feat: implement shell detection and initial command execution in sessions

Author: dorlugasigal

README.md

@@ -65,6 +65,12 @@ termbeam --password mysecret
 termbeam --tunnel --generate-password
 ```
 
+> Requires the [Azure Dev Tunnels CLI](https://learn.microsoft.com/en-us/azure/developer/dev-tunnels/get-started):
+>
+> - **Windows:** `winget install Microsoft.devtunnel`
+> - **macOS:** `brew install --cask devtunnel`
+> - **Linux:** `curl -sL https://aka.ms/DevTunnelCliInstall | bash`
+
 ## 📖 Usage
 
 ```bash

package-lock.json

@@ -57,7 +57,7 @@
   "dependencies": {
     "cookie-parser": "^1.4.7",
     "express": "^5.2.1",
-    "node-pty": "1.0.0",
+    "node-pty": "^1.1.0",
     "qrcode": "^1.5.4",
     "ws": "^8.19.0"
   },

package.json

@@ -231,8 +231,18 @@
         color: #e0e0e0;
         font-size: 15px;
         outline: none;
+        -webkit-appearance: none;
+        appearance: none;
       }
-      .modal input:focus {
+      .modal select {
+        background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23888' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
+        background-repeat: no-repeat;
+        background-position: right 12px center;
+        padding-right: 32px;
+        cursor: pointer;
+      }
+      .modal input:focus,
+      .modal select:focus {
         border-color: #533483;
       }
       .modal-actions {
@@ -459,8 +469,12 @@ <h1>📡 Term<span>Cast</span></h1>
         <h2>New Session</h2>
         <label for="sess-name">Name</label>
         <input type="text" id="sess-name" placeholder="My Session" />
-        <label for="sess-shell">Shell / Command</label>
-        <input type="text" id="sess-shell" placeholder="/bin/zsh" />
+        <label for="sess-shell">Shell</label>
+        <select id="sess-shell">
+          <option value="">Loading shells…</option>
+        </select>
+        <label for="sess-cmd">Initial Command <span style="color:#666;font-weight:normal">(optional)</span></label>
+        <input type="text" id="sess-cmd" placeholder="e.g. copilot, htop, vim" />
         <label for="sess-cwd">Working Directory</label>
         <div class="cwd-picker">
           <input type="text" id="sess-cwd" placeholder="/Users/dorlugasigal" />
@@ -568,6 +582,7 @@ <h3>
       }
 
       document.getElementById('new-session-btn').addEventListener('click', () => {
+        loadShells();
         modal.classList.add('visible');
       });
       document.getElementById('modal-cancel').addEventListener('click', () => {
@@ -581,11 +596,13 @@ <h3>
         const name = document.getElementById('sess-name').value.trim();
         const shell = document.getElementById('sess-shell').value.trim();
         const cwd = document.getElementById('sess-cwd').value.trim();
+        const initialCommand = document.getElementById('sess-cmd').value.trim();
 
         const body = {};
         if (name) body.name = name;
         if (shell) body.shell = shell;
         if (cwd) body.cwd = cwd;
+        if (initialCommand) body.initialCommand = initialCommand;
 
         const res = await fetch('/api/sessions', {
           method: 'POST',
@@ -596,6 +613,30 @@ <h3>
         location.href = data.url;
       });
 
+      // --- Shell detection ---
+      let shellsLoaded = false;
+      async function loadShells() {
+        if (shellsLoaded) return;
+        const shellSelect = document.getElementById('sess-shell');
+        try {
+          const res = await fetch('/api/shells');
+          const data = await res.json();
+          shellSelect.innerHTML = '';
+          for (const s of data.shells) {
+            const opt = document.createElement('option');
+            opt.value = s.cmd;
+            opt.textContent = `${s.name} (${s.cmd})`;
+            if (s.cmd === data.default || s.path === data.default) {
+              opt.selected = true;
+            }
+            shellSelect.appendChild(opt);
+          }
+          shellsLoaded = true;
+        } catch {
+          shellSelect.innerHTML = '<option value="">Could not detect shells</option>';
+        }
+      }
+
       // --- Swipe to delete ---
       async function deleteSession(id, e) {
         e.stopPropagation();

public/index.html

@@ -65,6 +65,11 @@
         align-items: center;
         gap: 8px;
       }
+      #status-bar .right {
+        display: flex;
+        align-items: center;
+        gap: 8px;
+      }
       #back-btn {
         background: none;
         border: none;
@@ -76,6 +81,22 @@
       #back-btn:active {
         color: #e0e0e0;
       }
+      #stop-btn {
+        background: #e74c3c;
+        border: none;
+        color: white;
+        font-size: 11px;
+        font-weight: 600;
+        cursor: pointer;
+        padding: 4px 10px;
+        border-radius: 6px;
+        display: flex;
+        align-items: center;
+        gap: 4px;
+      }
+      #stop-btn:active {
+        background: #c0392b;
+      }
       #status-dot {
         width: 8px;
         height: 8px;
@@ -207,8 +228,11 @@
         <span id="status-dot"></span>
         <span id="session-name">…</span>
       </div>
-      <span id="status-text">Connecting…</span>
-      <span id="version-text" style="font-size: 11px; color: #555; margin-left: 8px"></span>
+      <div class="right">
+        <span id="status-text">Connecting…</span>
+        <span id="version-text" style="font-size: 11px; color: #555"></span>
+        <button id="stop-btn" title="Stop session">■ Stop</button>
+      </div>
     </div>
 
     <div id="terminal-container"></div>
@@ -437,6 +461,15 @@
           connect();
         });
 
+        // Stop session
+        document.getElementById('stop-btn').addEventListener('click', async () => {
+          if (!confirm('Stop this session? The process will be killed.')) return;
+          try {
+            await fetch(`/api/sessions/${sessionId}`, { method: 'DELETE' });
+          } catch {}
+          location.href = '/';
+        });
+
         // Tap terminal area to toggle keyboard (intentional user action)
         container.addEventListener('click', () => term.focus());
 

public/terminal.html

@@ -32,10 +32,61 @@ Environment:
 `);
 }
 
+function getDefaultShell() {
+  const { execFileSync } = require('child_process');
+  const ppid = process.ppid;
+  console.log(`[termbeam] Detecting shell (parent PID: ${ppid}, platform: ${os.platform()})`);
+
+  if (os.platform() === 'win32') {
+    // Detect parent process on Windows via WMIC
+    try {
+      const result = execFileSync(
+        'wmic',
+        ['process', 'where', `ProcessId=${ppid}`, 'get', 'Name', '/value'],
+        { stdio: ['pipe', 'pipe', 'ignore'], encoding: 'utf8', timeout: 3000 },
+      );
+      const match = result.match(/Name=(.+)/);
+      if (match) {
+        const name = match[1].trim().toLowerCase();
+        console.log(`[termbeam] Detected parent process: ${name}`);
+        if (name === 'pwsh.exe') return 'pwsh.exe';
+        if (name === 'powershell.exe') return 'powershell.exe';
+      }
+    } catch (err) {
+      console.log(`[termbeam] Could not detect parent process: ${err.message}`);
+    }
+    const fallback = process.env.COMSPEC || 'cmd.exe';
+    console.log(`[termbeam] Falling back to: ${fallback}`);
+    return fallback;
+  }
+
+  // Unix: detect parent shell via ps
+  try {
+    const result = execFileSync('ps', ['-o', 'comm=', '-p', String(ppid)], {
+      stdio: ['pipe', 'pipe', 'ignore'],
+      encoding: 'utf8',
+      timeout: 3000,
+    });
+    const comm = result.trim();
+    if (comm) {
+      const shell = comm.startsWith('-') ? comm.slice(1) : comm;
+      console.log(`[termbeam] Detected parent shell: ${shell}`);
+      return shell;
+    }
+  } catch (err) {
+    console.log(`[termbeam] Could not detect parent shell: ${err.message}`);
+  }
+
+  // Fallback to SHELL env or /bin/sh
+  const fallback = process.env.SHELL || '/bin/sh';
+  console.log(`[termbeam] Falling back to: ${fallback}`);
+  return fallback;
+}
+
 function parseArgs() {
   let port = parseInt(process.env.PORT || '3456', 10);
   let host = '0.0.0.0';
-  const defaultShell = process.env.SHELL || '/bin/zsh';
+  const defaultShell = getDefaultShell();
   const cwd = process.env.TERMBEAM_CWD || process.env.PTY_CWD || process.cwd();
   let password = process.env.TERMBEAM_PASSWORD || process.env.PTY_PASSWORD || null;
   let useTunnel = false;

src/cli.js

@@ -1,6 +1,7 @@
 const path = require('path');
 const os = require('os');
 const fs = require('fs');
+const { detectShells } = require('./shells');
 
 const PUBLIC_DIR = path.join(__dirname, '..', 'public');
 
@@ -46,16 +47,23 @@ function setupRoutes(app, { auth, sessions, config }) {
   });
 
   app.post('/api/sessions', auth.middleware, (req, res) => {
-    const { name, shell, args: shellArgs, cwd } = req.body || {};
+    const { name, shell, args: shellArgs, cwd, initialCommand } = req.body || {};
     const id = sessions.create({
       name: name || `Session ${sessions.sessions.size + 1}`,
       shell: shell || config.defaultShell,
       args: shellArgs || [],
       cwd: cwd || config.cwd,
+      initialCommand: initialCommand || null,
     });
     res.json({ id, url: `/terminal?id=${id}` });
   });
 
+  // Available shells
+  app.get('/api/shells', auth.middleware, (_req, res) => {
+    const shells = detectShells();
+    res.json({ shells, default: config.defaultShell });
+  });
+
   app.delete('/api/sessions/:id', auth.middleware, (req, res) => {
     if (sessions.delete(req.params.id)) {
       res.json({ ok: true });

src/routes.js

@@ -6,7 +6,7 @@ class SessionManager {
     this.sessions = new Map();
   }
 
-  create({ name, shell, args = [], cwd }) {
+  create({ name, shell, args = [], cwd, initialCommand = null }) {
     const id = crypto.randomBytes(4).toString('hex');
     const ptyProcess = pty.spawn(shell, args, {
       name: 'xterm-256color',
@@ -16,6 +16,11 @@ class SessionManager {
       env: { ...process.env, TERM: 'xterm-256color' },
     });
 
+    // Send initial command once the shell is ready
+    if (initialCommand) {
+      setTimeout(() => ptyProcess.write(initialCommand + '\r'), 300);
+    }
+
     const session = {
       pty: ptyProcess,
       name,