diff --git a/implement-shell-tools/cat/check.sh b/implement-shell-tools/cat/check.sh
new file mode 100755
index 000000000..ec8b0a64a
--- /dev/null
+++ b/implement-shell-tools/cat/check.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+user_command=(${USER_COMMAND:-"node cat.js"})
+
+function test() {
+  args=${@}
+  echo "======"
+  echo "Testing cat ${args}"
+  echo "======="
+  diff -y <(cat ${args[@]}) <(${user_command[@]} ${args[@]})
+  echo ""
+  echo ""
+}
+
+test 'sample-files/1.txt'
+test '-n' 'sample-files/1.txt'
+test 'sample-files/*.txt'
+test '-n' 'sample-files/*.txt'
+test '-b' 'sample-files/3.txt'
diff --git a/implement-shell-tools/ls/check.sh b/implement-shell-tools/ls/check.sh
new file mode 100755
index 000000000..34490cf21
--- /dev/null
+++ b/implement-shell-tools/ls/check.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+user_command=(${USER_COMMAND:-"node ls.js"})
+
+function test() {
+  args=${@}
+  echo "======"
+  echo "Testing ls ${args}"
+  echo "======="
+  diff -y <(/bin/ls ${args[@]}) <(${user_command[@]} ${args[@]})
+  echo ""
+  echo ""
+}
+
+test
+test '-1'
+test '-1' 'sample-files'
+test '-1' '-a' 'sample-files'
diff --git a/implement-shell-tools/wc/check.sh b/implement-shell-tools/wc/check.sh
new file mode 100755
index 000000000..46761bf17
--- /dev/null
+++ b/implement-shell-tools/wc/check.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+user_command=(${USER_COMMAND:-"node wc.js"})
+
+function test() {
+  args=${@}
+  echo "======"
+  echo "Testing wc ${args}"
+  echo "======="
+  diff -y <(wc ${args[@]}) <(${user_command[@]} ${args[@]})
+  echo ""
+  echo ""
+}
+
+test 'sample-files/*'
+test '-l' 'sample-files/3.txt'
+test '-w' 'sample-files/3.txt'
+test '-c' 'sample-files/3.txt'
+test '-l' 'sample-files/*'