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Transcript of 16 Shell Programming
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!"# %&'() *)+,,
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!"# %&'() 5)+,, ,6 0'
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hJ 8V 5)+,, G/( 02W(
!"# %&'(# My first shell scriptclear
echo "Hello $USER"
echo "Today is \c ";date
echo "Number of user login : \c" ; who | wc l
echo "Calendar"
! )*+,- .// %&'(
!01%&'(
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wY% 5l I2a( )3 %)l(0
System Variable Meaning
BASH=/bin/bash Our shell name
BASH_VERSION=1.14.7(1) Our shell version name
COLUMNS=80 No. of columns for our screen
HOME=/home/vivek Our home directoryLINES=25 No. of columns for our screen
LOGNAME=students students Our logging name
OSTYPE=Linux Our Os type
PATH=/usr/bin:/sbin:/bin:/usr/sbin Our path settings
PS1=[\u@\h \W]\$ Our prompt settings
PWD=/home/students/Common Our current working directory
SHELL=/bin/bash Our shell nameUSERNAME=vivek User name who is currently login to this PC
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|9() (0)s< :?: I2a( :;< (0.>2 8B(0
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4c %: GL% %[( I2a(
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hJ 8V
$ vi variscript
#
#
# Script to test MY knowledge about variables!
#
myname=Vivek
myos = TroubleOS
myno=5
echo "My name is $myname"
echo "My os is $myos"
echo "My number is myno, can you see this number"
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!3() +:)C
Q} #)?#X+:)C C#C( 5%&2(0R @
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Q?: #)# %C?( 5l )H:
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+=#& I24f%):f5lf)H:Q?: %C?( %UX eR R R gR
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+=#& ] #)# ()E( ,6 F+:)C +=#& e G?() 02? 02? %&9 I24 %): e @6 2( &
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Q?: 8_4 (0CL:
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-&O(0 %)?2 a% %)}: :E4 ,3()
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QE4 ,3() GH: 8t ,234 G4 @6C
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Q?: %)
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Q_4 %&}: & ()?() 2
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fi
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Q_4 %&}: & ()?() 2
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#!/bin/sh
#
#Script to print file
#
if cat $1then
echo -e "\n\nFile $1, found and successfully echoed"
fi
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Q_4 %&}: & ()?() 2 +,5+ M
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!3() %+5%
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!3() %+5%
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!3() %+5%
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! #$%&'( )* +,*)-.'
!/bin/sh
Script to see whether argument is positive
if test $1 -gt 0
then
echo "$1 number is positive"
fi
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Q_4 %&}: ,L# C&
Q} #)?#for { variable name } in { list }
do
Cc cu l#nhdone
Ho$c:
C& +=#&]` +=#&k` +=#& 8CQ?: :E4 ,3()
8C(+ V d%t#p testforC& 2 2( ] k 8C
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Q_4 %&}: ,L# )2,+
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Q_4 %&}: :
