VTU - SS and OS programs 2012.-unix & OS

UNIX PROGRAMMING ::

                                            7A.sh

if test $# -eq 0

then

echo "no  arguments"

else

echo "input string is $*"

for x in "$@"

do

y=$x" "$y

done

echo "reversed  string $y"

fi                                                        

                                                                

                                           7B .c

#include<stdio.h>

int main()

{

char str[10];

int pid;

pid=fork();

 if(!pid)

 {

  printf("child process\n");

  printf("enter a command\n");

  scanf("%s",str);

  system(str);

  printf("finished with child\n");

 }

else

  {

  wait();

  }

}
----------------------------------------------------------------

                                           8A.sh

f1=`ls -l $1|cut -c2-10`

f2=`ls -l $2|cut -c2-10`

if [ $f1 = $f2 ]

then

echo "files $1  and  $2 have  same permission :$f1"

else

echo "permission are different "

echo 

echo "files $1 has file permission :$f1"

echo "files $2 has file permission :$f2"

fi

                                           8B.c

#include<sys/types.h>

#include<sys/stat.h>

#include<fcntl.h>

#include<unistd.h>

#include<stdio.h>

int main()

{

char buf1[]="123456789abcdefgh";

char buf2[]="hijklmnopqrstuvw";

int fd;

fd=creat("t.txt",O_WRONLY|777);

write(fd,buf1,16);

lseek(fd,48,SEEK_SET);

write(fd,buf2,16);

return 0;

}

-------------------------------------------------------------------------

                                        9A.sh

for i in $*
do
echo "echo $i 1>&2"
echo "cat >$i <<'end of $i'"
cat $i
echo "end of $i"
done

                                         9B.c

#include<stdio.h>

int main()

{

char str[10];

int pid;

pid=fork();

if(!pid)

{

printf("CHILD PROCESS :: ");

printf("\n parent pid: %d",getppid());

printf("\nchild pid: %d",getpid());

}

else

{

 wait();

 printf("\n PARENT PROCESS ::");

 printf("\n parent pid: %d",getpid());

 printf("\nchild pid: %d\n",pid);

}

return 0;

}
-------------------------------------------------------------------

OPERATING SYSTEM
10.ROUND ROBIN AND SHORTEST REMAINING TIME FIRST ALGORITHM

#include<stdio.h>
struct proc
{
int id;
int arrival;
int burst;
int rem;
int wait;
int finish;
int turnaround;
float ratio;
}process[10];  //structure to hold the process information
struct proc temp;
int no;
int chkprocess(int);
int nextprocess();
 void roundrobin(int, int, int[], int[]);
 void srtf(int);

main()
{
  int n,tq,choice;       
  int bt[10],st[10],i,j,k;
for(; ;)
{
printf("Enter the choice  \n");
printf(" 1. Round Robin\n 2. SRT\n 3. Exit \n");
scanf("%d",&choice);
switch(choice)
{
case 1:
printf("Round Robin scheduling algorithm\n");
printf("Enter number of processes:\n");
  scanf("%d",&n);
  printf("Enter burst time for sequences:");
  for(i=0;i<n;i++)
   {
     scanf("%d",&bt[i]);
     st[i]=bt[i]; //service time
   }
   printf("Enter time quantum:");
   scanf("%d",&tq);
   roundrobin(n,tq,st,bt);
   break;
case 2: 
printf("\n \n ---SHORTEST REMAINING TIME NEXT---\n \n ");
printf("\n \n Enter the number of processes: ");
scanf("%d", &n);
srtf(n);
break;
case 3: exit(0);
}// end of switch
}// end of for
}//end of main()

void  roundrobin(int n,int tq,int st[],int bt[])
 {        int time=0;
  int tat[10],wt[10],i,count=0,swt=0,stat=0,temp1,sq=0,j,k;
  float awt=0.0,atat=0.0;
 while(1)
   {
     for(i=0,count=0;i<n;i++)
     {
       temp1=tq;
     if(st[i]==0) //when service time of a process equals zero then count value is  incremented          
       {                                      
count++;
continue;
       }
       if(st[i]>tq)      // when service time of a process greater than time quantum then time
st[i]=st[i]-tq;     //quantum value subtracted from service time
       else
if(st[i]>=0)              
{
 temp1=st[i];      // temp1 stores the service time of a process
 st[i]=0;               // making service time equals 0
}
sq=sq+temp1;      // utilizing temp1 value to calculate turnaround time
tat[i]=sq;               // turn around time
    }  //end of for
     if(n==count)      // it indicates all processes  have completed their task because the count value 
     break;                       // incremented when service time equals 0
   } //end of while
for(i=0;i<n;i++)       // to calculate the wait time and turnaround time of each process
   {       
    wt[i]=tat[i]-bt[i];     // waiting time calculated from the turnaround time - burst time
    swt=swt+wt[i];       // summation of  wait time 
    stat=stat+tat[i];      // summation of turnaround time
   }
   awt=(float)swt/n;          // average wait time
   atat=(float)stat/n;         // average turnaround time
   printf("Process_no Burst time Wait time Turn around time\n");
   for(i=0;i<n;i++)
    printf("%d\t\t%d\t\t%d\t\t%d\n",i+1,bt[i],wt[i],tat[i]);
    printf("Avg wait time is %f\n Avg turn around time is %f\n",awt,atat);
 }// end of Round Robin

int chkprocess(int s)         // function to check process remaining time is zero or not
{
int i;
for(i = 1; i <= s; i++)
{
if(process[i].rem != 0)
return 1;
}
return 0;
} // end of chkprocess    
           
int nextprocess()        // function to identify the next process to be executed
{
int min, l, i;
min = 32000;   //any limit assumed
for(i = 1; i <= no; i++)
{
if( process[i].rem!=0 && process[i].rem < min)
{
min = process[i].rem;
l = i;
}
}
return l;
}  // end of nextprocess

void srtf(int n)
{
int i,j,k,time=0;
float tavg=0,wavg=0;
for(i = 1; i <= n; i++)
{
process[i].id = i;
printf("\n\nEnter the arrival time for process %d: ", i);
scanf("%d", &(process[i].arrival));
printf("Enter the burst time for process %d: ", i);
scanf("%d", &(process[i].burst));
process[i].rem = process[i].burst;
}
for(i = 1; i <= n; i++)
{
for(j = i + 1; j <= n; j++)
{
if(process[i].arrival > process[j].arrival)   //  sort  arrival time of a process
{
temp = process[i];
process[i] = process[j];
process[j] = temp;
}
}
}

no = 0;
j = 1;
       while(chkprocess(n) == 1)
{
if(process[no + 1].arrival == time)
{
no++;
if(process[j].rem==0)          
   process[j].finish=time;
j = nextprocess(); 
}
if(process[j].rem != 0)             // to calculate the waiting time of  a process
{
process[j].rem--;
for(i = 1; i <= no; i++)
{
if(i != j && process[i].rem != 0)
process[i].wait++;             
}
}
              else
{
process[j].finish = time;
j=nextprocess();
time--;
k=j;
}

time++;
}
process[k].finish = time;
printf("\n\n\t\t\t---SHORTEST REMAINING TIME FIRST---");
printf("\n\n Process  Arrival  Burst   Waiting  Finishing turnaround  Tr/Tb \n");
printf("%5s %9s %7s %10s %8s %9s\n\n", "id", "time", "time", "time", "time", "time");
     for(i = 1; i <= n; i++)
      {
                  process[i].turnaround = process[i].wait + process[i].burst; // calc of turnaround 
         process[i].ratio = (float)process[i].turnaround / (float)process[i].burst;        
  printf("%5d %8d %7d  %8d %10d %9d %10.1f ", process[i].id, process[i].arrival        process[i].burst, process[i].wait, process[i].finish,  process[i].turnaround,  process[i].ratio);
       tavg=tavg+ process[i].turnaround;    //summation of turnaround time
       wavg=wavg+process[i].wait;             // summation of waiting time
                    printf("\n\n");
}
tavg=tavg/n;        // average turnaround time
wavg=wavg/n;     // average wait time
            printf("tavg=%f\t wavg=%f\n",tavg,wavg);
   }// end of srtf

------------------------------------------------------------------------------------------------------------

11.Fibonacci series !!!

#include<stdio.h>
#include<omp.h>
#include<stdlib.h>

int main(int argc,char* argv[])
{
int FibNumber[25]={0};
int j, temp, tmp, id, i=0;
int n, tid, threads;
printf("Enter the number range\n");
scanf("%d",&n);
omp_set_num_threads(2);

#pragma omp parallel
{
printf("The number of threads are %d\n",omp_get_num_threads());
#pragma omp for private(tid,tmp,FibNumber)
for(j=1;j<=n;j++)
{
                 tmp = rand()%24;
printf("Thread id %d for Fib series generation  \n",omp_get_thread_num());
                #pragma omp critical
   {
for(i=1;i<=tmp;i++)
{
FibNumber[1] = 1;
FibNumber[2] = 1;
for(temp=3;temp<=tmp;temp++)    
FibNumber[temp] = FibNumber[temp-1]+FibNumber[temp-2];
}         
printf("Thread id %d for Fib series Printing \n",omp_get_thread_num());
printf("The number value is %d : ",tmp);
for(i=1;i<=tmp;i++)
printf("%d \t",FibNumber[i]);
printf("\n\n");
}

}

}
}

---------------------------------------------------------------------------------

12.Banker's algorithm :: 

#include<stdio.h>
#include<stdlib.h>
main()
{
int np,i,j,k,z,nr,p[10]={0},c[10];
int max[10][10],alloc[10][10],sum[10]={0},avail[10]={0};
printf("Enter the number of processes : ");
scanf("%d",&np);
printf("Enter the number of resources ");
scanf("%d",&nr);
printf("Enter the available resource \n");
for(i=0;i<nr;i++)
{
printf("Resources %d :",i+1);
scanf("%d",&c[i]);
}
printf("Enter the maximum resource\n");
for(i=0;i<np;i++)
{
for(j=0;j<nr;j++)
{
scanf("%d",&max[i][j]);
}
}
printf("Enter the allocated resource \n");
for(i=0;i<np;i++)
for(j=0;j<nr;j++)
scanf("%d",&alloc[i][j]);
printf("avail vector < ");
for(j=0;j<nr;j++)
{
for(i=0;i<np;i++)
{
sum[j]=sum[j]+alloc[i][j];
}
avail[j]=c[j]-sum[j];
printf("%d ",avail[j]);
}
printf(" >\n");
for(z=0;z<np;z++)
{
for(i=0;i<np;i++)
{
if(p[i]==0)
{
for(j=0;j<nr;j++)
{
if((max[i][j]-alloc[i][j])>avail[j])
{
break;
}
}
if(j==nr)
{
p[i]=1;
printf("process %d executed and terminated \n ",i+1);
printf("avail vector < ");
for(k=0;k<nr;k++)
{
avail[k]=avail[k]+alloc[i][k];
alloc[i][k]=0;
printf("%d ",avail[k]);
}
printf(" >\n");
}
}
}
} 
for(i=0;i<np;i++)
{
if(p[i]!=1)
{
printf("unsafe state \n");
exit(0);
}
}
printf("safe state \n");
}
----------------------------------------------------------------------------------------

12.Banker's algorithm :: 

#include<stdio.h>
struct process
{
int all[6],max[6],need[6],finished,request[6];
}p[10];
int avail[6],sseq[10],ss=0,check1=0,check2=0,n,pid,work[6];
int nor,nori;
void main()
{
int safeseq(void);
int ch,i=0,j=0,k,pid,ch1;
int violationcheck=0,waitcheck=0;
do
{
printf("\n\n\t 1. Input");
printf("\n\n\t 2. New Request");
printf("\n\n\t 3. Safe State or Not");
printf("\n\n\t 4. print");
printf("\n\n\t 5. Exit");
printf("\n\n\t Enter ur choice :");
scanf("%d",&ch);
switch(ch)
{
case 1:
printf("\n\n\t Enter number of processes : ");
scanf("%d",&n);
printf("\n\n\t Enter the Number of Resources : ");
scanf("%d",&nor);
printf("\n\n\t Enter the Available Resouces : ");
for(j=0;j<n;j++)
{
for(k=0;k<nor;k++)
{
if(j==0)
{
printf("\n\n\t For Resource type %d : ",k);
scanf("%d",&avail[k]);
}
p[j].max[k]=0;
p[j].all[k]=0;
p[j].need[k]=0;
p[j].finished=0;
p[j].request[k]=0;
}
}
for(i=0;i<n;i++)
{
printf("\n\n\t Enter Max and Allocated resources for P : ",i);
 for(j=0;j<nor;j++)
{
printf("\n\n\t Enter the Max of resource %d : ",j);
scanf("%d",&p[i].max[j]);
printf("\n\n\t Allocation of resource %d    :",j);
scanf("%d",&p[i].all[j]);
if(p[i].all[j]>p[i].max[j])
{
printf("\n\n\t Allocation should be less < or == max");
j--;
}
else
p[i].need[j]=p[i].max[j]-p[i].all[j];
avail[j]=avail[j]-p[i].all[j];
}
}
break;
case 2:
violationcheck=0;
waitcheck=0;
printf("\n\n\t Requesting process id :");
scanf("%d",&pid);
for(j=0;j<nor;j++)
{
printf("\n\n\t Number of Request for resource %d :",j);
  scanf("%d",&p[pid].request[j]);
if(p[pid].request[j]>p[pid].need[j])
violationcheck=1;
if(p[pid].request[j]>avail[j])
waitcheck=1;
}
if (violationcheck==1)
printf("\n\n\t The Process Exceeds it’s Max Need: Terminated");
else if(waitcheck==1)
printf("\n\n\t Lack of Resourcess : Process State – Wait");
else
{
for(j=0;j<nor;j++)
{
avail[j]=avail[j]-p[pid].request[j];
p[pid].all[j]=p[pid].all[j]+p[pid].request[j];
p[pid].need[j]=p[pid].need[j]-p[pid].request[j];
}
ch1=safeseq();
if(ch1==0)
{
for(j=0;j<nor;j++)
{
avail[j]=avail[j]+p[pid].request[j];
p[pid].all[j]=p[pid].all[j]-p[pid].request[j];
p[pid].need[j]=p[pid].need[j]+p[pid].request[j];
}
}
else if(ch1==1)
printf("\n\n\t Request Committed ");
}
break;
case 3:
if(safeseq()==1)
printf("\n\n\t The System is in safe state ");
else
printf("\n\n\t The System is Not in safe state ");
break;
case 4:
printf("\n\n\t Number of processes : %d",n);
printf("\n\n\t Number of Resources : %d",nor);
printf("\n\n\t Pid \t   Max \t   Allocated \t Need ");
for(i=0;i<n;i++)
{
printf("\n\n\t  P%d : ",i);
for(j=0;j<nor;j++)
printf(" %d",p[i].max[j]);
printf("\t");
for(j=0;j<nor;j++)
printf("%d",p[i].all[j]);
printf("\t");
for(j=0;j<nor;j++)
printf("%d",p[i].need[j]);
}
printf("\n\n\t Available :");
for(i=0;i<nor;i++)
printf("%d",avail[i]);
break;
case 5:
break;
}
}while(ch!=5);
}
int safeseq()
{
int tj,tk,i,j,k;
ss=0;
for(j=0;j<nor;j++)
work[j]=avail[j];
for(j=0;j<n;j++)
p[j].finished=0;
for( tk=0;tk<nor;tk++)
{
for(j=0;j<n;j++)
{
if(p[j].finished==0)
{
check1=0;
for(k=0;k<nor;k++)
if(p[j].need[k]<=work[k])
check1++;
if(check1==nor)
{
for(k=0;k<nor;k++)
{
work[k]=work[k]+p[j].all[k];
p[j].finished=1;
}
sseq[ss]=j;
ss++;
}
}
}
}
check2=0;
for(i=0;i<n;i++)
if(p[i].finished==1)
check2++;
printf("\n\n\t");
if(check2>=n)
{
printf("\n\n\t The system is in safe state");
for( tj=0;tj<n;tj++)
printf("P%d,",sseq[tj]);
return 1;
}
else
printf("\n\n\t The system is Not in safe state");
return 0;
}