

UUCP                         Overview                        UUCP




Unattended communication with remote systems


_U_U_C_P  stands  for ``UNIX  to  UNIX  copy''.  It  is  a system  of
commands that allows you to exchange files with other COHERENT or
UNIX systems,  in an unattended manner.  With  UUCP, you can send
mail to other  systems, upload files, and execute commands.  When
configured correctly, UUCP  also lets other users upload files to
your system, copy files  from it, and execute commands.  All this
can be done  without your having to sit at  your console and type
commands; thus, files can be transferred in the small hours, when
telephone rates are lower and computers are relative free.

UUCP gives  you access  to the  Usenet, a nation-wide  network of
UNIX  and COHERENT  users.   Access to  the Usenet  will let  you
exchange mail with any  of the thousands of Usenet users, receive
mail from  them, download source  code for many  useful programs,
and read the  latest news on a host of  subjects.  For details on
contacting  UUNET, a commercially  accessible Usenet  site, enter
the command:


        phone uunet


The UUCP protocol is  implemented through a suite of commands and
files.  The following Lexicon entries relate to UUCP:


     LL-ddeevv        File that describes devices used by UUCP
     LL.ssyyss        File that describes systems contacted by UUCP
     PPeerrmmiissssiioonnss  FIle that sets remote system permissions
     uuuucciiccoo       Transmit data to a remote site
     uuuuccpp         Prepare files for transmission
     uuuuccppnnaammee     File that sets your system's UUCP name
     uuuuddeeccooddee     Decode a binary file sent from a remote system
     uuuueennccooddee     Encode a binary file for sending to a remote system
     uuuuiinnssttaallll    Help install UUCP on your system
     uuuulloogg        Read UUCP log files
     uuuummvvlloogg      Move UUCP log files to backup archive
     uuuunnaammee       List UUCP names of known systems
     uuuurrmmlloocckk     Remote UUCP lock files
     uuuuttoouucchh      Touch a file to trigger uuuucciiccoo poll
     uuuuxx          Execute command on a remote system
     uuuuxxqq         Execute commands requested by a remote system


The following sections discuss problems that can arise when using
UUCP, as diagnosed by the Mark Williams Technical Support Staff.

***** Using Trailblazer Modems With UUCP *****

The Trailblazer modem has been designed to be used with UUCP.  It
is  extremely fast  and extremely  accurate; however,  some users


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reported  problems  in using  COHERENT  UUCP  with a  Trailblazer
modem.   The following  describes how  Mark Williams  Company has
configured the  Trailblazer modem that it  uses under COHERENT at
9600 baud.

To begin,  the following  gives the permissions  in /uussrr/lliibb/uuuuccpp
for selected files:


-rw-r--r--  1 uucp     uucp       196 Wed May 23 10:16 L-devices
-rw-r--r--  1 uucp     uucp       740 Tue May 22 15:40 L.sys
-rw-r--r--  1 uucp     uucp      2151 Wed Jul 11 10:44 Permissions


The  following gives  partial contents  of  file /uussrr/lliibb/uuuuccpp/LL-
ddeevviicceess:


#type    line   remote  baud    brand
#-----  ------  ------  ----    -----
ACU     com3l   com3r   2400    tb2400
ACU     com3l   com3r   9600    tbfast


The following gives  partial contents of file /uussrr/lliibb/uuuuccpp/LL.ssyyss
(note that # should be replaced by the actual phone number):


uunet Any ACU 9600 # FAST \d\r\c in:-\r-in: \dmwc\r\c rd: PASSWORD\r


The      following       gives      partial      contents      of
/uussrr/lliibb/uuuuccpp/PPeerrmmiissssiioonnss:


MACHINE=uunet LOGNAME=uuunet \
             COMMANDS=rmail:rnews: \
             READ=/usr/spool/uucppublic:/tmp \
             WRITE=/usr/spool/uucppublic:/tmp \
             SENDFILES=yes REQUEST=no


The  following gives  permissions  and partial  contents of  file
/eettcc/ttttyyss:


-rw-r--r--  1 root   root   163 Wed Jul 11 11:36 /etc/ttys

1lPconsole
1rPcom3r


Finally,  the following  gives permissions  on  /ddeevv/ccoomm33rr (while
enabled):



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c--s------  1 root   root   21  38 Wed Jul 11 11:50 /dev/com3r


To use  the Trailblazer, log  in as rroooott, and  type the following
commands:


             disable com3r
             kermit cbl 9600 /dev/com3l > /tmp/modem_dump


Note  that  we  disabled  the  ``remote''  device  but  used  the
``local''  modem device  when  using kkeerrmmiitt.  This  allows us  to
access the  modem registers without having to  wait for the modem
to assert the carrier detect signal.

While talking to the Trailblazer, we sent it AATTNN? followed by the
<EEnntteerr> key.  We then entered ^ (the  circumflex) followed by the
letter CC  in order to  exit from kkeerrmmiitt. The  following gives the
results contained in file /ttmmpp/mmooddeemm_dduummpp:


kermit: connected...

E0 F1 M1 Q9 T V0 W0 X3 Y0 &P0 &T4     Version BA5.01
S00=001 S01=000 S02=043 S03=013 S04=010 S05=008 S06=002 S07:060 \
             S08=002 S09=006
S10=007 S11=070 S12=050 S18=000 S25=005 S38=000
S41=000 S45=000 S47=004 S48:001 S49=000
S50=000 S51:252 S52=000         S54:003 S55=000 S56=017 S57=019 \
             S58:000 S59=000
S60=000 S61:230 S62=003 S63=001 S64=000 S65=000 S66=000 S67=000 \
             S68=255 S69=000
S90=000 S91=000 S92=000 S94=001 S95=000 S96=001
S100=000 S101=000 S102=000 S104=000 S105=001
S110=255 S111=255 S112=001
S121=000 S130=002 S131:001 S255=000
N0:
N1:
N2:
N3:
N4:
N5:
N6:
N7:
N8:
N9:
0
kermit: disconnected.


***** /etc/ttys Problems *****

Sometimes,  UUCP problems  will arise because  the entry  in file


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/eettcc/ttttyyss  for the  serial port  your modem  is using,  is either
missing or is incorrect.

To discover  which port UUCP  thinks your modem  is using, invoke
the command  uuuuiinnssttaallll. Then, under  its DDeevviicceess option,  look at
the _r_e_m_o_t_e  line.  The remote  device you specified  on this line
must be described in file /eettcc/ttttyyss.  If it is not, then you will
find  statements in  the log  file for the  site you  are calling
stating that a device was not found.

If you  see errors in the  log files that state  that a device is
not found, and you have checked the ``remote'' entry in uuuuiinnssttaallll
against the contents of /eettcc/ttttyyss, the next possible cause may be
the /eettcc/ttttyyss  entry for the  port.  Look for  trailing spaces at
the end of  the line that describes the ccoomm  port.  If you find a
space at the end of a line, delete it.

***** com Port Driver Permissions *****

By far, the most common problem deals with permissions associated
with the ccoomm port devices.  If you are trying to get UUCP to call
out on a port, and keep seeing errors of the form


             Dial failed, Line Problem


in the  output of uuuulloogg, you  may need to fix  permissions on the
port in question.

If you are using one ccoomm  port both for remote logins and to call
out using  UUCP, note the  following: When a port  is enabled for
remote  access via  a  modem, the  permissions for  the port  are
changed  so that  only the  superuser rroooott  can access  the port.
This prevents someone  from inadvertently trying to send data out
the port.  When the port is  later disabled so that UUCP can dial
out, the  permissions for that  ccoomm port _a_r_e _n_o_t  changed to give
everyone access  to the port.  Remember,  when UUCP is executing,
it is just another user with  the name ``uucp'' and does not have
rroooott privileges.

To set  the permissions properly, use the  command cchhmmoodd to reset
the permission  of the  ccoomm port  device in directory  /ddeevv.  For
example,  if your  UUCP connection  is via ccoomm11rr,  log in  as the
superuser rroooott and enter the command:


             chmod 666 /dev/com1*


Usually,  serial ports  should  have read  and write  permissions
turned on for all users.  The main exception to this rule is that
a port enabled for  logins becomes readable and writeable only by
rroooott. This  not a problem for  UUCP as the port  is disabled (and
permissions expanded) temporarily when uuuucciiccoo runs.


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***** Lock Files and Temporary Files *****

UUCP controls access to  the modem and to various directories and
sites via a set of ``lock  files''.  This is to prevent UUCP from
tripping over  its own feet by attempting to  write more than one
file to the same site at the same site.

When a UUCP session fails, it  may fail to remove all of its lock
files  before it  exits, depending  upon  the seriousness  of the
failure.  ``Stale''  lock files and temporary  files in directory
will  prevent  UUCP from  accessing  a given  site  or even  from
working altogether.  Symptoms of this problem are messages in the
log files that state:


             Site locked


This, of  course, is not  indicative of a problem  unless no UUCP
connection has been made recently (within the last minute or so).
To cure this problem, log in as the superuser rroooott and then enter
the command:


             uurmlock


This will remove all ``stale'' lock or temporary files.

***** UUCP Configuration Files *****

By far the  most common cause of problems are  mistakes in one or
another UUCP configuration  file.  If problems persist, check all
UUCP  configuration  files  against  the  descriptions  found  in
correspondingly  named Lexicon articles.   The files  in question
are ttttyyss, LL-ddeevviicceess, LL.ssyyss, and PPeerrmmiissssiioonnss.

***** UUCP Executable File Permissions *****

UUCP commands can invoke each other from time to time.  If a UUCP
executable file's  permissions are set  incorrectly, that command
may be prevented from being executed under certain conditions, or
from reading or writing certain key files.

Key    UUCP    executable    files   are    /uussrr/lliibb/uuuuccpp/uuuucciiccoo,
/uussrr/lliibb/uuuuccpp/uuuuxxqqtt, /uussrr/bbiinn/uuuuccpp, and /uussrr/bbiinn/uuuuxx. These files
must belong  to user and  group uuuuccpp. Permissions  on these files
must  be 6511  (-r-s--s--x).   See the  Lexicon  article for  the
command cchhmmoodd for further details on how to reset permissions for
files.

***** UUCP Connects, but ... *****

Once UUCP  is dialing out, it is  extremely difficult to diagnose


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problems, as they can occur  at either end of the connection.  In
most  cases, one  must  know both  systems  to diagnose  problems
related to  communication problems.  Check the following:

-> Check your  chat scripts.   Contact the other  system's system
   administrator to  be sure that  you are expecting  the correct
   prompts in the chat script for the system you are calling.

-> Use  the debugging  mode  of uuuucciiccoo  to watch  communications.
   Debugging mode  is accessed using the  uuuucciiccoo command suffixed
   by a  -xx#, where #  is 1 to  9 which determines  the debugging
   level.  For example

                /usr/lib/uucp/uucico -Smwcbbs -x1

   Please note, the  uuuucciiccoo debugging option is incompatible with
   certain non-COHERENT versions of uuuucciiccoo.

-> Note  also  that  the COHERENT  default  mailer  does not  yet
   support domains.  If  domain information is being sent to your
   system,  an error  may  result and  possibly cause  unexpected
   results or  errors from uuuucciiccoo.  The  error will usually state
   that a  log file could  not be written  to.  Alternate mailers
   are available from the various COHERENT archive sites, as well
   as the MWC UUCP bulletin board system.

***** Remote Won't Accept Files ... Where'd My Mail Go? *****

If  you see  messages in  your log  files that  a site  would not
accept a  file from your  site, the other  site may not  have its
permissions set to allow you to send files to it, or to write the
files you are sending to a directory that you specified.

When sending  files across systems, check the  length of the site
name.  Currently,  COHERENT can only work  with a seven-character
or shorter  site name.   If you  are using an  eight-character or
longer  site name,  COHERENT will  not properly  distribute files
transferred from  your site.  To change the  name of your system,
edit the contents of file /eettcc/uuuuccppnnaammee.

***** See Also *****

ccoomm, ccoommmmaannddss, LL-ddeevv, LL.ssyyss, PPeerrmmiissssiioonnss, tteerrmmiinnaall, uuuucciiccoo, uuuuccpp,
uuuuccppnnaammee, uuuuddeeccooddee, uuuueennccooddee,  uuuuiinnssttaallll, uuuulloogg, uuuummvvlloogg, uuuunnaammee,
uuuurrmmlloocckk, uuuuttoouucchh, uuuuxx, uuuuxxqqtt
_U_U_C_P, _R_e_m_o_t_e _C_o_m_m_u_n_i_c_a_t_i_o_n_s _U_t_i_l_i_t_y, tutorial











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