... * too greedy in sed

Question

I want to extract the version number from multiple lines in bash without using too many additional packages. So far I've tried sed

.

Here is the API:

3.81-8.1ubuntu1.1    should give :  3.81
2.68-1ubuntu2        should give :  2.68
1:1.11.3-1ubuntu2    should give :  1.11.3

And here is my sed command:

echo ... | sed -r 's/.*([0-9\.]+).*/\1/'

However, the discovery is .*

too greedy, especially in the latter case. I have tried several .*?

and .\{-}

with no success.

I can do it in two passes, but I'd rather learn to do it in one.

+3

regex grep sed

Offirmo 22 jan. 13 at 17:20

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2 answers

To overcome greed you need to be more strict with regex:

$ sed -r 's/.*([0-9]+\.[0-9]+\.?[0-9]+)-.*/\1/' file
3.81
2.68
1.11.3

This will match version numbers with major, minor, and build (optional), always followed by a hyphen.

+1

Chris seymour 22 jan. 13 at 17:50

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Kent · Accepted Answer · 2013-01-22T17:25:09+0000

is it OK for you?

 grep -Po "[\d\.]*(?=-)" file

Example:

kent$  cat tt
3.81-8.1ubuntu1.1
2.68-1ubuntu2
1:1.11.3-1ubuntu2

kent$  grep -Po "[\d\.]*(?=-)" tt
3.81
2.68
1.11.3