![Variables and the Environment
% env
[โฆvariables passed to sub-programsโฆ]
% NEW_VAR=โYesโ
% echo $NEW_VAR
Yes
% env
[โฆPATH but not NEW_VARโฆ]
% export NEW_VAR
% env
[โฆPATH and NEW_VARโฆ]](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-23-320.jpg)
![Logic: test
๏ฌtest
๏ฌ[ ]
๏ก[ 1 โlt 10 ]
๏ฌ[[ ]]
๏ก[[ โthis stringโ =~ โthisโ ]]
๏ฌ(( ))
๏ก(( 1 < 10 ))](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-31-320.jpg)
![Logic: test
๏ฌ [ -f /etc/passwd ]
๏ฌ [ ! โf /etc/passwd ]
๏ฌ [ -f /etc/passwd โa โf /etc/shadow ]
๏ฌ [ -f /etc/passwd โo โf /etc/shadow ]](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-32-320.jpg)
![Logic: if
if [ $USER โeq โborwicjhโ ]
then
:
# โelifโ a contraction of โelse ifโ:
elif ls /etc/oratab
then
:
else
then
:
fi](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-35-320.jpg)
![Logic: if
# see if a file exists
if [ -e /etc/passwd ]
then
echo โ/etc/passwd existsโ
else
echo โ/etc/passwd not found!โ
fi](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-36-320.jpg)
![Logic: while
a=0; LIMIT=10
while [ "$a" -lt "$LIMIT" ]
do
echo -n "$a โ
a=$(( a + 1 ))
done](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-44-320.jpg)
![Counters
COUNTER=0
while [ -e โ$FILE.COUNTERโ ]
do
COUNTER=$(( COUNTER + 1))
done
๏ฌNote: race condition](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-45-320.jpg)
![Searching: find
% find /home/borwicjh
-name โ*.lisโ
[all files matching *.lis]
% find /home/borwicjh
-mtime -1 โname โ*.lisโ
[*.lis, if modified within 24h]
% man find](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-58-320.jpg)
![Searching: locate
% locate .lis
[files with .lis in path]
% locate log
[also finds โ/var/log/messagesโ]](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-59-320.jpg)
![sqlplus
sqlplus $USER/$PASS @$FILE_SQL
$ARG1 $ARG2 $ARG3
if [ $? โne 0 ]
then
exit 1
fi
if [ -e /file/sql/should/create ]
then
[โฆuse SQL-created fileโฆ]
fi
๏ฌ Ask Amy Lamy! ๏](https://image.slidesharecdn.com/unixshell-scriptingbasics-160122000524/85/Unix-shell-scripting-basics-66-320.jpg)
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Unix shell scripting basics
- 2. Agenda ๏ฌWhat is a shell? A shell script? ๏ฌIntroduction to bash ๏ฌRunning Commands ๏ฌApplied Shell Programming
- 3. What is a shell?
- 4. What is a shell? /bin/bash
- 5. What is a shell? #!/bin/bash
- 6. What is a shell? INPUT shell OUTPUT ERROR
- 7. What is a shell? ๏ฌAny Program ๏ฌBut there are a few popular shellsโฆ
- 8. Bourne Shells ๏ฌ /bin/sh ๏ฌ /bin/bash โBourne-Again Shellโ Steve Bourne
- 9. Other Common Shells ๏ฌC Shell (/bin/csh) ๏ฌTurbo C Shell (/bin/tcsh) ๏ฌKorn Shell (/bin/ksh)
- 10. An aside: What do I mean by /bin ? ๏ฌC Shell (/bin/csh) ๏ฌTurbo C Shell (/bin/tcsh) ๏ฌKorn Shell (/bin/ksh)
- 11. An aside: What do I mean by /bin ? ๏ฌ /bin, /usr/bin, /usr/local/bin ๏ฌ /sbin, /usr/sbin, /usr/local/sbin ๏ฌ /tmp ๏ฌ /dev ๏ฌ /home/borwicjh
- 12. What is a Shell Script? ๏ฌA Text File ๏ฌWith Instructions ๏ฌExecutable
- 13. What is a Shell Script? % cat > hello.sh <<MY_PROGRAM #!/bin/sh echo โHello, worldโ MY_PROGRAM % chmod +x hello.sh % ./hello.sh Hello, world
- 14. What is a Shell Script? A Text File % cat > hello.sh <<MY_PROGRAM #!/bin/sh echo โHello, worldโ MY_PROGRAM % chmod +x hello.sh % ./hello.sh Hello, world
- 15. An aside: Redirection ๏ฌ cat > /tmp/myfile ๏ฌ cat >> /tmp/myfile ๏ฌ cat 2> /tmp/myerr ๏ฌ cat < /tmp/myinput ๏ฌ cat <<INPUT Some input INPUT ๏ฌ cat > /tmp/x 2>&1 INPUT env OUTPUT ERROR 0 1 2
- 16. What is a Shell Script? How To Run % cat > hello.sh <<MY_PROGRAM #!/bin/sh echo โHello, worldโ MY_PROGRAM % chmod +x hello.sh % ./hello.sh Hello, world
- 17. What is a Shell Script? What To Do % cat > hello.sh <<MY_PROGRAM #!/bin/sh echo โHello, worldโ MY_PROGRAM % chmod +x hello.sh % ./hello.sh Hello, world
- 18. What is a Shell Script? Executable % cat > hello.sh <<MY_PROGRAM #!/bin/sh echo โHello, worldโ MY_PROGRAM % chmod +x hello.sh % ./hello.sh Hello, world
- 19. What is a Shell Script? Running it % cat > hello.sh <<MY_PROGRAM #!/bin/sh echo โHello, worldโ MY_PROGRAM % chmod +x hello.sh % ./hello.sh Hello, world
- 20. Finding the program: PATH ๏ฌ% ./hello.sh ๏ฌecho vs. /usr/bin/echo ๏ฌ% echo $PATH /bin:/usr/bin:/usr/local/bin: /home/borwicjh/bin ๏ฌ% which echo /usr/bin/echo
- 21. Variables and the Environment % hello.sh bash: hello.sh: Command not found % PATH=โ$PATH:.โ % hello.sh Hello, world
- 22. An aside: Quoting % echo โ$USERโ $USER % echo โ$USERโ borwicjh % echo โโโ โ % echo โdeacnetsctโ deacnetsct % echo โโโ โ
- 23. Variables and the Environment % env [โฆvariables passed to sub-programsโฆ] % NEW_VAR=โYesโ % echo $NEW_VAR Yes % env [โฆPATH but not NEW_VARโฆ] % export NEW_VAR % env [โฆPATH and NEW_VARโฆ]
- 24. Welcome to Shell Scripting!
- 25. How to Learn ๏ฌ man ๏กman bash ๏กman cat ๏กman man ๏ฌ man โk ๏กman โk manual ๏ฌ Learning the Bash Shell, 2nd Ed. ๏ฌ โBash Referenceโ Cards ๏ฌ http://www.tldp.org/LDP/abs/html/
- 27. Continuing Lines: % echo This Is A Very Long Command Line This Is A Very Long Command Line %
- 28. Exit Status ๏ฌ$? ๏ฌ0 is True % ls /does/not/exist % echo $? 1 % echo $? 0
- 29. Exit Status: exit % cat > test.sh <<_TEST_ exit 3 _TEST_ % chmod +x test.sh % ./test.sh % echo $? 3
- 30. Logic: test % test 1 -lt 10 % echo $? 0 % test 1 == 10 % echo $? 1
- 31. Logic: test ๏ฌtest ๏ฌ[ ] ๏ก[ 1 โlt 10 ] ๏ฌ[[ ]] ๏ก[[ โthis stringโ =~ โthisโ ]] ๏ฌ(( )) ๏ก(( 1 < 10 ))
- 32. Logic: test ๏ฌ [ -f /etc/passwd ] ๏ฌ [ ! โf /etc/passwd ] ๏ฌ [ -f /etc/passwd โa โf /etc/shadow ] ๏ฌ [ -f /etc/passwd โo โf /etc/shadow ]
- 33. An aside: $(( )) for Math % echo $(( 1 + 2 )) 3 % echo $(( 2 * 3 )) 6 % echo $(( 1 / 3 )) 0
- 34. Logic: if if something then : # โelifโ a contraction of โelse ifโ: elif something-else then : else then : fi
- 35. Logic: if if [ $USER โeq โborwicjhโ ] then : # โelifโ a contraction of โelse ifโ: elif ls /etc/oratab then : else then : fi
- 36. Logic: if # see if a file exists if [ -e /etc/passwd ] then echo โ/etc/passwd existsโ else echo โ/etc/passwd not found!โ fi
- 37. Logic: for for i in 1 2 3 do echo $i done
- 38. Logic: for for i in /* do echo โListing $i:โ ls -l $i read done
- 39. Logic: for for i in /* do echo โListing $i:โ ls -l $i read done
- 40. Logic: for for i in /* do echo โListing $i:โ ls -l $i read done
- 41. Logic: C-style for for (( expr1 ; expr2 ; expr3 )) do list done
- 42. Logic: C-style for LIMIT=10 for (( a=1 ; a<=LIMIT ; a++ )) do echo โn โ$a โ done
- 44. Logic: while a=0; LIMIT=10 while [ "$a" -lt "$LIMIT" ] do echo -n "$a โ a=$(( a + 1 )) done
- 45. Counters COUNTER=0 while [ -e โ$FILE.COUNTERโ ] do COUNTER=$(( COUNTER + 1)) done ๏ฌNote: race condition
- 46. Reusing Code: โSourcingโ % cat > /path/to/my/passwords <<_PW_ FTP_USER=โsctโ _PW_ % echo $FTP_USER % . /path/to/my/passwords % echo $FTP_USER sct %
- 47. Variable Manipulation % FILEPATH=/path/to/my/output.lis % echo $FILEPATH /path/to/my/output.lis % echo ${FILEPATH%.lis} /path/to/my/output % echo ${FILEPATH#*/} path/to/my/output.lis % echo ${FILEPATH##*/} output.lis
- 48. It takes a long time to become a bash guruโฆ
- 49. Running Programs
- 50. Reasons for Running Programs ๏ฌCheck Return Code ๏ก$? ๏ฌGet Job Output ๏กOUTPUT=`echo โHelloโ` ๏กOUTPUT=$(echo โHelloโ) ๏ฌSend Output Somewhere ๏กRedirection: <, > ๏กPipes
- 51. Pipes ๏ฌLots of Little Tools echo โHelloโ | wc -c INPUT echo OUTPUT ERROR 0 1 2 INPUT wc OUTPUT ERROR 0 1 2 A Pipe!
- 52. Email Notification % echo โMessageโ | mail โs โHereโs your messageโ [email protected]
- 53. Dates % DATESTRING=`date +%Y%m%d` % echo $DATESTRING 20060125 % man date
- 54. FTP the Hard Way ftp โn โu server.wfu.edu <<_FTP_ user username password put FILE _FTP_
- 55. FTP with wget ๏ฌ wget ftp://user:[email protected]/file ๏ฌ wget โr ftp://user:[email protected]/dir/
- 56. FTP with curl curl โT upload-file -u username:password ftp://server.wfu.edu/dir/file
- 57. Searching: grep % grep rayra /etc/passwd % grep โr rayra /etc % grep โr RAYRA /etc % grep โri RAYRA /etc % grep โrli rayra /etc
- 58. Searching: find % find /home/borwicjh -name โ*.lisโ [all files matching *.lis] % find /home/borwicjh -mtime -1 โname โ*.lisโ [*.lis, if modified within 24h] % man find
- 59. Searching: locate % locate .lis [files with .lis in path] % locate log [also finds โ/var/log/messagesโ]
- 61. Make Your Life Easier ๏ฌTAB completion ๏ฌControl+R ๏ฌhistory ๏ฌcd - ๏ฌStudy a UNIX Editor
- 62. pushd/popd % cd /tmp % pushd /var/log /var/log /tmp % cd .. % pwd /var % popd /tmp
- 63. Monitoring processes ๏ฌps ๏ฌps โef ๏ฌps โu oracle ๏ฌps โC sshd ๏ฌman ps
- 64. โDOSโ Mode Files ๏ฌ#!/usr/bin/bash^M ๏ฌFTP transfer in ASCII, or ๏ฌdos2unix infile > outfile
- 65. sqlplus JOB=โZZZTESTโ PARAMS=โZZZTEST_PARAMSโ PARAMS_USER=โBORWICJHโ sqlplus $BANNER_USER/$BANNER_PW << _EOF_ set serveroutput on set sqlprompt "" EXECUTE WF_SATURN.FZ_Get_Parameters('$JOB', '$PARAMS', '$PARAMS_USER'); _EOF_
- 66. sqlplus sqlplus $USER/$PASS @$FILE_SQL $ARG1 $ARG2 $ARG3 if [ $? โne 0 ] then exit 1 fi if [ -e /file/sql/should/create ] then [โฆuse SQL-created fileโฆ] fi ๏ฌ Ask Amy Lamy! ๏
- 67. Passing Arguments % cat > test.sh <<_TEST_ echo โYour name is $1 $2โ _TEST_ % chmod +x test.sh % ./test.sh John Borwick ignore- this Your name is John Borwick
- 68. INB Job Submission Template $1: user ID $2: password $3: one-up number $4: process name $5: printer name % /path/to/your/script $UI $PW $ONE_UP $JOB $PRNT
- 69. Scheduling Jobs % crontab -l 0 0 * * * daily-midnight-job.sh 0 * * * * hourly-job.sh * * * * * every-minute.sh 0 1 * * 0 1AM-on-sunday.sh % EDITOR=vi crontab โe % man 5 crontab
- 70. THANK YOU