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https://drive.google.com/file/d/0B3CkQrAFbp82Z0F6dTlQUDVtWTA/view?usp=drivesdk
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https://drive.google.com/file/d/0B3CkQrAFbp82TXhocjUtc2o1R1k/view?usp=drivesdk
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#!/bin/bash
# isuserloggedin.sh
# Usage: isuserloggedin.sh username
# Shell script which checks after every one minute whether a user has logged in
# or not
# You can also run script in background using & then foreground it to view result
if [ $# -ne 1 ]
then
echo "You supplied wrong arguments"
echo "usage : `basename $0` username"
exit 1
fi
isuserexist()
{
grep -w "$1" /etc/passwd > /dev/null
if [ $? -eq 1 ]
then
echo "$1 is not a valid user"
exit 1
fi
}
isuserexist $1
time=0
while true
do
# you can replace following two statements with
# if `who|grep $1 > /dev/null`
who|grep $1 > /dev/null
if [ $? -eq 0 ]
then
echo "User $1 is logged in "
if [ $time -gt 60 ]
then
hours=$((time/60))
minutes=$((time%60))
echo "He is logged in $hours hour(s) $minutes minute(s) late"
else
echo "He is logged in $time minute(s) late"
fi
exit 0
else
let time++
# You can use following formats also
# time=`expr $time + 1 `
# time=$((time+1))
sleep 60
fi
done
Output:
[root@localhost shell]# sh isuserloggedin.sh
you have suplied wrong arguments
usage : isuserloggedin.sh username
[root@localhost shell]# sh isuserloggedin.sh root
User root is logged in
He is logged in 0 minute(s) late
[root@localhost shell]# sh isuserloggedin.sh roott
roott is not a valid user
Run script in background
[root@localhost shell]# sh isuserloggedin.sh venu &
[1] 15917
[root@localhost shell]# User venu is logged in
He is logged in 3 minute(s) late
[1]+ Done sh isuserloggedin.sh venu
Run script in background then foreground it
[root@localhost shell]# sh isuserloggedin.sh venu &
[1] 16223
[root@localhost shell]# fg
sh isuserloggedin.sh venu
User venu is logged in
He is logged in 1 minute(s) late
[root@localhost shell]#
# isuserloggedin.sh
# Usage: isuserloggedin.sh username
# Shell script which checks after every one minute whether a user has logged in
# or not
# You can also run script in background using & then foreground it to view result
if [ $# -ne 1 ]
then
echo "You supplied wrong arguments"
echo "usage : `basename $0` username"
exit 1
fi
isuserexist()
{
grep -w "$1" /etc/passwd > /dev/null
if [ $? -eq 1 ]
then
echo "$1 is not a valid user"
exit 1
fi
}
isuserexist $1
time=0
while true
do
# you can replace following two statements with
# if `who|grep $1 > /dev/null`
who|grep $1 > /dev/null
if [ $? -eq 0 ]
then
echo "User $1 is logged in "
if [ $time -gt 60 ]
then
hours=$((time/60))
minutes=$((time%60))
echo "He is logged in $hours hour(s) $minutes minute(s) late"
else
echo "He is logged in $time minute(s) late"
fi
exit 0
else
let time++
# You can use following formats also
# time=`expr $time + 1 `
# time=$((time+1))
sleep 60
fi
done
Output:
[root@localhost shell]# sh isuserloggedin.sh
you have suplied wrong arguments
usage : isuserloggedin.sh username
[root@localhost shell]# sh isuserloggedin.sh root
User root is logged in
He is logged in 0 minute(s) late
[root@localhost shell]# sh isuserloggedin.sh roott
roott is not a valid user
Run script in background
[root@localhost shell]# sh isuserloggedin.sh venu &
[1] 15917
[root@localhost shell]# User venu is logged in
He is logged in 3 minute(s) late
[1]+ Done sh isuserloggedin.sh venu
Run script in background then foreground it
[root@localhost shell]# sh isuserloggedin.sh venu &
[1] 16223
[root@localhost shell]# fg
sh isuserloggedin.sh venu
User venu is logged in
He is logged in 1 minute(s) late
[root@localhost shell]#
IMPORTANT: SOME DATES ARE CHANGED REFER NEW EXAM SCHEMES FROM IGNOU WEBSITE
IGNOU Examination Date Sheet
MCA IGNOU
M- Morning (10AM to 1PM)E- Evening (2PM to 5PM)
(ignou exam date sheet 2017) (ignou date sheet june 2017) (ignou term end exam)
Key Differences Between Strong Entity and Weak Entity
- The basic difference between strong entity and a weak entity is that the strong entity has a primary key whereas, a weak entity has the partial key which acts as a discriminator between the entities of a weak entity set.
- A weak entity always depends on the strong entity for its existence whereas, a strong entity is independent of any other entity’s existence.
- A strong entity is denoted with a single rectangle and a weak entity is denoted with a double rectangle.
- The relationship between two strong entities is denoted with single diamond whereas, a relationship between a weak and a strong entity is denoted with double diamond called Identifying Relationship.
- The strong entity may or may not show the total participation in its relations, but the weak entity always shows total participation in the identifying relationship which is denoted by the double line.
Design ER n Table accordingly
MVD
