diff --git a/day5/chat_tool/bob b/day5/chat_tool/bob
new file mode 100755
index 0000000..9c3ad54
Binary files /dev/null and b/day5/chat_tool/bob differ
diff --git a/day5/chat_tool/chat_tool.c b/day5/chat_tool/chat_tool.c
new file mode 100644
index 0000000..695b94a
--- /dev/null
+++ b/day5/chat_tool/chat_tool.c
@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/msg.h>
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <signal.h>
+
+typedef struct msg_
+{
+    long mType;        // 消息类型
+    char content[100]; // 正文数据
+    char name[32];     // 姓名
+} MSG;
+
+int main(int argc, char const *argv[])
+{
+    if (argc != 2)
+    {
+        printf("invalid, format is : ./xx name\n");
+        return 1;
+    }
+
+    key_t key = ftok("/", 160);
+    int msgqid = msgget(key, IPC_CREAT | 0666);
+    if (msgqid == -1)
+    {
+        perror("msgget");
+        return 1;
+    }
+    int pid = fork();
+    if (pid == 0)
+    {
+        // 子进程
+        while (1)
+        {
+            write(STDOUT_FILENO, "我说:", 7);
+            MSG msg;
+            scanf("%s", msg.content);
+            strcpy(msg.name, argv[1]);
+#ifdef BOB
+            msg.mType = 1;
+#else
+            msg.mType = 2;
+#endif
+            if (msgsnd(msgqid, &msg, sizeof(MSG) - sizeof(long), 0) != -1)
+            {
+                printf("send msg OK\n");
+                if (strncmp(msg.content, "bye", 3) == 0)
+                {
+                    break;
+                }
+            }
+        }
+        // kill(getppid(), SIGSTOP);
+        _exit(0);
+    }
+    else if (pid > 0)
+    {
+        // 父进程
+        while (1)
+        {
+            MSG msg;
+#ifdef BOB
+            msg.mType = 2;
+#else
+            msg.mType = 1;
+#endif
+            if (msgrcv(msgqid, &msg, sizeof(MSG) - sizeof(long), msg.mType, 0) != -1)
+            {
+                printf("\n%s >>> \"%s\"\n", msg.name, msg.content);
+
+                if (strncmp(msg.content, "bye", 3) == 0)
+                {
+                    break;
+                }
+                write(STDOUT_FILENO, "我说:", 7);
+            }
+        }
+        // kill(pid, SIGSTOP);
+        wait(NULL);
+    }
+
+    return 0;
+}
diff --git a/day5/chat_tool/lucy b/day5/chat_tool/lucy
new file mode 100755
index 0000000..aab3450
Binary files /dev/null and b/day5/chat_tool/lucy differ