client

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <semaphore.h>
#include <signal.h>

#define PERMISSION (0600)
#define SHM_NAME "memory_Shared"
#define SEM_SERVER "/serverSem12"
#define SEM_CLIENT "/clientSem12"
#define SEM_SERVER_USAGE "/server_usageSem12"
#define INPUT_BUFFER_SIZE (150)

#define LOGIN_CODE (100)
#define LOGIN_VALID (101)
#define LOGIN_INVALID (102)
#define BALANCE_CODE (103)
#define TAKEOUT_CODE (104)
#define TAKEOUT_FAILED (105)
#define TRANSFER_CODE (106)
#define TRANSFER_FAILED (107)
#define PAYIN_CODE (108)
#define LOGOUT_CODE (109)

/* @brief server semaphore ==*/
sem_t *sem_server;
/* @brief client semaphore ==*/
sem_t *sem_client;
/* @brief server usage semaphore ==*/
sem_t *sem_server_usage;
/* @brief Database input==*/
FILE *database_fd;
/* @brief flag for the while loop ==*/
int want_to_quit;
/* @brief if a write to stdout is needed ==*/
int write_out;
/* @brief program termination flag ==*/
int prog_term;
/* @brief name of the input flag==*/
char *input_filename;
/* @brief name of the output file ==*/
char *output_filename;
/* @brief pointer to a db entry ==*/
struct db_entry *database;
/*  @brief  poointer to first db entry==*/
struct db_entry *first_entry;//?????????
/**
*@brief prints the usage
*/
void usage(void);
/*
*@brief frees the resourcesvoid free_resources(void){

	sem_close(sem_server);
	sem_close(sem_client);
	sem_close(sem_server_usage);

	sem_unlink(SEM_SERVER);
	sem_unlink(SEM_CLIENT);
	sem_unlink(SEM_SERVER_USAGE);

	//free(input_filename);
	//fclose(database_fd);
	//free(database);
	//free(first_entry);
}

*/
void free_resources();
void bail_out(char *text);
void bail_out(char *text){
      printf(text);
      free_resources();
      exit(EXIT_FAILURE);
}

struct myshm{
	char* username;
	char* password;
	char* message;
	int code;
};

int main(int argc, char **argv){
      int c =0;

      int read_arg = 0;
      int login_arg=0;
      char *username;
      char *password;
      if(argc!=4){
	usage();
      }

      while((c = getopt(argc, argv, "rl") != -1)){
		switch (c){
		  case 'r':
		    if(read_arg>0){

		      usage();

		    }
		      read_arg+=1;
		      break;

		      case 'l':
		    if(login_arg>0){
		            printf("%d \n", argc);

		      usage();

		    }
		      login_arg+=1;
		      break;
			case '?':
				usage();
				break;

			default:

               // usage();
                break;
		}
	}
	username = argv[2];
	password = argv[3];

	struct myshm *shared;

	shared = malloc(sizeof(struct myshm));

	int shmfd = shm_open(SHM_NAME, O_RDWR | O_CREAT, PERMISSION);

	if(shmfd < 0){
		bail_out("Unable to open shared memory.");
	}

	shared = mmap(NULL, sizeof *shared, PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0);

	if(shared == MAP_FAILED){
		bail_out("Unable to open shared memory.");
	}

	if(close(shmfd) < 0){
		bail_out("Unable to close file descriptor.");
	}

	sem_server = sem_open(SEM_SERVER, 0);
	sem_client = sem_open(SEM_CLIENT, 0);
	sem_server_usage = sem_open(SEM_SERVER_USAGE, 0);

	if(sem_server == SEM_FAILED){
	  		printf("%d\n", errno);

		bail_out("Unable to open server semaphore.");
	}

	if(sem_client == SEM_FAILED){
		bail_out("Unable to open client semaphore.");
	}
	if(sem_server_usage == SEM_FAILED){
		bail_out("Unable to open client semaphore.");
	}
	sem_wait(sem_server_usage); // wait for my turn

	sem_wait(sem_client); // client server mutex


	sem_post(sem_server);
	sem_wait(sem_client);

	shared->username = username;
	shared->password = password;
	//myshm->message = message;


}
void usage(void){
  printf("USAGE: auth-client { -r | -l } username password\n");
  exit(EXIT_FAILURE);
}

void free_resources(void){

	sem_close(sem_server);
	sem_close(sem_client);
	sem_close(sem_server_usage);

	sem_unlink(SEM_SERVER);
	sem_unlink(SEM_CLIENT);
	sem_unlink(SEM_SERVER_USAGE);

	//free(input_filename);
	//fclose(database_fd);
	//free(database);
	//free(first_entry);
}