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Use jq to filter objects list with regex

My use case is filtering an array of objects that have an attribute that matches a particular regex and extract another attribute from that object.

Here is my dataset:

[
  {name: 'Chris', id: 'aabbcc'},
  {name: 'Ryan', id: 'ddeeff'},
  {name: 'Ifu', id: 'aaddgg'}
]

First get each element of an array.

> data | jq '.[]'
{name: 'Chris', id: 'aabbcc'}
{name: 'Ryan', id: 'ddeeff'}
{name: 'Ifu', id: 'aaddgg'}

Pipe the elements to select and pass an expression that will evaluate to truthy for each object.

> data | jq '.[] | select(true) | select(.name)'
{name: 'Chris', id: 'aabbcc'}
{name: 'Ryan', id: 'ddeeff'}
{name: 'Ifu', id: 'aaddgg'}

Then use the test function to compare an attribute to a regex.

> data | jq '.[] | select(.id|test("a."))'
{name: 'Chris', id: 'aabbcc'}
{name: 'Ifu', id: 'aaddgg'}

Extract the name attribute for a more concise list.

> data | jq '.[] | select(.id|test("a.")) | .name'
Chris
Ifu

Read more about jq