Making nginx replace a css stylesheet

Question

I'm using nginx with module HttpSubsModule to replace a few css stylesheets for another. My regex is

subs_filter '<link(.*)href="(.+\.css)([\?.]?[^"]*)(".*)>' '<link  href="new.css" rel="stylesheet" type="text/css">' irg;

It seems valid but subs_filter doesn't work with it. Simpler forms, such as

subs_filter (.*)css '<link  href="new.css" rel="stylesheet" type="text/css">' irg;

do work but catch a lot of false results.

How should I write this regex?

EDIT: The following version works on www.regexe.com replacing any link tag with a css file, but still doesn't work on nginx.

subs_filter '(<link.*href=")(.+\.css)([\?.]?[^"]*)(".*>)' '$1new.css$3$4' irg;

The docs say that it will not work with proxy compressed response. You can disable the compressed response like this: proxy_set_header Accept-Encoding "";. Does it help? — Wiktor Stribiżew
– Wiktor Stribiżew, Commented May 25, 2015 at 19:11
I've tried to be sure but no. Note that I can make some basic substitution, just not with the complexity I'd like. — noinstance
– noinstance, Commented May 25, 2015 at 19:15
Try with this regex: (<link.*?href=")(.+?\.css)([\?.]?[^"]*?)(".*?>). I think the reason might be in the regex greediness. — Wiktor Stribiżew
– Wiktor Stribiżew, Commented May 25, 2015 at 19:34
Nothing happens. So far I got this working: subs_filter href="(.*)css.*" test ir; but it is too broad. — noinstance
– noinstance, Commented May 25, 2015 at 21:27

Stephan · Accepted Answer · 2015-11-23 11:02:56Z

1

Try this:

subs_filter '(<link.*?href=(.))[^"']+\.css([^"']+\2[^>]*?>)' '$1new.css$3' irg;

Regular expression visualization

answered Nov 23, 2015 at 10:55

Stephan

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1 Comment

I'm no longer working on this but will give it a shot soon when I have the opportunity.