nginx内容替换模块我知道的有3个：

1. http_sub_module (nginx内置)：非常好用，但是只能是普通字符串替换，无法正则替换。
2. ngx_http_substitutions_filter_module (第三方)：只尝试了30分钟，但是这30分钟很折磨，我本以为它是强大的，但事实上它只不过在同一行内容中进行不完全的正则匹配替换，连换行都无法匹配，这种很大程度上失去了正则的色彩，基本没啥大前途。
3. replace-filter-nginx-module (第三方，推荐)：完全的正则匹配，接下来整理了下这个模块的安装过程。

安装

因为博主是非源码安装的nginx，所以使用源码安装这个模块的时候注意下，但是相差不多。

安装此模块需要先安装sregex运行库。

1. 提前准备好环境，需要用到下面的底层库，如果直接下载源码则不用安装git

apt update
apt install git make gcc -y  

2. 安装sregex

cd /usr/local/src
git clone https://github.com/agentzh/sregex
cd sregex
make
make install

3. 下载nginx对应版本的源码

# V是大写的
nginx -V

下载对应的源码包

cd /usr/local/src

# nginx源码
wget http://nginx.org/download/nginx-1.22.0.tar.gz
tar zxvf nginx-1.22.0.tar.gz
cd nginx-1.22.0

# replace-filter-nginx-module源码
git clone https://github.com/agentzh/replace-filter-nginx-module

4. 重新编译nginx并安装replace-filter-nginx-module

# 把新模块加入nginx编译命令(--add-module=/usr/local/src/nginx-1.22.0/replace-filter-nginx-module)
./configure --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib64/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --add-module=/usr/local/src/nginx-1.22.0/replace-filter-nginx-module --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -fPIC' --with-ld-opt='-Wl,-z,relro -Wl,-z,now -pie'

# 编译（最好不要直接make install，避免出问题）
make -j8

# 以上完成后，会在objs目录下生成一个nginx文件，先验证：
./nginx -t

# 查看新的模块是否已经开启
./nginx -V

如果在测试nginx阶段报错 ./objs/nginx: error while loading shared libraries: libsregex.so.0: cannot open shared object file: No such file or directory则需要进行类库地址关联，因为我们明明已经成功安装了libsregex.so.0

从上图可以看到nginx只从/usr/lib64路径下寻找，那么我们将类库直接复制过去就行

cp /usr/local/lib/libsregex.so.0 /usr/lib64

5. 替换nginx

mv /usr/sbin/nginx /usr/sbin/nginx.bak
cp objs/nginx /usr/sbin

6. 重新启动nginx (不要reload)

service nginx restart

7. 用法示例（博主已经在用，一瞬间发现，这个就是我需要的那个功能）

replace_filter_types   text/css application/x-javascript application/javascript text/xml text/plain;
replace_filter '<div class="big\s+img">.*\n</table></div>' '' g;

模块使用

支持以下Perl 5正则表达式语法特性

^             match the beginning of lines
$             match the end of lines

\A            match only at beginning of stream
\z            match only at end of stream

\b            match a word boundary
\B            match except at a word boundary

.             match any char
\C            match a single C-language char (octet)

[ab0-9]       character classes (positive)
[^ab0-9]      character classes (negative)

\d            match a digit character ([0-9])
\D            match a non-digit character ([^0-9])

\s            match a whitespace character ([ \f\n\r\t])
\S            match a non-whitespace character ([^ \f\n\r\t])

\h            match a horizontal whitespace character
\H            match a character that isn't horizontal whitespace

\v            match a vertical whitespace character
\V            match a character that isn't vertical whitespace

\w            match a "word" character ([A-Za-z0-9_])
\W            match a non-"word" character ([^A-Za-z0-9_])

\cK           control char (example: VT)

\N            match a character that isn't a newline

ab            concatenation; first match a, and then b
a|b           alternation; match a or b

(a)           capturing parentheses
(?:a)         non-capturing parantheses

a?            match 1 or 0 times, greedily
a*            match 0 or more times, greedily
a+            match 1 or more times, greedily

a??           match 1 or 0 times, not greedily
a*?           match 0 or more times, not greedily
a+?           match 1 or more times, not greedily

a{n}          match exactly n times
a{n,m}        match at least n but not more than m times, greedily
a{n,}         match at least n times, greedily

a{n}?         match exactly n times, not greedily (redundant)
a{n,m}?       match at least n but not more than m times, not greedily
a{n,}?        match at least n times, not greedily

支持以下转义序列

\t          tab
\n          newline
\r          return
\f          form feed
\a          alarm
\e          escape
\b          backspace (in character class only)
\x{}, \x00  character whose ordinal is the given hexadecimal number
\o{}, \000  character whose ordinal is the given octal number