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                  Invasion Course" two  Printing

            "UNIX Series System Invasion Course" two
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              "UNIX Series System Invasion Course" two 
              ------------------ UNIX is systematic and the commonly used order 
              synopsis
              ==========================================
              Everybody is urging me to write the course, but really was must 
              write too many too has been tedious.
              The order introduced no technology may not say, also is not 
              several speeches may say clearly. therefore repeatedlies delay.
              Embarrassed, let everybody wait for a long time.:)
              OK, first we have a look UNIX the explanation
              Unix
              Unix operating system
              In 1968, Ken Thompson (Cohen Tang Pu lived), Dennis Ritchie (the 
              Dennis Switzerland was wonderful) and AT&T (the Bell Lab) the 
              person when carried on about the MULTICS project research work, 
              they have completed the first order interpreter (SHELL) and some 
              simple file processing tools. They use the GE system are Pdp-7 
              carry on the overlapping translation, has written the assembly 
              (Assembler)... ... By now this system calculated on was initial 
              Unix. Natural, at that time they certainly were not such think. To 
              in 1969! First Unix is born, at that time the Unix support 
              hardware was DEC Corporation's Pdp-7, software is ken Thompson 
              develops. Initial Unix is similar with modern Unix on the frame 
              body, uses the I- pitch point, moreover has the special document 
              type to support the table of contents and the equipment. Therefore 
              also some people said Unix is has cut out MULTICS... ... But along 
              with Ken Thompson development at the same time, Dennis Ritchie, 
              person and so on Brain Kernighan also founded one kind of new 
              programming language that is the present C language. Person and 
              so on Ken also on completely rehas written a Unix core along with 
              the C development in 73 years with C, including Shell. This 
              without doubt increased the system stable performance, also caused 
              the programming and the debugging changes is much easier, along 
              with it, Unix has substituted on the Pdp-11 DEC Corporation's 
              operating system, but Ken afterwards announced the Unix code. This 
              will develop to Unix later has been very big promotion. 77 years, 
              Interactive the Systems Corporation starts to the end-user to sell 
              Unix, this enabled Unix to become the commercial product... ... 
              Continuously to today perfect Unix.
              Unix can popularly get up absolutely is not accidental, this it 
              itself characteristic is prominent with Unix is cannot separate. 
              Is worth rejoicing is very early Unix and present Unix all has it 
              to be possible to show off (probability) the characteristic, these 
              are: 1st, start asynchronous advancement ability; 2nd, consistent 
              document, equipment and advancement I/O; 3rd, level filing system; 
              4th, substitutes with other Shell tacitly approves Shell the 
              ability. Dr. Ken Thompson once won the Nobel prize. But in the 
              hacker domain, Unix is receives very much welcome, because the 
              network basically is take Unix as a foundation, at least the big 
              station is so. Furthermore is the Unix price is worth rejoicing. 
              But exists the question is Unix is very troublesome in the digit 
              dialing Modem disposition aspect.
              Simultaneously we also said Linux
              Linux
              Linux operating system
              Linux belongs to PC machine on Unix. It is the 90's initial period 
              first develops by Finland's Linus Torvalds, after development the 
              author has used GPL (public copyright agreement, one kind permits 
              any person by any way duplication and sending out procedure source 
              code form) the form carries on the issue. Linux has inherited the 
              Unix operating system stable, safe and is reliable and so on the 
              characteristic, simultaneously Linux greatly surpassed WinNT in 
              the running rate, Linux has also played the huge role in the 
              database commercial core domain. In addition the GPL release 
              superiority caused Linux at present to become has most received 
              one of user affection operating systems.
              Therefore we in here unification unix and linux introduced 
              together. they are very similar, their majority order all is same.
              Under we are called are UNIX.
              The UNIX system characteristic includes:
              The graduation shape of tree file organization, the document, the 
              table of contents table and the external instrumentation as the 
              document unification management, provided function complete order 
              program language "Shell language", has provided each kind of 
              programming language and the massive programming subsystem, the 
              system core and exterior procedure majority of uses the C language 
              compilation, uses the advancement image exchange technology, the 
              system efficiency is high.
                
              UNIX is the multiuser operating system, must use in front of the 
              system must input the user name and the password rear area, is 
              unmistakable after the system confirmation can use.
              The usual UNIX system user has two kinds:
              1.root --- root user
              This is the super user account, may use this account number to 
              carry on all operations to the system! Obtains to the system root 
              visit jurisdiction, also is the thing which the hackers goes all 
              out to pursue.
              2. Average consumer
              For the average consumer use, the concrete jurisdiction by the 
              root assignment. general attack step is, first obtains the average 
              consumer jurisdiction further to capture the root jurisdiction 
              again using the system loophole, namely ended in the root. here 
              average consumer to occupy the very important position. certainly 
              also to have the very many systems loophole to be allowed not to 
              need the average consumer jurisdiction also to be able to obtain 
              the system quite commonly used the root visit jurisdiction. for 
              instance: Sunos rpc.cmsd, Redhat rpc.statd, IRIX telnetd and so 
              on, all is the very good use long-distance overflow. has this kind 
              of long-distance overflow loophole the machine, the aggressor may 
              in long-distance directly obtain the system the root jurisdiction.
              Therefore, in UNIX, the cryptographic document is the very 
              important. many UNIX system encryption password all is the 
              preservation in the /etc/passwd document, but this document is 
              needs to be may read regarding the average consumer. Thus, so long 
              as has an account number to be allowed to obtain this document, 
              then uses some password test methods or software may guess the 
              user password. At present, the UNIX system mostly will encrypt the 
              password to establish to only has in the /etc/shadow document 
              which the super user will be allowed to read, will be allowed to 
              increase obtains the encryption password the difficulty. But we 
              still obtain on the machine from /etc/passwd the user to tabulate.
              Common UNIX system
              AIX
              BSD
              FreeBSD
              IRIX
              Hp-ux
              SunOS (Solaris)
              LINUX series
              More only had you about the UNIX system material to look for the 
              correlation the books to look. under changed over to the subject.
              Usually, the general simple invasion, we so long as under 
              understood the order was allowed to be very smooth has operated on 
              the goal machine.:)
              UNIX order foundation
              1. loses the difference to change
              In UNIX, each procedure has three special documents descriptions, 
              the standard input (standard input), the standard output (standard 
              output), the standard wrong output (standarderror).
              These three usually are accepts the terminal the input, but 
              demonstrates by the terminal.
              But UNIX provides the user to be allowed to use the common file or 
              the pipeline (pipe) substitutes for these standards to lose the 
              difference equipment.
              Inside sh, the user may > "and" < "carries on using" loses the 
              work which the difference changes.
              A. The output changes:
              Command > file
              You may change an instruction output result to a file, lets this 
              file store up this order the output result.
              But please note, if the document already existed in the system, 
              then the document will be able the quilt. Also will be the 
              original document content can vanish.
              Command >& file
              With > is same, but this form expressed continually the standard 
              wrong output together changes.
              In UNIX, the standard wrong output is uses for in the procedure 
              custom to demonstrate the wrong occurrence, therefore when not 
              changes, the standard wrong output result can change the 
              advancement, but the standard wrong output result still will show 
              in the terminal.
              Command >> file
              This standard shows represents increases the standard output 
              result to the document in. If the document has existed in the 
              system, then the standard output result will be able to add to the 
              document the terminal, if the document originally certainly will 
              not exist, then the document could open but saves the standard 
              wrong output result to the document in.
              Command >>& file
              Same, but this form represents continually the standard wrong 
              output together to increase to the document in.
                
              B. The input changes:
              Command < file
              The general procedure must have from the terminal input material, 
              but you may the material unification which must input the formula 
              enroll in the file, the use changes one and the input.
              Set ignoreeeof
              Because will change the output to be able to have has the file 
              cover danger, csh and tcsh will provide the user to avoid with 
              this way.
              When you carry out set ignoreeeof , when has the output changes 
              to already file of the existence, it can issue a file already the 
              news which exists.
              But changes in the processing increase on, if already set 
              ignoreeeof, then when must increase the file which does not exist 
              to, will be able to appear a wrong information.
              However if we seriously are must change have covered already the 
              file which exists, when or is must increase the file which does 
              not exist, how also has?
              We so long as in "> back" ">&" ">>" ">>&" add on exclamation mark 
              "!"  becomes ">!" ... Was allowed.
              2. pipelines (Pipe)
              Front is similar to change which said, the pipeline also is in the 
              standard loses the difference and the standard shows installs the 
              interplanting substitution movement by mistake, like first may 
              output some formula Lian Daoling a formula in the input. Its 
              grammar as follows:
              Command1  command2 [  command3.... ]
              Command1 & command2 [ & command3.... ] The <--- continually 
              standard wrong output as soon as appoints the pipeline
              3. prospects and background (onstage and backstage)
              Under sh, the advancement which newly produces may by way of order 
              back mark ';' '&' distinguishes the prospect and the background.
              If below grammar
              Command
              This expression has a prospect advancement, you must wait till it 
              to finish can again under another instruction.
              Command &
              Like this indicated has a prospect advancement, it can give you 
              similar below the news:
              [ 1 ] 21,304
              Then appears next to raise a signal, by gives the next instruction 
              for you.
              Then time which finished in this prospect advancement again gives 
              you like under the news, told you it to finish this advancement 
              execution.
              [ 1 ] Done command command1; Command2; Command3
              Like this expressed you request the system continuously to carry 
              out command1, command2, the command3 three instructions,
              Command2 must wait for command1, command3 must wait for command2, 
              but you must wait for the command3 execution finished can under 
              the instruction.
              Command1 & command2 & command3 & expressed like this you request 
              the system continuously to carry out command1, command2, the 
              command3 three instructions,
              But these three instructions all put on the background execution, 
              between each other does not have to wait for.
              Fg and bg
              Perhaps you can ask, already carried out the advancement may trade 
              the background by the prospect, or trades the scenery by the 
              background? May.
              In the prospect execution advancement, you may suspend according 
              to Ctl-Z the advancement, the system can give you a news:
              Suspended
              Then appears raises a signal. This time you may use fg to restore 
              it the prospect execution, or changes according to bg it the 
              background execution.
              But if has a prospect the advancement, you also may use the fg 
              instruction to call it the prospect.
              First you must inspect at present with the jobs instruction to 
              have how many under the background advancement, then the basis 
              demonstrated job id decided puts that advancement the prospect.
              If uses % fg %3 # to put third job the prospect.
              UNIX commonly used order introduction
              Under mainly explains under UNIX the basic order use, as a result 
              of the time and the length reason, is unable to write all UNIX 
              order.
              When you in use the order which here has not listed, may use 
              "--help" the parameter to inquire the help which this order 
              attaches.
              For instance: Ls -help will demonstrate the ls order the detailed 
              information.
              At the same time, you also may inquire the more detailed operating 
              instructions using man.
              Directly will knock into man to demonstrate all orders the 
              information.
              If you only want to look an order the information uses the 
              following form
              Man < life reputation >
              For instance will knock into man ls in the UNIX system to 
              demonstrate ls the detailed information.
              Presses the q key to withdraw from the man contact surface.
              Following order introduction according to alphabetical order 
              arrangement:
              Order: At
              Introduced: At, batch, atq, atrm: The arrangement, the inspection, 
              deletes in the formation the work.
              At [ -V ] [ -q formation ] [ -f filename ] [ -mldbv ] time
              At -c work [ work... ]
              Atq [ -V ] [ -q formation ] [ -v ]
              Atrm [ -V ] work [ work... ]
              Batch [ -V ] [ -q formation ] [ -f filename ] [ -mv ] [ time ]
              At carries out the work in the hypothesis time.
              Atq lists the user to arrange in the formation the work, if is the 
              super user, then lists in formation's all work.
              In atrm deletion formation's work.
              Batch with low priority movement work, so long as system loadavg 
              (system average load) <1.5 (or establishes in atrun value) it 
              starts to carry out the work.
              The super user may use at series in any situation the order.
              The common user uses the right which at series orders by document 
              /etc/at.allow, the /etc/at.deny control.
              If /etc/at.allow existence, then only has the row to be able to 
              use at series in this document user the order.
              If the /etc/at.allow document does not exist, then inspection 
              document /etc/at.deny this document.
              So long as does not arrange in order in this document the users 
              all may use at series the order.
              Lacks the province the disposition is /etc/at.deny is a spatial 
              document, this indicated all users all may use at series the 
order.
              Model:
              At -f work 4pm + 3 days after three days in afternoon 4 o'clock 
              execution files work work.
              At -f work 10am Jul 31 in July 31 morning in 10 o'clock execution 
              files work work.
              Order: Bash
              Introduced: Bash - GNU Bourne-Again the SHell free software 
              foundation (Free Software Foundation Inc) has the bash copyright.
              Bash is under Linux many orders in the interpreter, is compatible 
              with sh, and has contained in ksh and csh some useful 
              characteristics.
              Complies with IEEE Posix Shell and Tools specification (IEEE 
              Working Group 1003.2).
              Order: Cat
              Introduced: The cat - connection document and prints the standard 
              output.
              Cat is the CATenate abbreviation, frequently uses for to 
              demonstrate the document, is similar under DOS the TYPE order.
              Model:
              [ root@cnhonker.com/] # cat -b -E lessrc demonstration document 
              lessrc content
              1 back-line
              3 forw-scroll$
              4 back-scroll $
              5 goto-line$
              6 goto-end$
              [ root@cnhonker.com/] # cat myfile1 myfile2 >tmp
              Document myfile1, myfile2 links outputs document tmp
              Order: Cd
              Introduced: Cd - change current directory.
              Cd table of contents name
              If does not add the table of contents name, then returns to the 
              user the root table of contents, in addition the user must have 
              reads this table of contents the jurisdiction.
              Enters other user the table of contents so long as cd ~ user then.
              Model:
              Cnhonker:/tmp> cd id1
              Enters the id1 table of contents
              Cnhonker:/tmp/id1>cd ~lion
              Enters user lion the table of contents
              Cnhonker:~lion>
                
              Order: Chgrp
              Introduced: Chgrp - change document group.
              The group must change the group may be the group number 
              correspondence numeral; Also may be in the /etc/group document 
              group name.
              Filename: The blank space is separated must change the group 
              property rights the document to tabulate, supports ݬ. If the 
              user is not this document is the host or the super user, then 
              cannot change this document the group.
              Model
              [ root@cnhonker.com/] # chgrp -R book /opt/local/book/*. *
              Changes all documents group which /opt/local/book/ and its the 
              index takes down is book.
              Order: Chmod
              Introduced: Chmod - change file protection, file protection 
              control user visit to document power,
              Some three securities rank: Owner rank, group visit rank, other 
              user visit ranks,
              In these three ranks, also some three jurisdiction: Reads (r), 
              writes (w), execution (x).
              (User may ls -lg watch some document subordinate group)
              As for the document reads the jurisdiction to mean may look the 
              document the content, writes the document power to be allowed to 
              revise or the deletion document, carries out the jurisdiction to 
              be allowed to carry out it
              (Is similar to under DOS EXE, COM, the BAT document).
              As for the table of contents that, reads the jurisdiction to mean 
              may examine under the table of contents the content, writes the 
              jurisdiction to mean can establish the new document under the 
              table of contents, and may delete the document from the table of 
              contents, carries out the jurisdiction to mean may transform from 
              a table of contents to another table of contents.
              Protection jurisdiction: The form is [ ugoa... ] [ +-= ] [ 
              rwxXstugo... ] .. ] ... ] Which users "will ugoa" control to 
              change to this document jurisdiction:
              (u) document owner,
              (g) and document owner same group's users
              (o) other groups' users
              (a) all users, the instruction character "+" causes the user 
              choice the jurisdiction to supplement to each goal document. The 
              instruction character "-" causes these jurisdiction to abolish. 
              "=" Enables the goal document only to have these jurisdiction. 
              "rwxXstugo" chooses the new attribute.
              (r) reads the jurisdiction
              (w) writes the jurisdiction
              (x) carries out the power (or visit to table of contents power)
              (X) only has the goal document is may carry out to certain users 
              or this goal document is when a table of contents only then 
              supplements x attribute
              (s) simultaneously establishes the user or group ID
              (t) preserves the procedure the text to the commutation equipment 
              on
              (u) the goal document is the host
              (g) the goal document is the group which the host is at
              (o) other users.
              If expresses the attribute with the numeral, then
              (0) does not have the jurisdiction,
              (1) carries out the power,
              (2) reads the power,
              (4) writes the power,
              Then adds together it, therefore the digital attribute form should 
              be 3 from 0 to 7 octal numerals its order is (u) (g) (o).
              Filename: The blank space is separated must change the 
              jurisdiction the document to tabulate, supports ݬ.
              Model:
              Cnhonker~>chmod a+x destfile enable all users to have read-write 
              to document destfile carries out the power.
              Cnhonker~>chmod 644 destfile enables all users to be allowed to 
              read document destfile only to have is the host to be able to 
              change.
              Order: Chown
              Introduced: The chown - change document is advocates peace the 
              group.
              User: May be the user name or user id.
              Group: May be the group name or group's id.
              Filename: To the blank space is separated must change the 
              jurisdiction the document to tabulate, supports ݬ.
              Model:
              Cnhonker~>chown tlc:book destfile is document destfile the host to 
              alter to the tlc group to alter to book.
              Order: Chsh
              Introduced: The chsh change user registers shell.
              Chsh [ -s registers shell ] [ user ]
              The average consumer may change own registers shell, the super 
              user may change other users to register shell, all shell must be 
              sahell which lists in the /etc/shells document, but super user not 
              this limit.
              If user's shell is shell which limits then the user cannot change 
              it to register shell.
              If does not add the -s parameter then the chsh output user current 
              registers shell and the prompt user inputs new shell the way.
              Changes when shell all needs to input the user the password.
              Model:
              [ root@cnhonker.com/] # chsh
              Password: *****
              Changing the login shell for tlc Enter the new value, or press 
              return for the default Login Shell
              [ /bin/csh ]: /bin/tcsh
              [ root@cnhonker.com/] #
              Order: Clear
              Introduced: Clear - eliminates the screen (to be similar to DOS 
              cls)
              Model:
              Cnhonker~>clear
              Eliminates the screen, prompts the symbol to move to on the left 
              angle.
              Order: Cp
              Introduced: Cp - copy document.
              Cp [ options ] source document goal document
              Cp [ options ] source document... goal table of contents
              -f, --force: The deletion has existed goal document.
              -i, --interactive: Has existed in the deletion when goal document 
              produces the prompt.
              -R, --recursive entire catalogue copy.
              --help outputs the help information and the withdrawal in the 
              standard output.
              --version outputs the edition information and the withdrawal in 
              the standard output.
              Model:
              [ root@cnhonker.com/] # cp sourcefile destfile
              Copy document sourcefile to document destfile.
              [ root@cnhonker.com/] # cp * /tmp
              Under copy current directory all documents to /tmp table of 
              contents.
              Order: Crontab
              Introduced: Crontab - operates each user the protection procedure 
              and this execution timetable.
              Crontab file [ -u user ] - with document substitution at present 
              crontab which assigns.
              Crontab - [ -u user ] - inputs substitution at present with the 
              standard crontab.
              Crontab -l [ user ] - lists user at present crontab.
              Crontab -e [ user ] - edition user at present crontab.
              Crontab -d [ user ] - deletion user at present crontab.
              Crontab -c dir - assigns crontab the table of contents.
              Crontab document form: M H D m d cmd
              M: Minute (0-59)
              H: Hour (0-23)
              D: Day (1-31)
              M: Month (1-12)
              D: A week of in day (0-6, 0 is Sunday)
              Cmd: Must move the procedure, the procedure is sent in the sh 
              execution, this shell only has USER, HOME, the SHELL these three 
              environment variable.
              Under is an example document:
              # MIN HOUR DAY MONTH DAYOFWEEK COMMAND
              # Every day early morning 6 o'clock
              106 * * * date
              # Every two hours
              0 */2 * * * date
              # The evening 11 o'clock to the early morning 8 o'clock between 
              every two hours, early upside selects
              0 23-7/2, 8 * * * date
              # Each month 4 with each week Monday to Wednesday early morning 11 
              o'clock
              0,114 * mon-wed date
              # In January date early morning 4 o'clock
              041 jan * date
              Model:
              [ root@cnhonker.com/] # crontab -l
              Lists user at present crontab.
              # MIN HOUR DAY MONTH DAYOFWEEK COMMAND
              106 * * * date
              0 */2 * * * date
              0 23-7/2, 8 * * * date
              (Is usual, when puts back door, we may use this document to cause 
              machine to move our back door procedure in specific time.:)
              Order: Date
              Introduced: Date - printing or establishment system date and time.
              Date [ -u ] [ -d datestr ] [ -s datestr ] [ --utc ] [ --universal 
              ] [ --date=datestr ] [ --set=datestr ] [ --help ] [ --version ] [ 
              +FORMAT ] [ MMDDhhmm [ [ CC ] YY ] [ ss ] ]
              +FORMAT: How controls demonstrates the date
              Instruction:
              %: % Number
              N: New line
              T: TAB
              Time domain:
              %H hour (00. 23)
              %I hour (01. 12)
              %k hour (0. 23)
              %l hour (1. 12)
              %M minute (00. 59)
              %p AM or PM
              %r 12 hours (hh:mm:ss [ AP ] M)
              %s time which starts from 1970-01-01 00:00:00 UTC
              %S second (00. 61)
              %T 24 hours (hh:mm:ss)
              %X time expression (%H:%M:%S)
              The %Z time zone (for example EDT) like has not assigned the time 
              zone not to demonstrate
              Date territory:
              %a abbreviation form week name (Sun. Sat)
              %A week name (Sunday. Saturday)
              %b abbreviation form month name (Jan. Dec)
              %B month (January. December)
              %c date and time (Sat Nov 0:02:33 EST 1,989)
              %d each month several days (01. 31)
              %D date (mm/dd/yy)
              %h equates to %b
              A %j year several days (001. 366)
              %m month (01. 12)
              A %U year center several week, Sunday is the week first day (00. 
              53)
              %w each week several days (0. 6) 0 are Sundays
              A %W year center several week, Monday is the week first day (00. 
              53 (00. 53)
              %x date (mm/dd/yy)
              %y year latter two numerals (00. 99)
              %Y year (1970...)
              [ MMDDhhmm [ [ CC ] YY ] [ ss ]
              MM month
              DD date
              Hh hour
              Mm minute
              CC year first two (may option)
              YY year latter two (may option)
              The ss second (may option)
              Only has the super user only then to have the jurisdiction 
              establishes the system time (when start in CMOS reads out).
              -d datestr, --date dates: Demonstrated in datestr assigns date and 
              time.
              -s datestr, --set datestr: Establishes date and time which in 
              datestr assigns.
              -u, --universal: The demonstration or the hypothesis Greenwich 
              Mean Time (lack province for local time).
              --help: Outputs the help information and the withdrawal in the 
              standard output.
              --version: Outputs the edition information and the withdrawal in 
              the standard output.
              Model:
              Prints two day ago the time:
              [ root@cnhonker.com/] # date --date '2 days ago' Fri Aug 22 
              20:20:08 CDT 1,997
              Printing month and date:
              [ root@cnhonker.com/] # date '+%B %d' August 24
              Order: Echo
              Introduced: Echo is uses for to demonstrate a character string on 
              the terminal.
              Echo -n is when demonstrated  cannot have skip a line movement.
              Order: Exit
              Introduced: Exit uses for to withdraw from inferior landing.
              Order: File
              Introduced: File - survey document type.
              Model:
              Cnhonker:/tmp> file *
              Destfile: ASCII text
              Elm.rc.OLD: English text
              Portnum: Empty
              Rc.inet1.OLD: Bourne shell script text
              Order: Find
              Introduced: Find - uses for in the massive tables of contents to 
              search for the specific document the powerful tool.
              Find [ way... ] [ Match expression ]
              Model:
              Cnhonker:/> find./-name "passwd" -print
              . /usr/bin/passwd
              . /home/ftp/etc/passwd
              . /etc/passwd
              May discover under the current directory all documents named 
              passwd document. to take down including the index.
              This order function is extremely formidable.
              A more detailed content please look at the help.
              Order: Finger
              Introduced: Finger - inquires this machine or on other machine 
              user information,
              Usage: Finger user (this machine) or finger user @ip.
              We may use on mostly the machine
              Finger @ip
              Obtains user which the goal main engine current lands.
              Finger 0@ip
              Obtains the goal main engine the detailed user information.
              This order uses for to you to obtain the first account number is 
              very easy.
              Order: Ftp
              Introduced: Ftp hostname
              The concrete parameter situation please looked at in the alliance 
              main page the ftp use. or I before course.
              Order: Telnet
              Introduced: Ftp hostname [ port ]
              The concrete parameter situation please looked at in the alliance 
              main page the telnet use. or I before course.
              Order: Traceroute
              Introduced: Traceroute targethost
              This order will have to mention by name the way by root by the 
              /usr/sbin/traceroute festival to move this order to demonstrate 
              arrives route which far-end the machine will pass through
              Order: Grep
              Introduced: Grep, egrep, fgrep - searches for the match in the 
              document the line and the output.
              Model:
              Searches in document services includes ftp the line.
              Cnhonker:/etc> grep ftp services
              Ftp 21/tcp
              Tftp 69/udp
              Sftp 115/tcp
              Order: Gzip
              Introduced: Gzip, gunzip, zcat - compression or flat file.
              Model:
              [ root@cnhonker.com/] # gzip -v sourcefile
              Sourcefile: 15.2% -- replaced with sourcefile.gz
                
              Order: Head
              Introduced: Head - demonstration document first several lines.
              Model: Output document lessrc first line.
              [ root@cnhonker.com/] # head -n 1 lessrc
              Forw-line
              Order: Kill
              Introduced: Kill - stops an advancement
              Kill [ -s signal  -p ] [ -a ] advancement number...
              Kill -l [ signal ]
              Kill to the advancement which assigns sends out the specific 
              signal, if has not assigned the signal to send out the TERM 
              signal, the TERM signal will kill has not caught this signal the 
              advancement.
              Possibly must use KILL regarding certain advancements (9) the 
              signal to force to kill.
              For example: Kill -9 11,721. Will force to kill advancement 11721.
              In majority SHELL constructs the kill order
              Model: Massacres advancement 11721
              [ root@cnhonker.com/] # ps
              PID TTY STAT TIME COMMAND
              11,668 p1 S 0:00 -tcsh
              11,721 p1 T 0:00 cat
              11,737 p1 R 0:00 ps
              [ root@cnhonker.com/] # kill 11,721
              [ 1 ] Terminated cat
              Order: Last
              Introduced: The last - demonstration in the past how many user or 
              the terminal registered this machine.
              Last [ - number ] [ the -f filename ] [ -t tty ] [ the -h festival 
              mentions by name ] [ -i the IP address ] [ -l ] [ -y ] [ user... ]
              Model: The demonstration passes the situation which 3 times of 
              users fangh registers:
              [ root@cnhonker.com/] # last -3 fangh
              Fangh ttyp1 csun01.ihep.ac.c Tue Aug 26 18:46 still logged in
              Fangh ttyp2 csun01.ihep.ac.c Mon Aug 25 22:32 - 23:14 (00:41)
              Fangh ttyp2 csun01.ihep.ac.c Mon Aug 25 19:58 - 21:59 (02:01)
              Order: Less
              Introduced: Less - is opposite to more, uses for according to the 
              page demonstration document.
              Model: Demonstrates the test document
              [ root@cnhonker.com/] # less test
                
              Order: Ln
              Introduced: Ln - establishes the connection in the document 
between
              Ln [ parameter ] source document [ goal document ] ln [ parameter 
              ] source document... directory
              Moreover makes the change attribute to the chained file movement 
              is does not have the significance, because has the document 
              attribute which they links is only the document true attribute.
              Model:
              Connects document test document sourcefile
              [ root@cnhonker.com/] # ln -s sourcefile test
              [ root@cnhonker.com/] # ls -la
              Test lrwxrwxrwx 1 fangh users 10 Aug 26 20:36 test -> sourcefile

              Order: Ls
              Introduced: Ls, dir, vdir - lists under the table of contents 
              document (to be similar under DOS the DIR order).
              Model: Lists under current directory all documents
              [ root@cnhonker.com/] # ls -la
              Total 6
              Drwxr-x--- 2 fangh users 1,026 20:52./
              Drwxr-xr-x 19 root root 1,026 21:09../
              -rw-r--r-- 1 fangh users 15 Aug 21 21:57 bash_history
              -rw-r--r-- 1 fangh users 30 20:41 less
              -rw-r--r-- 1 fangh users 115 19:58 lessrc
              -rw-r--r-- 1 fangh users 72 Aug 24 18:43 sourcefile
              Lrwxrwxrwx 1 fangh users 10 Aug 26 20:36 test -> sourcefile
              Order: Mail, elm
              Introduced: May pass through from this the procedure gives letter 
              mail the other people.
              Use way: Mail [ username ]
              Mail -f mailboxfile like has the letter, then directly enters mail 
              to be allowed to read takes your mail
              Example:
              Mail -s "shadow" root@cnhonker.com < /etc/shadow
              Elm provides conveniently compares mail to lie between the 
              surface, moreover may make the on-line alias.
              You may enter the letter which about the elm use about the key 
              reads selectively takes, and may obtain the on-line according to h 
              the help document.
              Use way:
              Elm [ usernmae ] elm -f mailboxfile
              Order: Man
              Introduced: The man - demonstration has the certain form the 
              on-line handbook.
              Man regarding the novice and the expert said all is an extremely 
              useful tool, uses for fast to inquire the order and the procedure 
              application method and the parameter.
              The programmers also may use for to inquire the C function usage. 
              Regarding 'rn (1) ' or 'ctime (3) the ' such output, in 
              parentheses numeral refers to the chapter which in the Unix 
              handbook this document is at. When you hit man 3 ctime, the 
              expression is needs to consult in the 3rd center ctime content.
              Under is the common Unix handbook classification:
              1 user order
              2 system calls
              3 storehouses functions
              4 equipment and equipment driver
              5 document formats
              6 games
              7 useful mixed kinds, like great order package
              8 systems maintenances and management order
              Model:
              Inquires the ls usage
              Cnhonker~>man ls

              Order: Mtools
              Introduced: Mtools - uses for under UNIX to visit under DOS the 
              floppy disk tool bag.
              Tool introduction
              Mcd - enters the DOS child directory.
              Mcopy - copy DOS document.
              Mdel - deletes the DOS document.
              Mdeltree - deletes the DOS table of contents.
              Mdir - examines the DOS table of contents.
              Mformat - formatted DOS floppy disk
              Mkmanifest - founds to restore UNIX form filename SHELL
              Mlabel - adds the volume sign for the DOS floppy disk
              Mmd - founds the DOS table of contents.
              Mmove - moves under DOS the document.
              Mmount - mount DOS floppy disk.
              Mtype - demonstrates under DOS the document.
              Mrd - deletes under DOS the table of contents.
              Mren - changes name the DOS under document.
              Order: Mkdir
              Introduced: Mkdir - establishment table of contents (with under 
              DOS md).
              Order: More
              Introduced: More - watches the document in the terminal according 
              to the page the filter.
              The more function does not have less to be that formidable.
              Moreover less has also provided to the more simulation, but the 
              common user is possibly accustomed to the use with the DOS 
              environment under similar more.
              Model:
              Demonstrated document /etc/group and the search character strings 
              together bbs
              [ root@cnhonker.com/] # more +/bbs /etc/group
              .. skipping
              Users::100:games
              Nogroup::-2:
              Bbs:x:99:bbs, bbsroot, bbsuser
              Order: Mv
              Introduced: Mv - changes name the document.
              Mv [ parameter ] source document goal document
              Mv [ parameter ] the source document tabulates (support ݬ) the 
              goal table of contents
              Model: Sourcefile -> destfile
              [ root@cnhonker.com/] # mv -v sourcefile destfile
              Order: Nslookup
              Introduced: The nslookup- inquiry festival mentions by name with 
              the IP address corresponding relations, the usage: Nslookup [ 
              festival mentions by name the IP address ]
              Order: Passwd
              Introduced: Passwd - establishment user's password.
              Passwd [ -f-s ] [ user ]
              Passwd [ -g ] [ -rR ] group name
              Passwd [ -x max ] [ -n min ] [ -w warn ] [ -i inact ] user
              Passwd {-l-u-d-S} user
              The user may use passwd this order to change own registers the 
              password, the common user only can change he password, the super 
              user may change other all users the password, the super user and 
              group's superintendent may reorganize password, but also may use 
              this to order to change the user other information, like user's 
              entire name, the user registers shell, which user's password 
              expires time-gap and so on.
              Model:
              Change password
              [ root@cnhonker.com/] # passwd
              Changing password for fangh
              Old the password:oldpass - - password certainly does not 
              demonstrate Enter
              The new password (minimum of 5, maximum of 8 characters)
              Please use a combination of upper and lower case letters and 
              numbers.
              New password:
              Newpass Re-enter new password:
              Newpass Password changed.
              Order: Ping
              Introduced: Ping - this order uses for inquires far-end a machine 
              whether can arrive, and demonstrated needs the time, if you must 
              withdraw please press the control-C severance.
              Forms of field orders: Ping main engine name or ping IP address.

              Order: Ps
              Introduced: Ps - examination advancement condition.
              Under explains various fences significance:
              FLAGS: Long form F territory.
              UID: User's ID.
              PID: Advancement ID.
              PPID: Father advancement ID.
              PRI: Advancement priority.
              NI: Standard UNIX priority.
              SIZE: Hypothesized memory size.
              RSS: In leave a blank or opening size.
              WCHAN: Advancement waiting essence event.
              STAT: Advancement condition:
              The code is as follows.
              R: Is moving.
              S: Sleep.
              D: Cannot be broken sleep.
              T: Stops or the track.
              Z: Corpse advancement.
              W: The advancement in has not kept the page.
              N: The advancement has a negative nice value.
              TTY: Advancement control bench.
              PAGEIN: The main memory page defeat number (page defeat creates 
              page reads from floppy disk or CACHE takes).
              TRS: The text in keeps the size.
              SHARE: Sharing memory.
              SWAP: On commutation equipment K byte count.
              Model:
              Demonstrates the current advancement:
              [ root@cnhonker.com/] # ps -c
              PID TTY STAT TIME COMMAND
              8,724 p4 S 0:00 tcsh
              8,876 p6 R 0:00 ps
              Order: Pwd
              Introduced: The pwd - demonstration is working or the current 
              directory name.
              Model:
              Lists the current job category
              [ root@cnhonker.com/] # pwd
              /home/lion
              Order: Reset
              Introduced: Reset - repositions the terminal.
              In used the terminal in the process, sometimes can discover the 
              screen the character "the flower" has fallen, by now used reset to 
              be allowed to restore,
              For example after moves circuit analysis software PSPICE, can 
              discover the screen character is confused, uses reset to restore 
              normally.
              Reset transfers the tput function, sends out the replacement 
              signal to the terminal.
              If the screen has been locked in by Ctrl+S, may use Ctrl+Q to 
              relieve locking.
              Model:
              Repositions the terminal:
              [ root@cnhonker.com/] # reset
              Order: Rlogin, rsh
              Introduced: The rlogin significance is remote login,
              Also is by way of the network to other machine login.
              The rlogin form is:
              Rlogin host [ -l username ] option -l username
              Is after you when on distant place machine username and local host 
              different, must input option, otherwise rlogin will be able the 
              supposition you is same in that side username and local host, then 
              when first login inevitably will be able to have the mistake.
              Rsh is carries out certain instructions on the distant place 
              machine, but passes on the result local host.
              Rsh form as follows: Rsh host [ -l username ] [ command ]
              Is similar to rlogin parameter -l username, rsh -l username also 
              assigns remote host username.
              But command is must the instruction which carries out on remote 
              host.
              If has not assigned command, then rsh can carry out rlogin, is 
              similar to directly carries out rlogin.
              But rsh in execution time certainly cannot like the general login 
              procedure equally also to be able to ask your password,
              But is if you have not established trust table, then remote host 
              will not be able to accept your request.
              Rsh must have to be able to do in each possibility is on the 
              remote host machine establishes a file, is called rhosts.
              This file each line divides into two parts,
              First permits login hostname,
              The second part permits login username.
              For example, on www.cnhonker.com
              Your username is lion, but under your home rhosts
              Below has a line: Www1.cnhonker.com lion1
              Then in www1.cnhonker.com on machine user lion1
              May carry out rsh with the below method: % rsh www.cnhonker.com -l 
              lion1 cat mbox
              Lion1 on www.cnhonker.com mbox file content demonstration on local 
              www1.cnhonker.com.
              But if rhosts will have a such line, then on www1.cnhonker.com 
              user lion1 will be allowed not to use the input password but 
              directly lands by way of rsh or rlogin to www.cnhonker.com.
              Attention: The form which rhosts is which a hypothesis may trust 
              the person lands, therefore if does not establish when will be 
              able to let the illegal person have may seize the opportunity to 
              invade the system the opportunity.
              If you read man 5 rhosts, will be able to discover you will be 
              allowed with + to substitute for any hostname in the first fence, 
              the second fence with + will substitute for any username.
              If general user likes being loaf replaces row long string hostname 
              using "+ username", but like this will be able to cause even if 
              will have on PC to run UNIX user to have with your same user, also 
              could be under your permission to invade your system. Such easy to 
              create in the systematic security the danger.
              Similarly, very many people all are willing to increase "+ +" on 
              the black machine rhosts in the document. in order to to leave 
              behind the back door to the user.
              But, is like this is very easily discovered.
              Order: Rm
              Introduced: Rm - deletion document or table of contents.
              Attention, under LINUX if produces is similar to "-f" this kind of 
              filename document, the deletion is first with "--" the option. 
              This behind indicated with "-f" is not the option but is a 
filename
              For example "rm -- -file" is deletes the document "-file",
              Contains the special character when the deletion filename the 
              document, may use "the \+ special character", or includes with "" 
              the filename,
              For example must delete the document "this is a test" to be 
              allowed to use the following order: Rm this\ is\ a\ test or rm 
              "this is a test"
              Moreover must specially pay attention, uses rm -rf * this order, 
              if the user is the super user, and uses this order under root, 
              then the systematic all documents are deleted.
              But restores the document under UNIX nearly is a not impossible 
              matter.
              Thus must discretely treat this order.
              Moreover the suggestion user defines rm as "rm -i", and joins to 
              the user registers in the document.
              Model: Deletion document destfile
              [ root@cnhonker.com/] # rm -v destfile
              Order: Rmdir
              Introduced: Rmdir - deletes the spatial table of contents.
              Order: Su
              Introduced: Su - change user's ID or becomes the super user.
              Order: Tail
              Introduced: Tail - demonstration document last part
              Tail lacks the province to demonstrate the filename tabulates each 
              document finally ten lines, if does not have the filename or the 
              document named "-" then it reads from the standard input takes the 
              document,
              If has many documents then its can add on "==> in front of the 
              document filename <==" in order to differentiates.
              Model:
              Demonstrates document /etc/DIR_COLORS finally three lines:
              [ root@cnhonker.com/] # tail -v -n 3 /etc/DIR_COLORS

                
              Order: Tar
              Introduced: Tar - the GNU version document packs the backup tool.

              Model:
              All txt documents pack the current directory under and compress to 
              file away document bak.tar.gz
              [ root@cnhonker.com/] # tar czvf bak.tar.gz. /* txt
              Packs table of contents. /sec files away document sec.tar.gz
              [ root@cnhonker.com/] # tar czvf sec.tar.gz. /sec
                
              Order: Tcsh
              Introduced: Tcsh - has the filename automatic supplement and good 
              editor function C shell.
              Tcsh is the well-known Burkley UNIX C SHELL enhancement edition, 
              it both may take interactive registers SHELL and to be allowed to 
              take the script document the processor.
              Tcsh registers the shell start when the achievement, first reads 
              takes system disposition document /etc/csh.cshrc and 
              /etc/csh.login.
              After that is reading to user's root table of contents takes ~/ 
              tcshrc, if does not have ~/ tcshrc then reads takes ~/ cshrc,
              Then reads takes ~/ history, ~/ login finally is ~/ cshdirs.
              Must registers when the shell start read-only takes /etc/csh.cshrc 
              and ~/ tcshrc.
              Orders the good editor: The use direction key edits, about for 
              chooses the order in the historic record, about the key for goes 
              forward after the order line to move carries on the edition.
              The order supplemented and tabulates: Enters the order when the 
              user, frequently cannot remember the order or the table of 
              contents entire name, this time tcsh will be allowed to help the 
              user the surplus partial complements,
              For example the user enters "/usr/lost" but behind to forget the 
              part, will wait the user only to need by now to enter the TAB key, 
              tcsh can be automatic the surplus partial complements -- 
              "/usr/lost+found/", when the user produced the part had many 
              matches in the situation for example "/usr/l" then TAB will be 
              unable to complement, by now waited the user only to have to enter 
              "CTRL+D" then tcsh will list all matches situation for the user: 
              "lib/ local@ lost+found/", the user was allowed own to choose.

                
              Order: Top
              Introduced: Top - display system highest advancement
              Top this order may the immediate demonstration current system most 
              account for the CPU time the advancement, it simultaneously 
              provides an interactive contact surface to enable the user to be 
              allowed the viewing system advancement situation,
              It may defer to the CPU service condition, accounts for the memory 
              size, the movement time comes to the advancement arrangement, this 
              is a system administration item of essential tool.

                
              Order: Touch
              Introduced: Touch - change document time parameter.
              Touch the document visit time, the revision time establishes as 
              the system current time, if this document does not exist 
              establishes a spatial new document.
              Model: The current directory under document time parameter 
              revision is the current time:
              [ root@cnhonker.com/] # touch *

              Order: Umount, mount
              Introduced: Mount - loads a filing system.
              Umount - dismounts a filing system.
              Lists the system at present the mount filing system:
              [ root@cnhonker.com/] # mount
              /dev/hda1 on/type ext2 (rw)
              None on /proc type proc (rw)
              /dev/hda3 on /home type ext2 (rw)
              /dev/hda2 on /usr/local type ext2 (rw)
              The increase light drives:
              [ root@cnhonker.com/] # mount /dev/hdb /mnt
              Order: Useradd, adduser, userdel
              Introduced: Useradd, adduser increase user
              Userdel deletion user
              These orders only can by the root use.
              For instance
              Useradd -D lion according to tacitly approves the value to 
              increase user lion
              Passwd lion - - you must cause the user which you just increased 
              to become effective, had to have to use passwd to formulate the 
              password to this user.
              You may examine the help information obtains more materials.

                
              Order: Uudecode, uuencode
              Introduced: Uuencode - a binary file code is a text documents.
              Uudecode - the document which produces uuencode recovers.
              Not yet extremely is developed in Internet, very many users only 
              can use E-mail, must exchange software the speech is an extremely 
              troublesome matter,
              Because cannot use the E-mail direct transmission binary file, 
              thereupon uuencode and uudecode become the extremely useful two 
              tools.
              Uuencode produces the text documents 644 as starts take begin to 
              symbolize that, take end as the end mark in this middle is has 
              coded the document.
              After the code document will be bigger than the source document 
              about 35%.
              Uuencode produces the document will output the standard output, if 
              will have to save the document, please will use the pipeline 
              function its heavy direction detection to a disk file in.
              Uuencode source filename
              When code uses filename
              Uudecode must decode filename
                
              Order: Vi
              Introduced: Vi - function formidable UNIX editor.
              Vi synopsis
              Vi is in the UNIX world the most general entire screen editor, all 
              UNIX machine all provides in this editor Linux provides is vi 
              strengthens version -vim, but is with vi completely compatible.
              Vi original intention is "visual" namely the visible editor, the 
              user enters can demonstrate immediately.
              Moreover its formidable edition function may compare favorably 
              with with any newest editor, moreover the academic society vi may 
              let the user in any UNIX machine regardless of is SUN, HP, AIX, 
              SGI, or on Linux or FreeBSD all may handily edit the document.
              So long as enters in the order line vi may enter vi edition 
              environment.
              Vi has two kind of conditions, the input condition as well as the 
              instruction condition.
              The user may input the writing material under the input condition
              The instruction condition is uses for to carry out opens the 
              document, the archive, leaves vi and so on the operational order,
              After carries out vi first to enter the instruction condition, 
              this time inputs any character all processes as the instruction.
              Input "vi filename" then vi automatically loads the document or 
              starts a new document, vi screen left side can appear Volna "~", 
              represents the line of business is a white line.
              How has to enter the input condition?
              Below is the corresponding instruction:
              Supplements (append)
              A starts from the cursor behind the position to supplement the 
              writing, after the cursor writing along with the writing which 
              supplements to after moves.
              A starts from the cursor in the row most behind place to 
              supplement the writing.
              Insertion (insert)
              I starts from the cursor in front of the position to insert the 
              writing, after the cursor writing along with the writing which 
              supplements to after moves.
              I starts from the cursor in front of the row first non- blank 
              character to insert the writing.
              Starts (open)
              O increases a row in the cursor under the row and enters the input 
              condition.
              O increases a row in the cursor above the row and enters the input 
              condition.
              X deletion cursor sign in character.
              The dd deletion cursor is at row.
              The r revision cursor receives the character in the character 
              which must revise.
              R enters the rewriting condition, increases the writing to be able 
              to cover the original writing
              The s deletion cursor in the character, and enters the input 
              condition.
              The S deletion cursor is at the row, and enters the input 
              condition.
              Conclusion edition (quit)
              : Q conclusion edition (quit) if does not want to put on file but 
              must give up edit the document to use
              : Q! Forces to leave.
              : W puts on file the name which (write) after that the coca must 
              put on file.
              : After wq namely puts on file leaves.
              Zz function and
              : Wq is same.
              Order: Wc
              Introduced: Wc - counts in a document the byte count, the word 
              number, the number of lines.
              Order: W, who, who am i
              Introduced: W - examined other register user.
              Who - examined other register user.
              Who am i - examines own detailed situation
              Order: Which
              Introduced: Which - demonstration order full path.
              Which procedure name
              OK, the order introduced arrived here.
              :) 



              Original author: Huc 
              Origin: Huc 
              Altogether has 125 readers to read this article 

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