X&0 Game IPC FIFO windows [closed] - c++

Question

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 8 years ago.
Improve this question
i want to make a x&0 game with ipc in c.i declare 3 char arrays,read the witch line to choose and the on what position to put the x or 0.when i try to send line number through the fifo from the client the server recieves a different number.for example i send 1 and the server gets 3144200....this is the code it's not all just one read and write.
this is the server:
#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <iostream>
int main() {
HANDLE f1, f2;
DWORD x;
char l1[3]="\0";
char l2[3]="\0";
char l3[3]="\0";
char X='x';
char* a="";
char* lineChar="";
int n=1,lineInt=0,coor=0;
printf("I am the server \n");
printf("You will play with x\n");
// creating pipes
f1=CreateNamedPipe(TEXT("\\\\.\\PIPE\\fifo1"), PIPE_ACCESS_INBOUND,PIPE_TYPE_BYTE|PIPE_WAIT, 3, 0, 0, 0, NULL);
f2=CreateNamedPipe(TEXT("\\\\.\\PIPE\\fifo2"), PIPE_ACCESS_OUTBOUND,PIPE_TYPE_BYTE|PIPE_WAIT, 3, 0, 0, 0, NULL);
ConnectNamedPipe(f1, NULL);
ConnectNamedPipe(f2, NULL);
while(n<=9){
for(int i=0;i<=2;i++){
printf("[%s]",&l1[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l2[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l3[i]);
}
printf("\n");
printf("You will begin,select the line from 1 to 3 : \n");
scanf_s("%d",&lineInt);
x=0;
lineChar=reinterpret_cast<char*>(lineInt);
printf("%s",lineChar);
//strcpy_s(a,sizeof(lineChar),lineChar);
if (WriteFile(f2,lineChar,sizeof(lineChar)+1, &x, NULL)==0) {
printf("writing error..%d\n", x);
}
n++;
}
DisconnectNamedPipe(f1);
DisconnectNamedPipe(f2);
CloseHandle(f1);
CloseHandle(f2);
}
this is the client :
#include <windows.h>
#include <stdio.h>
#include <string.h>
#include<stdlib.h>
int main(){
HANDLE f1, f2;
DWORD x;
char l1[3]="\0";
char l2[3]="\0";
char l3[3]="\0";
char o='0';
char* lineChar="";
int n=1,lineInt=0,coor=0;
printf("I am the client \n");
printf("You will play with 0\n");
// connect to pipes created by server
f1=CreateFile(TEXT("\\\\.\\PIPE\\fifo1"), GENERIC_WRITE, FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
f2=CreateFile(TEXT("\\\\.\\PIPE\\fifo2"), GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
while(n<=9){
for(int i=0;i<=2;i++){
printf("[%s]",&l1[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l2[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l3[i]);
}
printf("\n");
x=0;
Sleep(3000);
if (ReadFile(f2, lineChar, sizeof(lineChar), &x, NULL)==0) {
printf("reading error..%d\n", x);
}
printf("%s",lineChar);
//lineInt=atoi(lineChar);
//printf("\n%d\n",lineInt);
n++;
}
CloseHandle(f1);
CloseHandle(f2);
}

Answer 1

You have lots or problems with strings and pointers in your code.
To start with you print out the single characters in the arrays as strings, which will cause weird output.
Secondly, and one of the causes of your problem, when you call WriteFile you use sizeof(lineChar) which returns the size of the pointer, not the length of the string. Use strlen instead.
The second cause of your problem is that you cast an integer to a string. This will not work! What the statement
lineChar=reinterpret_cast<char*>(lineInt);
does is that it makes a pointer out of the value in lineInt. This is not a valid pointer! There are a couple of ways to do it:
Use the new std::to_string to convert a value to a std::string.
Since you mix C and C++ anyway, you could use sprintf too.
Your programs have a lot of what is called undefined behavior, and you should be happy that neither of them crashes outright.

Answer 2

#include<stdio.h>
#include<string.h>
int main(){
char l1[3]="\0";
char l2[3]="\0";
char l3[3]="\0";
char x='x';
char o='0';
int n=1,lineInt=0,coor=0,next=1;
printf("X & 0 Game : \n");
while(n<=3){
for(int i=0;i<=2;i++){
printf("[%s]",&l1[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l2[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l3[i]);
}
printf("\n");
switch (next){
case 1 :{
printf("To select the line enter 1,2 or 3 : \n");
scanf_s("%d",&lineInt);
switch (lineInt){
case 1 :{
printf("Enter the coordinates : \n");
scanf_s("%d",&coor);
//printf("%c",x);
//printf("%d",coor);
//strcpy_s(&l1[coor],1,"x");
l1[coor]=x;
break;
}
case 2 :{
printf("Enter the coordinates : \n");
scanf_s("%d",&coor);
l2[coor]=x;
break;
}
case 3 :{
printf("Enter the coordinates : \n");
scanf_s("%d",&coor);
l2[coor]=x;
break;
}
next=2;
}
for(int i=0;i<=2;i++){
printf("[%s]",&l1[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l2[i]);
}
printf("\n");
for(int i=0;i<=2;i++){
printf("[%s]",&l3[i]);
}
printf("\n");
case 2 :{
printf("To select the line enter 1,2 or 3 : \n");
scanf_s("%d",&lineInt);
switch (lineInt){
case 1 :{
printf("Enter the coordinates : \n");
scanf_s("%d",&coor);
l1[coor]=o;
break;
}
case 2 :{
printf("Enter the coordinates : \n");
scanf_s("%d",&coor);
l2[coor]=o;
break;
}
case 3 :{
printf("Enter the coordinates : \n");
scanf_s("%d",&coor);
l2[coor]=o;
break;
}
next=2;
}
}
}
n++;
}
}
}