I am learning to create a REST api from a tutorial. In the tutorial there was one step which performs URL rewriting. The code is as follows:
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ %{ENV:BASE}index.php [QSA,L]
Can anybody please explain rewrite condition and %{ENV:BASE} part in it ?
The condition is simple:
If requested URI does not indicate to any existing file then redirect to ${ENV:BASE}index.php.
You can find description of RewriteRule flags here. Briefly speaking:
QSA stands for "query string append". It means that query string will be appended to replacement URI.
L means that is the last rule and no further rules will be processed.
On this page there is a good explanation for environment variables in htaccess:
The %{ENV:variable} form of TestString in the RewriteCond allows mod_rewrite's rewrite engine to make decisions conditional on environment variables. Note that the variables accessible in mod_rewrite without the ENV: prefix are not actually environment variables. Rather, they are variables special to mod_rewrite which cannot be accessed from other modules.
So, you can use environment variable in your rule like this ${ENV:<name>}. The variable has to be set earlier, of course.
${ENV:<name>} is used for avoiding repeated coding. Some conditions would be stored as variable and could be used in RewriteRules. For more details you can see this question.
