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Traverse (Read)

This is the simplest (and perhaps most used) operator. It is used to navigate deeply into yaml structures.

Simple map navigation

Given a sample.yml file of:
a:
b: apple
then
yq '.a' sample.yml
will output
b: apple

Splat

Often used to pipe children into other operators
Given a sample.yml file of:
- b: apple
- c: banana
then
yq '.[]' sample.yml
will output
b: apple
c: banana

Optional Splat

Just like splat, but won't error if you run it against scalars
Given a sample.yml file of:
cat
then
yq '.[]' sample.yml
will output

Special characters

Use quotes with square brackets around path elements with special characters
Given a sample.yml file of:
"{}": frog
then
yq '.["{}"]' sample.yml
will output
frog

Nested special characters

Given a sample.yml file of:
a:
"key.withdots":
"another.key": apple
then
yq '.a["key.withdots"]["another.key"]' sample.yml
will output
apple

Keys with spaces

Use quotes with square brackets around path elements with special characters
Given a sample.yml file of:
"red rabbit": frog
then
yq '.["red rabbit"]' sample.yml
will output
frog

Dynamic keys

Expressions within [] can be used to dynamically lookup / calculate keys
Given a sample.yml file of:
b: apple
apple: crispy yum
banana: soft yum
then
yq '.[.b]' sample.yml
will output
crispy yum

Children don't exist

Nodes are added dynamically while traversing
Given a sample.yml file of:
c: banana
then
yq '.a.b' sample.yml
will output
null

Optional identifier

Like jq, does not output an error when the yaml is not an array or object as expected
Given a sample.yml file of:
- 1
- 2
- 3
then
yq '.a?' sample.yml
will output

Wildcard matching

Given a sample.yml file of:
a:
cat: apple
mad: things
then
yq '.a."*a*"' sample.yml
will output
apple
things

Aliases

Given a sample.yml file of:
a: &cat
c: frog
b: *cat
then
yq '.b' sample.yml
will output
*cat

Traversing aliases with splat

Given a sample.yml file of:
a: &cat
c: frog
b: *cat
then
yq '.b[]' sample.yml
will output
frog

Traversing aliases explicitly

Given a sample.yml file of:
a: &cat
c: frog
b: *cat
then
yq '.b.c' sample.yml
will output
frog

Traversing arrays by index

Given a sample.yml file of:
- 1
- 2
- 3
then
yq '.[0]' sample.yml
will output
1

Traversing nested arrays by index

Given a sample.yml file of:
[[], [cat]]
then
yq '.[1][0]' sample.yml
will output
cat

Maps with numeric keys

Given a sample.yml file of:
2: cat
then
yq '.[2]' sample.yml
will output
cat

Maps with non existing numeric keys

Given a sample.yml file of:
a: b
then
yq '.[0]' sample.yml
will output
null

Traversing merge anchors

Given a sample.yml file of:
foo: &foo
a: foo_a
thing: foo_thing
c: foo_c
bar: &bar
b: bar_b
thing: bar_thing
c: bar_c
foobarList:
b: foobarList_b
!!merge <<:
- *foo
- *bar
c: foobarList_c
foobar:
c: foobar_c
!!merge <<: *foo
thing: foobar_thing
then
yq '.foobar.a' sample.yml
will output
foo_a

Traversing merge anchors with override

Given a sample.yml file of:
foo: &foo
a: foo_a
thing: foo_thing
c: foo_c
bar: &bar
b: bar_b
thing: bar_thing
c: bar_c
foobarList:
b: foobarList_b
!!merge <<:
- *foo
- *bar
c: foobarList_c
foobar:
c: foobar_c
!!merge <<: *foo
thing: foobar_thing
then
yq '.foobar.c' sample.yml
will output
foo_c

Traversing merge anchors with local override

Given a sample.yml file of:
foo: &foo
a: foo_a
thing: foo_thing
c: foo_c
bar: &bar
b: bar_b
thing: bar_thing
c: bar_c
foobarList:
b: foobarList_b
!!merge <<:
- *foo
- *bar
c: foobarList_c
foobar:
c: foobar_c
!!merge <<: *foo
thing: foobar_thing
then
yq '.foobar.thing' sample.yml
will output
foobar_thing

Splatting merge anchors

Given a sample.yml file of:
foo: &foo
a: foo_a
thing: foo_thing
c: foo_c
bar: &bar
b: bar_b
thing: bar_thing
c: bar_c
foobarList:
b: foobarList_b
!!merge <<:
- *foo
- *bar
c: foobarList_c
foobar:
c: foobar_c
!!merge <<: *foo
thing: foobar_thing
then
yq '.foobar[]' sample.yml
will output
foo_c
foo_a
foobar_thing

Traversing merge anchor lists

Note that the later merge anchors override previous
Given a sample.yml file of:
foo: &foo
a: foo_a
thing: foo_thing
c: foo_c
bar: &bar
b: bar_b
thing: bar_thing
c: bar_c
foobarList:
b: foobarList_b
!!merge <<:
- *foo
- *bar
c: foobarList_c
foobar:
c: foobar_c
!!merge <<: *foo
thing: foobar_thing
then
yq '.foobarList.thing' sample.yml
will output
bar_thing

Splatting merge anchor lists

Given a sample.yml file of:
foo: &foo
a: foo_a
thing: foo_thing
c: foo_c
bar: &bar
b: bar_b
thing: bar_thing
c: bar_c
foobarList:
b: foobarList_b
!!merge <<:
- *foo
- *bar
c: foobarList_c
foobar:
c: foobar_c
!!merge <<: *foo
thing: foobar_thing
then
yq '.foobarList[]' sample.yml
will output
bar_b
foo_a
bar_thing
foobarList_c

Select multiple indices

Given a sample.yml file of:
a:
- a
- b
- c
then
yq '.a[0, 2]' sample.yml
will output
a
c
Last modified 8mo ago