diff --git a/src/commands/env-command.ts b/src/commands/env-command.ts
index fac4f2fb..a29754fa 100644
--- a/src/commands/env-command.ts
+++ b/src/commands/env-command.ts
@@ -30,17 +30,18 @@ export function detectShell(flag?: string): ShellType {
   return 'bash';
 }
 
-/** Format a single env var export for the target shell */
+/** Format a single env var export for the target shell (single-quoted to prevent injection) */
 export function formatExportLine(shell: ShellType, key: string, value: string): string {
-  // Escape double quotes in value
-  const escaped = value.replace(/"/g, '\\"');
   switch (shell) {
     case 'fish':
-      return `set -gx ${key} "${escaped}"`;
+      // Fish: single quotes prevent expansion; escape embedded single quotes with \'
+      return `set -gx ${key} '${value.replace(/'/g, "\\'")}'`;
     case 'powershell':
-      return `$env:${key} = "${escaped}"`;
+      // PowerShell: single quotes prevent expansion; escape embedded single quotes with ''
+      return `$env:${key} = '${value.replace(/'/g, "''")}'`;
     default:
-      return `export ${key}="${escaped}"`;
+      // Bash/zsh: single quotes prevent all expansion; handle embedded single quotes
+      return `export ${key}='${value.replace(/'/g, "'\\''")}'`;
   }
 }
 
@@ -59,7 +60,7 @@ export function transformToOpenAI(envVars: Record<string, string>): Record<strin
 function parseFlag(args: string[], flag: string): string | undefined {
   // --flag=value style
   const eqMatch = args.find((a) => a.startsWith(`--${flag}=`));
-  if (eqMatch) return eqMatch.split('=')[1];
+  if (eqMatch) return eqMatch.split('=').slice(1).join('=');
   // --flag value style
   const idx = args.indexOf(`--${flag}`);
   if (idx >= 0 && idx + 1 < args.length && !args[idx + 1].startsWith('-')) {
@@ -220,6 +221,14 @@ export async function handleEnvCommand(args: string[]): Promise<void> {
       break;
   }
 
+  // Guard: format transformation may filter out all vars
+  if (Object.keys(output).filter((k) => output[k]).length === 0) {
+    console.error(
+      warn(`No ${format}-format vars found for profile '${profile}'. Try --format raw`)
+    );
+    process.exit(1);
+  }
+
   // Output shell-formatted exports to stdout
   for (const [key, value] of Object.entries(output)) {
     if (value) {
diff --git a/tests/unit/commands/env-command.test.ts b/tests/unit/commands/env-command.test.ts
index 898714e9..efcae254 100644
--- a/tests/unit/commands/env-command.test.ts
+++ b/tests/unit/commands/env-command.test.ts
@@ -3,13 +3,12 @@
  *
  * Tests pure utility functions: detectShell, formatExportLine, transformToOpenAI
  */
-import { describe, it, expect, beforeEach, afterEach } from 'bun:test';
+import { describe, it, expect, afterEach } from 'bun:test';
 import { detectShell, formatExportLine, transformToOpenAI } from '../../../src/commands/env-command';
 
 describe('env-command', () => {
   describe('detectShell', () => {
     const originalShell = process.env['SHELL'];
-    const originalPlatform = process.platform;
 
     afterEach(() => {
       if (originalShell !== undefined) {
@@ -59,32 +58,38 @@ describe('env-command', () => {
 
   describe('formatExportLine', () => {
     it('formats bash export', () => {
-      expect(formatExportLine('bash', 'API_KEY', 'sk-123')).toBe('export API_KEY="sk-123"');
+      expect(formatExportLine('bash', 'API_KEY', 'sk-123')).toBe("export API_KEY='sk-123'");
     });
 
     it('formats fish export', () => {
-      expect(formatExportLine('fish', 'API_KEY', 'sk-123')).toBe('set -gx API_KEY "sk-123"');
+      expect(formatExportLine('fish', 'API_KEY', 'sk-123')).toBe("set -gx API_KEY 'sk-123'");
     });
 
     it('formats powershell export', () => {
       expect(formatExportLine('powershell', 'API_KEY', 'sk-123')).toBe(
-        '$env:API_KEY = "sk-123"'
+        "$env:API_KEY = 'sk-123'"
       );
     });
 
-    it('escapes double quotes in values', () => {
-      expect(formatExportLine('bash', 'VAL', 'has "quotes"')).toBe(
-        'export VAL="has \\"quotes\\""'
+    it('escapes single quotes in values', () => {
+      expect(formatExportLine('bash', 'VAL', "it's here")).toBe(
+        "export VAL='it'\\''s here'"
       );
     });
 
     it('handles empty values', () => {
-      expect(formatExportLine('bash', 'EMPTY', '')).toBe('export EMPTY=""');
+      expect(formatExportLine('bash', 'EMPTY', '')).toBe("export EMPTY=''");
     });
 
     it('handles URLs with special characters', () => {
       const url = 'http://127.0.0.1:8317/api/provider/gemini';
-      expect(formatExportLine('bash', 'BASE_URL', url)).toBe(`export BASE_URL="${url}"`);
+      expect(formatExportLine('bash', 'BASE_URL', url)).toBe(`export BASE_URL='${url}'`);
+    });
+
+    it('prevents shell injection with $() in values', () => {
+      expect(formatExportLine('bash', 'TOKEN', 'safe$(whoami)')).toBe(
+        "export TOKEN='safe$(whoami)'"
+      );
     });
   });