如何部署CodeIgniter网站至服务器？解决部署后404错误

Hey there, let's walk through why you're getting that 404 error after uploading your CodeIgniter project to the server—this is a super common gotcha, and we can fix it quickly!

1. Base URL Mismatch (Most Likely Culprit) #

Your local setup uses localhost/project_name as the base, but the server needs the actual domain path. This throws off CodeIgniter's routing entirely.

• Open application/config/config.php
• Find the $config['base_url'] line and update it to match your server's path:

  $config['base_url'] = 'http://www.domain_name.com/project_name/';
  

  Don't forget the trailing slash—it matters for asset paths and routing.

2. .htaccess Problems or Rewrite Rules #

Local servers (like XAMPP/WAMP) often have rewrite enabled by default, but live servers might not. Plus, hidden .htaccess files can get left out when zipping/uploading.

• First, confirm your project root has an .htaccess file (it's hidden, so make sure you included it in your ZIP). For subdirectory deployments, the rules should look like this:

  RewriteEngine On
  RewriteBase /project_name/
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule ^(.*)$ index.php/$1 [L]
  

• If you're using Apache, check that mod_rewrite is enabled (ask your host if you're unsure). For Nginx, you'll need to add equivalent rewrite rules to your server block.

3. Case Sensitivity (Linux vs Windows) #

Local Windows machines ignore file case, but Linux servers don't. This is a sneaky one!

• CodeIgniter requires controller filenames to have a capitalized first letter, and the class name must match exactly. For example:
  • Filename: Controller_name.php (first letter capitalized)
  • Class inside: class Controller_name extends CI_Controller
• If your local filename was controller_name.php (all lowercase), the server won't recognize it—rename it to match the capitalization rule.

4. Incorrect File/Directory Permissions #

The server needs access to write to cache and logs folders, and read access to all core files.

• Set application/cache and application/logs to 755 (or 777 if 755 doesn't work—though 755 is more secure)
• Set all PHP files to 644 and directories to 755
• Avoid setting root or system files to 777—that's a major security risk.

5. Missing or Misconfigured Files #

Double-check that you uploaded every file from your local project—sometimes hidden files or system folders get skipped when zipping.

• Verify system/, application/, and index.php are all present in the server's project_name directory
• Open index.php and confirm $system_path and $application_folder point to the correct relative paths (they should match your local setup if the folder structure is identical)

6. Route Configuration Errors #

If your routes are pointing to the wrong controller (or using incorrect case), you'll get a 404 even if everything else is right.

• Open application/config/routes.php and check your default controller:

  $route['default_controller'] = 'controller_name';
  

• Make sure the controller name here matches the actual class name (including case)

Quick Troubleshooting Checklist #

• Did you include hidden files like .htaccess in your ZIP upload?
• Is base_url updated to your server's domain and project subdirectory?
• Is URL rewriting enabled on your server?
• Are controller filenames and class names properly capitalized?
• Do cache/log directories have the right permissions?

内容的提问来源于stack exchange，提问作者Tanmay