EmbLogic » arjunchamyal

fibonacci series using pointer

arjunchamyal — Sat, 07 Jun 2014 10:24:10 +0000

1 #include
2 #include
3 int main()
4 {
5 int a,b,c,i,n;
6 b=0;
7 c=1;
8 printf(“enter the value \n”);
9 scanf(“%d”,&a);
10 int *d;
11 d=(int*)malloc(sizeof(a));
12 *(d+0)=0;
13 *(d+1)=1;
14 i=2;
15 while(i 16 {
17 *(d+i)=b+c;b=c;c=*(d+i);
18 i++;
19 }
20 for(i=0;i 21 printf("%d\n",*(d+i));
22 }

fibonacci series using array

arjunchamyal — Sat, 07 Jun 2014 10:20:56 +0000

1 #include
2 int main()
3 {
4 int a,b,c,i,n;
5 b=0;
6 c=1;
7 printf(“enter the value \n”);
8 scanf(“%d”,&a);
9 int d[a];
10 d[0]=0;
11 d[1]=1;
12 i=2;
13 printf(“%d”,d[0]);
14 while(i 15 {
16 d[i]=b+c;b=c;c=d[i];
17 i++;
18 }for(i=0;i 20 printf("%d\n",d[i]);
21 }

19 for(i=0;i 20 printf("%d\n",d[i]);
21 }
22

IPC using MSG QUEUE

arjunchamyal — Tue, 01 Apr 2014 15:13:38 +0000

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date 2014.04.01.15.08.45; author arjun; state Exp;
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desc
@we are using msg queue in ipc project
@

1.1
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@Initial revision
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RCS

arjunchamyal — Sun, 30 Mar 2014 18:25:12 +0000

IT is revision control system.
With the help of this we can create an image file and we can change our data, and if we want back our previous data, we can do it with the help of rcs.
To do this, first you have to do rcs -i “name of file”,
after this you have to check in
ci “name of file”.
then check out with lock
co -l “name of file”.

IPC using FIFO

arjunchamyal — Sat, 29 Mar 2014 16:41:34 +0000

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desc
@ipc using fifo
here we are using one fifo for requesting client to server
we are able to collect the right data at server
@

1.1
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@Initial revision
@

IPC

arjunchamyal — Fri, 28 Mar 2014 17:11:40 +0000

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desc
@we are using 2 pipe for requesting client and same for processing client
but not use switch case in server.
@

1.5
log
@now we are able to collect the data at server from processing client
@

IPC using PIPE

arjunchamyal — Thu, 27 Mar 2014 15:49:04 +0000

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desc
@we are using 2 pipe for requesting client and same for processing client
but not use switch case in server.
@

1.3
log
@we are facing problem to read the data from client
@
text

IPC

arjunchamyal — Wed, 26 Mar 2014 15:35:08 +0000

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desc
@we are making a server which has 3 requesting client and 3 processing client
but right now it has 3 requesting client and 1processing client
we are using different pipe here for all type of client
all requesting client are working properly
bt processing client is not working properly
@

1.1
log
@Initial revision
@
text
@#include
#include
int main()
{
int pid,pfd[2],buf5[4],ret,z;
char a[4],b[4];
ret=pipe(pfd);
sprintf(a,”%d”,pfd[0]);
sprintf(b,”%d”,pfd[1]);
pid=fork();
if(pid>0)
{
printf(“i am parent\n”);
int i,retw,retr,pid1,add_ret,add_retr,add_pfd[2],buf1[3],buf2[3],buf[3],buf3[3];
char c[4],d[4],e[4],f[4],g[4],h[4],k[4],l[4],m[4],n[4];
retr=read(pfd[0],buf2,12);
for(i=0;i<3;i++)
printf("buf2[%d]=%d\n",i,buf2[i]);

add_ret=pipe(add_pfd);
sprintf(c,"%d",add_pfd[0]);
sprintf(d,"%d",add_pfd[1]);
pid1=fork();
if(pid1==0)
{
printf("i am child2\n");
execl("cl2","arjun",c,d,NULL);
}

add_retr=read(add_pfd[0],buf3,12);
for(i=0;i<3;i++)
printf("buf3[%d]=%d\n",i,buf3[i]);

int pid2,mul_pfd[2],mul_retr,mul_ret,buf4[3];
mul_ret=pipe(mul_pfd);
sprintf(e,"%d",mul_pfd[0]);
sprintf(f,"%d",mul_pfd[1]);

pid2=fork();
if(pid2==0)
{
printf("i am child3\n");
execl("cl3","arjun",e,f,NULL);
}

mul_retr=read(mul_pfd[0],buf4,12);
for(i=0;i<3;i++)
printf("buf4[%d]=%d\n",i,buf4[i]);

int pid3,padd_pfd[2],padd_retr,padd_ret,padd_retw,resadd;
padd_ret=pipe(padd_pfd);
sprintf(g,"%d",padd_pfd[0]);
sprintf(h,"%d",padd_pfd[1]);
pid3=fork();
if(pid3==0)
{
padd_retw=write(padd_pfd[1],buf2,12);
printf("i am pchild1\n");
execl("pcl1","arjun",g,h,NULL);
}
/*
printf("padd_retw=%d\n",padd_retw);
padd_retr=read(padd_pfd[0],&resadd,1);
printf("result is =%d",resadd);
*/
}
else
{
printf("i am child1\n");
execl("./cl1","arjun",a,b,NULL);
}

}

PIPE

arjunchamyal — Tue, 25 Mar 2014 15:09:30 +0000

we can use pipe between two related process only, related means both process has same pid in their past. after that we can read and write the data from any end.
To make a related process between two unrelated process, we have to do fork.
Now question is why we are using fork to make related process.
We are using fork to create a child process for our current process.
In this case child has its own pid but its ppid is same as current process pid.
It means both has a relation, but now problem is how we relate two different process.
we can create a relation between two different process with the help of execl().
We are using execl() in child only. besause if we are using execl() in parent thn it is not execute the whole process, it is terminated after the execl(). So it is compulsary to use execl() in child .
pipe has two descriptor one and zero.
zero for read abd One for write.
if pipe return zero it means it is created else it is not created.we have to pass the file descriptor to the other process through execl () in child.
Execl() takes string only and it is terminated by null.
and to make a string to pipe file descriptor, we are using sprintf function.
To take all the arrguments from child to other process we have to make the command line function to that funcion.
Now we can use pipe between two different process.

ipc using pipe

arjunchamyal — Tue, 25 Mar 2014 09:08:18 +0000

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1.2
date 2014.03.25.08.06.10; author arjun; state Exp;
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1.1
date 2014.03.25.05.16.16; author arjun; state Exp;
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desc
@we are using 2 pipe for requesting client and same for processing client
but not use switch case in server.
@

1.2
log
@we are using switch case in server to find out the operator.
@
text
@#include
#include
int main()
{
int i,pfd1[2],pfd2[2],pfd3[2],pfd4[2],pid1,pid2,pid3,pid4,pid5,pid6,ret1r,ret1w,ret2r,ret2w,ret3r,ret3w,ret4r,ret4w,ret5r,ret5w,ret6r,ret6w,ret1,ret2,ret3,ret4,buf1[4],buf2[4],buf3[4],buf4[4],addres,subres,mulres,ch;
char a[4],b[4],c[4],d[4],e[4],f[4],g[4],h[4];
ret1=pipe(pfd1);
ret2=pipe(pfd2);
ret3=pipe(pfd3);
ret4=pipe(pfd4);
sprintf(a,”%d”,pfd1[0]);
sprintf(b,”%d”,pfd1[1]);
sprintf(c,”%d”,pfd2[0]);
sprintf(d,”%d”,pfd2[1]);
sprintf(e,”%d”,pfd3[0]);
sprintf(f,”%d”,pfd3[1]);
sprintf(g,”%d”,pfd4[0]);
sprintf(h,”%d”,pfd4[1]);
pid1=fork();
if(pid1>0)
{
printf(“i am parent\n”);
ret1r=read(pfd1[0],buf1,12);

pid2=fork();
if(pid2==0)
{
printf(“i am child2\n”);
execl(“./cl2″,”arjun”,b,c,NULL);
}
else
{
ret2r=read(pfd1[0],buf2,12);
}
pid3=fork();
if(pid3==0)
{
printf(“i am child3\n”);
execl(“./cl3″,”arjun”,b,c,NULL);
}
else
{

ret3r=read(pfd1[0],buf3,12);
}
int *buff4[3]={(int*)buf1,(int*)buf2,(int*)buf3};
for(i=0;i<3;i++)
{
ch= *((int*)buff4[i]);
switch(ch)
{
case 43:
{
pid4=fork();
if(pid4==0)
{
ret4w=write(pfd3[1],buf1,12);
printf("i am pchild1\n");
execl("./pcl1","arjun",e,h,NULL);
}
else
{
ret4r=read(pfd4[0],&addres,4);
ret1w=write(pfd2[1],&addres,4);
}
}
break;
case 45:
{
pid5=fork();
if(pid5==0)
{
ret5w=write(pfd3[1],buf2,12);
printf("i am pchild2\n");
execl("./pcl2","arjun",e,h,NULL);
}
else
{
ret5r=read(pfd4[0],&subres,4);
ret2w=write(pfd2[1],&subres,4);
}
}
break;
default :
{
pid6=fork();
if(pid6==0)
{
ret6w=write(pfd3[1],buf2,12);
printf("i am pchild3\n");
execl("./pcl3","arjun",e,h,NULL);
}
else
{
ret6r=read(pfd4[0],&subres,4);
ret3w=write(pfd2[1],&subres,4);
}
}
break;
}
}

}
else
{
printf("i am child1\n");
execl("./cl1","arjun",b,c,NULL);
}
}
@

1.1
log
@Initial revision
@
text
@d5 1
a5 1
int i,pfd1[2],pfd2[2],pfd3[2],pfd4[2],pid1,pid2,pid3,pid4,pid5,pid6,ret1r,ret1w,ret2r,ret2w,ret3r,ret3w,ret4r,ret4w,ret5r,ret5w,ret6r,ret6w,ret1,ret2,ret3,ret4,buf1[4],buf2[4],buf3[4],buf4[4],addres,subres,mulres;
d48 2
a49 3

pid4=fork();
if(pid4==0)
d51 52
a102 3
ret4w=write(pfd3[1],buf1,12);
printf("i am pchild1\n");
execl("./pcl1","arjun",e,h,NULL);
a103 32
else
{
ret4r=read(pfd4[0],&addres,4);
ret1w=write(pfd2[1],&addres,4);
}

pid5=fork();
if(pid5==0)
{
ret5w=write(pfd3[1],buf2,12);
printf("i am pchild2\n");
execl("./pcl2","arjun",e,h,NULL);
}
else
{
ret5r=read(pfd4[0],&subres,4);
ret2w=write(pfd2[1],&subres,4);
}
pid6=fork();
if(pid6==0)
{
ret6w=write(pfd3[1],buf2,12);
printf("i am pchild3\n");
execl("./pcl3","arjun",e,h,NULL);
}
else
{
ret6r=read(pfd4[0],&subres,4);
ret3w=write(pfd2[1],&subres,4);
}

C library function – atoi()

arjunchamyal — Thu, 13 Mar 2014 14:57:09 +0000

The library function atoi converts string argument to integer just like sscanf.
This function returns the converted integer number as an int value. If no valid conversion could be performed, it returns zero.

What is ELF file format

arjunchamyal — Mon, 03 Mar 2014 06:10:55 +0000

It is Extensible linking format.

It was chosen as standard binary file format for Unix like system .

It is extensible and flexible by design so it is used in many operating systems and on many different platform.