diff --git a/m5r_interpreter.py b/m5r_interpreter.py
index 167af17..fdc6459 100644
--- a/m5r_interpreter.py
+++ b/m5r_interpreter.py
@@ -2,72 +2,124 @@ import re
 import subprocess
 import tempfile
 import os
+import shutil
+
+def safe_run(cmd, timeout=8, **sub_kwargs):
+    try:
+        result = subprocess.run(
+            cmd,
+            capture_output=True,
+            text=True,
+            timeout=timeout,
+            **sub_kwargs
+        )
+        out = result.stdout
+        err = result.stderr
+        rc = result.returncode
+    except subprocess.TimeoutExpired:
+        return "", "[ERROR: timed out]", 1
+    except FileNotFoundError:
+        return "", f"[ERROR: Not installed: {cmd[0]}]", 1
+    except Exception as e:
+        return "", f"[ERROR: {e}]", 1
+    else:
+        return out, err, rc
+
+def lang_header(name):
+    s = f"\n====== [{name.upper()} BLOCK] ======\n"
+    return s
 
 def interpret(source):
     outputs = []
 
-    # Python segments
+    # Python
     for segment in re.findall(r'<\?py(.*?)\?>', source, re.S):
         code = segment.strip()
         with tempfile.NamedTemporaryFile('w', delete=False, suffix='.py') as f:
             f.write(code)
             path = f.name
-        res = subprocess.run(['python', path], capture_output=True, text=True)
-        outputs.append(res.stdout)
+        out, err, rc = safe_run(['python', path])
+        outputs.append(lang_header("python") + out)
+        if err or rc:
+            outputs.append(f"[PYTHON ERROR]\n{err}")
         os.unlink(path)
 
-    # JavaScript segments
+    # JavaScript
     for segment in re.findall(r'<\?js(.*?)\?>', source, re.S):
         code = segment.strip()
         with tempfile.NamedTemporaryFile('w', delete=False, suffix='.js') as f:
             f.write(code)
             path = f.name
-        res = subprocess.run(['node', path], capture_output=True, text=True)
-        outputs.append(res.stdout)
+        out, err, rc = safe_run(['node', path])
+        outputs.append(lang_header("js") + out)
+        if err or rc:
+            outputs.append(f"[JS ERROR]\n{err}")
         os.unlink(path)
 
-    # PHP segments
+    # PHP
     for segment in re.findall(r'<\?php(.*?)\?>', source, re.S):
         code = segment.strip()
         with tempfile.NamedTemporaryFile('w', delete=False, suffix='.php') as f:
             f.write("<?php\n" + code + "\n?>")
             path = f.name
-        res = subprocess.run(['php', path], capture_output=True, text=True)
-        outputs.append(res.stdout)
+        out, err, rc = safe_run(['php', path])
+        outputs.append(lang_header("php") + out)
+        if err or rc:
+            outputs.append(f"[PHP ERROR]\n{err}")
         os.unlink(path)
 
-    # CSS segments (print as message, not executed)
+    # CSS (just pretty print)
     for segment in re.findall(r'<\?css(.*?)\?>', source, re.S):
         css = segment.strip()
-        outputs.append(f"[CSS Styling Loaded]\n{css}\n")
+        outputs.append(lang_header("css") + "[CSS Styling Loaded]\n" + css + "\n")
 
-    # C# segments (assumes csc installed)
+    # Bash/Shell
+    for segment in re.findall(r'<\?sh(.*?)\?>', source, re.S):
+        code = segment.strip()
+        with tempfile.NamedTemporaryFile('w', delete=False, suffix='.sh') as f:
+            f.write(code)
+            path = f.name
+        os.chmod(path, 0o700)
+        out, err, rc = safe_run(['bash', path])
+        outputs.append(lang_header("shell") + out)
+        if err or rc:
+            outputs.append(f"[BASH ERROR]\n{err}")
+        os.unlink(path)
+
+    # C#
     for segment in re.findall(r'<\?cs(.*?)\?>', source, re.S):
         code = segment.strip()
         with tempfile.NamedTemporaryFile('w', delete=False, suffix='.cs') as f:
             f.write(f"using System; class Program {{ static void Main() {{ {code} }} }}")
             path = f.name
         exe_path = path.replace('.cs', '.exe')
-        compile_res = subprocess.run(['csc', '/nologo', '/out:' + exe_path, path], capture_output=True, text=True)
-        if os.path.exists(exe_path):
-            run_res = subprocess.run([exe_path], capture_output=True, text=True)
-            outputs.append(run_res.stdout)
+        compile_out, compile_err, compile_rc = safe_run(['csc', '/nologo', '/out:' + exe_path, path])
+        if not os.path.exists(exe_path) or compile_rc:
+            outputs.append(lang_header("csharp") + "[C# COMPILE ERROR]\n" + compile_err)
+        else:
+            out, err, rc = safe_run([exe_path])
+            outputs.append(lang_header("csharp") + out)
+            if err or rc:
+                outputs.append(f"[C# ERROR]\n{err}")
             os.unlink(exe_path)
         os.unlink(path)
 
-    # C++ segments (assumes g++ installed)
+    # C++ (requires g++)
     for segment in re.findall(r'<\?cpp(.*?)\?>', source, re.S):
         code = segment.strip()
         with tempfile.NamedTemporaryFile('w', delete=False, suffix='.cpp') as f:
             f.write(f"#include <iostream>\nusing namespace std;\nint main() {{ {code} return 0; }}")
             path = f.name
         exe_path = path.replace('.cpp', '')
-        compile_res = subprocess.run(['g++', path, '-o', exe_path], capture_output=True, text=True)
-        if os.path.exists(exe_path):
-            run_res = subprocess.run([exe_path], capture_output=True, text=True)
-            outputs.append(run_res.stdout)
+        compile_out, compile_err, compile_rc = safe_run(['g++', path, '-o', exe_path])
+        if not os.path.exists(exe_path) or compile_rc:
+            outputs.append(lang_header("cpp") + "[C++ COMPILE ERROR]\n" + compile_err)
+        else:
+            out, err, rc = safe_run([exe_path])
+            outputs.append(lang_header("cpp") + out)
+            if err or rc:
+                outputs.append(f"[C++ ERROR]\n{err}")
             os.unlink(exe_path)
         os.unlink(path)
 
-    # Print combined output
     print(''.join(outputs))