#include

#include

#include

#include

#include

#include

#include

int main$($int argc, char $**$argv$)\{$

$/*************************************************************$

write code for the main process that will establish

the communication channel between cleint and server using

pipes

$*************************************************************/$

pid$\_$t pid;

int fd$[2]$;

$//$ Create pipe

if $($pipe$($fd$)==-1)\{$

perror$("$pipe$")$;

exit$($EXIT$\_$FAILURE$)$;

$\}$

pid $=$ fork$()$;

if $($pid $<0)\{$

perror$("$Fork failed

$")$;

exit$($EXIT$\_$FAILURE$)$;

$\}$

if $($pid $==0)\{//$ Child process $($server$)$

close$($fd$[1])$; $//$ Close write end in child

server$($fd$[0],$ fd$[1])$;

exit$($EXIT$\_$SUCCESS$)$;

$\}$ else $\{//$ Parent process $($client$)$

close$($fd$[0])$; $//$ Close read end in parent

client$($fd$[1],$ fd$[0])$;

wait$($NULL$)$; $//$ Wait for child process to finish

$\}$

return $0$;

$\}$

#include

#include

#include

#include

#include

#include

#include

void client$($int readfd, int writefd$)\{$

char buf$[$MAX$\_$BUFF$]$;

size$\_$t len;

$/*************************************************************$

write client code to be used by the parent process

$*************************************************************/$

$//$ implement client functionality

while $(1)\{$

$//$ Read expression from stdin

printf$("$Enter expression: $")$;

fgets$($buf$,$ MAX$\_$BUFF, stdin$)$;

$//$ Check for termination condition

if $($strcmp$($buf$,$ "END

$")==0)\{$

$//$ Send termination signal to server

write$($writefd$,$ "END", $4)$;

break;

$\}$

$//$ Send expression to server

write$($writefd$,$ buf, strlen$($buf$)+1)$;

$//$ Read result from server

read$($readfd$,$ buf, MAX$\_$BUFF$)$;

printf$("$RESULT: $\%$s$",$ buf$)$;

$\}$

$//$ Close file descriptors

close$($readfd$)$;

close$($writefd$)$;

$\}$

#include

#include

#include

#include

#include

#include

#include

void server$($int readfd, int writefd$)\{$

$/*************************************************************$

write server code to be used by the child process

$*************************************************************/$

char buf$[$MAX$\_$BUFF$]$;

size$\_$t len;

$//$ Implement server functionlity here

while $(1)\{$

$//$ Read expression from client

read$($readfd$,$ buf, MAX$\_$BUFF$)$;

$//$ Check for termination signal

if $($strcmp$($buf$,$ "END"$)==0)\{$

break;

$\}$

$//$ Evaluate expression

double result $=$ calculate$($buf$)$;

$//$ Convert result to string and send to client

sprintf$($buf$,"\%$f

$",$ result$)$;

write$($writefd$,$ buf, strlen$($buf$)+1)$;

$\}$

$//$ Close file descriptors

close$($readfd$)$;

close$($writefd$)$;

$\}$

#include

#include

#include

#include

#include

#include

#include

double calculate$($char $*$buf$)\{$

$/*************************************************************$

Implement the expression evaluation functionality which

will be invoked by the server whenever required.

$*************************************************************/$

double operands$[20]$;

char op$[20]$;

int oprnInd $=0$;

double result $=0\mathrm{.}0$;

$//$ implement expression evaluation functionality here

char $*$token $=$ strtok$($buf$,"")$;

while $($token $!=$ NULL$)\{$

if $($sscanf$($token$,"\%$lf$",$ &operands$[$oprnInd$])==1)\{$

oprnInd$++$;

$\}$ else $\{$

strcpy$($op$,$ token$)$; $//$ Corrected variable name from 'ops' to $\text{'}$op$\text{'}$

$\}$

token $=$ strtok$($NULL$,"")$;

$\}$

$//$ Perform calculation based on BODMAS rule

result $=$ operands$[0]$;

int i;

for $($i $=0$; i $<$ oprnInd; $++$i$)\{$

if $($strcmp$($op $+$ i$,"+")==0)$

result $+=$ operands$[$i $+1]$;

else if $($strcmp$($op $+$ i$,"-")==0)$

result $-=$ operands$[$i $+1]$;

else if $($strcmp$($op $+$ i$,"*")==0)$

result $*=$ operands$[$i $+1]$;

else if $($strcmp$($op $+$ i$,"/")==0)$

result $/=$ operands$[$i $+1]$;

else if $($strcmp$($op $+$ i$,"\%")==0)$

result $=($int$)$result $\%($int$)$operands$[$i $+1]$;

$\}$

return result;

$\}$