- 1. Linux: Basic Operations - 2Minsuk Lee Hansung University,
Seoul, Korea [email protected] MC2.0 CC-BY 2.0 KR, Korea
OSS Promotion Forum, NIPA
2. Simple Shell usage Invoking Terminal Type any command and
[ENTER] BIG TIPs !! Use ,, [INS], [DEL],[HOME],[END] keys to edit
command line Try [tab] - It completes filename or shows all
available choices When output stops, try [SPACE], mouse scroll, q
to continue or to quit $ exit -- will end the terminalNEAOSS
MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA 3. man (1) Shows
manual page of Linux commands, libraries, utilities Usage : $ man
[options] [section] item Item can be program, function, file,
anything in /usr/share/man/*/ Options : Sections1. Executable
programs or shell commands2. System calls (functions provided by
the kernel)3. Library calls (functions within program libraries)4.
Special files (usually found in /dev)5. File formats and
conventions e.g. /etc/passwd6. Games7. Miscellaneous (including
macro packages and conventions), e.g. man(7), groff(7)8. System
administration commands (usually only for root)9. Kernel routines
[Non standard]$ man printf show man page of shell command printf$
man 3 printf show man page of printf() library$ man -a printf show
man page of both of the twoNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 4. man (2) Options :-a : display all
available manual pages of the item-k : list all man page items
includes the given item name ($ apropos r item)-f : shows very
short descriptions-Tps : output as Postscript format (to be
converted into pdf) Example$ man man$ man -Tps 3 printf | ps2pdf -
printf.pdf Alternatives$ info item : shows detail information, if
the item is available in /usr/share/info$ command help : shows help
messages (options) of the command PLEASE READ MAN PAGES OF
COMMANDS, FUNCTIONS YOU USE !!NEAOSS MC2.0CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 5. Name pattern matching Specifying multiple
files(directories) Work for ALL commands * means any string
(multiple, any characters including null) ? means any single
character [a-s] : means any single character between a and s E.g.,
[1-7c-f], [acf2A-Z], $ rm * : means everything in current directory
$ rm directory/* : means everything in directory $ rm s*s : means
files or directories start and end with s $ rm 6[ab]x* : means
files or directories start with 6ax or 6bx See man page of bash ( $
man bash ) for more Such as ?(patten-list), *(patten-list),
+(pattern-list), NEAOSS MC2.0 CC-BY 2.0 KR, Korea OSS Promotion
Forum, NIPA 6. Pipe and redirection Standard Input and Output In
Shell, Its Keyboard input and Screen Output, by default Pipe feeds
standard output into other commands standard input Redirection
redirects the standard input/output from/to files$ ls l | more :
feed the output of ls l to more$ ls 1 | sort r | more : ls -1 then,
sort in reverse order, and more$ ls l > file : redirect the
output of ls l to file (overwrite or create)$ ls l >> file :
redirect the output of ls l to file (append)$ cat a b > c :
concatenate file a and b into file c $ sort < source >
destination : sort source, into destination Standard Error$ command
2> file : redirect error message of command to fileNEAOSS
MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA 7. grep Prints
lines matching a pattern Usage : $ grep [options] pattern file
Options : -i : ignore case -n : print line number -H : with file
name -r : read all files under directory recursivelyNEAOSS
MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA 8. find (1)
Searches for files in a directory hierarchy Usage : $ find
[options] [path...] [expression] Options :-H, -L, -P : controls
symbolic links (see, $man find) Expression for [match test]
[Action] : Match test-name : $ find / -name thisname finds files
with thisname, thisname can be pattern (*, ?, )-executable :
executable files-user : $ find / -name user1 finds files belonging
to user1-atime : $ find / -atime n finds files accessed within n
days-ctime , -mtime : files created or modified within n days-newer
: $ find / -newer file finds files modified more recently than
file-type c : $ find / -type c finds files of type c, (c can be d :
directory, f : regular file, l : symbolic link, b,c:device file)-
Action-delete : delete the found files-exec command : apply command
to the found files in command {} is used for found file command
ends with ; ( is escape code)-NEAOSS MC2.0CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 9. find (2) Example Just find find and
grepNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA 10.
ps Reports a snapshot of the current processes Usage : ps [options]
Options :ax : all process in system, same as er : only running
processnnn : only process id nnn, same as -pid pid_list list (e.g.,
$ ps pid 107,109)l, s, u, v, x : format long, signal,
user-oriented, virtual memory, register formatm : shows threads
after processNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum,
NIPA 11. pstree Display a tree of processes Usages : $ pstree
[options] [pid_or_user] $ pstree myuser (Terminal related part) $
pstreeNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA 12.
top (1) Display Linux tasks Usage : $ top [options] [pid][Commands
to change ]See man page !NEAOSS MC2.0CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 13. top (2) ; multiple commands >
redirectionx.c Ctrl-D to end edit Compile x.c to loop & execute
background execute ./loop Ctrl-Z to suspend bg resume in
backgroundNEAOSS MC2.0 CC-BY 2.0 KR, Korea OSS Promotion Forum,
NIPA 14. top (3) top with a endless loop task top with two endless
loop tasksNEAOSS MC2.0 CC-BY 2.0 KR, Korea OSS Promotion Forum,
NIPA 15. kill Send a signal to a process Usage : $ kill signal
[pid] $ kill -9 100 : kills process 100 $ kill -9 -1 : kill all
(you can kill) Signals :-9 (KILL) : kill process-1 (HUB) :
restartOthers : see man page !NEAOSS MC2.0 CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 16. tar, bzip2, gzip (1) Compresses files and
directories Usage : $ tar [options] path $ tar cvf name.tar
directory : Archive (no compress) directory into name.tar $ tar xvf
name.tar : Extract name.tar Options : c : create, x : extrace, t :
list v : verbose (lists file names) j : use bzip2, z : use gzip for
compress / uncompress f filename : specify archive filename Bzip2 :
compress a file into file.bz2 $ bzip2 file to compress, $ bzip2 d
file.bz2 to uncompress gzip : compress a file into file.gz $ gzip
file to compress, $ gzip d file.gz to uncompress Example $ tar cjf
file.bz2 files-directories : tar & compress files-directories
into file.bz2 $ tar xjvf file.bz2 : uncompress and untar
file.bz2NEAOSS MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA
17. tar, bzip2, gzip (2) tar & bzip2 list archiveRemove temp
directoryun-bzip2 and untarNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 18. df, du df report file system disk space
usage Usage : $ df [options] [file] Options-h : human readable
units ! du estimates file space usage Usage : $ du [options] [file]
Options-h : human readable units !-s : display only totalNEAOSS
MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA 19. sudo Execute
a command as another user (such as super user) Usage : $ sudo [u
username] [command] $ sudo u other-user /bin/bash : invoke shell
with user other-user $ sudo /bin/bash : invoke superusers shell $
sudo command : run command in superuser permission Only selected
user can get superuser permission (defined in /etc/sudoers) ? $
sudo rm -rf ./*vs. $ sudo rm rf /*NEAOSS MC2.0 CC-BY 2.0 KR, Korea
OSS Promotion Forum, NIPA 20. chown, chmod Changes owner,
permission of files and direct Usage : $ chown [owner][:group]
file$ chmod mode file Options-R : recursively change Permission
issue$ chown can be done by superuser$ chmod needs enough
permission Permission (read,write,execute)mRWXRWXRWXuserothersgroup
Type (file, directory, device)NEAOSS MC2.0CC-BY 2.0 KR, Korea OSS
Promotion Forum, NIPA 21. hostname, uname $ hostname : name of this
computer Search domain, name server are defined in /etc/resolv.conf
$ uname : Operating System Name as compiledNEAOSS MC2.0 CC-BY 2.0
KR, Korea OSS Promotion Forum, NIPA 22. ifconfigUse GUI Configures
a network interface To configure Network ! Usage : $ ifconfig
[interface or a]$ ifconfig interface [aftype] options | address ...
interface is the name of network device (e.g., eth0 : Ethernet, lo
: loopback)NEAOSS MC2.0 CC-BY 2.0 KR, Korea OSS Promotion Forum,
NIPA 23. ping Send ICMP ECHO_REQUEST to network hosts Usage : $
ping [options] destination destination is ip-address (a.b.c.d) or
hostname Options :-c count : stop after count-i interval : ping
interval-n : display ip address rather than hostname-s packetsize :
set packet sizeNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum,
NIPA 24. netstat (1) Prints network connections, routing tables,
interface statistics, masquerade connections, and multicast
memberships Usage : $ netstat [options] Options :-r : print routing
table-i : print interface statistics-n : display ip address rather
than hostname-p : print pid and program name-l : print only
listening sockets-a : print both listening & non listening-t,
-u : print socket using tcp, udp protocolNEAOSS MC2.0 CC-BY 2.0 KR,
Korea OSS Promotion Forum, NIPA 25. netstat (2)NEAOSS MC2.0 CC-BY
2.0 KR, Korea OSS Promotion Forum, NIPA 26. Network files
/etc/hosts : stores hostname and ip-address /etc/resolv.conf :
ip-address of name server /etc/services : name of network
servicesNEAOSS MC2.0CC-BY 2.0 KR, Korea OSS Promotion Forum, NIPA
27. Lets Practice find & grep Build up directories Try $ find ,
$ grep, and mix it TopEdit x.c, compile into loop$ topRun loop
background and $ top,And once more, see how loop processes share
the CPUTry $ pstree to find loop process$ kill the loop process
Tar, bzip2 As in slide Try $ df, $ du, $ chown, $ chmod, $ sudo Try
$ ping, $ netstat [options], $ ifconfigNEAOSS MC2.0CC-BY 2.0 KR,
Korea OSS Promotion Forum, NIPA
