unix shell script 2003/03/24 for sparcs ’03 김군훈. index what is shell? shell configuration...
TRANSCRIPT
Index
• What is shell?• Shell configuration & Environment variable.• Standard input/output/error,
Redirection, Pipelining.• Shell script examples.• Shell script syntax.• Special parameter• Making shell.• Homework.
What is shell?
• Command / Interpreter– Bourn Shell– C Shell– Korn Shell– Bash– Tcsh Kerne
l
Shell
Program
Program
Program
User
Bash Configuration
• .bash_login: Login initialization like .login• .bash_logout: Logout actions• .bashrc: Shell configuration• .bash_profile: Login shell configuration• .inputrc: Individual readline initialization file
• .bash_history: Command history file
Environment Variable.
• PWD– Current working directory.
• PATH– The search path.
• PS1– The primary prompt string.
• MAIL– Filename to check mail.
Shell Var.
Environ. Var.
export
- set
- env
Standard input, output, error
1 - STDOUT
0 - STDIN
2 – STDERR
: : :1 - STDOUT
0 - STDIN
2 – STDERR
: : :
Program1 FD
Program2 FD
Redirection & Pipelining
File
File
Program
Program
<
|
>
Etc..
>> << <<< 2>&1 2> &> …
Script Examples - Start
#!/bin/sh
mutt
telnet ara
telnet ska
telnet pie
Script Examples(2) – Color Table
#!/usr/local/bin/bash
esc="\033["
echo -e " 40 41 42 43 44 45 46 47"
for fore in 30 31 32 33 34 35 36 37; do
line1="$fore "
line2=" "
for back in 40 41 42 43 44 45 46 47; do
line1="${line1}${esc}${back};${fore}m 보통 ${esc}0m "
line2="${line2}${esc}${back};${fore};1m 밝은 ${esc}0m "
done
echo -e "$line1\n$line2"
done
Script Examples(3) – Dictionary$ sh eng_dic shell
shell [LINK] 발음듣기
[INLINE] shell [ [INLINE] 雩 ] n.
1 a 조가비 (seashell); ( 굴의 ) 껍질
b ( 거북 [INLINE] 새우 [INLINE] 게 등의 ) 등딱지 , 껍데기
c ( 콩의 ) 깍지 , 꼬투리
d 시초 ( 翅 ?), 딱지 날개
e ( 번데기의 ) 외피
f ( 과일 [INLINE] 종자 등의 ) 껍질 ; [ pl. ] 카카오 껍질 (cacao shells)
#!/bin/sh
WORD=$*
WORD=$(echo ${WORD} |od -tx1 -w1000 |head -1 \
|sed -e 's/^[0-9]\+ //' -e 's/ 0a$//' -e 's/20/+/g' -e 's/ /%/g' -e 's/^/%/' \
|tr '[a-z]' '[A-Z]')
lynx -nolist -verbose -dump http://kr.engdic.yahoo.com/result.html?p=${WORD} \
|grep -v "bu2.gif" |tail +14 |tac |tail +11 |tac \
|sed -e 's/[phon[0-9]\+\.gif] //g' -e 's/[phon[0-9]\+\.gif]//g' \
|less -r
Script Examples(4) – Etc.
• Automatic install program.• Homework submit program.
– Homework num., source file– Delay due
• Homework marking program.– Compare optimized solution– Check execution time.
• Check empty IP address.
Shell script syntax - for
• for name [ in word ] ; do list ; done
102 Name: sparcs.kaist.ac.kr
103 Name: ara.kaist.ac.kr
104 Name: baram.kaist.ac.kr
105 Name: gurum.kaist.ac.kr
106 Name: sparcs6.kaist.ac.kr
107 Name: sparcs7.kaist.ac.kr
108 Name: sparcs8.kaist.ac.kr
109 Name: sparcs9.kaist.ac.kr
110 Name: ftp.kaist.ac.kr
. . . . . . . . . . . . . . . .
#!/usr/local/bin/bash
for ((i=102;i<151;i++));
do data=`nslookup 143.248.234.$i 2> /dev/null| tail +4|head -1`;
echo $i $data;
done;
Shell script syntax(2) - if
• if list; then list; [ elif list; then list; ] ... [ else list; ] fi
$ ./diff abc abc
abc
abc
It’s same
$ ./diff abcc abcd
abcc
Abcd
It’s different
#!/bin/sh
echo $1;
echo $2;
if [ "$1" = "$2" ]; then
echo "It's same";
else
echo "It's different";
fi
Shell script syntax(3) – select
• select name [ in word ] ; do list ; done
1) Hello
2) Quit
#? 1
Hello World
#? 2
done
#!/usr/local/bin/bash
OPTIONS="Hello Quit"
select opt in $OPTIONS; do
if [ "$opt" = "Quit" ]; then
echo done
exit
elif [ "$opt" = "Hello" ]; then
echo Hello World
else
clear
echo bad option
fi
done
Shell script syntax(4) - case
• case word in [ [(] pattern [ | pattern ] ... ) list ;; ] ... esac
#!/bin/sh
case $1 in
all)
telnet ara; telnet ska; telnet noah;;
a)
telnet aka;;
s)
telnet ska;;
n)
telnet noah;;
esac
Shell script syntax(5) – Etc.
• while list; do list; done• until list; do list; done• [ function ] name () { list; }
Special Parameters
• 0 : Name of the shell or shell script• $ : Process ID of the this shell• ! : Process ID of last background comma
nd• # : Number of arguments• @ : Positional parameter• 1, 2, 3, .. 9 : n-th argument
Making Shell
• 2003 SP Seminar on summer vacation– For studying system programming.– For being a SPARCS man.– A flower of circle activation.
• SP + ARCS = SPARCS
Homework
• airlover 라는 폴더를 만든다 .• 위에서 만든 폴더에 이름이 SPARCS 03 학번
회원들의 아이디인 파일을 만들고 그 회원이 마지막으로 접속한 시각을 기록한다 .
• 하나의 파일로 묶은 후 압축해서 airlover.tar.bz2 라는 파일로 만든다 .
• airlover 폴더를 지운다 .• 실행하면 자동으로 압축이 풀리게 만든다 .• c.f) /SPARCS/mail/aliases.d/sparcs2003
Reference
• http://kldp.org/HOWTO/html/Adv-Bash-Scr-HOWTO/index.html
• Sh/Bash/Csh/Tcsh man pages