==Phrack Inc.==
Volume Two, Issue 22, File 5 of 12
/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|
|/ |/
/| An Indepth Guide In Hacking UNIX /|
|/ and |/
/| The Concept Of Basic Networking Utility /|
|/ |/
/| By Red Knight /|
|/ |/
/| Member of the /|
|/ Phreakers/Hackers Underground Network |/
/| /|
|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/|/
Brief History On UNIX
~~~~~~~~~~~~~~~~~~~~~
Its because of Ken Tompson that today we are able to hack Unix. He used to
work for Bell Labs in the 1960s. Tompson started out using the MULTICS OS
which was later eliminated and Tompson was left without an operating system to
work with.
Tompson had to come up with something real quick. He did some research and and
in 1969 UNIX came out, which was a single user and it did not have many
capabilities. A combined effort with others enabled him to rewrite the version
in C and add some good features. This version was released in 1973 and was
made available to the public. This was the first begining of UNIX in its
presently known form. The more refined version of UNIX, today know as UNIX
system V developed by Berkley University has unique capabilities.
Various types of UNIXes are CPIX, Berkeley Ver 4.1, Berkeley 4.2, FOS, Genix,
HP-UX, IS/I, OSx, PC-IX, PERPOS, Sys3, Ultrix, Zeus, Xenix, UNITY, VENIX, UTS,
Unisys, Unip lus+, UNOS, Idris, QNIX, Coherent, Cromix, System III, System 7,
Sixth edition.
The Article Itself
~~~~~~~~~~~~~~~~~~
I believe that hacking into any system requires knowledge of the operating
system itself. Basically what I will try to do is make you more familiar with
UNIX operation and its useful commands that will be advantageous to you as a
hacker. This article contains indepth explainations. I have used the UNIX
System V to write this article.
Error Messages: (UNIX System V)
~~~~~~~~~~~~~~
Login Incorrect - An invalid ID and/or password was entered. This means
nothing. In UNIX there is no way guessing valid user IDs.
You may come across this one when trying to get in.
No More Logins - This happens when the system will not accept anymore logins.
The system could be going down.
Unknown Id - This happens if an invalid id is entered using (su) command.
Unexpected Eof In File - The file being stripped or the file has been damaged.
Your Password Has Expired - This is quite rare although there are situations
where it can happen. Reading the etc/passwd will
show you at how many intervals it changes.
You May Not Change The Password - The password has not yet aged enough. The
administrator set the quotas for the users.
Unknown Group (Group's Name) - Occurs when chgrp is executed, group does not
exist.
Sorry - Indicated that you have typed in an invalid super user password
(execution of the su).
Permission Denied! - Indicated you must be the owner or a super user to change
password.
Sorry <( Of Weeks) Since Last Change - This will happen when password has has
not aged enough and you tried to change
it (password).
(Directory Name): No Permission - You are trying to remove a directory which
you have no permission to.
(File Name) Not Removed - Trying to delete a file owned by another user that
you do not have write permission for.
(Dirname) Not Removed - Ownership of the dir is not your that your trying to
delete.
(Dirname) Not Empty - The directory contains files so you must have to delete
the files before execcant open [file name] - defined
wrong path, file name or you have no read permission.
Cp: (File Name) And (File Name) Are Identical - Self explanatory.
Cannot Locate Parent Directory - Occurs when using mv.
(File name) Not Found - File which your trying to move does not exist.
You Have Mail - Self explanatory.
Basic Networking Utility Error Messages
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cu: Not found - Networking not installed.
Login Failed - Invalid id/pw or wrong number specified.
Dial Failed - The systen never answered due to a wrong number.
UUCP Completely Failed - Did not specify file after -s.
Wrong Time to Call - You called at the time at a time not specified in the
Systems file.
System not in systems - You called a remote not in the systems file.
Logon Format
~~~~~~~~~~~~
The first thing you must do is switch to lower case. To identifing a UNIX,
this is what you will see;
AT&T Unix System V 3.0 (eg of a system identifier)
login:
or
Login:
Any of these is a UNIX. Here is where you will have to guess at a user valid
id. Here are some that I have come across; glr, glt, radgo, rml, chester, cat,
lom, cora, hlto, hwill, edcasey, and also some containing numbers; smith1,
mitu6, or special characters in it; bremer$, jfox. Login names have to be 3
to 8 chracters in length, lowercase, and must start with a letter. In some
XENIX systems one may login as "guest"
User Level Accounts (Lower Case)
~~~~~~~~~~~~~~~~~~~
In Unix there are what is called. These accounts can be used at the "login:"
prompt. Here is a list:
sys bin trouble daemon uucp nuucp rje lp adm
Super-User Accounts
~~~~~~~~~~~~~~~~~~~
There is also a super-user login which make UNIX worth hacking. The accounts
are used for a specific job. In large systems these logins are assingned to
users who have a responsibilty to maintain subsystems.
They are as follows (all lower case);
root - This is a must the system comes configured with it. It has no
restriction. It has power over every other account.
unmountsys - Unmounts files
setup - System set up
makefsys - Makes a new file
sysadm - Allows useful S.A commands (doesn't need root login)
powerdown - Powering system down
mountfsys - Mounts files
checkfsys - Checks file
These accounts will definitly have passwords assigned to them. These accounts
are also commands used by the system administrator. After the login prompt you
will receive a password prompt:
password:
or
Password:
Enter the password (it will not echo). The password rule is as follows; Each
password has to contain at least 6 characters and maximum of 8 characters. Two
of which are to be alphabetic letters and at least one being a number or a
special character. The alphabetic digits could be in upper case or lower
case. Here are some of the passwords that I have seen; Ansuya1, PLAT00N6,
uFo/78, ShAsHi.., Div417co.
The passwords for the super user accounts will be difficult to hack try the
accounts interchangebly; login:sysadm password:makefsys, or rje1, sysop,
sysop1, bin4, or they might contain letters, numbers, or special chracters in
them. It could be anything. The user passwords are changed by an aging
proccess at successive intervals. The users are forced to changed it. The
super-user will pick a password that will not need changing for a long period
of time.
You Have Made It!
~~~~~~~~~~~~~~~~~
The hard part is over and hopefully you have hacked a super-user account.
Remember Control-d stops a process and also logs you off. The next thing you
will probably see is the system news. Ex;
login:john
password:hacker1
System news
There will be no networking offered to the users till
August 15, due to hardware problems.
(Just An Example)
$
$ (this is the Unix prompt) - Waiting for a command to be entered.
- Means your logged in as root (Very Good).
A Word About The XENIX System III (Run On The Tandy 6000)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The largest weakness in the XENIX System III occurs after the installation
of the Profile-16 or more commonly know as the Filepro-16. I have seen the
Filepro-16 installed in many systems. The installation process creates an
entry in the password file for a user named \fBprofile\fR, an account that who
owns and administors the database. The great thing about it is that when the
account is created, no password is assigned to it. The database contains
executable to maintain it. The database creation programs perform a
\fBsetuid\fR to boot up the \fBoot\fR thereby giving a person the whole C
Shell to gain Super User privilege same as root. Intresting huh!
(* Note: First the article will inform you of how the Unix is made up.)
The Unix is made if three components - The Shell, The Kernal, File System.
The Kernal
~~~~~~~~~~
You could say that the kernal is the heart of the Unix operating system. The
kernal is a low level language lower than the shell which maintains processes.
The kernal handles memory usage, maintains file system the sofware and hardware
devices.
The Shell
~~~~~~~~~
The shell a higher level language. The shell had two important uses, to act as
command interpreture for example using commands like cat or who. The shell is
at work figuring out whether you have entered a command correctly or not. The
second most important reason for the shell is its ability to be used as
programing language. Suppose your performing some tasks repeatedly over and
over again, you can program the shell to do this for you.
(Note: This article will not cover shell programming.)
( Instead B.N.N will be covered. )
The File System
~~~~~~~~~~~~~~~
The file system in Unix is divided into 3 catagories: Directories, ordinary
files and special files (d,-).
Basic Stucture:
(/)-this is abreviation for the root dirctory.
root level root
(/) system
-------------------------------------|---------------------------------- level
| | | | | | | |
/unix /etc /dev /tmp /lib /usr /usr2 /bin
| _____|_____
login passwd | | |
level /john /cathy
________________________|_______________
| | | | | |
.profile /mail /pers /games /bin /michelle
*.profile - in case you | __|______ | __|_______
wish to change your environment, but capital | | data | | |
after you log off, it sets it to othello starwars letter letter1
default.
/unix - This is the kernal.
/etc - Contains system administrators files,Most are not available to the
regular user (this dirrctory contains the /passwd file).
Here are some files under /etc directory:
/etc/passwd
/etc/utmp
/etc/adm/sulog
/etc/motd
/etc/group
/etc/conf
/etc/profile
/dev - contains files for physical devices such as printer and the disk drives
/tmp - temporary file directory
/lib - dirctory that contains programs for high level languages
/usr - this directory contains dirctories for each user on the system
/bin - contain executable programs (commands)
The root also contains:
/bck - used to mount a back up file system.
/install - Used to install and remove utilities
/lost+found - This is where all the removed files go, this dir is used by fsck
/save -A utility used to save data
/mnt - Used for temporary mounting
**Now the fun part scouting around**
Local Commands (Explained In Details)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
At the unix prompt type the pwd command. It will show you the current working
directory you are in.
$ pwd
$ /usr/admin - assuming that you have hacked into a super user account
check fsys
$
This gives you the full login directory. The / before tell you the location of
the root directory.
Or
(REFER TO THE DIAGRAM ABOVE)
$ pwd
$ /usr/john
$
Assuming you have hacked into John's account.
Lets say you wanted to move down to the Michelle directory that contains
letters. You would type in;
$ cd michelle or cd usr/john/michelle
$ pwd
$ /usr/john/michelle
$
Going back one directory up type in:
$ cd ..
or going to your parent directory just type in "cd"
Listing file directories assuming you have just logged in:
$ ls /usr/john
mail
pers
games
bin
michelle
This wont give you the .profile file. To view it type
$ cd
$ ls -a
:
:
.profile
To list file names in Michelle's directory type in:
$ ls michelle (that if your in the johns directory)
$ ls /usr/john/michelle(parent dir)
ls -l
~~~~~
The ls -l is an an important command in unix.This command displays the whole
directory in long format :Run this in parent directory.
$ ls -l
total 60
-rwxr-x--- 5 john bluebox 10 april 9 7:04 mail
drwx------ 7 john bluebox 30 april 2 4:09 pers
: : : : : : :
: : : : : : :
-rwxr-x--- 6 cathy bluebox 13 april 1 13:00 partys
: : : : : : :
$
The total 60 tells one the ammount of disk space used in a directory. The
-rwxr-x--- is read in triples of 3. The first chracter eg (-, d, b, c) means
as follows: - is an ordinary file, d is a directory, b is block file, c is a
character file.
The r stands for read permission, w is write permission, x is execute. The
first column is read in 3 triples as stated above. The first group of 3 (in
-rwxr-x---) after the "-" specifies the permission for the owner of the file,
the second triple are for the groups (the fourth column) and the last triple
are the permissions for all other users. Therefore, the -rwxr-x--- is read as
follows.
The owner, John, has permission to read, write, and execute anything in the bin
directory but the group has no write permission to it and the rest of the users
have no permission at all. The format of one of the lines in the above output
is as follows:
file type-permissions, links, user's name, group, bytes taken, date, time when
last renued, directory, or file name.
*** You will be able to read, execute Cathy's ***
*** file named partly due to the same group. ***
Chmod
~~~~~
The chmod command changes permission of a directory or a file. Format is
chmod who+, -, =r , w, x
The who is substituted by u-user, g-group, o-other users, a-all.
The + means add permission, - means remove permission, = - assign.
Example: If you wanted all other users to read the file name mail, type:
$ chmod o+r mail
Cat
~~~
Now suppose you wanted to read the file letter. There are two ways to doing
this. First go to the michelle directory then type in:
$ cat letter
line one ...\
line two ... }the output of letter
line three../
$
or
If you are in the parent directory type in:
$ cat /usr/john/michelle/letter
and you will have the same output.
Some cat options are -s, -u, -v, -e, -t
Special Chracters in Unix
~~~~~~~~~~~~~~~~~~~~~~~~~
* - Matches any number of single characters eg. ls john* will list all
files that begin with john
[...] - Matchs any one of the chracter in the [ ]
? - Matches any single chracter
& - Runs a process in the backgroung leaving your terminal free
$ - Values used for variables also $n - null argument
> - Redirectes output
< - Redirects input to come from a file
>> - Redirects command to be added to the end of a file
| - Pipe output (eg:who|wc-l tells us how many users are online)
"..." - Turn of meaning of special chracters excluding $,`
`...` - Allows command output in to be used in a command line
'...' - Turns of special meaning of all chracters
Continuation Of Local Commands
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
man [command] or [c/r] -will give you a list of commands explainations
help - available on some UNIX systems
mkdir [dir name(s)] - makes a directory
rmdir [dir name(s)] - removes directory.You wont be able to remove the
directory if it contains files in them
rm [file name(s)] - removes files. rm * will erase all files in the current
dir. Be carefull you! Some options are:
[-f unconditional removal] [-i Prompts user for y or n]
ps [-a all processes except group leaders] [-e all processes] [-f the whole
list] - This command reports processes you are running eg:
$ps
PID TTY TIME COMMAND
200 tty09 14:20 ps
The systems reports (PID - process idenetification number which is a number
from 1-30,000 assigned to UNIX processes)
It also reports the TTY,TIME and the COMMAND being executed at the time.
To stop a process enter :
$kill [PID] (this case its 200)
200 terminated
$
grep (argument) - searches for an file that contains the argument
mv (file names(s)) ( dir name ) - renames a file or moves it to another
directory
cp [file name] [file name] - makes a copy of a file
write [login name ] - to write to other logged in users. Sort of a chat
mesg [-n] [-y] - doesn't allow others to send you messages using the write
command. Wall used by system adm overrides it.
$ [file name] - to execute any file
wc [file name] - Counts words, characters,lines in a file
stty [modes] - Set terminal I/O for the current devices
sort [filename] - Sorts and merges files many options
spell [file name] > [file name] - The second file is where the misspelt words
are entered
date [+%m%d%y*] [+%H%%M%S] - Displays date acoording to options
at [-r] [-l] [job] - Does a specified job at a specified time. The -r Removes
all previously scheduled jobs.The -l reports the job and
status of all jobs scheduled
write [login] [tty] - Sends message to the login name. Chat!
Su [login name]
~~~~~~~~~~~~~~~
The su command allows one to switch user to a super user to a user. Very
important could be used to switch to super user accounts.
Usage:
$ su sysadm
password:
This su command will be monitored in /usr/adm/sulog and this file of all files
is carefully monitered by the system administrator.Suppose you hacked in john's
account and then switched to the sysadm account (ABOVE) your /usr/adm/su log
entry would look like:
SU 04/19/88 21:00 + tty 12 john-sysadm
Therfore the S.A(system administrator) would know that john swithed to sysadm
account on 4/19/88 at 21:00 hours
Searching For Valid Login Names:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Type in-
$ who ( command informs the user of other users on the system)
cathy tty1 april 19 2:30
john tty2 april 19 2:19
dipal tty3 april 19 2:31
:
:
tty is the user's terminal, date, time each logged on. mary, dr.m are valid
logins.
Files worth concatenating(cat)
/etc/passwd file
~~~~~~~~~~~~~~~~
The etc/passwd is a vital file to cat. For it contains login names of all
users including super user accounts and there passwords. In the newer SVR3
releases they are tighting their security by moving the encrypted passwords
from /etc/passwd to /etc/shadow making it only readable by root.
This is optional of course.
$ cat /etc/passwd
root:D943/sys34:0:1:0000:/:
sysadm:k54doPerate:0:0:administration:usr/admin:/bin/rsh
checkfsys:Locked;:0:0:check file system:/usr/admin:/bin/rsh
:
other super user accs.
:
john:hacker1:34:3:john scezerend:/usr/john:
:
other users
:
$
If you have reached this far capture this file as soon as possible. This is a
typical output etc/passwd file. The entries are seperated by a ":". There
made be up to 7 fields in each line.
Eg.sysadm account.
The first is the login name in this case sysadm.The second field contains the
password. The third field contains the user id."0 is the root." Then comes
the group id then the account which contains the user full name etc. The sixth
field is the login directory defines the full path name of the the paticular
account and the last is the program to be executed. Now one can switch to
other super user account using su command descibed above. The password entry
in the field of the checkfsys account in the above example is "Locked;". This
doesn't mean thats its a password but the account checkfsys cannot be accessed
remotely. The ";" acts as an unused encryption character. A space is also
used for the same purpose. You will find this in many UNIX systems that are
small systems where the system administrator handles all maintaince.
If the shawdowing is active the /etc/passwd would look like this:
root:x:0:1:0000:/:
sysadm:x:0:0:administration:/usr/admin:/bin/rsh
The password filed is substituted by "x".
The /etc/shawdow file only readable by root will look similar to this:
root:D943/sys34:5288::
:
super user accounts
:
Cathy:masai1:5055:7:120
:
all other users
:
The first field contains users id: The second contains the password (The pw
will be NONE if logining in remotely is deactivated): The third contains a
code of when the password was last changed: The fourth and the fifth contains
the minimum and the maximum numbers of days for pw changes (its rare that you
will find this in the super user logins due to there hard to guess passwords)
/etc/options
~~~~~~~~~~~~
The etc/options file informs one the utilities available in the system.
-rwxr-xr-x 1 root sys 40 april 1:00 Basic Networking utility
/etc/group
~~~~~~~~~~
The file has each group on the system. Each line will have 4 entries separated
by a ":". Example of concatenated /etc/group:
root::0:root
adm::2:adm,root
bluebox::70:
Group name:password:group id:login names
** It very unlikely that groups will have passwords assigned to them **
The id "0" is assigned to /
Sending And Recieving Messages
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Two programs are used to manage this. They are mail & mailx. The difference
between them is that mailx is more fancier thereby giving you many choices like
replying message, using editors, etc.
Sending
~~~~~~~
The basic format for using this command is:
$mail [login(s)]
(now one would enter the text after finishing enter "." a period on the next
blank line)
$
This command is also used to send mail to remote systems. Suppose you wanted
to send mail to john on a remote called ATT01 you would type in:
$mail ATT01!john
Mail can be sent to several users, just by entering more login name after
issuing the mail command
Using mailx is the same format:(This I'll describe very briefly) $mailx john
subject:(this lets you enter the subject)
(line 1)
(line 2)
(After you finish enter (~.) not the brackets of course, more commands are
available like ~p, ~r, ~v, ~m, ~h, ~b, etc.).
Receiving
~~~~~~~~~
After you log on to the system you will the account may have mail waiting.
You will be notified "you have mail."
To read this enter:
$mail
(line 1)
(line 2)
(line 3)
?
$
After the message you will be prompted with a question mark. Here you have a
choice to delete it by entering d, saving it to view it later s, or just press
enter to view the next message.
(DON'T BE A SAVANT AND DELETE THE POOR GUY'S MAIL)
Super User Commands
~~~~~~~~~~~~~~~~~~~
$sysadm adduser - will take you through a routine to add a user (may not last
long)
Enter this:
$ sysadm adduser
password:
(this is what you will see)
/--------------------------------------------------------------------------\
Process running succommmand `adduser`
USER MANAGMENT
Anytime you want to quit, type "q".
If you are not sure how to answer any prompt, type "?" for help
If a default appears in the question, press for the default.
Enter users full name [?,q]: (enter the name you want)
Enter users login ID [?,q]:(the id you want to use)
Enter users ID number (default 50000) [?,q) [?,q]:( press return )
Enter group ID number or group name:(any name from /etc/group)
Enter users login home directory:(enter /usr/name)
This is the information for the new login:
Users name: (name)
login ID:(id)
users ID:50000
group ID or name:
home directory:/usr/name
Do you want to install, edit, skip [i, e, s, q]? (enter your choice if "i"
then)
Login installed
Do you want to give the user a password?[y,n] (its better to enter one)
New password:
Re-enter password:
Do you want to add another login?
\----------------------------------------------------------------------------/
This is the proccess to add a user. Since you hacked into a super user account
you can make a super user account by doing the following by entering 0 as an
user and a group ID and enter the home directory as /usr/admin. This will give
you as much access as the account sysadm.
**Caution** - Do not use login names like Hacker, Cracker,Phreak etc. This is
a total give away.
The process of adding a user wont last very long the S.A will know when he
checks out the /etc/passwd file
$sysadm moduser - This utility allows one to modify users. DO NOT ABUSE!!
!
Password:
This is what you'll see:
/----------------------------------------------------------------------------\
MODIFYING USER'S LOGIN
1)chgloginid (This is to change the login ID)
2)chgpassword (Changing password)
3)chgshell (Changing directory DEFAULT = /bin/sh)
ENTER A NUMBER,NAME,INITIAL PART OF OF NAME,OR ? OR ? FOR HELP, Q TO
QUIT ?
\----------------------------------------------------------------------------/
Try every one of them out.Do not change someones password.It creates a havoc.
If you do decide to change it.Please write the original one down somewhere
and change back.Try not to leave to many traces after you had your fun. In
choice number 1 you will be asked for the login and then the new one. In
choice number 2 you will asked for the login and then supplied by it correct
password and enter a new one. In choice 3 this is used to a pchange the login
shell ** Use full ** The above utilites can be used separatly for eg (To
change a password one could enter: $sysadm chgpasswd not chapassword, The rest
are same)
$sysadm deluser - This is an obviously to delete a user password:
This will be the screen output:
/---------------------------------------------------------------------------\
Running subcommand 'deluser' from menu 'usermgmt'
USER MANAGEMENT
This fuction completely removes the user,their mail file,home directory and all
files below their home directory from the machine.
Enter login ID you wish to remove[q]: (eg.cathy)
'cathy' belongs to 'Cathy Franklin'
whose home directory is /usr/cathy
Do you want to remove this login ID 'cathy' ? [y,n,?,q] :
/usr/cathy and all files under it have been deleted.
Enter login ID you wish to remove [q]:
\--------------------------------------------------------------------------/
This command deletes everthing owned by the user.Again this would be stupid to
use.
Other Super User Commands
~~~~~~~~~~~~~~~~~~~~~~~~~
wall [text] control-d - to send an anouncement to users logged in (will
override mesg -n command). Execute only from /
/etc/newgrp - is used to become a member of a group
sysadm [program name]
delgroup - delets groups
diskuse - Shows free space etc.
whoson - self explanatory
lsgroup - Lists group
mklineset -hunts various sequences
Basic Networking Unility (BNU)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The BNU is a unique feature in UNIX.Some systems may not have this installed.
What BNU does is allow other remote UNIXes communicate with yours without
logging off the present one.BNU also allowes file transfer between computers.
Most UNIX systems V will have this feature installed.
The user program like cu,uux etc are located in the /usr/bin directory
Basic Networking Files
~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/uucp/[file name]
[file name]
systems - cu command to establishes link.Contains info on remote computers
name, time it can be reached, login Id, password, telephone numbers
devices - inter connected with systems files (Automatic call unit same in two
entries) also contains baud rate, port tty1, etc.
dialers - where asscii converation must be made before file tranfers etc.
dialcodes - contains abreiviations for phone numbers that can be used in
systems file
other files are sysfiles, permissions, poll, devconfig
Logining On To Remote And Sending+Receiving Files
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cu - This command allows one to log on to the local as well as the remote Unix
(or a non unix)without haveing to hang up so you can transfer files.
Usage:[options]
$ cu [-s baud rate][-o odd parity][-e even parity][-l name of comm line]
telephone number | systemname
To view system names that you can communicate with use the 'unname' command:
Eg. of output of names:
ATT01
ATT02
ATT03
ATT04
$ cu -s300 3=9872344 (9872344 is the tel)
connected
login:
password:
Local Strings
~~~~~~~~~~~~~
<~.> - will log you off the remote terminal, but not the local
- puts you back on the remote unix local (the directory which you
are in)
"%put [file name] - reverse of above
Ct
~~
ct allows local to connect to remote.Initiates a getty on a remote terminal.
Usefull when using a remote terminal.BNU has call back feature that allows the
user on the remote who can execute a call back meaning the local can call the
remote.[ ] are options
$ ct [-h prevent automatic hang up][-s bps rate][-wt set a time to call back
abbrieviated t mins] telephone number
Uux
~~~
To execute commands on a remote (unix to unix)
usage:[ ] are options
$ uux [- use standard output][-n prevent mail notification][-p also use
standard output] command-string
UUCP
~~~~
UUCP copies files from ones computer to the home directory of a user in remote
system. This also works when copying files from one directory to another in
the remote. The remote user will be notified by mail. This command becomes
use full when copying files from a remote to your local system. The UUCP
requires the uucico daemon will call up the remote and will perform file login
sequence, file transfer, and notify the user by mail. Daemons are programs
runining in the background. The 3 daemons in a Unix are uucico, uusched,
uuxqt.
Daemons Explained: [nows a good time to explain the 3 daemons]
~~~~~~~~~~~~~~~~~
Uuxqt - Remote execution. This daemon is executed by uudemon.hour started by
cron.UUXQT searchs in the spool directory for executable file named
X.file sent from the remote system. When it finds a file X .file where
it obtains process which are to be executed. The next step is to find
weather the processes are available at the time.The if available it
checks permission and if everthing is o.k it proceeds the background
proccess.
Uucico - This Daemon is very immportant for it is responsible in establishing
a connection to the remote also checks permission, performs login
procedures,transfers + executes files and also notifies the user by
mail. This daemon is called upon by uucp,uuto,uux commands.
Uusched - This is executed by the shell script called uudemon.hour. This
daemons acts as a randomizer before the UUCICO daemon is called.
Usage:
$ uucp [options] [first full path name!] file [destination path!] file example:
$ uucp -m -s bbss hackers unix2!/usr/todd/hackers
What this would do is send the file hackers from your computer to the remotes
/usr/todd/hackers making hackers of course as file. Todd would mail that a
file has been sent to him. The Unix2 is the name of the remote. Options for
UUCP: (Don't forget to type in remotes name Unix2 in case)
-c dont copy files to spool directory
-C copy to spool
-s[file name] - this file will contain the file status(above is bbss)
-r Dont start the comm program(uucico) yet
-j print job number(for above eg.unix2e9o3)
-m send mail when file file is complete
Now suppose you wanted to receive file called kenya which is in the
usr/ dan/usa to your home directory /usr/john assuming that the local systems
name is ATT01 and you are currently working in /usr/dan/usa,you would type in:
$uucp kenya ATT01!/usr/john/kenya
Uuto
~~~~
The uuto command allows one to send file to remote user and can also be used to
send files locally.
Usage:
$ uuto [file name] [system!login name]( omit systen name if local)
Conclusion
~~~~~~~~~~
Theres always more one can say about the UNIX, but its time to stop. I hope
you have enjoyed the article. I apologize for the length. I hope I made the
UNIX operating system more familiar. The contents of the article are all
accurate to my knowledge. Hacking into any system is illegal so try to use
remote dial-ups to the job. Remember do not abuse any systems you hack into
for a true hacker doesn't like to wreck, but to learn.
Watch for my new article on using PANAMAC airline computers coming soon.
Red Knight
P/HUN!
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