diff --git a/fun.h b/fun.h
index 0f4f5ee..967fdf1 100644
--- a/fun.h
+++ b/fun.h
@@ -1,8 +1,11 @@
 #ifndef FUN_H_INCLUDED
 #define FUN_H_INCLUDED
-
 #define MAXLINE (80)
 
+#include "fun_1.c"
+#include "fun_2.c"
+
+
 void history(char *cmdline);
 void print_his(char *argv);
 
diff --git a/fun_1.c b/fun_1.c
index 9640173..1570845 100644
--- a/fun_1.c
+++ b/fun_1.c
@@ -1,7 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "fun.h"
+#include <wait.h>
+//#include "fun.h"
 
 
 void eval(char *cmdline)
@@ -10,10 +11,8 @@ void eval(char *cmdline)
     char buf[MAXLINE];
     int isBg;
     int pid;
-
     strcpy(buf,cmdline);
     isBg = parseline(cmdline,argv);
-
     if(argv[0] == NULL)
     {
 	    return;
@@ -21,28 +20,23 @@ void eval(char *cmdline)
 
     if(!builtin_cmd(argv))
     {
-/*
         if((pid=fork())==0)
         {
-            setpgid(0,0);
             if(execvp(argv[0],argv)<0)
             {
                 printf("%s:Command not found.\n",argv[0]);
                 exit(0);
             }
         }
-
         if(!isBg)
         {
-            waitfg(pid);
+            wait(NULL);
         }
         else
         {
-            printf("[%d] (%d) %s",pid2jid(pid),pid,cmdline);
+            return;
         }
-*/
     }
-    return;
 }
 
 int parseline(const char *cmdline, char **argv)
@@ -103,6 +97,10 @@ int parseline(const char *cmdline, char **argv)
 
 int builtin_cmd(char **argv)
 {
+    if(Is_pipe(argv)==1)
+    {
+        return 1;
+    }
 	if(!strcmp(argv[0],"quit")||!strcmp(argv[0],"exit"))
     {
 		exit(0);
@@ -112,7 +110,23 @@ int builtin_cmd(char **argv)
         print_his(argv[1]);
 		return 1;
 	}
-    if(!strcmp(argv[0],"jobs"))
+    if(!strcmp(argv[0],"cd"))
+    {
+	    if (argv[1] == NULL)
+	    {
+	    	return 1;
+	    }
+	    else
+	    {
+		    if (chdir(argv[1]) != 0)
+		    {
+		    	perror("Error: ");
+		    }
+		    return 1;
+	    }
+	}
+
+    if(!strcmp(argv[0],"mytop"))
     {
 		return 1;
 	}
diff --git a/fun_2.c b/fun_2.c
index b7d0d71..7892d3c 100644
--- a/fun_2.c
+++ b/fun_2.c
@@ -1,5 +1,5 @@
 #include <string.h>
-#include "fun.h"
+//#include "fun.h"
 
 static int num = 0;
 static char storage[MAXLINE][MAXLINE];
@@ -20,4 +20,55 @@ void print_his(char *argv)
     }
     for(; i<num; i++)
         puts(storage[i]);
+}
+
+int Is_pipe(char **argv)
+{
+    int i = 0;
+    char *cmd_0[MAXLINE];
+    char *cmd_1[MAXLINE];
+    while (argv[i]!=NULL)
+    {
+        cmd_0[i] = argv[i];
+        if(!strcmp(argv[i],"|"))
+        {
+            cmd_0[i] = NULL;
+            i++;
+            while (argv[i]!=NULL)
+            {
+                cmd_1[i] = argv[i];
+                i++;
+            }
+            cmd_1[i] = NULL;
+            shell_pip(cmd_0, cmd_1);
+            return 1;
+        }
+        i++;
+    }
+    return 0;
+}
+
+void shell_pip(char **cmd_0, char **cmd_1)
+{/*
+	int pid;    
+    int fd[2];
+    pipe(fd); 
+    pid = fork();
+    if (pid == 0) 
+    { 
+        dup2(fd[0], 0); 
+        close(fd[0]);
+        close(fd[1]);
+
+//        mysys_simple(&Cmd[1]);
+        execvp(cmd_1[0],cmd_1);
+        exit(0);
+    }
+    dup2(fd[1], 1); 
+    close(fd[0]);
+    close(fd[1]);
+
+//    mysys_simple(&Cmd[0]);
+    execvp(cmd_0[0],cmd_0);
+*/
 }
\ No newline at end of file
diff --git a/hello b/hello
new file mode 100755
index 0000000..29ae68f
Binary files /dev/null and b/hello differ
diff --git a/main b/main
new file mode 100755
index 0000000..1f82560
Binary files /dev/null and b/main differ
diff --git a/main.c b/main.c
index 010211e..d717389 100644
--- a/main.c
+++ b/main.c
@@ -2,16 +2,19 @@
 #include <stdlib.h>
 #include "fun.h"
 
+
 int main()
 {
     char cmdline[MAXLINE];
 
     while(1)
     {
+        int bufsize = MAXLINE;
         printf("COMMAND->");
-        fgets(cmdline, MAXLINE, stdin);
+        fgets(cmdline, MAXLINE, stdin);    
         eval(cmdline);
         history(cmdline);
     }
+    
     return 0;
 }