Hi There,
Well U can make FCFS/SJF in SHELL but during my first year I made it in c++.
Anyway You can also relate the c file to SHELL!
Here's the code for cpp file.
1. SJF :
*********
#include<iostream.h>
int n,time=0;
int *t=new int[n],*t1=new int[n];
int *arr=new int[n],*w=new int[n];
int sort(int pr[],int prt[],int c)
{
int i,tem,tem2,cmp=0;
for( i=0;i<(c-1);i++)
{
for(int j=(c-1);i<j;j--)
{
cmp++;
if(prt[j]<prt[j-1])
{
tem=prt[j]; tem2=pr[j];
prt[j]=prt[j-1]; pr[j]=pr[j-1];
prt[j-1]=tem; pr[j-1]=tem2;
}
else
continue;
}
}
return pr[0];
}
int sjf()
{
int i,j,c,*prt=new int[n],*pr=new int[n],proc;
for(i=0;i<time;i++)
{
c=0;
for(j=0;j<n;j++) //how many process r coming at i arrival time
{
if(arr[j]<=i && t[j]!=0)
{
pr[c]=j;
prt[c]=t[j];
c++;
}
else continue;
}
if(c==0) //If no process comes at i,increase waiting time
{
for(j=0;j<n;j++)
{
if(t[j]!=0 && arr[j]<i) w[j]++;
else continue;
}
}
else //else get the the shortest burst time t[] process
{
proc=sort(pr,prt,c);
t[proc]=0;
for(j=0;j<n;j++)
{
if(t[j]!=0 && arr[j]<i) w[j]++;
else continue;
}
}
}//end of time
return 0;
}
int main()
{
int i;
//cout<<"Enter the Number of Processes : "; cin>>n;
n=4;
t[0]=7;t[1]=4;t[2]=1;t[3]=4;
arr[0]=0;arr[1]=2;arr[2]=4;arr[3]=5;
for(i=0;i<n;i++)
{
w
=0;
t1=t;
time=time+t;
}
sjf();
for(i=0;i<n;i++) cout<<"P["<<(i+1)<<"] "<<arr<<" "<<t1<<" "<<w<<endl;
return 0;
}
********
U can compile the same in gcc under linux!
2. FCFS :
********
#include<iostream.h>
#include<conio.h>
int main()
{
clrscr();
int n,i;
cout<<"Enter number of processes : ";
cin>>n;
int *a=new int[n],*t=new int[n],*arr=new int[n];
clrscr();
cout<<"Process\t "<<"Arrival time\t"<<" Burst time";
for(i=0;i<n;i++)
{
gotoxy(1,i+3); cout<<"P["<<(i+1)<<"]";
gotoxy(17,i+3); cin>>arr;
gotoxy(38,i+3); cin>>t;
}
int *w=new int[n],*trn=new int[n],tot=0,tot1=0,avw=0,avtrn=0,*res=new int[n];
for(i=0;i<n;i++) { w=0; res=0;}
gotoxy(1,n+6);
cout<<"\t\tF I R S T C OM E F I R S T S E R V E";
gotoxy(1,n+7);
cout<<"\nProcess\t "<<"Waiting time\t"<<" Turnaround Time\t"
<<" Response time"<<endl;
for(i=0;i<n;i++)
{
if(i==0) {trn=t;}
else
{
tot=tot+t[i-1];
w=tot-arr;
trn=w+t;
}
tot1=tot1+t;
res=tot1;
avw=avw+w; avtrn=avtrn+trn;
gotoxy(1,i+n+10); cout<<"P["<<(i+1)<<"]";
gotoxy(17,i+n+10); cout<<w;
gotoxy(37,i+n+10); cout<<trn;
gotoxy(62,i+n+10); cout<<res;
}
cout<<"\nAverage waiting time = "<<((float)avw/n)<<endl;
cout<<"Average turnaround time = "<<((float)avtrn/n)<<endl;
getch();
return 0;
}
********
