Program1 Accepts Input From User, Then Program2 Prints Out To Screen - c++

Question

I have a server and a client program. Server program prompts user to enter text, then sends user input to client. The client prints out user text to screen. So far server program prompts user to enter text and when I run client program it displays nothing. Any recommendations to make programs work. Below are both programs.
// server.cpp
// g++ -o server server.cpp -lpthread -lrt
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <semaphore.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string>
#include <ctype.h>
#include <iostream>
using namespace std;
string UserInput(string);
#define SHMSZ 27
char SEM_NAME[]= "vik";
int main(void)
{
char ch;
int shmid;
key_t key;
char *shm,*s;
sem_t *mutex;
string input;
//name the shared memory segment
key = 1000;
//create & initialize semaphore
mutex = sem_open(SEM_NAME,O_CREAT,0644,1);
if(mutex == SEM_FAILED)
{
perror("unable to create semaphore");
sem_unlink(SEM_NAME);
exit(-1);
}
//create the shared memory segment with this key
shmid = shmget(key,SHMSZ,IPC_CREAT|0666);
if(shmid<0)
{
perror("failure in shmget");
exit(-1);
}
//attach this segment to virtual memory
shm = (char*) shmat(shmid,NULL,0);
//start writing into memory
s = shm;
// Enter user input
//cout << "Enter your input: ";
//cin >> input;
// Display user input
//cout << "You entered: "<< input << endl;
//return 0;
while(1)
{
cout << "Enter your input: ";
cin >> input;
sem_wait(mutex);
//*s++ = count;
sem_post(mutex);
//return 0;
}
//the below loop could be replaced by binary semaphore
while(*shm != '*')
{
sleep(1);
}
sem_close(mutex);
sem_unlink(SEM_NAME);
shmctl(shmid, IPC_RMID, 0);
_exit(0);
}
-
// client.cpp
// g++ -o client client.cpp -lpthread -lrt
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>
#include <semaphore.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <iostream>
#include <string>
#include <ctype.h>
using namespace std;
string UserInput(string);
#define SHMSZ 27
char SEM_NAME[]= "vik";
int main(void)
{
char ch;
int shmid;
key_t key;
char *shm,*s;
sem_t *mutex;
string input;
//name the shared memory segment
key = 1000;
//create & initialize existing semaphore
mutex = sem_open(SEM_NAME,0,0644,0);
if(mutex == SEM_FAILED)
{
perror("reader:unable to execute semaphore");
sem_close(mutex);
exit(-1);
}
//create the shared memory segment with this key
shmid = shmget(key,SHMSZ,0666);
if(shmid<0)
{
perror("reader:failure in shmget");
exit(-1);
}
//attach this segment to virtual memory
shm = (char*) shmat(shmid,NULL,0);
//start reading
s = shm;
while(1)
{
cout << "You entered: " << input << endl;
//cin >> input;
sem_wait(mutex);
putchar(*s);
sem_post(mutex);
return 0;
}
//once done signal exiting of reader:This can be replaced by another semaphore
*shm = '*';
sem_close(mutex);
shmctl(shmid, IPC_RMID, 0);
exit(0);
}