How to implement if nesting in nginx

nginx 不支持 if 嵌套，也不允许在 if 中使用逻辑判断，会报如下错误：

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

当业务需要多个条件判断时，可以借助中间变量来实现

如：我们的网站在 pc 端有多个子域名, 而移动端只有一个域名，对应关系如下：

• 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

要实现的效果：在移动端访问 pc 域名时 301 跳转到对应的移动端域名

nginx 的重写规则如下：

# 是否为移动端
set $mobile 0;
if ($http_user_agent ~* (mobile|nokia|iphone|ipad|android|samsung|htc|blackberry)) {
  set $mobile 1;
}

# 获取子域名
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 detailed content of How to implement if nesting in nginx. For more information, please follow other related articles on the PHP Chinese website!