Operating system practical file du, Assignments of Operating Systems

Download Operating system practical file du and more Assignments Operating Systems in PDF only on Docsity!

OPERATING SYSTEM

KANCHAN SAGAR

20/CS/

SEM = 3

rd

PRACTICAL FILE

Q1) // C program to illustrate use of fork() & // exec() system call for process creation #include <stdio.h> #include <sys/types.h> #include <unistd.h> #include <stdlib.h> #include <errno.h> #include <sys/wait.h> int main(){ pid_t pid; int ret = 1; int status; pid = fork(); if (pid == -1){

// pid == -1 means error occured printf("can't fork, error occured\n"); exit(EXIT_FAILURE); } else if (pid == 0){ // pid == 0 means child process created // getpid() returns process id of calling process // Here It will return process id of child process printf("child process, pid = %u\n",getpid()); // Here It will return Parent of child Process means Parent process it self printf("parent of child process, pid = %u\n",getppid()); // the argv list first argument should point to // filename associated with file being executed // the array pointer must be terminated by NULL // pointer char * argv_list[] = {"ls","-lart","/home",NULL}; // the execv() only return if error occured. // The return value is - execv("ls",argv_list); exit(0); }

else{ // a positive number is returned for the pid of // parent process // getppid() returns process id of parent of // calling process // Here It will return parent of parent process's ID printf("Parent Of parent process, pid = %u\n",getppid()); printf("parent process, pid = %u\n",getpid()); // the parent process calls waitpid() on the child // waitpid() system call suspends execution of // calling process until a child specified by pid // argument has changed state // see wait() man page for all the flags or options // used here if (waitpid(pid, &status, 0) > 0) { if (WIFEXITED(status) && !WEXITSTATUS(status)) printf("program execution successful\n"); else if (WIFEXITED(status) && WEXITSTATUS(status)) { if (WEXITSTATUS(status) == 127) { // execv failed

printf("execv failed\n"); } else printf("program terminated normally," " but returned a non-zero status\n"); } else printf("program didn't terminate normally\n"); } else { // waitpid() failed printf("waitpid() failed\n"); } exit(0); } return 0; }

Q2) #include<stdio.h> #include<stdlib.h> int main() { printf("### Kernel Information ###\n\n"); system("cat /proc/version_signature | awk '{printf "Kernel Version: %s\n", $0}'"); printf("\n### CPU Information ###\n\n"); system("cat /proc/cpuinfo | awk '/processor|model/{print}'"); return 0; } Q3) #include<stdio.h> #include<stdlib.h> int main() { system("clear"); printf("First version \ncpu model \n"); system("cat /proc/cpuinfo |awk 'NR==5{print}' "); printf("kernel version \n"); system("cat /proc/version"); printf("\nAmount of time lastn booted \n"); system("cat /proc/uptime"); printf("Amount of memory configured in the system.\n"); system("cat /proc/meminfo |awk 'NR==4{print}'");

printf("\nAmount of memory currently available\n"); system("cat /proc/meminfo |awk 'NR==2{print}'"); return(0); }

Q4) #include #include<sys/stat.h> using namespace std; int main(int argc, char*argv[]){ int i; struct stat buffer; if(argc<2){ cout<<"USAGE
n"<<argv[1]; } for(i=1;i<argc;i++){ cout<<"\nFILE NAME IS = "; cout<< argv[i]<<endl; if(stat(argv[i], &buffer)<0){

cout<<"ERROR IN OBTAINING FILE STATS\n"; } else{ cout<<"\nOWNER USER ID, UID = "<<buffer.st_uid<<"\n\nGROUP ID, GID = "<<buffer.st_gid<<endl; cout<<"\nACCESS PERMISSION = "<<buffer.st_mode<<endl; cout<<"\nACCESS TIME = "<<buffer.st_atime<<"\n"; } } return(0); } Output: Q5) // C++ program for implementation of RR scheduling #include using namespace std; // Function to find the waiting time for all // processes void findWaitingTime(int processes[], int n,

int bt[], int wt[], int quantum) { // Make a copy of burst times bt[] to store remaining // burst times. int rem_bt[n]; for (int i = 0 ; i < n ; i++) rem_bt[i] = bt[i]; int t = 0; // Current time // Keep traversing processes in round robin manner // until all of them are not done. while (1) { bool done = true; // Traverse all processes one by one repeatedly for (int i = 0 ; i < n; i++) { // If burst time of a process is greater than 0 // then only need to process further if (rem_bt[i] > 0) { done = false; // There is a pending process

if (rem_bt[i] > quantum) { // Increase the value of t i.e. shows // how much time a process has been processed t += quantum; // Decrease the burst_time of current process // by quantum rem_bt[i] -= quantum; } // If burst time is smaller than or equal to // quantum. Last cycle for this process else { // Increase the value of t i.e. shows // how much time a process has been processed t = t + rem_bt[i]; // Waiting time is current time minus time // used by this process wt[i] = t - bt[i];

// As the process gets fully executed // make its remaining burst time = 0 rem_bt[i] = 0; } } } // If all processes are done if (done == true) break; } } // Function to calculate turn around time void findTurnAroundTime(int processes[], int n, int bt[], int wt[], int tat[]) { // calculating turnaround time by adding // bt[i] + wt[i] for (int i = 0; i < n ; i++) tat[i] = bt[i] + wt[i]; } // Function to calculate average time

void findavgTime(int processes[], int n, int bt[], int quantum) { int wt[n], tat[n], total_wt = 0, total_tat = 0; // Function to find waiting time of all processes findWaitingTime(processes, n, bt, wt, quantum); // Function to find turn around time for all processes findTurnAroundTime(processes, n, bt, wt, tat); // Display processes along with all details cout << "Processes "<< " Burst time " << " Waiting time " << " Turn around time\n"; // Calculate total waiting time and total turn // around time for (int i=0; i<n; i++) { total_wt = total_wt + wt[i]; total_tat = total_tat + tat[i]; cout << " " << i+1 << "\t\t" << bt[i] <<"\t " << wt[i] <<"\t\t " << tat[i] <<endl; }

cout << "Average waiting time = " << (float)total_wt / (float)n; cout << "\nAverage turn around time = " << (float)total_tat / (float)n; } // Driver code int main() { // process id's int processes[] = { 1, 2, 3}; int n = sizeof processes / sizeof processes[0]; // Burst time of all processes int burst_time[] = {10, 5, 8}; // Time quantum int quantum = 2; findavgTime(processes, n, burst_time, quantum); return 0; }

Q6) // C++ program for implementation of FCFS // scheduling #include using namespace std; // Function to find the waiting time for all // processes void findWaitingTime(int processes[], int n, int bt[], int wt[]) { // waiting time for first process is 0 wt[0] = 0; // calculating waiting time

for (int i = 1; i < n ; i++ ) wt[i] = bt[i-1] + wt[i-1] ; } // Function to calculate turn around time void findTurnAroundTime( int processes[], int n, int bt[], int wt[], int tat[]) { // calculating turnaround time by adding // bt[i] + wt[i] for (int i = 0; i < n ; i++) tat[i] = bt[i] + wt[i]; } //Function to calculate average time void findavgTime( int processes[], int n, int bt[]) { int wt[n], tat[n], total_wt = 0, total_tat = 0;

//Function to find waiting time of all processes findWaitingTime(processes, n, bt, wt); //Function to find turn around time for all processes findTurnAroundTime(processes, n, bt, wt, tat); //Display processes along with all details cout << "Processes "<< " Burst time " << " Waiting time " << " Turn around time\n"; // Calculate total waiting time and total turn // around time for (int i=0; i<n; i++) { total_wt = total_wt + wt[i]; total_tat = total_tat + tat[i]; cout << " " << i+1 << "\t\t" << bt[i] <<"\t "

<< wt[i] <<"\t\t " << tat[i] <<endl; } cout << "Average waiting time = " << (float)total_wt / (float)n; cout << "\nAverage turn around time = " << (float)total_tat / (float)n; } // Driver code int main() { //process id's int processes[] = { 1, 2, 3}; int n = sizeof processes / sizeof processes[0]; //Burst time of all processes int burst_time[] = {10, 5, 8};

findavgTime(processes, n, burst_time); return 0; } Q7) #include using namespace std; int main() { int n,temp,tt=0,min,d,i,j;

float atat=0,awt=0,stat=0,swt=0; cout<<"enter no of process"<<endl; cin>>n; int a[n],b[n],e[n],tat[n],wt[n]; for(i=0;i<n;i++) { cout<<"enter arival time "; //input cin>>a[i]; } for(i=0;i<n;i++) { cout<<"enter brust time "; //input cin>>b[i]; } for(i=0;i<n;i++) { for(j=i+1;j<n;j++) { if(b[i]>b[j]) { temp=a[i]; a[i]=a[j];

a[j]=temp; temp=b[i]; b[i]=b[j]; b[j]=temp; } } } min=a[0]; for(i=0;i<n;i++) { if(min>a[i]) { min=a[i]; d=i; } } tt=min; e[d]=tt+b[d]; tt=e[d]; for(i=0;i<n;i++) { if(a[i]!=min)

{

e[i]=b[i]+tt; tt=e[i]; } } for(i=0;i<n;i++) { tat[i]=e[i]-a[i]; stat=stat+tat[i]; wt[i]=tat[i]-b[i]; swt=swt+wt[i]; } atat=stat/n; awt=swt/n; cout<<"Process Arrival-time(s) Burst-time(s) Waiting-time(s) Turnaround-time(s)\n"; for(i=0;i<n;i++) { cout<<"P"<<i+1<<" "<<a[i]<<" "<<b[i]<<" "<<wt[i]<<" "<<tat[i]<<endl; } cout<<"awt="<<awt<<" atat="<<atat; //average waiting time and turn around time }

Q8) // C++ program to implement Shortest Job first with Arrival // Time #include using namespace std; int mat[10][6]; void swap(int* a, int* b) { int temp = *a; *a = *b; *b = temp; } void arrangeArrival(int num, int mat[][6]) { for (int i = 0; i < num; i++) {

for (int j = 0; j < num - i - 1; j++) { if (mat[j][1] > mat[j + 1][1]) { for (int k = 0; k < 5; k++) { swap(mat[j][k], mat[j + 1][k]); } } } } } void completionTime(int num, int mat[][6]) { int temp, val; mat[0][3] = mat[0][1] + mat[0][2]; mat[0][5] = mat[0][3] - mat[0][1]; mat[0][4] = mat[0][5] - mat[0][2]; for (int i = 1; i < num; i++) { temp = mat[i - 1][3]; int low = mat[i][2]; for (int j = i; j < num; j++) { if (temp >= mat[j][1] && low >= mat[j][2]) { low = mat[j][2]; val = j;

}

}

mat[val][3] = temp + mat[val][2]; mat[val][5] = mat[val][3] - mat[val][1]; mat[val][4] = mat[val][5] - mat[val][2]; for (int k = 0; k < 6; k++) { swap(mat[val][k], mat[i][k]); } } } int main() { int num, temp; cout << "Enter number of Process: "; cin >> num; cout << "...Enter the process ID...\n"; for (int i = 0; i < num; i++) { cout << "...Process " << i + 1 << "...\n"; cout << "Enter Process Id: "; cin >> mat[i][0]; cout << "Enter Arrival Time: ";

cin >> mat[i][1]; cout << "Enter Burst Time: "; cin >> mat[i][2]; } cout << "Before Arrange...\n"; cout << "Process ID\tArrival Time\tBurst Time\n"; for (int i = 0; i < num; i++) { cout << mat[i][0] << "\t\t" << mat[i][1] << "\t\t" << mat[i][2] << "\n"; } arrangeArrival(num, mat); completionTime(num, mat); cout << "Final Result...\n"; cout << "Process ID\tArrival Time\tBurst Time\tWaiting " "Time\tTurnaround Time\n"; for (int i = 0; i < num; i++) { cout << mat[i][0] << "\t\t" << mat[i][1] << "\t\t" << mat[i][2] << "\t\t" << mat[i][4] << "\t\t" << mat[i][5] << "\n"; }