How can I rewrite this nginx "if" statement?

Question

For example, I want to do this:

if ($http_user_agent ~ "MSIE 6.0" || $http_user_agent ~ "MSIE 7.0" (etc, etc)) {
    rewrite ^ ${ROOT_ROOT}ancient/ last;
   break;
}

instead of this:

if ($http_user_agent ~ "MSIE 6.0") {
    rewrite ^ ${ROOT_ROOT}ancient/ last;
   break;
}
if ($http_user_agent ~ "MSIE 7.0") {
    rewrite ^ ${ROOT_ROOT}ancient/ last;
   break;
}

Nginx rejects this syntax (minus the (etc, etc)), and I don't see anything in the docs about this.

Also, we opted not to use $ancient_browser directive, so that's not an option.

In this case it's as simple as `if ($http_user_agent ~ "MSIE [67]\.")`. You forgot that it's regexp. — Alexey Ten, Apr 21 '15 at 07:19
@AlexeyTen you should write an answer with that -- IMO it's preferable to the other solution offered. — Bryce Johnson, Apr 21 '15 at 16:35

Eric Ly · Accepted Answer · 2021-03-03T07:44:15.217

75

Edit:

As Alexey Ten didn't add a new answer, I'll edit mine to give his better answer in this case.

if ($http_user_agent ~ "MSIE [67]\.")

Original answer:

Nginx doesn't allow multiple or nested if statements however you can do this :

set $test 0;
if ($http_user_agent ~ "MSIE 6\.0") {
  set $test 1;
}
if ($http_user_agent ~ "MSIE 7\.0") {
  set $test 1;
}
if ($test = 1) {
  rewrite ^ ${ROOT_ROOT}ancient/ last;
}

It is not shorter but it allows you to do the check and put the rewrite rule only once.

Alternative answer:

In some cases, you can also use | (pipe)

if ($http_user_agent ~ "(MSIE 6\.0)|(MSIE 7\.0)") {
  rewrite ^ ${ROOT_ROOT}ancient/ last;
}

edited Mar 03 '21 at 07:44

answered Apr 20 '15 at 19:43

Eric Ly

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You can also use | (pipe) as an alternative like: if ($http_user_agent ~ "(MSIE 6.0)|(MSIE 7.0)") – dmonti Apr 23 '18 at 19:22
Note: as ~ does a regexp match, the '.' should be escaped as '\.' in all cases – Kutzi Feb 23 '21 at 09:45
You can also use the map with two variables, for example: https://serverfault.com/questions/760380/how-to-specify-several-variables-in-the-map-directive-of-nginx – fireman777 Apr 08 '21 at 10:48

How can I rewrite this nginx "if" statement?

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