diff --git a/Makefile b/Makefile
index acb016c65..35a2cf917 100644
--- a/Makefile
+++ b/Makefile
@@ -60,6 +60,10 @@ limbo-wasm:
 test: limbo test-compat test-sqlite3
 .PHONY: test
 
+test-shell: limbo
+	./testing/memory-repl.tcl
+.PHONY: test-shell
+
 test-compat:
 	SQLITE_EXEC=$(SQLITE_EXEC) ./testing/all.test
 .PHONY: test-compat
diff --git a/testing/memory-repl.tcl b/testing/memory-repl.tcl
index ad4fac7a0..99ac4013c 100755
--- a/testing/memory-repl.tcl
+++ b/testing/memory-repl.tcl
@@ -1,12 +1,15 @@
 #!/usr/bin/env tclsh
 
-set sqlite_exec [expr {[info exists env(SQLITE_EXEC)] ? $env(SQLITE_EXEC) : "sqlite3"}]
+set sqlite_exec "./target/debug/limbo"
+set cwd [pwd]
 
 proc start_sqlite_repl {sqlite_exec init_commands} {
-    set command [list $sqlite_exec ":memory:"]
+	set command [list $sqlite_exec -q]
     set pipe [open "|[join $command]" RDWR]
     puts $pipe $init_commands
     flush $pipe
+    fconfigure $pipe -buffering none -blocking 0 -translation binary
+	puts [fconfigure $pipe]
     return $pipe
 }
 
@@ -15,13 +18,18 @@ proc execute_sql {pipe sql} {
     flush $pipe
     puts $pipe "SELECT 'END_OF_RESULT';"
     flush $pipe
-    set output ""
-    while {[gets $pipe line] >= 0} {
-        if {$line eq "END_OF_RESULT"} {
-            break
-        }
-        append output "$line\n"
-    }
+	set output ""
+	while {true} {
+		if {[gets $pipe line] >= 0} {
+			if {$line eq "END_OF_RESULT"} {
+				break
+			}
+			append output "$line\n"
+		} elseif {[eof $pipe]} {
+			puts "EOF reached."
+			break
+		}
+	}
     return [string trim $output]
 }
 
@@ -29,8 +37,8 @@ proc run_test {pipe sql expected_output} {
     set actual_output [execute_sql $pipe $sql]
     if {$actual_output ne $expected_output} {
         puts "Test FAILED: '$sql'"
-        puts "returned '$actual_output'"
         puts "expected '$expected_output'"
+        puts "returned '$actual_output'"
         exit 1
     }
 }
@@ -40,33 +48,29 @@ proc do_execsql_test {pipe test_name sql expected_output} {
     run_test $pipe $sql $expected_output
 }
 
+
 set init_commands {
-CREATE TABLE users (
-        id INTEGER PRIMARY KEY,
-		first_name TEXT,
-		last_name TEXT,
-		age INTEGER
-	);
-    CREATE TABLE products (
-	id INTEGER PRIMARY KEY,
-	name TEXT,
-	price INTEGER
-	);
+CREATE TABLE users (id INTEGER PRIMARY KEY, first_name TEXT, last_name TEXT, age INTEGER);
+    CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT, price INTEGER);
     INSERT INTO users (id, first_name, last_name, age) VALUES
 	(1, 'Alice', 'Smith', 30), (2, 'Bob', 'Johnson', 25), (3, 'Charlie', 'Brown', 66), (4, 'David', 'Nichols', 70); INSERT INTO products (id, name, price) VALUES (1, 'Hat', 19.99), (2, 'Shirt', 29.99), (3, 'Shorts', 39.99), (4, 'Dress', 49.99);
-    CREATE TABLE t(x1, x2, x3, x4);
+    CREATE TABLE t (x1, x2, x3, x4);
     INSERT INTO t VALUES (zeroblob(1024 - 1), zeroblob(1024 - 2), zeroblob(1024 - 3), zeroblob(1024 - 4));
 }
 
 set pipe [start_sqlite_repl $sqlite_exec $init_commands]
 
-do_execsql_test $pipe schema {
-  .schema 
+do_execsql_test $pipe select-1 {
+	SELECT 1;
+} {1}
+
+do_execsql_test $pipe schema-1 {
+.schema
 } {CREATE TABLE users (id INTEGER PRIMARY KEY, first_name TEXT, last_name TEXT, age INTEGER);
 CREATE TABLE products (id INTEGER PRIMARY KEY, name TEXT, price INTEGER);
 CREATE TABLE t (x1, x2, x3, x4);}
 
-do_execsql_test $pipe "select-avg" {
+do_execsql_test $pipe select-avg {
   SELECT avg(age) FROM users;
 } {47.75}
 
@@ -110,14 +114,14 @@ do_execsql_test $pipe select-count-constant-false {
   SELECT count(*) FROM users WHERE false;
 } {0}
 
-# **atrocious hack to test that we can open new connection
-do_execsql_test $pipe test-open-new-db {
-  .open testing/testing.db 
-} {}
 
-# now grab random tests from other areas and make sure we are querying that database
+# test that we can open new connection
+puts $pipe ".open testing/testing.db"
+flush $pipe
+
+# run a few random tests to be sure we are connected to right db
 do_execsql_test $pipe schema-1 {
-  .schema users
+.schema users
 } {CREATE TABLE users (
         id INTEGER PRIMARY KEY,
         first_name TEXT,
@@ -145,6 +149,74 @@ do_execsql_test $pipe where-clause-eq-string {
     select count(1) from users where last_name = 'Rodriguez';
 } {61}
 
+
+# Test the null value can be set/unset
+
+puts $pipe ".nullvalue limbo"
+
+do_execsql_test $pipe test-select-nullvalue {
+SELECT NULL;
+} {limbo}
+
+do_execsql_test $pipe test-set-nullvalue {
+.nullvalue ''
+} {}
+
+do_execsql_test $pipe test-set-nullvalue-back {
+SELECT NULL;
+} {''}
+
+
+# Test that the .show command demonstrates which db is open
+do_execsql_test $pipe test-show {
+.show
+} [subst {Settings:
+Output mode: raw
+DB: testing/testing.db
+Output: STDOUT
+Null value: ''
+CWD: $cwd
+Echo: off}]
+
+
+# Set up the output file name
+set output_file "limbo_output.txt"
+
+puts $pipe ".output $output_file"
+flush $pipe
+
+# Run the .show command to capture its output
+puts $pipe ".show"
+flush $pipe
+
+# Stop redirecting output to the file
+puts $pipe ".output"
+flush $pipe
+
+do_execsql_test $pipe test-set-outputfile-stdout {
+SELECT 1;
+} {1}
+
+# Check if the output file exists
+if {![file exists $output_file]} {
+    puts "Test FAILED: output file not created"
+    exit 1
+}
+
+set file_contents [read [open $output_file]]
+
+set expected_line "Output: $output_file"
+if {[string first $expected_line $file_contents] == -1} {
+    puts "Test FAILED: Expected line not found in file"
+    puts "Expected: $expected_line"
+    puts "File contents:\n$file_contents"
+    exit 1
+} else {
+    puts "Test PASSED: File contains the expected line"
+}
+
+file delete -force $output_file
+
 puts "All tests passed successfully."
 close $pipe
 exit 0