nginx_substitutions_filter Note: this module is not distributed with the Nginx source. Installation instructions can be found below.

Description nginx_substitutions_filter is a filter module which can do both regular expression and fixed string substitutions on response bodies. This module is quite different from the Nginx's native Substitution Module. It scans the output chains buffer and matches string line by line, just like Apache's mod_substitute (http://httpd.apache.org/docs/trunk/mod/mod_substitute.html).

Example location / {

    subs_filter_types text/html text/css text/xml;
    subs_filter st(\d*).example.com $1.example.com ir;
    subs_filter a.example.com s.example.com;

}

Directives

• subs_filter_types

• subs_filter

  subs_filter_types syntax: subs_filter_types mime-type [mime-types]

  default: subs_filter_types text/html

  context: http, server, location

  subs_filter_types is used to specify which content types should be checked for subs_filter. The default is only text/html.

  This module just works with plain text. If the response is compressed, it can't uncompress the response and will ignore this response. This module can be compatible with gzip filter module. But it will not work with proxy compressed response. You can disable the compressed response like this:

  proxy_set_header Accept-Encoding "";

  subs_filter syntax: subs_filter source_str destination_str [gior]

  default: none

  context: http, server, location

  subs_filter allows replacing source string(regular expression or fixed) in the nginx response with destination string. Substitution text may contain variables. More than one substitution rules per location is supported. The meaning of the third flags are:

• g(default): Replace all the match strings.

• i: Perform a case-insensitive match.

• o: Just replace the first one.

• r: The pattern is treated as a regular expression, default is fixed string.

  Installation To install, get the source with subversion:

  git clone git://github.com/yaoweibin/ngx_http_substitutions_filter_module.git

  and then compile nginx with the following option:

  ./configure --add-module=/path/to/module

  Known issue

• CHANGES Changes with nginx_substitutions_filter 0.6.0 2012-06-30

• refactor this module

  Changes with nginx_substitutions_filter 0.5.2 2010-08-11

• do many optimizing for this module

• fix a bug of buffer overlap

• fix a segment fault bug when output chain return NGX_AGAIN.

• fix a bug about last buffer with no linefeed. This may cause segment fault. Thanks for Josef Fröhle

  Changes with nginx_substitutions_filter 0.5 2010-04-15

• refactor the source structure, create branches of dev

• fix a bug of small chunk of buffers causing lose content

• fix the bug of last_buf and the nginx's compatibility above 0.8.25

• fix a bug with unwanted capture config error in fix string substitution

• add feature of regex captures

  Changes with nginx_substitutions_filter 0.4 2009-12-23

• fix many bugs

  Changes with nginx_substitutions_filter 0.3 2009-02-04

• Initial public release

  Reporting a bug Questions/patches may be directed to Weibin Yao, yaoweibin@gmail.com.