diff --git a/.gitignore b/.gitignore
index 83991e6..b45ef3f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -56,4 +56,4 @@ Temporary Items
 
 # Visual Studio Code
 .vscode
-
+.idea
diff --git a/build/dockerfile b/build/dockerfile
index e7a3b6a..a2152a7 100644
--- a/build/dockerfile
+++ b/build/dockerfile
@@ -6,6 +6,8 @@ COPY words /usr/local/tomcat/webapps/
 
 USER mario
 
+RUN bash -c 'echo bar >> /tmp/foo.txt'
+
 RUN apt-get update && apt-get install -y vim
 
 CMD catalina.sh run
diff --git a/build/tester.go b/build/tester.go
index c56dbdc..6cfb60a 100644
--- a/build/tester.go
+++ b/build/tester.go
@@ -172,8 +172,8 @@ func Assert2Ephemeral(command *parser.Command) (*parser.Command, error) {
 		}
 		test += "-f " + command.Args[2]
 		ephemeral.Args = append(ephemeral.Args, test)
-    
-    case "CURRENT_USER_IS":
+
+	case "CURRENT_USER_IS":
 		if len(command.Args) != 3 {
 			return nil, fmt.Errorf("Condition %s accept one and only one argument (found %d)", "CURRENT_USER_IS", len(command.Args)-2)
 		}
@@ -182,7 +182,7 @@ func Assert2Ephemeral(command *parser.Command) (*parser.Command, error) {
 		if command.Args[0] == commands.AssertFalse {
 			test += "! "
 		}
-		test += "$(whoami) = \"" + command.Args[2] + "\"" 
+		test += "$(whoami) = \"" + command.Args[2] + "\""
 		ephemeral.Args = append(ephemeral.Args, test)
 
 	case "IS_INSTALLED":
@@ -194,12 +194,23 @@ func Assert2Ephemeral(command *parser.Command) (*parser.Command, error) {
 		if command.Args[0] == commands.AssertFalse {
 			test += "! "
 		}
-        test += isInstalledGeneric(command.Args[2])
+		test += isInstalledGeneric(command.Args[2])
 		ephemeral.Args = append(ephemeral.Args, test)
-    
+
+  case "FILE_CONTAINS":
+    if len(command.Args) != 4 {
+        return nil, fmt.Errorf("Condition %s accept two and only two argument (found %d)", "FILE_CONTAINS", len(command.Args)-3)
+    }
+    ephemeral.Args = append(ephemeral.Args, "bash", "-c")
+    test := "grep -q "
+    if command.Args[0] == commands.AssertFalse {
+		test += "! "
+    }
+    test += command.Args[2] + " " + command.Args[3]
+    ephemeral.Args = append(ephemeral.Args, test)
 
 	default:
-		return nil, fmt.Errorf("Condition %s is not supported. Only %s, %s, %s and %s are currently supported. Please open an issue if you want to add support for it.", command.Args[1], "USER_EXISTS", "FILE_EXISTS", "CURRENT_USER_IS", "IS_INSTALLED")
+		return nil, fmt.Errorf("Condition %s is not supported. Only %s, %s, %s and %s are currently supported. Please open an issue if you want to add support for it.", command.Args[1], "USER_EXISTS", "FILE_EXISTS", "CURRENT_USER_IS", "IS_INSTALLED", "FILE_CONTAINS")
 	}
 
 	return ephemeral, nil
@@ -222,10 +233,10 @@ func PrintTestsStats(stats *TestStats) {
 
 // func isInstalledDebian(packagename string) string {
 //     return "\"$(dpkg-query -W -f='${Status}' " +
-//            packagename + 
+//            packagename +
 //            ")\" = \"install ok installed\""
 // }
 
 func isInstalledGeneric(packagename string) string {
-    return "command -v \"" + packagename + "\"  1>/dev/null 2>&1"
+	return "command -v \"" + packagename + "\"  1>/dev/null 2>&1"
 }
diff --git a/build/tester_test.go b/build/tester_test.go
index 09b0e3d..bd7d11b 100644
--- a/build/tester_test.go
+++ b/build/tester_test.go
@@ -25,8 +25,8 @@ func TestNewTester(t *testing.T) {
 		t.Errorf("Failed to test file %s", tests)
 	}
 
-	if blockNum := len(tests.testBlocks); blockNum != 7 {
-		t.Errorf("Expected 7 blocks, found %d", blockNum)
+	if blockNum := len(tests.testBlocks); blockNum != 8 {
+		t.Errorf("Expected 8 blocks, found %d", blockNum)
 	}
 }
 
@@ -40,14 +40,16 @@ func TestInjection(t *testing.T) {
 		{Args: []string{"EPHEMERAL", "bash", "-c", "test ! -f /usr/local/tomcat/webapps/words"}},
 		{Args: []string{"COPY", "words", "/usr/local/tomcat/webapps/"}},
 		{Args: []string{"EPHEMERAL", "bash", "-c", "test -f /usr/local/tomcat/webapps/words"}},
-		{Args: []string{"EPHEMERAL",  "bash", "-c", "test $(whoami) = \"root\""}},
+		{Args: []string{"EPHEMERAL", "bash", "-c", "test $(whoami) = \"root\""}},
 		{Args: []string{"USER", "mario"}},
-		{Args: []string{"EPHEMERAL",  "bash", "-c", "test $(whoami) = \"mario\""}},
-//		{Args: []string{"EPHEMERAL",  "bash", "-c", "test ! \"$(dpkg-query -W -f='${Status}' vim)\" = \"install ok installed\""}},
-		{Args: []string{"EPHEMERAL",  "bash", "-c", "! command -v \"vim\"  1>/dev/null 2>&1"}},
+		{Args: []string{"EPHEMERAL", "bash", "-c", "test $(whoami) = \"mario\""}},
+		{Args: []string{"RUN", "bash", "-c", "echo bar >> /tmp/foo.txt"}},
+		{Args: []string{"EPHEMERAL", "bash", "-c", "grep -q bar /tmp/foo.txt"}},
+		//		{Args: []string{"EPHEMERAL",  "bash", "-c", "test ! \"$(dpkg-query -W -f='${Status}' vim)\" = \"install ok installed\""}},
+		{Args: []string{"EPHEMERAL", "bash", "-c", "! command -v \"vim\"  1>/dev/null 2>&1"}},
 		{Args: []string{"RUN", "apt-get", "update", "&&", "apt-get", "install", "-y", "vim"}},
-		{Args: []string{"EPHEMERAL",  "bash", "-c", "command -v \"vim\"  1>/dev/null 2>&1"}},
-//		{Args: []string{"EPHEMERAL",  "bash", "-c", "test \"$(dpkg-query -W -f='${Status}' vim)\" = \"install ok installed\""}},
+		{Args: []string{"EPHEMERAL", "bash", "-c", "command -v \"vim\"  1>/dev/null 2>&1"}},
+		//		{Args: []string{"EPHEMERAL",  "bash", "-c", "test \"$(dpkg-query -W -f='${Status}' vim)\" = \"install ok installed\""}},
 		{Args: []string{"CMD", "catalina.sh", "run"}},
 	}
 
diff --git a/build/testfile b/build/testfile
index 414901a..b158d43 100644
--- a/build/testfile
+++ b/build/testfile
@@ -14,8 +14,12 @@ ASSERT_TRUE CURRENT_USER_IS 'root'
 @AFTER USER_MARIO
 ASSERT_TRUE CURRENT_USER_IS 'mario'
 
+@AFTER RUN_BASH
+ASSERT_TRUE CONTAINS 'bar' '/tmp/foo.txt'
+
 @BEFORE RUN_APT
 ASSERT_FALSE IS_INSTALLED 'vim'
 
 @AFTER RUN_APT
-ASSERT_TRUE IS_INSTALLED 'vim'
\ No newline at end of file
+ASSERT_TRUE IS_INSTALLED 'vim'
+