PART-I: MCS-041
Q.1.(a)
A.1.(a)
More command:-
More is a filter for paging through text one screen at a time. It does not provide as many options or enhancements as less, but is nevertheless quite useful and simple to use.
Syntax :-
where ,
| num lines | Sets the number of lines that makes up a screenful. lines must be an integer. |
| -d | With this option, more will prompt the user with the message "[Press space to continue, 'q' to quit.]" and display "[Press 'h' for instructions.]" when an illegal key is pressed, instead of ringing a bell. |
| -l | more usually treats ^L (CONTROL-L, the form feed) as a special character, and will pause after any line that contains it. The -l option will prevent this behavior. |
| -f | Causes more to count logical, rather than screen lines (i.e., long lines are not wrapped). |
| -p | Do not scroll. Instead, clear the whole screen and then display the text. This option is switched on automatically if the more executable is named page. |
| -c | Do not scroll. Instead, paint each screen from the top, clearing the remainder of each line as it is displayed. |
| -s | Squeeze multiple blank lines into one blank line. |
| -u | Do not display underlines. |
| +/string | Search for the string string, and advance to the first line containing string when the file is displayed. |
| +num | Start displaying text at line number num. |
EXAMPLE :--- more .profile .shrc -p
PIPE Command:-
Pipe is a symbol used to provide output of one command as input to another command. The output of the command to the left of the pipe is sent as input to the command to the right of the pipe. The symbol is |.
For example:
$ cat apple.txt | wc
In the above example the output of apple.txt file will be sent as input for wc command which counts the no. of words in a file. The file for which the no. of words counts is the file apple.txt.
Pipes are useful to chain up several programs, so that multiple commands can execute at once without using a shell script.
For example:
$ cat apple.txt | wc
In the above example the output of apple.txt file will be sent as input for wc command which counts the no. of words in a file. The file for which the no. of words counts is the file apple.txt.
Pipes are useful to chain up several programs, so that multiple commands can execute at once without using a shell script.
EXAMPLE :--- more .profile | .shrc -p
A.1.(b) Head and Tail Command :-
head, by default, prints the first 10 lines of each FILE to standard output. With more than one FILE, it precedes each set of output with a header identifying the file name. If no FILE is specified, or when FILE is specified as a dash ("-"), head reads from standard input.
head syntax:-
head [OPTION]... [FILE]...
Tail prints the last 10 lines of each FILE to standard output. With more than one FILE, it precedes each set of output with a header giving the file name. If no FILE is specified, or if FILE is specified as a dash ("-"), tail reads from standard input.
tail syntax
tail [OPTION]... [FILE]...Now , using of pipe with Head and Tail:-
head myfile.txt -n 10 | tail myfile.txt -n 15
A.1.(c)
/etc/passwd file stores essential information, which is required during login i.e. user account information. /etc/passwd is a text file, that contains a list of the system’s accounts, giving for each account some useful information like user ID, group ID, home directory, shell, etc. It should have general read permission as many utilities, like ls use it to map user IDs to user names, but write access only for the superuser/root account.
For Ex :- cat /etc/passwd myfile.txt
A.1.(d) grep -n root /etc/passwd
A.1.(e) Find Command is used for finding the particular file.
find /tmp -user username - ls
OR
A.1.(f) cron
cron can be used to schedule a particular function to occur every minute, hour, day, week, or month.It's normal to use the crontab to perform the editing functions as this automates the process for the cron daemon and makes it easier for normal users to use cron.
At
'at' executes a command once on a particular day, at a particular time. at will add a particular command to be executed
Examples
| at 21:30 |
You then type the commands you want executed then press the end-of-file key (normally CTRL-D ). Also try:
at now + time |
This will run at the current time + the hours/mins/seconds you specify (use at now + 1 hour to have command(s) run in 1 hour from now...)
You can also use the -f option to have at execute a particular file (a shell script).
at -f shell_script now + 1 hour |
This would run the shell script 1 hour from now.
A.1.(g) PS Command:-
The ps command displays active processes.
Syntax
The syntax for the ps command is:
ps [options]
Grep Command:-
grep, which stands for "global regular expression print," processes text line by line and prints any lines which match a specified pattern.
grep syntax
grep [OPTIONS] PATTERN [FILE...]Example:-
$ ps aux | grep fnord wayne 15745 0.0 0.0 13580 928 pts/6 S+ 03:58 0:00 grep fnord.A.1.(h)
Linux and Unix-like operating system come with the kill command to terminates stalled or unwanted processes without having to log out or restart the server.
The kill command sends the specified signal such as kill process to the specified process or process groups. If no signal is specified, the TERM signal is sent. Please note that kill command can be internal as part of modern shells built-in function or external located at /bin/kill. Usage and syntax remain similar regardless internal or external kill command.
Step #1: Find out the PID (process id)
Use the ps or pidof command to find out PID for any program. For example, if process name is lighttpd, you can use any one of the following command to obtain process ID:
Sample outputs:
3486
OR
Sample outputs:
lighttpd 3486 0.0 0.1 4248 1432 ? S Jul31 0:00 /usr/sbin/lighttpd -f /etc/lighttpd/lighttpd.conf lighttpd 3492 0.0 0.5 13752 3936 ? Ss Jul31 0:00 /usr/bin/php5-cg
Step #2: kill the process using a PID
The PID # 3486 is assigned to the lighttpd process. To kill the lighttpd server, you need to pass a PID as follows:
OR
This will terminate a process with a PID of 3486.
# kill 3486OR
$ sudo kill 3486This will terminate a process with a PID of 3486.
How do I verify that the process is gone / killed?
Use the ps or pidof command:
$ ps aux | grep lighttpd
$ pidof lighttpdA note about sending stronger signal # 9 (SIGKILL)
If no signal specified in the kill command, signal # 15 (SIGTERM), is sent by default. So the kill 3486 command is same as the following command:
OR
$ sudo kill -15 3486
$ sudo kill -SIGTERM 3486
# kill -15 3486
# kill -SIGTERM 3486OR
$ sudo kill -15 3486
$ sudo kill -SIGTERM 3486
A.1(i)
Sort Command :-
Sort command in unix or linux system is used to order the elements or text. Sort command has the capability of sorting numerical values and strings. The sort command can order the lines in a text file.
The syntax of sort command is:
The syntax of sort command is:
sort [options] filename
$ tr “old set of character” “new set character” <file name >
A.1.(j) $ Sort file name
-c (check whether specific file is according to the given order)
-m (It merge the previously sorted file and display standard o/!’)
-u (convert lower to upper) .
Q.2.(a)
A.2.(a) Shell Program :- The shell provides you with an interface to the UNIX system. It gathers input from you and executes programs based on that input. When a program finishes executing, it displays that program's output.
A shell is an environment in which we can run our commands, programs, and shell scripts. There are different flavors of shells, just as there are different flavors of operating systems. Each flavor of shell has its own set of recognized commands and functions
str=””
i=0
temp = ‘ ‘
len= 0
count = 0
echo “Enter any string”
read str
len = ‘echo $str | we –e’
len = ‘expr $len -1’
while [$i-le $len ]
do
temp = ‘echo $str | cut –c $i’
if [ $temp-eq 65 –o $temp –eq 69 –o
$temp –eq 73 –o $temp –eq 79 –o $temp –iq 85
then
count = expr$count = 1
fi
I = expr $i + 1’
Done
Echo “Numebr of Vovels in the string are: $count” .
Q.2.(c)
A.2.(b) Shell Scripting:-
The basic concept of a shell script is a list of commands, which are listed in the order of execution. A good shell script will have comments, preceded by a pound sign, #, describing the steps.
There are conditional tests, such as value A is greater than value B, loops allowing us to go through massive amounts of data, files to read and store data, and variables to read and store data, and the script may include functions.
Shell scripts and functions are both interpreted. This means they are not compiled.
We are going to write a many scripts in the next several tutorials. This would be a simple text file in which we would put our all the commands and several other required constructs that tell the shell environment what to do and when to do it.
res = 0
while [$res –eq 0]
do
echo “Enter any letter.”
Read ltr
Echo $ltr | grep “[a-z]”>/dev/null
If [S? –eq 0]
Then
res =1
else
echo ‘You did not entered a letter, Please enter a letter\(a to z\)”
fi
done
echo “Files starting with letter\($ltr\)” in a directory\:
$PWD
Is $1 | grep “^$ltr”
Q.2.(c)
A.2.(c) Shell Scripting:-
if |S = -eq1]
ten
terminal = “tty”
exec<S1
flag = 1
fi
nol-o
now = o
while read chae "b"
do
nol= ‘expr &nol+1’
set -- &line
now = ‘expr $now +$#’
done
fi
PART-II: MCS-043
Q.1.(a)
A.1.(a)
MCA_Evaluation_System
create table Regional_center
(
rid int primary key,
rname varchar(50) notnull,
rcode int
);
create table Study_center
(
sid int primary key
rid int foreign key notnull ,
sname varchar(50) notnull,
scode int
);
create table programme
(
pid int primary key
pname varchar(50) notnull,
);
create table course
(
cid int primary key,
pid int foreign key notnull,
cname varchar(50) notnull
);
create table Counsellor(
coid int primary key,
pid int foreign key notnull,
sid int foreign key notnull
);
create table Student
(
stid int primary key,
enrollment int notnull,
sname varchar(50) notnull,
sid int foreign key notnull,
pid int foreign key not null
);
create table Assignments
(
aid int foreign key,
cid int foreign key,
enrollmengt int notnull,
stid int foreign key
);
create table termendexam
(
pid int foreign key,
cid int forign key
);
create table total_marks
(
tid int primary key,
enrollment int,
pid int foreign key,
pname varchar(50) foreign key,
sname varchar(50) foreign key,
ccode varchar(50),
total_marks int, p
percentage float,
grade varchar(10)
);
A.1.(b)
(i)To find the total no. of marks for all the assignments submitted by a student in 5 semesters, if the enrolment no. is given.
Ans:- Select * from total_marks , assignments where total_marks.enrollment = assignments.enrollment ;
(ii) To find the total no. of marks for all the Term End Exams of a student in 5 semesters, if the enrolment no. is given.
Ans:- Select * from total_marks , termendexam where total_marks.enrollment = assignments.enrollment ;
(iii) To display the list of student who have passed in all the first semester assignments.
Ans:- Select * from total_marks , assignments where total_marks.pid= assignments.pid and enrollment = 147687647;
(iv) To display the list of all the students who scored more than 70% in MCS-011.
Ans:- Select * from total_marks where percentage>= 70 and cname = 'MCS-011 ;
(v) To display the list of all the students who were failed in MCS-011 course.
Ans:- Select * from total_marks where percentage <=35 ;
Q.1.(c)
A.1.(c)
Oracle lets you define procedures called triggers that run implicitly when an
INSERT, UPDATE, or DELETE statement is issued against the associated table or, in some cases, against a view, or when database system actions occur. These procedures can be written in PL/SQL or Java and stored in the database, or they can be written as C callouts.
Triggers are similar to stored procedures. A trigger stored in the database can include SQL and PL/SQL or Java statements to run as a unit and can invoke stored procedures. However, procedures and triggers differ in the way that they are invoked. A procedure is explicitly run by a user, application, or trigger. Triggers are implicitly fired by Oracle when a triggering event occurs, no matter which user is connected or which application is being used.
Data Access for Triggers
When a trigger is fired, the tables referenced in the trigger action might be currently undergoing changes by SQL statements in other users' transactions. In all cases, the SQL statements run within triggers follow the common rules used for standalone SQL statements. In particular, if an uncommitted transaction has modified values that a trigger being fired either needs to read (query) or write (update), then the SQL statements in the body of the trigger being fired use the following guidelines:
- Queries see the current read-consistent materialized view of referenced tables and any data changed within the same transaction.
- Updates wait for existing data locks to be released before proceeding.
The following examples illustrate these points.
Data Access for Triggers Example 1
Assume that the
salary_check trigger (body) includes the following SELECT statement:SELECT min_salary, max_salary INTO min_salary, max_salary
FROM jobs
WHERE job_title = :new.job_title;
For this example, assume that transaction T1 includes an update to the
max_salary column of the jobs table. At this point, the salary_check trigger is fired by a statement in transaction T2. The SELECT statement within the fired trigger (originating from T2) does not see the update by the uncommitted transaction T1, and the query in the trigger returns the old max_salary value as of the read-consistent point for transaction T2.
No comments:
Post a Comment