How to implement nested if method in nginx

Nginx does not support nested if statements, nor does it allow logical judgment in if statements. The following error will be reported:

nginx: [emerg] "if" directive is not allowed

When the business requires multiple condition judgments, it can be implemented with the help of intermediate variables

For example, our website has multiple subdomains on the PC side, but only one domain name on the mobile side. The corresponding relationship is as follows:

• www.test.com --> m.test.com
• sub1.test.com --> m.test.com/sub1
• sub2.test.com --> m.test.com/sub2
• sub3.test.com --> m.test.com/sub3

The effect to be achieved: When accessing the PC domain name on the mobile terminal, 301 jump to the corresponding mobile terminal domain name

The rewrite rules for nginx are as follows:

# Is it a mobile terminal? set $mobile 0;
if ($http_user_agent ~* (mobile|nokia|iphone|ipad|android|samsung|htc|blackberry)) {
  set $mobile 1;
}

# Get the subdomain set $prefix 1;
if ($host ~* "sub1.test.com") {
  set $prefix 2;
}
if ($host ~* "sub2.test.com") {
  set $prefix 3;
}
if ($host ~* "sub3.test.com") {
  set $prefix 4;
}
set $sign "${mobile}${prefix}";
if ($sign = 11) {
  rewrite ^(.*) http://m.test.com$1 permanent;
}
if ($sign = 12) {
  rewrite ^(.*) http://m.test.com/sub1$1 permanent;
}
if ($sign = 13) {
  rewrite ^(.*) http://m.test.com/sub2$1 permanent;
}
if ($sign = 14) {
  rewrite ^(.*) http://m.test.com/sub3$1 permanent;
}

The above is the full content of this article. I hope it will be helpful for everyone’s study. I also hope that everyone will support 123WORDPRESS.COM.