diff --git a/CMakeLists.txt b/CMakeLists.txt
index c855f88..5bb56d9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,5 +3,4 @@ project(qotd C)
 
 set(CMAKE_C_STANDARD 99)
 
-add_executable(server server/main.c server/quote.c server/quote.h server/server.c server/server.h)
-add_executable(client client/main.c client/client.c client/client.h)
\ No newline at end of file
+add_executable(qotd main.c quote.c quote.h server.c server.h config.h)
\ No newline at end of file
diff --git a/README.md b/README.md
index 8be92bc..a59a300 100644
--- a/README.md
+++ b/README.md
@@ -7,14 +7,14 @@ A [RFC 865](https://datatracker.ietf.org/doc/html/rfc865) compliant Quote of the
 * tcp client
 * udp server
 * udp client
+* IPv6 compat
 
 ## Todo
-* IPv6
-* t h r e a d s to accept several clients and/or run both udp and tcp servers from same executable
+* t h r e a d s to accept several clients and/or run both udp and tcp servers from same executable and instance
 * macros (#define XXX yyy) for currently hard-coded values
+* switches (-x) and options (--xxxx) ?
 * logging ?
 * conf files ?
-* switches (-x) and options (--xxxx) ?
 
 ## Installation
 
@@ -27,7 +27,7 @@ make
 ```
 
 ## Use
-A "quotes.txt" file in the same folder as the server containing one quote per line. Quotes are separated by the line feed ('\n') caracter.
+A "quotes.txt" file in the same folder as the server containing one quote per line. Quotes are separated by the line feed `\n` character.
 
 Server as root (because port 17)
 ```sh
diff --git a/client/client.c b/client/client.c
deleted file mode 100644
index 0eabfe6..0000000
--- a/client/client.c
+++ /dev/null
@@ -1,90 +0,0 @@
-//
-// Created by k0rb4k on 11/10/2021.
-//
-
-#include "client.h"
-
-extern int errno;
-
-int tcp() {
-    struct sockaddr_in server;
-    int sock;
-
-    int proto = IPPROTO_IP;
-    enum __socket_type socketType = SOCK_STREAM;
-
-    server.sin_family = AF_INET;
-    server.sin_addr.s_addr = inet_addr("127.0.0.1");
-    server.sin_port = htons(17);
-
-    sock = socket(server.sin_family, socketType, proto);
-    if (sock == -1) {
-        puts("socket not created");
-        return 1;
-    }
-    puts("socket created");
-
-    if (connect(sock, (const struct sockaddr *) &server, sizeof(server)) < 0) {
-        puts("connection failed");
-        return 2;
-    }
-    puts("connected to server");
-
-    char *payload = "I dream of sushi";
-    if (send(sock, payload, strlen(payload), 0) < 0) {
-        puts("error while sending payload");
-        return 3;
-    }
-    puts("payload sent");
-
-    char response[2048];
-    if (recv(sock, response, 2048, 0) < 0) {
-        puts("receive failed");
-        return 4;
-    }
-    printf("server response : %s\n", response);
-
-    close(sock);
-
-    return 0;
-}
-
-int udp() {
-    struct sockaddr_in server;
-    int sock;
-    unsigned long addressLength = sizeof server;
-
-    int proto = IPPROTO_UDP;
-    enum __socket_type socketType = SOCK_DGRAM;
-
-    server.sin_family = AF_INET;
-    server.sin_addr.s_addr = inet_addr("127.0.0.1");
-    server.sin_port = htons(17);
-
-    sock = socket(server.sin_family, socketType, proto);
-    if (sock == -1) {
-        puts("socket not created");
-        return 1;
-    }
-    puts("socket created");
-
-    char *payload = "I dream of sushi";
-    if (sendto(sock, payload, strlen(payload), 0, (const struct sockaddr *) &server, addressLength) < 0) {
-        puts("error while sending payload");
-        perror("sendto");
-        return 3;
-    }
-    puts("payload sent");
-
-    char response[2048];
-    if (recvfrom(sock, response, 2048, 0, (struct sockaddr *) &server, (socklen_t *) &addressLength) < 0) {
-        puts("receive failed");
-        perror("recvfrom");
-        return 4;
-    }
-    printf("server response : %s\n", response);
-
-    close(sock);
-
-    return 0;
-}
\ No newline at end of file
diff --git a/client/client.h b/client/client.h
deleted file mode 100644
index 17bb0cd..0000000
--- a/client/client.h
+++ /dev/null
@@ -1,20 +0,0 @@
-//
-// Created by k0rb4k on 11/10/2021.
-//
-
-#ifndef QOTD_CLIENT_H
-#define QOTD_CLIENT_H
-
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <string.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <errno.h>
-
-int tcp();
-
-int udp();
-
-#endif //QOTD_CLIENT_H
diff --git a/client/main.c b/client/main.c
deleted file mode 100644
index 0b9604f..0000000
--- a/client/main.c
+++ /dev/null
@@ -1,12 +0,0 @@
-//
-// Created by k0rb4k on 22/04/2021.
-//
-
-#include "client.h"
-
-int main(int argc, char *argv[]) {
-    // TODO: arg options for tcp or udp
-    tcp();
-
-    return 0;
-}
\ No newline at end of file
diff --git a/config.h b/config.h
new file mode 100644
index 0000000..9083199
--- /dev/null
+++ b/config.h
@@ -0,0 +1,12 @@
+//
+// Created by k0rb4k on 26/11/2021.
+//
+
+#ifndef QOTD_CONFIG_H
+#define QOTD_CONFIG_H
+
+#define QUOTES_FILE "./quotes.txt"
+#define MESSAGE_STRING_LENGTH 2048
+#define DEFAULT_LISTEN_PORT 17 // should be 17 to be RFC compliant
+
+#endif //QOTD_CONFIG_H
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..4fcf290
--- /dev/null
+++ b/main.c
@@ -0,0 +1,8 @@
+#include "server.h"
+
+int main(int argc, char *argv[]) {
+    // TODO: shell args
+    server(1, 1);
+
+    return 0;
+}
diff --git a/server/quote.c b/quote.c
similarity index 98%
rename from server/quote.c
rename to quote.c
index 5c746b4..9645269 100644
--- a/server/quote.c
+++ b/quote.c
@@ -3,6 +3,7 @@
 //
 
 #include "quote.h"
+#include "config.h"
 
 void getRandomQuote(char quote[2048]) {
     int lineCount;
diff --git a/server/quote.h b/quote.h
similarity index 90%
rename from server/quote.h
rename to quote.h
index fba8603..b7deeda 100644
--- a/server/quote.h
+++ b/quote.h
@@ -11,8 +11,6 @@
 #include <bits/types/FILE.h>
 #include <bits/types/struct_FILE.h>
 
-#define QUOTES_FILE "./quotes.txt"
-
 void getRandomQuote(char quote[2048]);
 
 void getQuote(long line, char quote[2048]);
diff --git a/server.c b/server.c
new file mode 100644
index 0000000..9b54806
--- /dev/null
+++ b/server.c
@@ -0,0 +1,127 @@
+//
+// Created by k0rb4k on 30/03/2021.
+//
+
+#include "server.h"
+#include "config.h"
+
+//TODO: object-like C
+
+extern int errno;
+
+_Noreturn void udpListen(int serverSocket, struct sockaddr * clientAddress, unsigned long addressLength) {
+    char clientMessage[MESSAGE_STRING_LENGTH], quote[MESSAGE_STRING_LENGTH];
+
+    for (;;) {
+        // receive data
+
+        if (recvfrom(serverSocket, clientMessage, MESSAGE_STRING_LENGTH, 0, clientAddress, (socklen_t *) &addressLength) >= 0) {
+            printf("received: %s\n", clientMessage);
+
+            // send data
+            getRandomQuote(quote);
+            printf("sending: %s\n", quote);
+            if (sendto(serverSocket, quote, strlen(quote), 0, clientAddress, addressLength) == -1) {
+                perror("udp: sendto");
+            }
+        } else {
+            perror("udp: recvfrom");
+        }
+    }
+}
+
+void tcpListen(int serverSocket, struct sockaddr * clientAddress, unsigned long addressLength) {
+    int clientSocket;
+    char quote[MESSAGE_STRING_LENGTH] = "", clientMessage[MESSAGE_STRING_LENGTH] = "";
+
+    listen(serverSocket, 5);
+    puts("server listening");
+
+    // accept connections
+    //TODO: t h r e a d s
+    while ((clientSocket = accept(serverSocket, clientAddress, (socklen_t *) &addressLength)) >= 0) {
+        puts("client connected");
+
+        // receive data
+        if (recv(clientSocket, clientMessage, MESSAGE_STRING_LENGTH, 0) >= 0) {
+            printf("client says: %s\n", clientMessage);
+
+            // send data
+            getRandomQuote(quote);
+            printf("responding: \"%s\"\n", quote);
+            if (send(clientSocket, quote, strlen(quote), 0) == -1) {
+                perror("tcp: send");
+            }
+        } else {
+            perror("tcp: recv");
+        }
+
+        close(clientSocket);
+
+        puts("closed connection");
+    }
+
+    if (clientSocket < 0) {
+        puts("client connection failed");
+        exit(3);
+    }
+}
+
+void server(int tcp, int ipv6) {
+    int serverSocket, socketType, socketProtocol;
+    unsigned long serverAddressLength, clientAddressLength;
+    struct sockaddr *serverAddress, *clientAddress;
+    struct sockaddr_in serverAddress4, clientAddress4;
+    struct sockaddr_in6 serverAddress6, clientAddress6;
+
+    if (ipv6) {
+        serverAddress6.sin6_family = AF_INET6;
+        serverAddress6.sin6_addr = in6addr_any;
+        serverAddress6.sin6_port = htons(DEFAULT_LISTEN_PORT);
+        serverAddress = (struct sockaddr *) &serverAddress6;
+        serverAddressLength = sizeof serverAddress6;
+
+        clientAddress6.sin6_family = AF_INET6;
+        clientAddress = (struct sockaddr *) &clientAddress6;
+        clientAddressLength = sizeof clientAddress6;
+    } else {
+        serverAddress4.sin_family = AF_INET;
+        serverAddress4.sin_addr.s_addr = INADDR_ANY;
+        serverAddress4.sin_port = htons(DEFAULT_LISTEN_PORT);
+        serverAddress = (struct sockaddr *) &serverAddress4;
+        serverAddressLength = sizeof serverAddress4;
+
+        clientAddress4.sin_family = AF_INET;
+        clientAddress = (struct sockaddr *) &clientAddress4;
+        clientAddressLength = sizeof clientAddress4;
+    }
+
+    if (tcp) {
+        socketType = SOCK_STREAM;
+        socketProtocol = IPPROTO_TCP;
+    } else {
+        socketType = SOCK_DGRAM;
+        socketProtocol = IPPROTO_UDP;
+    }
+
+    // create sock
+    serverSocket = socket(serverAddress->sa_family, socketType, socketProtocol);
+    if (serverSocket == -1) {
+        puts("socket not created");
+        exit(1);
+    }
+    puts("socket created");
+
+    // bind sock
+    if (bind(serverSocket, serverAddress, serverAddressLength) < 0) {
+        puts("bind failed");
+        exit(2);
+    }
+
+    // TODO: threads to run both at the same time
+    if (tcp) {
+        tcpListen(serverSocket, clientAddress, clientAddressLength);
+    } else {
+        udpListen(serverSocket, clientAddress, clientAddressLength);
+    }
+}
diff --git a/server/server.h b/server.h
similarity index 54%
rename from server/server.h
rename to server.h
index d42e0c6..5f4a381 100644
--- a/server/server.h
+++ b/server.h
@@ -6,7 +6,7 @@
 #define QOTD_SERVER_H
 
 #include <sys/socket.h>
-//#include <sys/types.h>
+#include <sys/types.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <stdlib.h>
@@ -17,10 +17,10 @@
 
 #include "quote.h"
 
-#define MESSAGE_STRING_LENGTH 2048
+void server(int tcp, int ipv6);
 
-void tcpServer();
+void tcpListen(int serverSocket, struct sockaddr *clientAddress, unsigned long addressLength);
 
-_Noreturn void udpServer();
+_Noreturn void udpListen(int serverSocket, struct sockaddr *clientAddress, unsigned long addressLength);
 
 #endif //QOTD_SERVER_H
diff --git a/server/main.c b/server/main.c
deleted file mode 100644
index 846bbf1..0000000
--- a/server/main.c
+++ /dev/null
@@ -1,10 +0,0 @@
-#include "server.h"
-
-int main(int argc, char *argv[]) {
-//    char quote[1024];
-//    getRandomQuote(quote);
-//    printf("%s\n", quote);
-    tcpServer();
-
-    return 0;
-}
diff --git a/server/server.c b/server/server.c
deleted file mode 100644
index b08e979..0000000
--- a/server/server.c
+++ /dev/null
@@ -1,129 +0,0 @@
-//
-// Created by k0rb4k on 30/03/2021.
-//
-
-#include "server.h"
-
-//TODO: refactor
-//TODO: object-like C
-
-extern int errno;
-
-unsigned long addressLength = sizeof(struct sockaddr_in);
-
-
-void tcpServer() {
-    int serverSocket, clientSocket;
-    long recvLen;
-//    unsigned long addressLength = sizeof(struct sockaddr_in);
-    struct sockaddr_in serverAddress, clientAddress;
-    char quote[MESSAGE_STRING_LENGTH] = "";
-    char clientMessage[MESSAGE_STRING_LENGTH] = "";
-
-    /*initialize socket info*/
-    serverAddress.sin_family = AF_INET;
-    serverAddress.sin_addr.s_addr = INADDR_ANY;
-    serverAddress.sin_port = htons(17);
-
-    /*create socket*/
-    serverSocket = socket(serverAddress.sin_family, SOCK_STREAM, IPPROTO_IP);
-    if (serverSocket == -1) {
-        puts("socket not created");
-        exit(1);
-    }
-    puts("socket created");
-
-    /*bind socket to address:port*/
-    if (bind(serverSocket, (const struct sockaddr *) &serverAddress, addressLength) < 0) {
-        puts("bind failed");
-        exit(2);
-    }
-    puts("address bound");
-
-    /*start listening*/
-    listen(serverSocket, 5);
-    puts("server listening");
-
-    /*accept connections*/
-    //TODO: t h r e a d s
-    while ((clientSocket = accept(serverSocket, (struct sockaddr *) &clientAddress, (socklen_t *) &addressLength)) >=
-           0) {
-        puts("client connected");
-
-        /*receive data*/
-        while ((recvLen = recv(clientSocket, clientMessage, MESSAGE_STRING_LENGTH, 0))) {
-            if (recvLen < 0) {
-                puts("receive failed");
-            } else {
-                printf("client says: %s\n", clientMessage);
-
-                /*send data*/
-                getRandomQuote(quote);
-                printf("responding: \"%s\"\n", quote);
-                send(clientSocket, quote, strlen(quote), 0);
-            }
-        }
-
-        puts("client disconnected");
-    }
-
-    if (clientSocket < 0) {
-        puts("client connection failed");
-        exit(3);
-    }
-}
-
-_Noreturn void udpServer() {
-    int sock;
-//    unsigned long addressLength = sizeof(struct sockaddr_in);
-    struct sockaddr_in serverAddress, clientAddress;
-    char quote[MESSAGE_STRING_LENGTH] = "";
-    char clientMessage[MESSAGE_STRING_LENGTH] = "";
-
-    /*initialize sock info*/
-    memset(&serverAddress, 0, addressLength);
-    memset(&clientAddress, 0, addressLength);
-
-    serverAddress.sin_family = AF_INET;
-    serverAddress.sin_addr.s_addr = INADDR_ANY;
-    serverAddress.sin_port = htons(17);
-
-    /*create sock*/
-    sock = socket(serverAddress.sin_family, SOCK_DGRAM, IPPROTO_UDP);
-    if (sock == -1) {
-        puts("sock not created");
-        exit(1);
-    }
-    puts("sock created");
-
-    /*bind sock to address:port*/
-    if (bind(sock, (const struct sockaddr *) &serverAddress, sizeof serverAddress) < 0) {
-        puts("bind failed");
-        exit(2);
-    }
-    puts("address bound");
-
-    /*accept connections*/
-    //TODO: t h r e a d s ?
-    while (1) {
-        /*receive data*/
-        int recvLen = recvfrom(sock, clientMessage, MESSAGE_STRING_LENGTH, 0,
-                               (struct sockaddr *) &clientAddress, (socklen_t *) &addressLength);
-
-        uint16_t port = ntohs(clientAddress.sin_port);
-        char *ipv4 = inet_ntoa(clientAddress.sin_addr);
-
-        printf("recvLen = %d from = %s:%d\nmsg = `%s`\n", recvLen, ipv4, port, clientMessage);
-
-        perror("recvfrom");
-        if (recvLen >= 0) {
-            printf("client says: %s\n", clientMessage);
-
-            /*send data*/
-            getRandomQuote(quote);
-            printf("responding: `%s`\n", quote);
-            sendto(sock, strcat(quote, "\n"), sizeof quote, 0, (struct sockaddr *) &clientAddress, addressLength);
-            perror("sendto");
-        }
-    }
-}