Subject: Linux Frequently Asked Questions 3/5 [monthly posted]
From: [email-masked]
Date: Tue, 8 Jun 1993 14:46:58 GMT
Newsgroups: comp.os.linux,comp.os.linux.announce,comp.answers,news.answers

Archive-name: linux-faq/part3
Last-Modified: 93/06/07
Version: 1.18

*********************************************************
*							*
*   Answers to Frequently asked questions about Linux   *
*							*
*********************************************************

This post contains Part 3 of the Linux FAQ (4 parts).
It must be read *after* the 2 first parts. 

===================================8<====>8============================
CONTENTS (of this part)

	VI. 	MISCELLANEOUS HINTS 		(part3)
	VII.	MORE HINTS			(part3)
	VIII. 	EMACS for LINUX			(part3)

===================================8<====>8============================

VI. MISCELLANEOUS HINTS 
=======================
*** This section is maintained by Matt Welsh ([email-masked]). Please
*** mail me if you have any changes/updates/questions. Thanks -mdw

Special gcc information are located in section X. A special section is
devoted to it since it's *the* compiler of Linux. I have subsectionned
this part in 3 subsections: 

VI.A Misc Information
VI.B Minor/Major Information

VI.C Serial Information

VI.A. Misc information
~~~~~~~~~~~~~~~~~~~~~~

  VI.01)  It seems that $#@! ported on linux don't run correctly, what
do I do about reporting bugs?

ANSWER: (Matt Welsh) It's possible that either the program itself has a bug
or that Linux has a problem that this program brings out. :) But first check
that the size of the file(s) corresponds that of the files(s) on the FTP
sites where it's available. If they're different, either you downloaded them
incorrectly (i.e. you forgot to turn on "bin") or whoever put them on the
FTP site uploaded them incorrectly. 

If that's not the problem, then post to comp.os.linux asking about the 
program, to verify that it is a bug. PLEASE: when posting possible "bug 
reports" include all error and output information from running/compiling
the program. Just saying "it doesn't work" isn't very helpful. Also mention
your specific setup, Linux version, GCC version, etc. Some of these things
depend on running under certain versions and you may have missed that
information. 

Note that my "[email-masked]" bug reporting list has been
phased out. It turns out that Linux has so few bugs, most of which are
resolved on the newsgroup or through Linus before I can accumulate them
and post. :) In short: if there's a bug in Linux or in Linux-ported
software, it will usually be fixed in the next patchlevel or version.

  VI.02)  Has $#@! been ported to Linux?

ANSWER: First check out the FTP sites and read the monthly INFO-SHEET,
as well as the new "Linux News" and the META-FAQ's (all of which are 
either available on the FTP sites and/or posted to the newsgroup as they're
written). Also check out the "Linux Project Registry" (posted to the 
newsgroup and on the FTP sites) which lists ongoing/current Linux projects.
Also look in the "old" Linux digests and mailing-list archives, kept on
tsx-11.mit.edu and nic.funet.fi. Also, see if there's a GNU(*) version
of the program you're looking for (which are available everywhere).
Since Linux uses GCC as its native compiler, most GNU software ports
directly to Linux without problems. If all else fails, ask on the
mailing list or newsgroup if the program is ported and where it's
available. 

(*) GNU stands for GNU's Not Unix, which (besides being a recursive
acronym) is a project started by the Free Software Foundation (the FSF)
to write a freely distributable version of Unix.  The GNU kernel is
named HURD, and is based on Mach.  It is currently being written, and is
not yet done.  Many of the GNU utilities, however, are completed and are
much more functional than the original Unix utilities.  Since they are
freely available, Linux is using them as well.

  VI.03)  I've ported $#@! to Linux, what should i do to add it in the 
standard distribution?

ANSWER: (Matt Welsh) First read the previous Q/A, then talk to the
maintainers of the various releases (MCC interim, SLS, and so on)
about including your program with those releases. The best way to make
programs available to the rest of the world is to upload it to one of
the Linux FTP sites (such as tsx-11.mit.edu:/pub/incoming or
sunsite.unc.edu:/pub/Linux/Incoming). 

BTW Whenever you submit binaries, please think that if you link them
with shared libraries, this might cause problems for those who (gasp!)
don't have the shared libraries installed. You can either link them
using -static, and if someone wants to build a shared version on their
own machine they can get the sources (which you should also make
available) and build it themself. Or else provide the shared lib.

  VI.04)  I want to port $#@! to Linux, what are the flags?

ANSWER: Recall that Linux implements subset of SYSV and POSIX, so
-DUSG and -DPOSIX work in general. 

NOTE1: SIGBUS is not there, and can be safely commented out in general.
NOTE2: see section related to GCC, in the third part of this FAQ, for
more details. 

VI.B. Major/Minor device number
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*** This section is maintained by Rick Miller, any comments,
*** suggestions, remarks should be mailed to him at <[email-masked]>
*** Last Update: April 1993

This is a list of the device names, along with Major and minor numbers,
which the Linux kernel may currently recognize.  I say "may" because some
of them may require patches to your kernel, others must be configured-in
using the Linux kernel's "make config" routine before compiling.

My profuse thanks to all the writers of device drivers for Linux, and to
all those patient folks who took the time to explain their devices to me.
May they become obscenely rich.  Until then, I hope this list will help
prevent driver collisions and perhaps lend a clue to a newbie or two.

        IF YOU WANT ANY CHANGES OR ADDITIONS TO THIS LIST, *TELL ME*!

        DEVICES NOT LISTED HERE SHOULD USE MAJOR NUMBERS *ABOVE 127*
        UNTIL ALLOCATED A MORE PERMANENT NUMBER IN THE LOWER RANGE.
        (I suggest using a more-or-less random number to avoid the
         chance of collisions with any other experimental drivers.)

        TO HAVE MAJOR/MINOR NUMBERS ALLOCATED (OFFICIALLY) FOR
        YOUR DEVICE DRIVER, SEND E-MAIL TO:  [email-masked]

  VI.05)  What are the device minor/major numbers?

Majors:
  0.  Unnamed .......  (unknown) ....  for proc-fs, NFS clients, etc. (???)
  1.  Memory ........  (character) ..  mem ramdisk kmem null port zero core
  2.  Floppy ........  (block) ......  fd[0-3]<[dhDH]{360,720,1200,1440}>
  3.  AT-Disk .......  (block) ......  hd[a-b]<[0-8]>
  4.  Tty ...........  (character) ..  tty's and pty's
  5.  Dial-out ......  (character) ..  tty cua*
  6.  Parallel ......  (character) ..  par[0-2] lp[0-2]
  8.  SCSI-Disk .....  (block) ......  sd[a-h]<[0-8]>
  9.  SCSI-Tape .....  (character) ..  <n>st[0-1] or <n>rmt[0-1]
 10.  Mouse .........  (character) ..  logibm psaux inportbm atibm (mouse)
 11.  CD-ROM ........  (block) ......  scd[0-1]
 12.  QIC-tape? .....  (character) ..  rmt{8,16} tape<{-d,-reset}>
 13.  XT-disk .......  (block) ......  xd[a-b]<[0-8]>
 14.  Audio .........  (character) ..  audio dsp midi mixer sequencer
 15.  Joystick ......  (character) ..  js[0-1]
 16.  Socket ........  (character) ..  net arp
 17.  AF_UNIX .......  (character) ..  unix
 18.  AF_INET .......  (character) ..  inet ip icmp tcp udp
 19.  WE-driver .....  (character) ..  we[0-3]
 20.  DP8390-driver .  (character) ..  wd[0-3] ec[0-3] ne[0-3]
 21.  Sony-CD-ROM ...  (block) ......  sonycd
 22.  2nd AT-Cntrlr .  (block) ......  hd1[a-b]<[0-8]>
 23.  Mitsumi CD-ROM   (block) ......  mcd
 31.  Link Interface   (character?) .  ???

Breakdown of minors by Majors:
------------------------------
  0.  Unnamed .......  (unknown) ....  for proc-fs, NFS clients, etc.
        Minors?

  1.  Memory ........  (character) ..  ram mem kmem null port zero core
        (0.  /dev/ram:  was supposed to be the ramdisk, but never got used.
         As of this date it has not been implemented and probably won't be.)
        1.  /dev/mem
        1.  /dev/ramdisk: a BLOCK device (the RAM-disk)
        2.  /dev/kmem
        3.  /dev/null
        4.  /dev/port
        5.  /dev/zero
        6.  /dev/core:  like /dev/mem, but in "core"-file format for gdb

  2.  Floppy ........  (block) ......  fd[0-3]<[dhDH]{360,720,1200,1440}>
        Minors are [[4 * type] + drive] where drive 0-3 == A:-D: (floppy)
        and type is:    0: Autodetect           4: 720k on 3.5" DD
                        1: 360k on 5.25" DD     5: 360k on 5.25" HD
                        2: 1.2M on 5.25" HD     6. 720k on 5.25" HD
                        3: 360k on 3.5" DD      7. 1.44M on 3.5" HD

        0. /dev/fd0:  Autodetected first floppy.
        1. /dev/fd1:  Autodetected second floppy.
        2. /dev/fd2:  Autodetected third floppy.
        3. /dev/fd3:  Autodetected fourth floppy.
        4. /dev/fd0d360:  360k on 5.25" DD in first drive
        5. /dev/fd1d360:  360k on 5.25" DD in second drive
                (You can work out the rest of the intermediates...)
        8. /dev/fd0h1200:  1.2M on 5.25" HD in first drive
        12. /dev/fd0D360 (/dev/fd0H360):  360k on 3.5" DD in first drive
        16. /dev/fd0D720 (/dev/fd0H720):  720k on 3.5" DD in first drive
        20. /dev/fd0h360:  360k on 5.25" HD in first drive
        24. /dev/fd0h720:  720k on 5.25" HD in first drive
        28. /dev/fd0H1440:  1.44M on 3.5" HD in first drive

     Naming goes like this:
        fd[drive][media][size]
         where: [drive]=0-3:  Corresponds to DOS's "A:"-"D:".
                [media]={d,h,D,H}:  d=Double Density 5.25" diskette
                                    h=High Density 5.25" diskette
                                    D=Double Density 3.5" diskette
                                    H=High Density 3.5" diskette
                [size]={360,720,1200,1440} kilobytes.

     Floppies are assumed to be double-sided (DS), and
        drives are assumed to be high-density devices.

  3.  AT-Disk .......  (block) ......  hd[a-d]<[0-8]>
     (For IDE, MFM, and RLE drives and controllers.)
      On the first AT controller card:
        0.  /dev/hda (/dev/hda0):  The whole first HD, including its MBR.
        1-4.  /dev/hda{1-4}:  Primary partitions on the first hard drive.
        5-8.  /dev/hda{5-8}:  Extended partitions on the first hard drive.
        64.  /dev/hdb (/dev/hdb0):  The whole second HD, including its MBR.
        65-68.  /dev/hdb{1-4}:  Primary partitions on the second hard drive.
        69-72.  /dev/hdb{5-8}:  Extended partitions on the second hard drive.
      On the second AT controller card:
        128.  /dev/hdc (/dev/hdc0):  The whole third HD, including its MBR.
        129-132.  /dev/hdc{1-4}:  Primary partitions on the third hard drive.
        133-136.  /dev/hdc{5-8}:  Extended partitions on the third hard drive.
        192.  /dev/hdd (/dev/hdd0):  The whole fourth HD, including its MBR.
        193-196.  /dev/hdd{1-4}:  Primary partitions on the fourth hard drive.
        197-200.  /dev/hdd{5-8}:  Extended partitions on the fourth hard drive.

        Notes:  BE *VERY* CAREFUL WITH the four "whole drive" devices (hda,
                hdb, hdc, and hdd)!!  These four devices embody the *entire*
                *drive*, not just one partition.  The only things that use
                them are things that need to read/change the partition table
                (like fdisk).

                Linux doesn't order anything.  It perceives partitions in the
                order in which they appear in the partition table.  Thus,
                /dev/hd?1 may follow /dev/hd?2 in the cylinder numbering.

                The names of the hard drives are not the same as under Minix.

  4.  Tty ...........  (character) ..  tty's and pty's
        0.  /dev/tty0:  This is the currently active Virtual Console.
        1-9.  /dev/tty[1-9]:  Specific virtual consoles.
        10-63.  /dev/ttyV[10-63]:  More virtual consoles that nobody uses.
        64-127.  /dev/tty[0-?][0-63]:  Dial-in serial ([controller][port]).
        128-191.  /dev/pty[p-s][0-f]:  PTY Masters.
        192-255.  /dev/tty[p-s][0-f]:  PTY Slaves. ([0-f]=0123456789abcdef)

        Notes:  NOTICE THE NEW NAMING FOR SERIAL LINES.  Serial lines will
                be named either "tty..." or "cua..." (See Major #5) followed
                by the one-digit number of the *board* the line is from, and
                the number of the line on that board.  The four default lines
                are considered to be on board "0", so what DOS calls "COM2:"
                should now be known as "/dev/tty01" or "/dev/cua01".

                For more information on the use of multi-port boards, read
                the documentation which accompanies the serial patches.

  5.  Dial-out ......  (character) ..  tty cua*
        0.  /dev/tty:  the tty that owns the process calling it.
        64-127.  /dev/cua[0-?][0-63]:  Dial-out serial ([controller][port]).
                (See Major #4 for NEW NAMING CONVENTION.)

  6.  Parallel ......  (character) ..  par[0-2] lp[0-2]
     Parallel (printer) ports.  (Increasable in include/linux/lp.h)
        0.  /dev/par0 (/dev/lp0):  First XT parallel port
        1.  /dev/par1 (/dev/lp1):  First AT parallel port
        2.  /dev/par2 (/dev/lp2):  Second AT parallel port

        Notes:  The number of line printers is defined by LP_NO which is
                found in [/usr/src]/linux/include/lp.h.

  7.  Unused.  (First come, first serve.)
        This one's getting old.  No minor numbers are yet assigned.
        It's not even in the source code.  Maybe it never will be...

  8.  SCSI-Disk .....  (block) ......  sd[a-h]<[0-8]>
        Minors numbers are ((16 * Drive) + Partition)
        where
          Drive is the number of the physical drive in order of detection
        and
          Partition is as follows:
                0   is the whole drive
                1-4 are the DOS "primary" partitions
                5-15 are the DOS "extended" (or "logical") partitions, so...

        0.  /dev/sda (/dev/sda0):  The first (detected) SCSI drive.
        1-4.  /dev/sda[1-4]:  Primary partitions on the first SCSI drive.
        5-15.  /dev/sda[5-15]:  Extended partitions on the first SCSI drive.
        16.  /dev/sdb (/dev/sdb0):  The second (detected) SCSI drive.
        17-20.  /dev/sdb[1-4]:  Primary partitions on the second drive.
        21-31.  /dev/sdb[5-15]:  Extended partitions on the second drive.
        32.  /dev/sdc (/dev/sdc0):  The third (detected) SCSI drive.
        ...and so on.

  9.  SCSI-Tape .....  (character) ..  <n>st[0-1] or <n>rmt[0-1]
        0.  /dev/st0:  First (detected) SCSI tape drive, rewind-on-close.
        1.  /dev/st1:  Second (detected) SCSI tape drive, rewind-on-close.
        128.  /dev/nst0:  First (detected) SCSI tape, *no* rewind-on-close.
        129.  /dev/nst1:  Second (detected) SCSI tape, *no* rewind-on-close.

 10.  Mouse .........  (character) ..  logibm psaux inportbm atibm (mouse)
     (MGR may require that /dev/mouse be linked to one of these...)
                NOTE THE CHANGES TO DIFFERENTIATE MOUSE TYPES!
                (Please implement these in the distributions.)
        0.  /dev/logibm:  Logitec-'compatible' bus mouse
        1.  /dev/psaux:  PS/2 mouse port (may not work on some lap-tops, yet)
        2.  /dev/inportbm:  MicroSoft "InPort" bus mouse
        3.  /dev/atibm:  ATI XL bus mouse

 11.  CD-ROM ........  (block) ......  scd[0-1]
        0.  /dev/scd0:  The first (detected) SCSI CD-ROM.
        1.  /dev/scd1:  The second (detected) SCSI CD-ROM.
        ("There's not much more to it than that" says Eric Youngdale.)

 12.  QIC-tape? .....  (character) ..  rmt{8,16} tape<{-d,-reset}>
     (I really don't have much info on this one... )
        6.  /dev/rmt8:  QIC-120
        8.  /dev/rmt16 (/dev/tape):  QIC-150
        136.  /dev/tape-d:  (It has something to do with being 128+8... ?)
        255.  /dev/tape-reset:  For resetting only.

 13.  XT-disk .......  (block) ......  xd[a-b]<[0-8]>
     XT (8-bit) hard disk controller devices.
        Minor numbers are assigned in the same manner as for the
        normal (AT-type) Hard Drive devices ("/dev/hd*").

 14.  Audio .........  (character) ..  audio dsp midi mixer sequencer
        0.  /dev/mixer:  Mixer and Control Device
        1.  /dev/sequencer:  FM-synthesizer and Midi
        2.  /dev/midi:  (for future use)
        3.  /dev/dsp:  Digitized voice (DAC/ADC)
        4.  /dev/audio:  (Reserved for compatibility with Sun)

 15.  Joystick ......  (character) ..  js[0-1]
        0.  /dev/js0:  (Left/Right?) joystick.
        1.  /dev/js1:  (Right/Left?) joystick.

 16.  Socket ........  (character) ..  net arp
        0.  /dev/net:  Generic layer (sockets)
        1.  /dev/arp:  Address Resolution Protocol (ARP)

 17.  AF_UNIX .......  (character) ..  unix
        0.  /dev/unix:  AF_UNIX protocol layer

 18.  AF_INET .......  (character) ..  inet ip icmp tcp udp
        0.  /dev/inet:  AF_INET protocol layer
        1.  /dev/ip:  Inernet Protocol (IP)
        2.  /dev/icmp:  Internet Control Message Protocol (ICMP)
        3.  /dev/tcp:  Transmission Control Protocol (TCP)
        4.  /dev/udp:  User Datagram Protocol (UDP)

 19.  WE-driver .....  (character) ..  we[0-3]
        0-3.  /dev/we[0-3]:  "WE" driver

 20.  DP8390-driver .  (character) ..  wd[0-3] ec[0-3] ne[0-3]
        0-3.  /dev/wd[0-3]:  "DP8390" driver, WD8003
        8-11.  /dev/ec[0-3]:  "DP8390" driver, 3C503
        16-19.  /dev/ne[0-3]:  "DP8390" driver, NE2000

 21.  Sony-CD-ROM ...  (block) ......  sonycd
        0.  /dev/sonycd:  Sony CDU-535 CD-ROM, I think.

 22.  2nd AT-Cntrlr .  (block) ......  hd1[a-b]<[0-8]>
     Minor numbers are like those of the primary AT-Disk controller.
        THIS MAY WORK FOR HARD-CARDS.
     (Note the "1" in the device name for the secondary controller.
      This is because we may eventually wish to change the names of
      the primary-controller drives to "hd0[a-b]...".)

 23.  Mitsumi CD-ROM   (block) ......  mcd
     I don't know much about this one.

 31.  Link Interface   (character?) .  ???
        0.  ???
     Link Interface for use with Christoph Niemann's driver for the
     INMOS C012-based high-speed serial link interface card (useful
     for talking to transputers or video digitizers).

  VI.06)  (Chuck Boyer) Could some one clear up the devices meaning?

ANSWER: (Jim Winstead Jr)
>port

This allows programs to access the hardware ports directly.  Not
something you generally mess around with much.

>ptyp0-3
>ptypa...tty

These are the pseudo-tty 'master' devices.  Each pty connection uses
a slave-master set of tty devices.

>tty0...

tty[1-8] are the virtual consoles associated with Alt-F[1-8].  tty0 is
the current virtual console (so writing something to tty0 goes to the
current vc).

>tty64 I've figured out is the modem connection

Yes, that would correspond to COM1 under DOS.  However, the tty64 name
is obsolete - ttys[1-4] should be used instead.

>ttyp0...
>ttypa...

These are the pseudo-tty 'slave' devices.

>ttys1...

These are the serial devices.  ttys1 corresponds to COM1 under DOS,
ttys2 corresponds to COM2, etc.

VI.C Special Serial
~~~~~~~~~~~~~~~~~~~
*** This section is maintained by Jim Gifford
*** (jgifford@attmail,world.std}.com), some addenda were sent by
*** Juha Ursin ([email-masked])
*** Last update May 1993.

Douglas E. Quale:
This has come up a couple of times already (including the case of
serial mice as well), but for the record stty acts on stdin not
stdout.  Old stty's (from V7 through BSD4.3) used stdout, but this is
suboptimal and doesn't conform to POSIX.  The GNU stty you are likely
using on Linux uses stdin, as does the stty distributed with BSD
Networking Release 2.  (Also, ``stty -a'' is more informative about
possible parameters, although it's pretty hard for me to remember what
90% of that stuff does without refering to the man page.)
Jim Gifford:
However, there are a few older (of mysterious origin) stty's that work
on stdout(I have one myself!)

  VI.07)  Is there a list somewhere where I can get help with serial
   communications under Linux?

ANSWER: (Jim Gifford -- [email-masked])
   There is a list for the discussion of serial communications under
   Linux.  It is for problems, drivers, new developments, etc... with
   the Linux serial devices. The list is: [email-masked]
   To join, send mail to [email-masked]
   I hope that this list will prove beneficial to the improvement of
   Linux. This list is maintained by Michael K. Johnson as
   [email-masked]

  VI.08)  When I run kermit under Linux, I get "Warning, Read access
   to lock directory denied". What am I doing wrong?

ANSWER: Nothing, you just need to create /usr/spool/uucp (kermit 4.6?)
   or /usr/spool/locks (this is for the kermit5A), which is where kermit
   like to lock files.

  VI.09)  What are the major, minor numbers for the serial ports under linux?

ANSWER:   Major 4, Minor :
   64      /dev/ttys0      - com1
   65      /dev/ttys1      - com2
   66      /dev/ttys2      - com3
   67      /dev/ttys3      - com4

  VI.10)  can anyone give me a sample /etc/inittab entry for login
   from a pc attached to serial line /dev/ttys2?

ANSWER: "Humberto speaking :), updated by Rick Miller"
   First set up the modem to turn off echo and enable auto answer, I do
   this in kermit by connecting to the modem and typing "ate0s0=1"
   followed by enter (w/o quotes). Then setup inittab to spawn getty on
   the modem
   ttys2:vt100:/etc/getty -m 1200 ttys2
 	(Replace "vt100" with the name of the /etc/termcap entry for the
 	 terminal type you will use, or use "dumb" if you don't have one.)

   Then it should work. Some modems can be permanently set to disable
   echo and set auto answer, see your manual.

   Jim Weigand says:
     disable all messages. This will prevent getty from hanging up
   your modem.
   Set       For:
   ATE0      No echo
   ATQ1      No messages
   ATS0=2    Answer 2nd ring
   ATS7=60   1 minute to answer (shorter if 2400 baud)
   You can use kermit to set these. Do an AT&W to save for power-up.

   Michael K. Johnson says:
   If you would rather not save these commands as defaults to come up
   on power-up, perhaps because you want to use your current modem
   settings under a DOS communications package, you can also shove
   these command out ttys? from /etc/rc (or /etc/rc.local) using
   the command:
      echo "<modem_settings>" > /dev/ttys?

  VI.11)  How do I set parameters like parity for serial login?

ANSWER: Use stty and redirect input from the serial line.
ex: stty parodd < /dev/ttys2 which gives ttys2 odd parity.  
type stty -a to get an idea of possible parameters. 
Or 'man stty' as well :)

  VI.12)  (Juha Ursin) I run SLS pl6, kernel is pl8 and I use
libc.4.3.2.
Trying to allow login on my terminal (on ttyS1 with only three wires
(RX, TX, GND) connected). Getty 9600 /dev/ttyS1 starts and I get the
login prompt, but the password prompt newer appears.

ANSWER: (Ted Ts'o)
Setting CLOCAL is the correct way to solve this --- it is not a bug in
the kernel.  Since you only have three wires connected, it means that
the carrier detect line was left floating, and probably floated to
ground.  Thus, the /dev/ttyS1 device blocked waiting for carrier detect
to go high.  The reason why the login prompt appeared is that getty
opened /dev/ttyS1 with the NODELAY flag; but when /dev/ttyS1 was
reopened for /bin/login, it did not have the NODELAY flag, and you ended
up blocking.

That's what the CLOCAL flag is for --- it indicates that the serial port
is hooked up to a local (hence CLOCAL) terminal, and so the carrier
detect line should be ignored.  In general, whenever the carrier detect
line is not supported by a serial device, or if your RS-232 cable does
not support the CD wire, the CLOCAL flag should be set.

  VI.13)  (Juha) Where are my Call-out-mode -serial ports (cuaX) ?,
When should I use these cuaX ports ?, Why on my system ttys3 is used
instead of ttyS3 ?

ANSWER: (Ted) Ask the person who created the install procedure (Peter
MacDonald, in the case of SLS).

>When should I use these cuaX ports? 

When you're dialing out (i.e., kermit, cu, seyon, uucp, etc.).

>On my configuration ttyS3 is named ttys3 incorrectly - why? 

Again, see the person who created the install procedure.  Recent
versions of SLS create the serial devices using the new convention
(ttyS3).  ttys3 represents an older convention, and some older install
procedures may not have switched over.

  VI.14)  (Juhan) What other possibly free IRQ's there are than IRQ5 ?,
Can I use IRQ7 when not printing ?,

ANSWER: (Ted)
IRQ 2 is also often free, although some networking cares use them.

> Can I use IRQ 7 when not printing? 

It's generally a bad idea to have two cards plugged in sharing an IRQ
address.  It happens to work with most serial cards, but it doesn't
alwas work.  You can use IRQ 7 if you don't have a parallel port plugged
into your system.  If you do have a parallel port plugged in, you can
try using IRQ 7; it might work, it might not.  Be sure to also make sure
that the printer works after you plug in your serial card configured to
use IRQ 7.  Another alternative: If you are using the version of the
parallel printer driver that doesn't use interrupts, you can go to your
parallel port board, and disable the IRQ, thus freeing IRQ 7.

     Is pin 1 nearest to the plate or is it 31?

If this is a sample PC ISA card, then A1 is the pin closest the "back" of
the card, and on the top, if the pins are held down and the "back" of
the card is to your right:

 ----------------------------------------------------------------------
 |                                                                    |
 |                                                                    |
 |                                                                    |
 |                                                                    |
 |                                                                    |
 |                                                                    |
 +---------------------------------+          +---+               +---+
                                   |          |   |               |
                                   +----------+   +---------------+
                                                   A             A
                                                   3             1
                                                   1

The "B1..B31" pins are on the reverse side of the card.

VII. MORE HINTS 
=============== 

This part try to keep track of the different information
that appeared in comp.os.linux and on the list since beginning of
March. I tried to update it for KERNEL_VERSION, so there might be some
mistakes. Moreover take care to use the correct library and include
stuff, and the ad-hoc gcc you use !!!

 VII.01)  How can I backup my Hd under Linux ?

ANSWER: I know at least two ways. One possibility is tar and mtools,
another possibility is the diskbackup/diskrestore of Diamano Bolla
(digest37 vol. #2) which saves big hd to floppies using the
stdin/stdout. These utilities have been uploaded to the major sites in
file disksplit.tar.Z.
An example usage (Roger Binns) is:

tar cvf - bin dev usr etc .. | compress | diskbackup

and to restore:

diskrestore | uncompress | tar xvf -

BTW: if you are on Ethernet you could send your files via tar..|rsh (tar...)
or even via NFS to a host which is regularly backed up !

 VII.02)  Where is 'which' ?

ANSWER: It depends on the sh you are running:
in bash 	'type -path'
in tcsh		it's a builtin

for rc you can try the following (untested by me) script from
Kevin Brown: 

#!/bin/sh
for i in `echo $PATH | sed 's/:/ /g'` ; do
  for j in ""$@" ; do
	if test -x "$i/$j" ; then
	   echo "$i/$j"
         fi
  done
done

 VII.03)  How to use setterm: for the novice?

ANSWER:The setterm utility provides access to most of Virtual Consoles
(VCs) functionality.  You can set your screen up to blank at 10
minutes using:
	        setterm -blank 10

You can set colors, and clear the screen.  For a full list of commands,
just type "setterm" with no arguments.
        
There are a few tricks with the screen dumper can really make VCs go a 
long way.  Here are a few of the common ones that I use:

		setterm dump

Dumps the contents of the current VC to screen.dump (in the current dir).
					
		setterm dump 4
				
Dumps the contents of VC 4 to screen.dump
		
		setterm -file mydumpfile -dump 4

Dump the contents of VC 4 to the file mydumpfile

		setterm -file /dev/tty0 -dump 4

Dumps the contents of VC 4 to the current VC.
					
		setterm -file /dev/tty4 -dump

Dumps the contents of the current VC to VC 4.
		
		setterm -file /dev/ttys1 -dump
				
Dumps the contents of the current VC to the serial port.
Handy if you are logged on and want to paste a screen full without
having to resort to doing a file transfer.

		setterm -file mydumpfile -append 4
				
Appends to instead of overwriting the dump file.  Useful if you
have several screens you wish to concatenate.

 VII.04)  I've tried clear/reset which exist on most of unix but it
doesn't work, have I missed something? 

ANSWER: setterm -clear or setterm -reset will solve your missing.  For
clear, you can also write a small script (which use the cl: part of
/etc/termcap wrt your TERM), or use bash where ctrl-l will do it for
you.

 VII.05)  I know there are VC, but where is the setterm stuff?

ANSWER: It's in the current distribution (i.e. on the images), the
source can be found in virtcons.tar.Z at nic.

 VII.06)  I know there are shared libraries; does there exist an easy
way to check an executable for sharing ? 

ANSWER: (Claude Morin:) There exists at tsx-11 ldd.tar.Z If you follow
the instructions, you will be able to type "ldd <executable>" to List
the Dynamic Dependencies of the executables. In other words 'ldd'
prints the name of the shared libraries needed by the executable,
nothing appears for static one. 

ANSWER: (Josh Yelon & HJ Lu) - very old binaries.
(J.Y.) An executable which shares a library is linked with an
(ordinary, non-shared) "stub" version of the library. One of the first
thing this stub does (when the executable is run) is to ask the kernel
to load the (big) "shared version" of the library (which is usually
named /lib/lib.XX.XX) The upshot of this is that in the code for the
stub (part of the executable), is the string "/lib/lib.XX.XX"; which
can be searched by using 'strings' or 'grep'.
(HJ. L.) if you have gcc2.11a or later the shared image is changed to
/lib/libxxxx_vyy_zzz. And you should better use nm to find
"__shared_lib" (nm failed on stripped executable). You can also write 
a function for "file", which can even check the version number ....

 VII.07)  What is the rdev program provided in the images?

ANSWER: It's a program from Werner Almesberger of ETH. With no
argument it prints the first line of /etc/mtab. With one argument, a
boot-image, it prints the device configured as the root device, and
with two arguments, a boot image and a device, it sets the device as
default root in the specified image.

 VII.08)  How to start Linux from drive B?

ANSWER: There is a DOS utility called boot_b.exe (look at DOS ftp).
Another simple way is to open the box and invert the cables.

 VII.09)  The program boot_b works fine /but/ once the first disk is
read the system go back to the first drive, any hints?

ANSWER: Yes, change the bootimage in just the same way that you change
it to boot on the hard drive, execept that the major/minor pair is
different. All these information are in the file INSTALL-0.10.
Remember that if you use a sun or other endian machine, you will need
to reverse the byte order when you run the filter program (also in the
same file).

 VII.10)  How can I get Linux to boot directly from the harddisk?

ANSWER: (Rick) The best option right now is LILO version ALPHA.8. It
has been generally agreed that the days of using "shoelace" are at an
end. See Section III of this FAQ for LILO information.

 VII.11)  I use shoelace, but I want to change my root partition, what
is the process to get rid of it? 

ANSWER: With Norton utility you can put back a standard boot sector.
Another possibility is to restore the old boot sector (the one you
should have backup *before* installing shoelace).

 VII.12)  Sometimes, when I want to remove a directory, I get an error
message, is it a (known) bug?

ANSWER: No, There is no bug at all, you probaly have another shell 
on another VC whose working directory is either the one you try to 
remove, either a subdirectory of it.

 VII.13)  I'm looking for init, getty, login, passwd stuff, where 
can I find them? 

ANSWER: You should find it in shadow.tar.Z (only sources), at least 
at tsx in the usr.bin directory. Many people have reported some troubles 
with the *OLD* shadow-passwd (shadow-bin.tar.Z and shadow-src.tar.Z, so 
do not use them anymore); an alternative might be the mcc-interim
which contains standard passwd binary. There is also the Peter Orbaek's
admutil-1.?.tar.Z and poeigl-1.?.tar.Z which contains source for
shutdown, su, chsh, passwd and a system V init compatible. 

 VII.14)  How can I setup a user account other than root ?

ANSWER: You can either use the adduser program, either do it manually.
In the later case, you have to:
a) edit /etc/passwd as root and add a line of the following format:
user:passwd:uid:gid:user name:home directory:login shell

user is the login name; uid is the numeric user id, it should be
unique; gid is the numeric group id, this number should correspond to
an entry in /etc/group. The passwd field should be left blank 'cause
it is stored in an encrypted form [to set this field just use the
passwd program].
example
faq::200:5:Marc-Michel:/home/faq:/bin/sh
b) Still as root, you shoud now create the home directory and set the
correct ownership.
mkdir /home/faq
chown faq /home/faq
chgrp 5 /home/faq

 VII.15)  I've been trying to get Linux to run on my [3/4]86 box. It
can't even boot. Any suggestions?

ANSWER: The most common error/problem is writing the bootimage to a
low density disk. It fits, but the bootstrap code will only recognize
high density disk. So try to format explicitely disk as high density:
- for 3.5",  'format a: /n:18 /t:80 '
- for 5.25", 'format a: /n:15 /t:80 '

 VII.16)  Does there exist games, languages (other than C), and
anything which make the system more friendly?

ANSWER: Yes, among other things there are rogue and yahtzee; TeX;
Prolog, Perl.. but in general, if you want some extra tool port it to
Linux this is also a good beta-testing exercice. 

 VII.17)  Whenever I use uemacs 3.1X on a symlink, the symlink does
not exist anymore, why?

ANSWER: (Tristram Mabbs) Since ue3.10, uemacs uses 'safe save' mode,
writing the file to a temporary and moving it OVER the original. In
the process, this deletes the original. To prevent this just add the
following in your emacs '.rc' file: set $ssave FALSE

 VII.18)  I have an SVGA, but Linux detect an EGAc/EGAm; is it normal?

ANSWER: (Jim Winstead) This is correct actually. You have an EGA+ card
(SVGA) with a Color/Mono monitor. The only four possibilties are EGAc,
EGAm, *MDA and *CGA (according to the code in
kernel/chr_drv/console.c).
The true test, if Linux detects your video card, is if you press
<RETURN> at the "Press <RETURN> to see SVGA- ..." boot-time message.
If you have a SVGA  recognized card, it will ask you to choose a
screen size. If not detected, the default is 80x50 mode. 
BTW if you have no SVGA, press the <space> and you are in 80x25 mode.

If you have dowloaded the kernel, you can automatically skip this
query at boot-time if you set the SVGA_MODE variable in the main
Makefile before compiling a new bootimage. 

 VII.19)  How can I change the keyboard repeat rate?

ANSWER: (Michael K Johnson) In boot/setup.S there are the lines:
! set the keyboard repeat rate to max
	mov	ax,#0x0305
	mov	bx,0x0000
	int	0x16

If you don't want to change the repeat rate at all, just comment out
these lines. If you want something in the middle, change the
	mov	bx,0x000
by	mov	bx,0x??yy
where ??yy is determined by (Ralf Brown's interrupt list)
bh= delay value (0x00 = 250ms to 0x03= 1000ms (one sec))
	this is the delay before the repeat is performed
bl= repeat rate (0x00 =30/sec to 0x1f=2/sec; 0x0c=10/sec [default])

 VII.20)  I compiled fdformat.c and ran it on 1.44Mb and 1.2Mb, the
results are unreadable, any clue? 

ANSWER: (M. Pereckas) fdformat only low-level formats the disk. to use
the fdformatted disk with DOS filesystem, run mformat on the disk.
Mformat writes DOS filesystem information but is unable to low-format
:). In order to put a Linux filesystem on a (low)formatted disk you
have to mkfs it. 

 VII.21)  Is it possible to disable the 3-fingers salute
(ctrl-alt-del) ?

ANSWER: Yes, in kernel/sys.c you can read the following:

/*
 * this indicates wether you can reboot with ctrl-alt-del: the deault is yes
 */
static int C_A_D = 1;

there is also a small utility written by Linus in digest242 vol#2

 VII.22)  Could some one explain the information provided at boot-time?

ANSWER: (Jim Winstead Jr)
> serial port at 0x03f8 is a 16450 
> serial port at 0x02f8 is a 16450 (what's that the uart chip?)

Right, the last number should either be 8250, 16450, 16550, or 16550a,
and on the two 16550 models, it will report that FIFO's have been
disable (16550) or enabled (16550a).

> 8 virtual consoles (that's how many alt-F's I can get going?                 
>      but only F1-4 actually work)

You can get sessions running on Alt-F[1-8], but the 'standard'
/etc/inittab only runs getty/login on Alt-F[1-4].  You can start
sessions on the other consoles by using 'doshell' or adding lines to
/etc/inittab.

> 4 pty's (are these the consoles F1-4?)

No, those are 'pseudo' ttys, which programs like MGR use to simulate
tty connections.  That's probably a gross over-simplification, but it
gives you the general idea, I think.  :)

> p_init: lp1 exists (0) (is that the (l)ine (p)rinter?)

Right.

 VII.23)  What is the meaning of files ended by .T.Z (or .taz) ?

ANSWER: The suffix Z is for compressed files (to uncompress them use
the command `uncompress file.Z`).
The suffix T indicates a "tar file" the usual suffix is tar but, the
14 chars filename limit of the Minix filesystem makes it cumbersome to
use .tar.Z (to untar a file ended by .T, use the command 
`tar options file.T` (see the man page for more details).

For the .taz file, change them as .T.Z and go-ahead.

 VII.24)  What is the meaning of files ended by .T.z (or .tpz) ?

ANSWER: The suffix z is for files compressed with the
gzip utility, which is being used more frequently because it provides
better compression.  These can be uncompressed with the `gzip -d
file.z` command.

 VII.25)  I have upgraded the kernel from XX to YY (XX > YY), however the
login screen still says YY.

ANSWER: Just change the message in one of these files: /etc/issue and
/etc/motd. The former contains the message before the login, the later
is the one after you are logged in.

 VII.26)  What is doshell good for ?

ANSWER: It's an old program provided in the early Linux version (0.12)
when the getty was not already there, it spawns a shell on any tty's.
(Mattew Gream): I do this quite often ( getty on tty1, 2, 3 and my
rc.local spawns a shell on tty4 as follows
	 '/usr/bin/doshell /dev/tty4 /bin/tcsh &'

 VII.27)  I don't have the kernel sources, how can I change the keyboard
language?

ANSWER: You can use the fixkbd program written by Laurent JULLIARD
([email-masked]). Its purpose is to fix the keyboard
map used in your kernel image. It works more or less a la "rootdev"
(or rdev). It can be found on tsx-11.mit.edu in
/pub/linux/binaries/sbin/fixkbd.tar.Z.  

 VII.28)  Does there exist a possibility to track down the source of
kernel pannic messages ?

ANSWER:  Here's info from Linus on how to track down the source
of kernel panic messages. The values for EIP, address, and so on are
JUST EXAMPLES: the EIP, EFLAGS, etc. can be anything.

The lines after ">" were written by me; the responses by Linus.

> Unable to handle kernel paging request at address C000000A

This means something in the kernel tried to access kernel memory at
address 0x00A (the C0000000 offset is due to the kernel starting at
virtual address 0xC0000000).  The first page of kernel address space is
unmapped to find these kinds of incorrect references (it's probably a
NULL dereference to a structure member at offset 0xA). 

> Oops: 0002

Error code. This tells you if it's a read or write (forget which ritgh
now, and don't have any books handy)

> EIP: 0008:000290D2

This is where it happened: segment 0008 (kernel code segment) and offset
0x290D2 into the kernel. So to find this, you generally do something
like

	nm /usr/src/linux/tools/system | sort | less

and search for the function that contains the address 0x290D2.

> EFLAGS: 00010087
> fs: 0017

Eflags and fs when the exception happened. You usually don't need this.

> base: C0000000, limit: 000A0000
> Pid: 0, process nr: 0

In what process the exception happened. This is the swapper, which also
means the thing is fatal (other processes you can just kill). That it's
in the swapper process probably means that it's an interrupt that did
it, as the swapper doesn't really do anything.

> 89 50 04 c7 03 00 00 00 00 c7

This is the instruction that resulted in the error.  I usually
disassemble them by hand and see what it is, then I try to find out
exactly where in the function this assembly sequence comes up (probably
by compiling the .c file to a .s file and looking around). 
Alternatively you can just run 'gdb' on /usr/src/linux/tools/system, but
gdb has some problems. 

> task[0] (swapper) killed: unable to recover
> kernel panic: Trying to free up swapper memory space
> In swapper task - not syncing

This is just to tell you not to expect anything from the kernel any
more: linux cannot go on without the swapper task.

> How can I decode the numbers in the message? 
> Also, note that sometimes the "Unable to handle..."
> message is followed by the "Oops: 0002" block, but
> the last message is sometimes something else (i.e. not
> always a "task[0] (swapper)...." message, but something
> from the TCP driver in this case. 

It depends on where it happened. If it's an interrupt, it can
essentially happen in any task (all interrupts are handled in the task
that happens to be currently active), while "normal" code happens in the
task that calls it.

VIII. EMACS for LINUX
=====================
*** This section is maintained by Rick Sladkey ([email-masked])
*** Last Update March 1993.

VIII.A. GENERAL INFORMATION 
VIII.B. GNU EMACS for LINUX

VIII.A. GENERAL INFORMATION
~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is a short list of Frequently Asked Questions about GNU Emacs
under Linux.  It does not address general questions about Emacs which
are not Linux specific.  For general help about Emacs, 1) learn to use
and read the online documentation, 2) read the real Emacs FAQ found in
emacs/etc/FAQ, and 3) read the newsgroup gnu.emacs.help.

                                        Rick Sladkey <[email-masked]>

VIII.B. GNU EMACS for LINUX
~~~~~~~~~~~~~~~~~~~~~~~~~~~
VIII.01)  What version of the compiler was used?  Which shared libaries?

ANSWER: This describes version of GNU Emacs 18.59 for Linux 0.99.5 and above
compiled with GCC 2.2.3 using the libc.so.4.3 and libX11.so.3.0 shared
libraries.

VIII.02)  Which files do I need?

ANSWER:
emacs-18.59b.tar.Z		this file, sample default.el and diffs
				for this version, the eight-bit patch,
				iso-latin-1.el and eight-bit.el
emacs-etc-18.59b.tar.Z		emacs support programs and misc info
emacs-bin-18.59b.tar.Z		shared emacs binary and its doc file
x11emacs-bin-18.59b.tar.Z	shared x11emacs binary and its doc file

VIII.03)  How do I install them?

ANSWER: For the latter three files, just cd to /usr and untar them.

VIII.04)  What if I want to compile Emacs myself?

ANSWER: It is fairly easy (and highly recommended) to compile Emacs
yourself if you have the the disk space.  In this case you only need
the standard Emacs distribution (emacs-18.59.tar.Z from any GNU archive)
and the Linux diffs and support files (emacs-18.59b.tar.Z from a Linux
archive).  The diffs are quite small and mostly amount to a
configuration file.

VIII.05)  What about Epoch or Lucid Emacs?  Are these available for Linux?

ANSWER: Yes.  Thomas Dunbar has been maintaining Epoch for Linux and
Chipsy Sperber has compiled Lucid Emacs.  Both of these work well
under Linux.  Look in a Linux archive index for where to find them.

VIII.06)  Does Linux Emacs support eight-bit input/output?

ANSWER: Yes.  It is new with this version.  It uses the so-called
"ctl-arrow" patch.  See the file README.8bit for more information.

VIII.07)  How much disk space is required?

ANSWER: Anywhere from 1 to 15 Meg.  Emacs works reasonably well with no
support files at all.  With a judicious selection from lisp/*.elc and
etc/*, quite a lot can be done using only 2 Meg.  If you want all of
lisp/*.elc, info/*, and etc/* this will require 4 to 6 Meg.  If you
unpack the whole source you need 8 Meg.  If you collect info files
like rare coins and install a lot of big lisp packages then Emacs may
need its own partition. :-)

VIII.08)  Why can't Emacs find its support files anymore?

ANSWER: This is because older versions of Emacs were compiled with
"/usr/local/emacs" based paths.  The current version is compiled with
"/usr/emacs" paths.  If you have a previous installation, just "mv
/usr/local/emacs /usr" and you're done.  If you can't bear to part
with the "/usr/local" pathnames because of inertia then do "ln -s
/usr/local/emacs /usr" and you can have them both.

VIII.09)  How do I get Emacs to recognize my cursor keys?

ANSWER: Simple.  Don't use them. :-)  Seriously, there are as many
ways to do this are there are elisp hackers but the preferred way is
to follow the pattern set by the other terminal definition files in
emacs/lisp/term/*.el.  For just arrow keys you can just copy vt220.el
to console.el and that's it.  For function keys and the others see
the sample default.el included with emacs-18.59b.tar.Z.

VIII.10)  What packages are particularly useful under Linux?

ANSWER: Because info format is the documentation standard of the GNU
project and just about everything except the kernel comes from FSF,
you will find that Dave Gillespie's enhanced info package is very
useful.  It allows multiple info directories, space bar paging, and
supports compressed info files. Please learn to use info.  Imagine
Unix life without man.

Others that I highly recommend are Sebastian Kremer's enhanced
dired directory editor, Dave Gillespie's calc calculator, Masanobu
UMEDA's gnus for usenet news, and Kyle Jone's vm for mail.

All can be found in the OSU Emacs archive, ftp.cis.ohio-state.edu,
/pub/gnu/emacs/elisp-archive.  See the real FAQ for more details.

VIII.11)  Does Linux Emacs use the shared libraries?

ANSWER: Yes.  It works fine with the DLL libraries and should not
require a new binary when the C or X libraries are updated.

VIII.12)  Does Linux Emacs support the X Window System?

ANSWER: Yes.  However, there are two binaries.  One without X support
(about 485k) and one with X support (about 515k).

VIII.13)  Do I need both Emacs if I don't always use X?

ANSWER: No. The X11 version works equally well inside or outside of X.
If you get the message "Check your DISPLAY variable" it means that
you have defined DISPLAY in your ~/.profile (or whatever).  You can
fix this by starting Emacs with 'emacs -nw' or by removing the DISPLAY
variable from your ~/.profile and putting it in you ~/.xinitrc.

VIII.14)  Why doesn't Emacs use the settings in my
.Xdefaults/.Xresources file? 

ANSWER: You are probably using the word "emacs" and your X version of
emacs is called x11emacs.  Either use the word "Emacs" in your resource
file or rename x11emacs to emacs.  See above question on why this
is reasonable.

VIII.15)  I read about some menu that is supposed to pop up when I
press some mouse button.  Does this work with Linux Emacs?

ANSWER: Yes.  This requires XMenu support to be compiled in.  Former
versions did not support it because it did not work correctly.

VIII.16)  Sometimes Emacs crashes with a SIGALRM message.  What's
wrong? 

ANSWER: The old answer about upgrading to a newer version of bash
was incorrect.  The problem was in the implementation of sleep(3)
in the old C library.  It is fixed as of libc-4.3.

	   ===================8<==========>8================

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#	LaBRI 			 |					    #
#  351 cours de la Liberation    |  e-mail:  [email-masked]   #
#  33405 Talence Cedex		 |  e-mail:  [email-masked]    #
#  				 |					    #
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- 
	 There will be a sig when our local net is reliable.
	       For now, I would rather stay anonymous.