Apache2 Rewrite URL - LO Man Hei

# Apache2 Rewrite URL

#### Installation

Install Apache2 web server if it is not installed
```
sudo apt install apache2 -y
```
Activate rewrite module
```
sudo a2enmod rewrite
```

#### Usage

General usage
```
RewriteEngine  on
RewriteRule [match_uri] [rewrite_uri] [flags]
```

match_uri, rewrite_uri can be matched with regex

```txt
RewriteRule ^match\.html$ rewrite.html [NC,L]

# Behavior: 
#    input URL: http://domain.com/match.html
#    return as: http://domain.com/rewrite.html
```

#### Examples

##### **#1** Hide index.* from URL

1\. Open `/etc/apache2/apache2.conf`:
```bash
sudo nano /etc/apache2/apache2.conf
```

2\. Add `RewriteRule`, e.g. for `/var/www/html`:
```txt
<Directory /var/www/html>
        Options Indexes FollowSymLinks
        RewriteEngine  on
        RewriteRule ^(.*)/index\.([a-zA-Z]+)$ /$1/ [R=301,L]
</Directory>
```

##### **#2** using /1/2/3 instead of ?a=1&b=2&c=3 for URL parameters

1\. Open `/etc/apache2/apache2.conf`:
```bash
sudo nano /etc/apache2/apache2.conf
```

2\. Add `RewriteRule`, e.g. for `/var/www/html/blog`:
```txt
<Directory /var/www/html/blog>
    Options Indexes FollowSymLinks
    RewriteEngine  on
    RewriteRule ^([^/]+)/([^/]+)/([^/]+)/?$ ?t=$1&d=$2&f=$3
</Directory>
```

> - Below two URL behavior the same:  
> - https://lomanhei.com/blog/Software/2021-09-26/Apache2-Rewrite-URL  
> - https://lomanhei.com/blog/?t=Software&d=2021-09-26&f=Apache2-Rewrite-URL

##### **#3** Rewrite URL using .htaccess

> In general, you should only use .htaccess files when you don't have access to the main server configuration file.

1\. Ensure the server configuration allows `.htaccess` files override certain directory, e.g. `/var/www/html`:
```txt
<Directory "/var/www/html">
    AllowOverride All
</Directory>
# Behavior: it allows override for "/var/www/html" and all of its sub directories
```

2\. Add `.htaccess` to the target directory, e.g. /var/www/html/testing:
```txt
RewriteEngine  on
RewriteRule ^(.*)$ /404.html [R=301,L] 
# Behavior: it redirects all access under /var/www/html/testing to /404.html
```

#### Source

**Documentation link**: [Apache mod_rewrite](http://httpd.apache.org/docs/current/rewrite/)

**Reference**: [When (not) to use .htaccess files](https://httpd.apache.org/docs/current/howto/htaccess.html#when)

**Reference**: [Apache Rewrite with Htaccess 理解與技巧](https://medium.com/%E6%B5%A6%E5%B3%B6%E5%A4%AA%E9%83%8E%E7%9A%84%E6%B0%B4%E6%97%8F%E7%BC%B8/htaccess-with-rewrite-3dba066aff11)

Back to Contents

Loading