Shell Scripting Interview Questions

Using KSH while loop#!/bin/ksh
#Get the count of total number of arguments passed while executing this script
int i = $#; #total number of arguments passed#
names=$@; #list of actual arguments passed#
while [ ${i} -gt 0 ]
do
echo '${names[i]}';
i=`expr i - 1`;
done
exit 0;

$ cat rev2
i=$#
echo "$@" > file_1

while [ $i -gt 0 ]
do
cut -f $i -d" " file_1 >> file_2
i=`echo $i-1|bc`
done

echo `cat file_2`;
rm -f file_1 file_2;

$ sh rev2 A B C D E
E D C B A

Code
echo $1
echo $2
echo $3

Try this:

echo "one two three" | xargs

the output is: one two three

a) vi /etc/default/login
comment the line of /dev/console

b)vi .rhosts
enter the hostname by which the only user can connect with your system....bt no one else.....
c) disable the ftp for the selected users in /etc/ftpusers file ...

Unix is having 3 ways of Security Mechanism:1. By granting or revoking File permissions. Owner or Admin can change permissions to be given to group or others by using chmod command in Unix.2. Login is...

in 2 ways it can be done:
1st way
$ echo $?  

2nd way:

$ pwd 2> error| cat error|wc -l
       0
$ cat h 2> error| cat error|wc -l
       1

pwd or cat or any command if outpt is 0 then successful else failed.

find $HOME -mmin -5 -ls     # run the same in cron

find . -mtime 0   # find files modified between now and 1 day ago (i.e., within the past 24 hours)find . -mtime -1  # find files modified less than 1 day ago (i.e., within the past...

cat file1 file2 >  file3

Bash does not support this kind of feature, you can do this in PERL, because PERL supports all feature which are needed to work with CSV worksheets.

a=10.50
b=11.01

if [ $a -gt $b ]
        then
        echo a is greater than b
else 
        echo a is less than b
fi

a1=10.50

b1=11.01

st=$(echo "$a1 > $b1" | bc)

if [ $st -eq 1 ];

then

# 1 == true

echo "True"

else

echo "False"

fi

global variable is created using export command in ksh - export x='name' In csh its created using setenv command-setenv x 'name'this 'x' variable will be visible in curren...

try this simple script it will clear your concept :-

script a.sh :-
----------
export A=3
B=5
sh b.sh
--------

script b.sh :-
-----------
echo "exported variable $A is :- $A"
echo "Variable $B -- $B "

---------

A persists in b.sh whereas B doesn't.

K Shell,
Bourne Shell,
Bash,
C-Shell

ashell
bshell
bash (born again shell)
cshell
kshell
zshell

Contains the list of arguments passed to the function.

It contains the actual arguments passed to a shell script

crontab 0 4 * * * command

1st step$ cat > cmdfile//<Minute> <Hour> <Day Of Month> <Day Of Week> <Command>    0           &n...

$ORACLE_HOME/bin/sqlplus username/password@remote_db

IF the Database is DB2 then the script is :

ls -R | grep -v "/" | sort | uniq

grep -v "/"  -- is used to filter out directories

read string1
string_rev=`rev string1`
if [ string1 = string_rev ]
then
 echo palindrome
else
 echo not a palindrome
fi

echo enter a string read stringlen=`expr length "$string"`i=$lenreverse=''while [ $i -gt 0 ]dochar=`echo $string | cut -c $i`reverse="$reverse$char"i=`expr $i - 1`doneecho ...

#! at the start of the file indicates that this is a shell script file, rather than a normal file./bin/ksh -- runs the shell script in ksh shell.By default the shell script runs in the current shell (...

#! line states the interpreter to be used by the shell to interpret the script.

Here, ksh interpreter is invoked for interpretation of the script.

While loopThe syntax for while is: while conditiondo statements...done For loopsThe syntax for the for loop: for name [in list]do statements that can use $name...done Untill loopsThe ...

3 loops

for
while
until  --> Just reverse of while loop

-----------------------
"if-elif" or "if else" or "case" not comes in the loop

Most UNIX servers are configured not to use FTP or TELNET for security purposes, and if you use FTP it has limited number of data can be transfered on one transaction hence I preferred using another w...

If you can't get Samba, or you're not the Admin so you can't install it anyway, then use FTP, as it's almost guaranteed to be installed and running on both machines.  The only han...

To find a user's UID or GID in Unix, use the id command. To find a specific user's UID, at the Unix prompt, enter: id -u username Replace username with the appropriate user's username. To find ...

UID - User idGID - Group idWe can find out using sample command fire @ $ promoit "id" you will user id & group id.e. g step 1 : $ id ---> O/p get display immediately uid=232(vi...

dos2unix only removes the control-M characters at the end of the line.  You need to use sed to do the search and replace for '' to '/'.

Command to list all the differences between two dir:

diff -r > diff.txt

Diff.txt will show you all the differences.

We can use test also in command line

test 1.2 -gt 1.1 | echo "abhishek"

You will get o/p

abhishek.

You can make you og 'bc' command to do the arithmatic operations in shell script.
Following script illustrates a sample implimentation

a=1.2
b=3.1
x=$(echo $a+$b|bc)
echo [$x]

Where the arithmatic operation that is desired is marked in bold.