TCP client C

client.c

#include <stdio.h> 
#include <stdlib.h> 
#include <errno.h> 
#include <string.h>
#include <sys/types.h>

#ifdef _WIN32
#include <winsock2.h>
#include "windows.h"
#endif
#ifdef __linux__
#include <pthread.h>
#include <sys/socket.h> 
#endif

#pragma warning(disable:4996) 
#pragma comment(lib, "Ws2_32.lib")
#define bzero(b,len) (memset((b), '\0', (len)), (void) 0)

char					buf[8192];						// our read buffer from socket stream
char					storage;						// information to display
SOCKET					SendingSocket;
SOCKADDR_IN				ServerAddr, ThisSenderInfo;
struct sockaddr_in		myaddr;
WSADATA					wsaData;
int						RetCode;

void TCP_connect(char ip[255], int port) {
	// start winsock
	WSAStartup(0x101, &wsaData);
	//printf("Client: Winsock DLL status is %s.\n", wsaData.szSystemStatus);

	// create socket
	SendingSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (SendingSocket == INVALID_SOCKET)
	{
		printf("Client: socket() failed! Error code: %ld\n", WSAGetLastError());
		WSACleanup();
	}
	//else
	//	printf("Client: socket() is OK!\n");

	ServerAddr.sin_family = AF_INET;
	ServerAddr.sin_port = htons(port);
	ServerAddr.sin_addr.s_addr = inet_addr(ip);

	// create connection
	RetCode = connect(SendingSocket, (SOCKADDR *)&ServerAddr, sizeof(ServerAddr));
	if (RetCode != 0)
	{
		printf("Client: connect() failed! Error code: %ld\n", WSAGetLastError());
		closesocket(SendingSocket);
		WSACleanup();
	}
	else
	{
		printf("Client connected. Ready for send/receive data.\n");
	}
}

void sendPkt(char *sndBuf) {
	int res = send(SendingSocket, sndBuf, (int)strlen(sndBuf) + 1, 0);
	//printf("Bytes Sent: %d\n", res);
}

void readWin32Stream() {
	while (1) {
		int result;
		do {
			result = recv(SendingSocket, buf, 512, 0);
			if (result > 0) {
				//printf("[DEBUG] raw data received: %s\n", buf);
				int bal = result;
				int ptr = strlen(buf); // count chars before first occurrence of null char
				int prevNull = 0;
				if (ptr > 0) {
					//printf("[DEBUG] null found! bal=%d ptr=%d result=%d\n", bal, ptr, result);
					int beforeNull = ptr;
					while (bal >= beforeNull)
					{
						//printf("[DEBUG] bal=%d beforeNull=%d prevNull=%d\n", bal, beforeNull, prevNull);
						char* storage = malloc(8192);
						strncpy(storage, buf + prevNull, beforeNull + 1); //create our temporary storage variable for a section of our socket streaam
						int tmpStore = beforeNull + 1;

						//printf("[DEBUG] storage size=%d, storage=%s\n",sizeof(storage), storage);
						// find another null char
						int scndPtr = strlen(buf + beforeNull + 1);
						if (scndPtr > 0) {
							//printf("[DEBUG] Found another null char in the buffer\n");
							beforeNull = scndPtr; //another null char in stream?
							//printf("[DEBUG] New beforeNull = %d\n", scndPtr);
						}

						bal = (bal - tmpStore); //count remaining bytes
						prevNull = tmpStore;

						printf("received: %s\n", storage);
						memset(storage, 0, sizeof storage); //empty storage

						if (bal > 0)
						{
							//printf("[DEBUG] balance remaining: %d\n", bal);
							strncpy(storage, buf + beforeNull + bal, 0); //store remaining bytes
						}

						if (beforeNull <= 0) {
							memset(buf, 0, sizeof buf); //clear buffer
							break;
						}
					}
				}
			}
		} while (result > 0);
	}
}

void readLinuxStream() {
	while (1) {
		//code goes here
	}
}

#ifdef _WIN32
DWORD WINAPI readThread(LPVOID lpParameter) {
	//printf("listening thread is running\n");
	readWin32Stream();
	return 0;
}
#endif
#ifdef __linux__
void *readThread(void *sntCmd)
{
	readLinuxStream();
}
#endif

int main(void)
{
	// make connection
	TCP_connect("127.0.0.1", 13000);

	// send test
	sendPkt("lm|");

	// read buffer test
	readStream();

	/*#ifdef _WIN32
		DWORD  threadID;
		HANDLE thread = CreateThread(NULL, 0, readThread, NULL, 0, &threadID);
		CloseHandle(thread);
	#endif
	#ifdef __linux__
		pthread_t tid;
		pthread_create(&tid, NULL, &readThread, &cmd);
		pthread_detach(&tid);
	#endif*/
}