keycode 83  = KP_4
       keycode 84  = KP_5
       keycode 85  = KP_6
       keycode 87  = KP_1
       keycode 88  = KP_2
       keycode 89  = KP_3
       keycode 90  = KP_0
       keycode 91  = KP_Decimal




  Make sure that your /etc/X11/XF86Config does not contain these three
  lines:



         ServerNumLock
         Xleds
         XkbDisable




  and in case, comment them out. To re-enable the keypad, you'll issue
  the command xmodmap .Xmodmap.num.



  4.14.3.  Graphical Login with xdm


  To be greeted by a graphical login, edit the file /etc/inittab, which
  should include a line like this:



       x:5:respawn:/usr/bin/X11/xdm -nodaemon




  where 5 is the runlevel corresponding to X11 (S.u.S.E. uses 4). Modify
  the line that defines the default runlevel (usually 2 or 3), changing
  it as above:



       id:5:initdefault:



  The number of colours is specified in /etc/X11/xdm/Xserver:



       :0 local /usr/X11R6/bin/X :0 -bpp 16 vt07  # first X server, 65k colours
       :1 local /usr/X11R6/bin/X :1 -bpp 32 vt08  # second X server, true colour




  If you already have .xinitrc, copy it to .xsession and make the latter
  executable with chmod +x .xsession. Now issue the command telinit 5
  and you're in business.



  4.14.4.  Window Manager


  Once X works, there are endless possibilities of configuration; it
  depends on the window manager you use, there are tens to choose from.
  Mostly, it's all down to editing one or more ASCII files in your home
  directory; in other cases you don't have to edit a thing, and use an
  applet or even a menu.

  Some examples:


  o  the fvwm family: copy /etc/X11/fvwm/system.fvwmrc (or similar) to
     your home using the appropriate name, browse it and start
     experimenting. You may waste a lot of time before you get the
     precise look and feel you like;

  o  WindowMaker: it has several config files that live under
     $HOME/GNUstep, and a cool configuration applet;

  o  KDE and Gnome: nothing to edit manually here: everything can be
     done via the menu.

  In short: if you don't mind editing config file, choose something like
  icewm, fvwm*, blackbox etc; if you do mind, the choice is currently
  restricted to KDE, Gnome, WindowMaker, and XFCE.

  It's important to have a good .xinitrc. An example:






















  #!/bin/sh
  # $HOME/.xinitrc

  usermodmap=$HOME/.Xmodmap
  xmodmap $usermodmap

  xset s noblank  # turn off the screen saver
  xset s 300 2    # screen saver start after 5 min
  xset m 10 5     # set mouse acceleration

  rxvt -cr green -ls -bg black -fg white -fn 7x14 \
    -geometry 80x30+57+0 &

  if [ "$1" = "" ] ; then  # default
    WINMGR=wmaker
  else
    WINMGR=$1
  fi

  $WINMGR




  Although it doesn't appear to be strictly required, make it executable
  with chmod +x .xinitrc.

  This .xinitrc lets you choose the window manager: try


       $ startx startkde # or other w.m.




  (it doesn't work with some S.u.S.E. versions, though).



  4.14.5.  Defaults for X11 Apps


  Find out where the app-defaults directory is (it should be
  /usr/X11R6/lib/X11/app-defaults). Several apps keep a configuration
  file there.



  4.15.  Users' Configurations


  When you're done editing the dot files, copy them to /etc/skel as seen
  in Section ``Software Configuration''.



  4.16.  Making .rpms


  rpm is such a wonderful method of keeping packages under control that
  I'm reluctant to install .tar.gz archives but in very few special
  cases (e.g., security). Whenever you install a tarball, consider
  turning it into an .rpm archive, then reinstall it; consult the RPM
  HOWTO. Also, if you use modern gcc versions like egcs or pgcc, it may
  be advisable to put this in your /etc/rpmrc:

       optflags: i386 -O2 -mpentium






  4.17.  Upgrading


  If you upgrade your machine, do your backup as usual and remember to
  save a few additional files. Some could be /etc/X11/XF86Config,
  /usr/bin/fax, all the stuff in /usr/local, the kernel configuration,
  the whole /etc, and all the mail in /var/spool/mail.

  Then it's time to upgrade (in rare cases, downgrade!) applications
  that your distribution ship with, and to add additional packages. Keep
  a list of these ones.



  5.  Configuration Software


  There are several programs that make Linux easy to setup and
  configure. Some are becoming sort of standard: Red Hat, Caldera and
  other distributions ship with apps like setup, printtool, netcfg,
  usertool, etc, while S.u.S.E. ships with a comprehensive configuration
  program called Yast. Other useful programs are:


  o  The Dotfile Generator: fine X app with modules to configure
     packages like emacs, bash, procmail and more. Its page is at
     <http://www.imada.ou.dk/~blackie/dotfile>;

  o  Linuxconf: the ultimate configuration tool. It can do everything,
     both in console and under X. Go to
     <http://www.solucorp.qc.ca/linuxconf> at once.



  6.  The End




  6.1.  Copyright


  Unless otherwise stated, Linux HOWTO documents are copyrighted by
  their respective authors. Linux HOWTO documents may be reproduced and
  distributed in whole or in part, in any medium physical or electronic,
  as long as this copyright notice is retained on all copies. Commercial
  redistribution is allowed and encouraged; however, the author would
  like to be notified of any such distributions.

  All translations, derivative works, or aggregate works incorporating
  any Linux HOWTO documents must be covered under this copyright notice.
  That is, you may not produce a derivative work from a HOWTO and impose
  additional restrictions on its distribution. Exceptions to these rules
  may be granted under certain conditions; please contact the Linux
  HOWTO coordinator at the address given below.

  In short, we wish to promote dissemination of this information through
  as many channels as possible. However, we do wish to retain copyright
  on the HOWTO documents, and would like to be notified of any plans to
  redistribute the HOWTOs.

  If you have questions, please contact Tim Bynum, the Linux HOWTO
  coordinator, at  <linux-howto@metalab.unc.edu> via email.



  6.2.  Feedback


  Perhaps even more than other HOWTOs, this one needs and welcomes your
  suggestions, criticisms, and contributions. Not only is feedback
  welcome: it's necessary. If you think something is missing or wrong,
  please email me.  If you have a distribution other than Red
  Hat/Mandrake and your config files are different or placed in other
  directories, please tell me and I'll include your tips. My aim is
  making life with Linux as easy as possible.

  Linux has a huge number of packages, so it's impossible to include
  directions for all of them. Please keep your requests/suggestions
  pertinent to the ``most reasonable'' programs---I'll leave it to your
  common sense.



  6.3.  Disclaimer


  ``Configuration HOWTO'' was written by Guido Gonzato,
  <REMOVE_MEguido@ibogeo.df.unibo.it>. (Remove ``REMOVE_ME''.)  Many
  thanks to all other HOWTO authors and man pages writers/maintainers,
  whose work I've shamelessly pilfered; and to all people who provided
  me with feedback.

  This document is provided ``as is''. I put great effort into writing
  it as accurately as I could, but you use the information contained in
  it at your own risk. In no event shall I be liable for any damages
  resulting from the use of this work.

  I hope you'll find this work useful, though. Whenever I install a new
  Linux box, I actually do...

  Enjoy,

  Guido   =8-)





















