Regular Expression in sed for multiple replacement

2019-03-22 15:26发布

问题:

I want to sanitise some input and replace several characters with acceptable input, e.g. a Danish 'å' with 'aa'.

This is easily done using several statements, e.g. /æ/ae/, /å/aa/, /ø/oe/, but due to tool limitations, I want to be able to do this in a single regular expression.

I can catch all of the relevant cases (/[(æ)(ø)(å)(Æ)(Ø)(Å)]/) but I replacement does not work as I want it to (but probably completely as intended):

 $ temp="RødgrØd med flæsk"

 $ echo $temp
 RødgrØd med flæsk

 $ echo $temp | sed 's/[(æ)(ø)(å)(Æ)(Ø)(Å)]/(ae)(oe)(aa)(Ae)(Oe)(Aa)/g'
 R(ae)(oe)(aa)(Ae)(Oe)(Aa)dgr(ae)(oe)(aa)(Ae)(Oe)(Aa)d med fl(ae)(oe)(aa)(Ae)(Oe)(Aa)sk

(first echo line is to show that it isn't an encoding issue)

Just as an aside, the tool issue is that I should like to also use the same regex in a Sublime Text 2 snippet.

Anyone able to discern what is wrong with my regex statement?

Thanks in advance.

回答1:

Split it up into several sed statements, separated by ;:

sed 's/æ/ae/g;s/ø/oe/g;s/å/aa/g;s/Æ/Ae/g;s/Ø/Oe/g;s/Å/Aa/g'


回答2:

With

sed -e 's/Find/Replace/g;s/Find/Replace/g;[....];/Find/Replace/g'

you'll do the trick.

So, translate into what you need

sed -e 's/æ/ae/g;s/ø/oe/g;s/å/aa/g;s/Æ/Ae/g;s/Ø/Oe/g;s/Å/Aa/g'


回答3:

This might work for you (GNU sed):

sed -r 's/$/\næaeøoeåaaÆAeØOeÅAa/;:a;s/([æøåÆØÅ])(.*\n.*\1(..))/\3\2/;ta;s/\n.*//' file

It works by adding a lookup table to the end of the line, looping until all keys are replaced then removes the lookup table.