diff --git a/simpleChatting/Makefile b/simpleChatting/Makefile
index 5f33c51278b7ad5b47fd99e660ba43538e4ee449..e0c7d7b4a730f78cd46154a0789dfe3a1d46ce31 100644
--- a/simpleChatting/Makefile
+++ b/simpleChatting/Makefile
@@ -3,22 +3,22 @@ all : client server control
 CC = gcc
 
 client : client.o
-        $(CC) -o client client.o
+	$(CC) -o client client.o
 
 server : server.o
-        $(CC) -o server server.o
+	$(CC) -o server server.o
 
 control : control.o
-        $(CC) -o control control.o
+	$(CC) -o control control.o
 
 client.o : client.c comn.h
-        $(CC) -c client.c
+	$(CC) -c client.c
 
 server.o : server.c comn.h
-        $(CC) -c server.c
+	$(CC) -c server.c
 
 control.o : control.c comn.h
-        $(CC) -c control.c
+	$(CC) -c control.c
 
 clean :
-        rm client.o server.o control.o client server control
\ No newline at end of file
+	rm client.o server.o control.o
diff --git a/simpleChatting/client.c b/simpleChatting/client.c
new file mode 100755
index 0000000000000000000000000000000000000000..576b81722a82258e041cedddafb208849066ff67
--- /dev/null
+++ b/simpleChatting/client.c
@@ -0,0 +1,212 @@
+#include "comn.h"
+
+void UserConn();
+void UserDisConn();
+void UserChat();
+void UserOut();
+
+void setSignal();
+
+int main(int argc, char* argv[]) {
+
+	printf("\n[ client process ]\n");
+	setSignal();
+	shmid = shmget((key_t)0301, sizeof(shData), IPC_EXCL);
+	if (shmid == -1) {
+		printf("### no server process ###\n");
+		exit(1);
+	}
+
+	if (shmctl(shmid, IPC_STAT, &info) == -1) {
+		printf("### shmctl fail ###");
+		exit(1);
+	}
+
+	if (argc < 2) {
+		printf("### write user name ###\n");
+		exit(1);
+	}
+
+
+	printf("user count : %d\n", info.shm_nattch);
+
+	if (info.shm_nattch > 3) {
+		printf("### max user in. sorry ###\n");
+		exit(1);
+	}
+
+	shmaddr = shmat(shmid, (void*)0, 0);
+	if (shmaddr == (void*)-1) {
+		printf("### shmat fail ###\n");
+		exit(1);
+	}
+
+	shData = (struct SharedData*)shmaddr;
+
+	if (strlen(argv[1]) > MAX_USER_NAME) {
+		printf("### user name max size 10 ###\n");
+		exit(1);
+	}
+
+	int i = 0;
+	for (i = 0; i < MAX_USER_CNT; i++) {
+		if (shData->client[i].pid != 0) {
+			if (strcmp(shData->client[i].name, argv[1]) == 0) {
+				printf("### [ %s ] is duplicate user name ###\n", argv[1]);
+				exit(1);
+			}
+		}
+	}
+
+	if (shData->client[0].pid == 0) {
+		shData->client[0].pid = getpid();
+		sprintf(shData->client[0].name, "%s", argv[1]);
+	} else {
+		shData->client[1].pid = getpid();
+		sprintf(shData->client[1].name, "%s", argv[1]);
+	}
+
+	pid_t server_pid = shData->pid;
+
+	kill(server_pid, SIGUSR1);
+
+	// message queue create
+	if ((msqid = msgget((key_t)4225, IPC_CREAT | 0666)) == -1) {
+		printf("msgget fail\n");
+		exit(1);
+	}
+
+	char msg_buf[MAX_CHAT_LENGTH];
+
+	printf("=====================\n");
+	printf(" user enter chatting\n");
+	printf("=====================\n");
+
+	while (1) {
+		if ((shData->client[0].pid != 0) && (shData->client[1].pid != 0)) {
+			memset(chat.message, 0, sizeof(chat.message));
+			memset(msg_buf, 0, sizeof(msg_buf));
+
+			printf("> ");
+
+			fgets(msg_buf, sizeof(msg_buf), stdin);	// input buf
+
+			// send user info
+			chat.send_pid = getpid();
+			strcpy(chat.message, msg_buf);
+
+			if (strlen(chat.message) != 0) {
+				// chat -> message queue
+				if ((msgsnd(msqid, &chat, sizeof(chat), 0)) == -1) {
+					printf("### msgsnd fail ###\n");
+					exit(1);
+				}
+
+				// show chat to other user
+				if (shData->client[0].pid == getpid()) {
+//					printf("%s> %s\n", shData->client[0].name, msg_buf);
+					kill(shData->client[1].pid, SIGUSR2);
+				} else {
+//					printf("%s> %s\n", shData->client[1].name, msg_buf);
+					kill(shData->client[0].pid, SIGUSR2);
+				}
+			}
+		}
+		sleep(1);
+	}
+
+	return 0;
+}
+
+void UserConn() {
+	if (shData->client[1].pid == 0) {
+		printf("\n [ %s ] entered.\n", shData->client[0].name);
+	} else {
+		printf("\n [ %s ] entered.\n", shData->client[1].name);
+	}
+	printf("-------------------------\n");
+}
+
+void UserChat() {
+	// message queue -> chat
+	if ((msgrcv(msqid, &chat, sizeof(chat), 0, 0)) == -1) {
+		printf("### msgrcv fail ###\n");
+		exit(1);
+	}
+	
+	shData = (struct SharedData*)shmaddr;
+
+	if (chat.send_pid == shData->client[0].pid) {
+		printf("\n%s >> %s\n", shData->client[0].name, chat.message);
+	} else {
+		printf("\n%s >> %s\n", shData->client[1].name, chat.message);
+	}
+}
+
+void UserDisConn() {
+	pid_t server_pid = shData->pid;
+
+	if (shmctl(shmid, IPC_STAT, &info) == -1) {
+		printf("### shmctl fail ###");
+		exit(1);
+	}
+
+	if (info.shm_nattch < 3) {
+		// message queue delete
+		if (msgctl(msqid, IPC_RMID, 0) == -1) {
+			printf("### msgctl fail ###\n");
+			exit(1);
+		}
+	}
+
+	if (shData->client[0].pid == getpid()) {
+		shData->client[0].pid = -1;
+		kill(server_pid, SIGALRM);
+		kill(shData->client[1].pid, SIGALRM);
+		printf("\n ### user [ %s ] out ###\n", shData->client[0].name);
+		exit(1);
+	} else {
+		shData->client[1].pid = -1;
+		kill(server_pid, SIGALRM);
+		kill(shData->client[0].pid, SIGALRM);
+		printf("\n### user [ %s ] out ###\n", shData->client[1].name);
+		exit(1);
+	}
+}
+
+void UserOut() {
+	int i = 0;
+	for (i = 0; i < MAX_USER_CNT; i++) {
+		if (shData->client[i].pid != getpid()) {
+			printf("\n ### user [ %s ] out ###\n", shData->client[i].name);
+		}
+	}
+}
+
+void setSignal() {
+
+	struct sigaction chat_signal;
+	struct sigaction conn_sign;
+	struct sigaction disconn_sign;
+	struct sigaction leave_signal;
+
+	chat_signal.sa_handler = UserChat;
+	sigemptyset(&chat_signal.sa_mask);
+	chat_signal.sa_flags = 0;
+	sigaction(SIGUSR2, &chat_signal, NULL);
+
+	conn_sign.sa_handler = UserConn;
+	sigemptyset(&conn_sign.sa_mask);
+	conn_sign.sa_flags = 0;
+	sigaction(SIGUSR1, &conn_sign, NULL);
+
+	leave_signal.sa_handler = UserOut;
+	sigemptyset(&leave_signal.sa_mask);
+	leave_signal.sa_flags = 0;
+	sigaction(SIGALRM, &leave_signal, NULL);
+
+	disconn_sign.sa_handler = UserDisConn;
+	sigemptyset(&disconn_sign.sa_mask);
+	disconn_sign.sa_flags = 0;
+	sigaction(SIGINT, &disconn_sign, NULL);
+}
diff --git a/simpleChatting/comn.h b/simpleChatting/comn.h
index de89e9765b29c4b6526ae034b20fdad4e70e741f..54cabdc7eef8875c6e3e86b7b5080c20a6ac8e45 100644
--- a/simpleChatting/comn.h
+++ b/simpleChatting/comn.h
@@ -1,35 +1,35 @@
 #include <stdio.h>
-#include <string.h>
 #include <stdlib.h>
-#include <unistd.h>
+#include <string.h>
 #include <signal.h>
+#include <unistd.h>
+#include <errno.h>
 #include <sys/types.h>
 #include <sys/ipc.h>
 #include <sys/shm.h>
+#include <sys/msg.h>
 
 #define MAX_USER_CNT 2
 #define MAX_USER_NAME 10
 #define MAX_CHAT_LENGTH 255
 
-int isServerConn = -1;
+int msqid = 0;
 int shmid = 0;
-void *shmaddr = NULL;
-struct shmid_ds info;
+void* shmaddr = NULL;	// detach shared memory addr
+struct shmid_ds info;	// buffer pointer with get shared memmory info
 
-typedef struct UserData
-{
-    int pid;
-    char name[MAX_USER_NAME];
-}UserData;
+struct ClientData {
+	int pid;
+	char name[MAX_USER_NAME];
+};
 
-typedef struct SharedData
-{
-    int pid;
-    UserData user[MAX_USER_CNT];
-}SharedData;
+struct SharedData {
+	int pid;
+	int cliencnt;
+	struct ClientData client[MAX_USER_CNT];
+} *shData;
 
-typedef struct MessageData
-{
-    int send_pid;
-    char content[MAX_CHAT_LENGTH];
-}MsgData;
+struct ChatData {
+	int send_pid;
+	char message[MAX_CHAT_LENGTH];
+} chat;
diff --git a/simpleChatting/control.c b/simpleChatting/control.c
new file mode 100755
index 0000000000000000000000000000000000000000..16c29327e25a5b9838a06dff01f2109da31e092a
--- /dev/null
+++ b/simpleChatting/control.c
@@ -0,0 +1,158 @@
+#include "comn.h"
+
+pid_t pid;
+
+void connShMemory();
+
+int main(int argc, char* argv[]) {
+
+	printf("\n[ control process ]\n\n");
+	
+	connShMemory();
+
+	// 1. status
+	if (strcmp(argv[1], "status") == 0) {
+//		shmid = shmget((key_t)0301, sizeof(shData), IPC_EXCL | IPC_CREAT | 0666);
+//		printf("shmid :: %d\n", shmid);
+
+//		if (shmid == -1) {
+//			printf("server not connected\n");
+//			exit(1);
+//		}
+
+//		if (shData == NULL) {
+//			printf("no running process\n");
+//			exit(1);
+//		}
+		
+		// declare struct pointer
+		shData = (struct SharedData*)shmaddr;
+
+		if(shData == NULL) {
+			printf("### shData NULL. no running process ###\n");
+			exit(1);
+		}
+
+		// server process
+		if (shData->pid != 0) {
+			printf("### [ %d ] server process running ###\n", shData->pid);
+
+			int i = 0;
+			for (i = 0; i < MAX_USER_CNT; i++) {
+				if (shData->client[i].pid != 0) {
+					printf("### user [ %s ] running ###\n", shData->client[i].name);
+				}
+			}
+		}
+
+		exit(1);
+	}
+
+	// 2. server
+	if (strcmp(argv[2], "server") == 0) {
+		if (strcmp(argv[1], "start") == 0) {
+			// check shared memory
+//			shmid = shmget((key_t)0301, sizeof(shData), IPC_EXCL);
+//			printf("shmid :: %d\n", shmid);
+//			if (shmid != -1) {
+				// one server running ok
+//				printf("server running\n");
+//				exit(1);
+//			}
+			// fork set
+			pid = fork();
+			if (pid == -1) {
+				printf("### fork fail ###\n");
+			} else if (pid == 0) {
+				// parent : new pid, child : return 0
+				execl("./server", "start", (char*)0);
+			}
+		}
+
+		else if (strcmp(argv[1], "stop") == 0) {
+//			shmid = shmget((key_t)0301, sizeof(shData), IPC_EXCL);
+//			if (shmid == -1) {
+//				printf("no running server\n");
+//				exit(1);
+//			}
+
+//			if ((shmaddr = shmat(shmid, (void*)0, 0)) == (void*)-1) {
+//				printf("shmat fail\n");
+//				exit(1);
+//			}
+
+			shData = (struct SharedData*)shmaddr;
+			if(shmid != -1) {
+				printf("### no running server stop start ###\n");
+				exit(1);
+			}
+
+			kill(shData->pid, SIGINT);
+			printf("### running server stop ###\n");
+		}
+		else {
+			printf("### wrong keyword ###\n");
+		}
+	}
+
+	// 3. client
+	if (strcmp(argv[2], "client") == 0) {
+		shmid = shmget((key_t)0301, sizeof(shData), IPC_EXCL);
+		if (shmid == -1) {
+			printf("### shmget fail ###\n");
+			exit(1);
+		}
+
+		if ((shmaddr = shmat(shmid, (void*)0, 0)) == (void*)-1) {
+			printf("### shmat fail ###\n");
+			exit(1);
+		}
+
+		shData = (struct SharedData*)shmaddr;
+
+		if (strcmp(argv[1], "stop") == 0) {
+			int i = 0;
+			for (i = 0; i < MAX_USER_CNT; i++) {
+				if (strcmp(argv[3], shData->client[i].name) == 0) {
+					kill(shData->client[i].pid, SIGINT);
+					printf("### user [ %s ] stop by control ###\n", argv[3]);
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+
+void connShMemory() {
+	shmid = shmget((key_t)0301, sizeof(shData), IPC_EXCL | IPC_CREAT | 0666);
+	printf("connShMemory shmid :: %d\n", shmid);
+	
+	if (shmid == -1) {
+		// shared memory check -> create, conn
+		shmid = shmget((key_t)0301, sizeof(shData), IPC_CREAT | 0666);
+		if(shmid == -1) {
+	        	printf("### shmget fail ###\n");
+			
+			// shared memory separate / disconn
+			if(shmdt(shmaddr) == -1) {
+				printf("### shmdt fail ###\n");
+				exit(1);
+			}
+		} else {
+			// shared memory allocate / conn
+                	shmaddr = shmat(shmid, (void*)0, 0);
+	                if(shmaddr == (void*)-1) {
+        	                printf("### shmat fail ###\n");
+                	        exit(1);
+               		}
+        	}
+        } else {
+		// shared memory delete
+		if(shmctl(shmid, IPC_RMID, 0) == -1) {
+			printf("### shmctl fail ###\n");
+			exit(1);
+		}
+	}
+}
diff --git a/simpleChatting/server.c b/simpleChatting/server.c
new file mode 100755
index 0000000000000000000000000000000000000000..5a3034ed0cb7cb3df8d67ac6482e6027cf011379
--- /dev/null
+++ b/simpleChatting/server.c
@@ -0,0 +1,154 @@
+#include "comn.h"
+
+void UserConnServer();		// user connect to server
+void UserDisConnServer();	// user disconnect to server
+void MatchUserChat();		// users matching chat
+void ServerStop();		// server stop
+
+void setSignal();
+
+int main(int argc, char* argv[]) {
+	printf("\n [ server process ]\n");
+	// regist signal(user conn, user disconn, server stop, chat)
+	setSignal();
+	if (strcmp(argv[0], "start") == 0) {
+		shmid = shmget((key_t)0301, sizeof(shData), IPC_CREAT | 0666);
+		printf("shmid :: %d\n", shmid);
+		if (shmid == -1) {
+			printf("### shmget fail ###\n");
+			exit(1);
+		}
+
+		shmaddr = shmat(shmid, (void*)0, 0);
+		if (shmaddr == (void*)-1) {
+			printf("### shmat fail ###\n");
+			exit(1);
+		}
+
+		shData = (struct SharedData*)shmaddr;
+
+		shData->pid = getpid();
+
+		if(shData == NULL) {
+			printf("### start server. shData NULL ###\n");
+		}
+
+		int i = 0;
+		for (i = 0; i < MAX_USER_CNT; i++) {
+			shData->client[i].pid = 0;
+			memset(shData->client[i].name, 0, sizeof(shData->client[i].name));
+		}
+
+		printf("========================\n");
+		printf("\tServer Start\n");
+		printf("========================\n");
+
+		while (1) {
+			while (1) {
+				if (info.shm_nattch == 3) {
+					break;
+				}
+
+				if (shmctl(shmid, IPC_STAT, &info) == -1) {
+					printf("### shmctl fail ###");
+					exit(1);
+				}
+
+				sleep(1);
+			}
+
+			MatchUserChat();
+
+			while (1) {
+				if (shmctl(shmid, IPC_STAT, &info) == -1) {
+					printf("### shmctl fail ###");
+					exit(1);
+				}
+
+				// waiting
+				if (info.shm_nattch < 3) {
+					break;
+				}
+
+				sleep(1);
+			}
+		}
+
+	}
+	return 0;
+}
+
+void UserConnServer() {
+	printf("\n==================================\n");
+	if (shData->client[1].pid != 0) {
+		printf("Connect Success : %s [%d]\n", shData->client[1].name, shData->client[1].pid);
+	}
+	else {
+		printf("Connect Success : %s [%d]\n", shData->client[0].name, shData->client[0].pid);
+	}
+	printf("==================================\n");
+}
+
+void MatchUserChat() {
+	kill(shData->client[0].pid, SIGUSR1);
+	printf("%d %d \n", strlen(shData->client[0].name), strlen(shData->client[1].name));
+	printf("%s %s chatting match\n", shData->client[0].name, shData->client[1].name);
+	printf("==================================\n");
+}
+
+void UserDisConnServer() {
+	int i = 0;
+	for (i = 0; i < MAX_USER_CNT; i++) {
+		if (shData->client[i].pid == -1) {
+			printf("DisConnect : %s\n", shData->client[i].name);
+			shData->client[i].pid = 0;
+			memset(shData->client[i].name, 0, sizeof(shData->client[i].name));
+
+		}
+	}
+}
+
+void ServerStop() {
+
+	int i = 0;
+	for (i = 0; i < MAX_USER_CNT; i++) {
+		if (shData->client[i].pid != 0) {
+			kill(shData->client[i].pid, SIGINT);
+		}
+	}
+
+	if (shmdt(shmaddr) == -1) {
+		printf("shmdt fail\n");
+		exit(1);
+	}
+	if (shmctl(shmid, IPC_RMID, 0) == -1) {
+		printf("shmctl fail\n");
+		exit(1);
+	}
+
+	printf("========================\n");
+	printf("\tServer Stop\n");
+	printf("========================\n");
+	exit(1);
+}
+
+void setSignal() {
+	struct sigaction conn_sign;
+	struct sigaction disconn_sign;
+	struct sigaction server_stop_sign;
+
+	conn_sign.sa_handler = UserConnServer;
+	sigemptyset(&conn_sign.sa_mask);
+	conn_sign.sa_flags = 0;
+	sigaction(SIGUSR1, &conn_sign, NULL);
+
+	disconn_sign.sa_handler = UserDisConnServer;
+	sigemptyset(&disconn_sign.sa_mask);
+	disconn_sign.sa_flags = 0;
+	sigaction(SIGALRM, &disconn_sign, NULL);
+
+	server_stop_sign.sa_handler = ServerStop;
+	sigemptyset(&server_stop_sign.sa_mask);
+	server_stop_sign.sa_flags = 0;
+	sigaction(SIGINT, &server_stop_sign, NULL);
+}