What is wrong with this simple rewrite rule that doesnt redirect?

问题

Good day to everyone,

I'm struggling trying to understand what is wrong with this simple rule that doesn't work. I have a website that has URLs like that: site.com/support, I now want to redirect all the URLs site.com to site.com/en, site.com/support/ to site.com/en/support/, ....

After many tries and search, I came up with the 2 following rules:

RewriteRule ^(?![a-z]{2}/)(.*)$ /en/$1 [R=301,L] # redirect to default language
RewriteRule ^([a-z]{2})/(.*)$ /$2?lang=$1 [QSA,L]

each of these rules work perfectly separately, but result in a too many redirects when combined (?lang=en&lang=en&lang=en...)

any one could tell me pls what is wrong?

Thanks

回答1:

Problem is that both rules are modifying REQUEST_URI and causing each other to execute repeatedly until browser detects a redirect loop and stops redirecting with an error.

You can fix it by using:

RewriteEngine On

# redirect to default language
RewriteCond %{ENV:REDIRECT_STATUS} !200
RewriteRule ^(?![a-z]{2}/)(.*)$ /en/$1 [R=301,L,NE]

RewriteRule ^([a-z]{2})/(.*)$ /$2?lang=$1 [QSA,L]

RewriteCond %{ENV:REDIRECT_STATUS} !200 condition will prevent redirect loop as Apache will set REDIRECT_STATUS env variable to 200 after first successful execution of 1st rule.

来源：https://stackoverflow.com/questions/52688593/what-is-wrong-with-this-simple-rewrite-rule-that-doesnt-redirect