BDU - CSE: 4/8/12

Multi threading, Thread Life Cycle, Daemon thread, Difference between application and applet, Types of applet, applet life cycle of JAVA PROGRAMMING. Notes by Akila Mam.

Multi Threading - Java

OOAD Important Questions

Object Oriented Analysis and Design - Ali Bahrami. All five units - Important Questions.

IMP OOAD

Event Classes in Java

Notes given by Akila Mam

Event Classes in Java

import a.*;

interface Area
{
float compute(float x, float y);
}

class Rectangle implements Area
{
public float compute(float x, float y)
{
return(x * y);
}
}

class Triangle implements Area
{
public float compute(float x,float y)
{
return(x * y/2);
}
}

class InterfaceArea
{
public static void main(String args[])
{
Rectangle rect = new Rectangle();
Triangle tri = new Triangle();
Area area;
area = rect;
System.out.println("Area Of Rectangle = "+ area.compute(1,2));
area = tri;
System.out.println("Area Of Triangle = "+ area.compute(10,2));
}
}

Upper to Lower Case

echo "program to convert uppercase to lower case"
echo "enter the filename to be created:"
read str
vi $str
echo "1.lowercase to uppercase"
echo "2.uppercase to lowercase"
echo "select your choice:"
read ch
case $ch in
1)cat $str | tr "{a-z}" "{A-Z}" | tee $str cat $str;;
2)cat $str | tr "{A-Z}" "{a-z}" | tee $str cat $str;;
*)echo "invalid choice"
esac

Unlink

clear
echo
ch=0
while [ $ch_lt 2 ]
do
echo "1.create file
2.unlink"
echo
echo "enter your choice:"
read ch
echo $ch
case $ch in
1)echo "enter file name:"
read fn
vi $fn;;
2)unlink $fn;
esac
done

System Calls

clear
echo "program to show file commands"
con='Y'
while [ $con='Y' ]
do
echo "1.list of files and folders
2.user's
3.process running currently
4.today's date
5.calender
6.quit"
echo "enter your choice:"
read choice
case $choice in
1)ls;;
2)who;;
3)ps;;
4)date;;
5)cal;;
6)exit;;
*)echo "invalid choice"
esac
echo
echo "Do you want to continue(y/n)"
read con
if [ $con='n' ]
then
exit;
echo "continue"
fi
done

Sorting and Unsorting a File

clear
echo
ch=0
while [ $ch -lt 6 ]
do
echo
echo "1.create a file
2.sort a file
3.sorted file
4.unsorted file
5.clear
6.quit "
echo
echo "Enter your choice:"
read ch
echo $ch
case $ch in
1) echo "Enter file name"
read fn
vi $fn;;
2) echo "sorted process is over";;
3) sort $fn;;
4) cat $fn;;
5) clear;;
6) exit;;
esac
done

Signalling

#include<stdio.h>
#include<stdlib.h>
#include<signal.h>
void signal_callback_handler(int signum)
{
printf("caught signal%d \n",signum);
exit(signum);
}
int main()
{
signal(SIGINT,signal_callback_handler);
while(1)
{
printf("program processing stuff here \n");
sleep(1);
}
return EXIT_SUCCESS;
}

Semaphores

#include<sys/types.h>
#include<sys/ipc.h>
#include<sys/sem.h>
#include<stdio.h>
#define KEY (1492)
void main()
{
int id;
union semun
{
int val;
struct semid_ds *buf;
ushort * array;
}
argument;
argument.val=0;
id=semget(KEY,1,0666 | IPC_CREAT);
if (id<0)
{
fprintf(stderr,"unable to obtain semaphore.\n");
}
if(semctl(id,0,SETVAL,argument)<0)
{
fprintf(stderr,"cannot set semaphore value.\n");
}
else
{
fprintf(stderr,"semaphore %d initialized.\n",KEY);
}
}

PipeLining

#include<sys/types.h>
#include<unistd.h>
#include<stdio.h>
#include<stdlib.h>
void
read_from_pipe(int file)
{
FILE *stream;
int c;
stream=fdopen(file,"r");
while((c=fgetc(stream))!=EOF)
putchar(c);
fclose(stream);
}

void
write_to_pipe(int file)
{
FILE *stream;
stream=fdopen(file,"w");
fprintf(stream,"Hello,world!\n");
fprintf(stream,"Gud bye,world!\n");
fclose(stream);
}

int main (void)
{
pid_t pid;
int mypipe[2];
if (pipe(mypipe))
{
fprintf(stderr,"pipe failed \n");
return EXIT_FAILURE;
}
pid=fork();
if(pid==(pid_t)0)
{
close(mypipe[1]);
read_from_pipe(mypipe[0]);
return EXIT_SUCCESS;
}
else if (pid<(pid_t)0)
{
fprintf(stderr,"forkfailed \n");
return EXIT_FAILURE;
}
else
{
close(mypipe[0]);
write_to_pipe(mypipe[1]);
return EXIT_SUCCESS;
}
}

Mark Statement

clear
echo "enter stud's name:"
read name
echo "enter roll no:"
read roll
echo "enter mark in p1:"
read m1
echo "enter mark in p2:"
read m2
echo "enter mark in p3:"
read m3
echo "enter mark in p4:"
read m4
echo "enter mark in p5:"
read m5
echo "enter mark in p6:"
read m6
clear
echo "......."
echo "result"
echo "......."
echo "name:$name"
echo
echo "roll no:$roll"
echo
echo "M.Tech"
echo
echo "p1:$m1"
echo
echo "p2:$m2"
echo
echo "p3:$m3"
echo
echo "p4:$m4"
echo
echo "p5:$m5"
echo
echo "p6:$m6"
echo
echo "Total:`expr $m1 + $m2 + $m3 + $m4 + $m5 + $m6`"
echo
echo "Average:`expr $m1 / 6 + $m2 / 6 + $m3 / 6 + $m4 / 6 + $m5 / 6 + $m6 / 6`%"
echo
if [ $m1 -gt 50 -a $m2 -gt 50 -a $m3 -gt 50 -a $m4 -gt 50 -a $m5 -gt 50 -a $m6 -gt 50 ]
then
echo "Pass"
else
echo "Fail"
fi
echo
echo "......"

Insert and Search

clear
echo "Enter your file name:"
read fn
search=` find $fn `
if [ $fn = $search ]
then
echo "Enter your word to be searched:"
read se
word=`fgrep -a -o -m 1 $se $fn`
if [ $se = $word ]
then
choice=`zenity --list \
--title="search result" \
--column= " "\
"sucess-found the specified word"`
else
choice=`zenity --list \
--title="search result" \
--column=" "\
"failed-specified word not found"`
fi
else
choice=`zenity --list \
--title="error" \
--column=" "\
"failed-file not found"`
fi

Fork Child

#include <stdio.h>
int main(void)
{
int pid;
pid=fork();
if(pid==0)
{
int j;
for(j=0;j<10;j++)
{
printf("child:=%d\n",j);
sleep(1);
}
exit(0);
}
else if(pid>0)
{
int i;
for(i=0;i<10;i++)
{
printf("parent:%d\n",i);
sleep(1);
}
}
else
{
fprintf(stderr,"couldn't fork");
exit(1);
}
}

Fan of Process

#include<stdio.h>
#include<sys/types.h>
#include<unistd.h>
int main()
{
int i;
int n=10;
pid_t childpid;
for(i=1;i<n;++i)
if((childpid=fork())<=0)
break;
fprintf(stderr,"this is process %ld with parent %ld\n",(long)getpid(),(long)getpid());
}

Error Checking

#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
const char *FILE_NAME="File.c";
int main ( int argc, char ** argv )
{
int fd=0;
printf ("FINDING %s...\n",FILE_NAME);
fd = open (FILE_NAME,O_RDONLY,0644);
if
(fd<0)
{
perror("Error opening file");
printf("Error opening file:%s\n",strerror( errno ) );
}
else
{
printf("\n File Present");
}
return EXIT_SUCCESS;
}

Error Handling

#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int divident = 50;
int divisor = 0;
int quotient;
if (divisor == 0)
{
fprintf (stderr,"Division by zero ! aborting.....\n");
exit(EXIT_FAILURE);
}
else
{
quotient=divident /divisor ;
exit (EXIT_SUCCESS);
}
}

Chain of Process

#include<stdio.h>
#include<sys/types.h>
#include<unistd.h>
int main()
{
int i;
int n=10;

pid_t childpid;

for(i=1;i<n;++i)
if(childpid=fork())
break;

printf("this is process %ld with parent %ld\n",(long)getpid(),(long)getppid());

}

Computer architecture Q . Paper {MCA}

*Please download and rotate the second image

Just practice these questions for the exams.
Hope U find this useful.

Unit 5 - Input Output Organization

This post contains the notes for the fifth unit - INPUT OUTPUT ORGANIZATION of our COMPUTER ORGANIZATION AND ARCHITECTURE. If strictly follows the cook by Carl Hamacher and I have added some important points and Diagrams too. U can view and download it from here itself

Unit 5 I/O organization

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