CODEWITHSUNDEEP
bashshellsed
pmiranda
pmiranda

Reputation: 8470

Extract string from text file with sed

I have a text file called .env like this:

SOME_VAR="value"
SOME_VAR_2="value2"
NODE_ENV="staging"
SOME_VAR_3="value3"

I need to extract the string in between " and " where the lines begin with NODE_ENV=

In other words, I need the string staging from that file. Then I need to use a command like.

Right now I have this:

git checkout $(cat .environment)

Where .environment is a file with a single value staging, so with that command I got:

git checkout $(cat .environment)

but now I need what I said before, to extract the value from a file with multiple lines in the mentioned format.

I tried with sed but I'm not sure how to use it:

sed -r '/NODE_ENV.*/I!d;s/.*:.(.*).}$/\1/' .env

but that's:

NODE_ENV="staging"

and what I need is to get:

staging

Upvotes: 0

Views: 726

Answers (3)

Bohemian
Bohemian

Reputation: 425358

You can combine some simple commands:

grep NODE_ENV .env | sed -E 's/.*"(.*)"/\1/'

Upvotes: 0

vmicrobio
vmicrobio

Reputation: 331

You can use grep to extract this value:

grep -Po '(?<=NODE_ENV=")[^"]*' .env

output will be:

staging

Upvotes: 1

Barmar
Barmar

Reputation: 782498

Your regexp is looking for a : character, but there's no : in the file. You should be looking for ="..." and use the capture group to match what's between the ".

sed -n -r '/NODE_ENV/s/.*="(.*)"/\1/p' .env

Use the -n option to disable default printing, then append p to the command to print that matching line after the substitution.

Upvotes: 1

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