CODEWITHSUNDEEP
bashsedyaml
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Reputation: 5092

insert key value pair to yaml file with correct indent by sed

A example of env.yaml file is shown below

package:
  name: "xyz"
  version: "2.3.1"

build:
  noarch: python

requirements:
  build:
    - python

how to add a build/number:123 to the yaml file with correct indentation as follows?

package:
  name: "xyz"
  version: "2.3.1"

build:
  noarch: python
  number: 123

requirements:
  build:
    - python

The tricky thing is, there is a build key under requirement section, and I don't want any number added under that

Upvotes: 0

Views: 1315

Answers (3)

potong
potong

Reputation: 58488

This might work for you (GNU sed):

sed -E '/^\s+\S/h;/^build:/{:a;n;/^$/!ba;x;s/\S.*/number: 123/p;x}' file

Make a copy of any indented line and then append the copy (replacing its content by the desired result) at the end of the build: stanza.

N.B. This is based on the data provided, the programmer can be more specific and choose an indented line like name: in the package: stanza if s/he prefers.

Upvotes: 0

Ed Morton
Ed Morton

Reputation: 204258

sed is the best tool for doing simple s/old/new/ on individual strings, that is all. For anything more than that you should use awk (assuming you don't have access to a tool that understands whatever language your input file is written in, if applicable)

$ cat tst.awk
/^build:/ { f=1 }
!NF { prt(); f=0 }
{ print; prev=$0 }
END { prt() }

function prt() {
    if (f) {
        sub(/[^[:space:]].*/,"",prev)
        print prev "number: 123"
    }
}


$ awk -f tst.awk file
package:
  name: "xyz"
  version: "2.3.1"

build:
  noarch: python
  number: 123

requirements:
  build:
    - python

Upvotes: 2

PandaCheLion
PandaCheLion

Reputation: 476

If sed is to be used, and assuming the line sequence is fixed and that both the file content order is fixed and the values to insert:

sed -ri 's/^(\s+)noarch: python/&\n\1job: 123/' env.yaml

Upvotes: 1

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