GitBook: [v2.x] 10 pages modified

removed repeated word

.gitbook/assets/convert.md

@@ -0,0 +1,60 @@
+## Yaml to Json
+To convert output to json, use the --tojson (or -j) flag. This is supported by all commands.
+
+Each matching yaml node will be converted to json and printed out on a separate line.
+
+Given a sample.yaml file of:
+```yaml
+b:
+  c: 2
+```
+then
+```bash
+yq r -j sample.yaml
+```
+
+will output
+```json
+{"b":{"c":2}}
+```
+
+Given a sample.yaml file of:
+```yaml
+bob:
+  c: 2
+bab:
+  c: 5
+```
+then
+```bash
+yq r -j sample.yaml b*
+```
+
+will output
+```json
+{"c":2}
+{"c":5}
+```
+
+## Json to Yaml
+To read in json, just pass in a json file instead of yaml, it will just work :)
+
+e.g given a json file
+
+```json
+{"a":"Easy! as one two three","b":{"c":2,"d":[3,4]}}
+```
+then
+```bash
+yq r sample.json
+```
+will output
+```yaml
+a: Easy! as one two three
+b:
+  c: 2
+  d:
+  - 3
+  - 4
+```
+

.github/ISSUE_TEMPLATE/bug_report.md

@@ -10,6 +10,9 @@ assignees: ''
 **Describe the bug**
 A clear and concise description of what the bug is.
 
+version of yq: 
+operating system:
+
 **Input Yaml**
 Concise yaml document(s) (as simple as possible to show the bug)
 data1.yml:

README.md

@@ -1,128 +1,36 @@
-# yq
+---
+description: yq is a lightweight and portable command-line YAML processor
+---
 
-![Build](https://github.com/mikefarah/yq/workflows/Build/badge.svg)  ![Docker Pulls](https://img.shields.io/docker/pulls/mikefarah/yq.svg) ![Github Releases (by Release)](https://img.shields.io/github/downloads/mikefarah/yq/total.svg) ![Go Report](https://goreportcard.com/badge/github.com/mikefarah/yq)
+# Yq
 
+### Install[¶]() <a id="install"></a>
 
-a lightweight and portable command-line YAML processor
+On MacOS:
 
-The aim of the project is to be the [jq](https://github.com/stedolan/jq) or sed of yaml files.
+```text
-
-## New version!
-V3 is officially out - if you've been using v2 and want/need to upgrade, checkout the [upgrade guide](https://mikefarah.gitbook.io/yq/upgrading-from-v2).
-
-## Install
-
-### [Download the latest binary](https://github.com/mikefarah/yq/releases/latest)
-
-### MacOS:
-```
 brew install yq
 ```
-### Ubuntu and other Linux distros supporting `snap` packages:
+
-```
+On Ubuntu and other Linux distros supporting `snap` packages:
+
+```text
 snap install yq
 ```
 
-#### Snap notes
+On Ubuntu 16.04 or higher from Debian package:
-`yq` installs with with [_strict confinement_](https://docs.snapcraft.io/snap-confinement/6233) in snap, this means it doesn't have direct access to root files. To read root files you can:
 
-```
+```text
-sudo cat /etc/myfile | yq r - a.path
-```
-
-And to write to a root file you can either use [sponge](https://linux.die.net/man/1/sponge):
-```
-sudo cat /etc/myfile | yq w - a.path value | sudo sponge /etc/myfile
-```
-or write to a temporary file:
-```
-sudo cat /etc/myfile | yq w - a.path value | sudo tee /etc/myfile.tmp
-sudo mv /etc/myfile.tmp /etc/myfile
-rm /etc/myfile.tmp
-```
-
-### On Ubuntu 16.04 or higher from Debian package:
-```sh
-sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys CC86BB64
 sudo add-apt-repository ppa:rmescandon/yq
 sudo apt update
 sudo apt install yq -y
 ```
-Supported by @rmescandon
 
-### Go Get:
+or, [Download latest binary](https://github.com/mikefarah/yq/releases/latest) or alternatively:
-```
+
-GO111MODULE=on go get github.com/mikefarah/yq/v3
+```text
+GO111MODULE=on go get github.com/mikefarah/yq/v2
 ```
 
-## Run with Docker
+[View on GitHub](https://github.com/mikefarah/yq)
 
-Oneshot use:
-
-```bash
-docker run --rm -v ${PWD}:/workdir mikefarah/yq yq [flags] <command> FILE...
-```
-
-Run commands interactively:
-
-```bash
-docker run --rm -it -v ${PWD}:/workdir mikefarah/yq sh
-```
-
-It can be useful to have a bash function to avoid typing the whole docker command:
-
-```bash
-yq() {
-  docker run --rm -i -v ${PWD}:/workdir mikefarah/yq yq $@
-}
-```
-
-## Features
-- Written in portable go, so you can download a lovely dependency free binary
-- [Colorize the output](https://mikefarah.gitbook.io/yq/usage/output-format#colorize-output)
-- [Deep read a yaml file with a given path expression](https://mikefarah.gitbook.io/yq/commands/read#basic)
-- [List matching paths of a given path expression](https://mikefarah.gitbook.io/yq/commands/read#path-only)
-- [Return the lengths of arrays/object/scalars](https://mikefarah.gitbook.io/yq/commands/read#printing-length-of-the-results)
-- Update a yaml file given a [path expression](https://mikefarah.gitbook.io/yq/commands/write-update#basic) or [script file](https://mikefarah.gitbook.io/yq/commands/write-update#basic)
-- Update creates any missing entries in the path on the fly
-- Deeply [compare](https://mikefarah.gitbook.io/yq/commands/compare) yaml files
-- Keeps yaml formatting and comments when updating
-- [Validate a yaml file](https://mikefarah.gitbook.io/yq/commands/validate)
-- Create a yaml file given a [deep path and value](https://mikefarah.gitbook.io/yq/commands/create#creating-a-simple-yaml-file) or a [script file](https://mikefarah.gitbook.io/yq/commands/create#creating-using-a-create-script)
-- [Prefix a path to a yaml file](https://mikefarah.gitbook.io/yq/commands/prefix)
-- [Convert to/from json to yaml](https://mikefarah.gitbook.io/yq/usage/convert)
-- [Pipe data in by using '-'](https://mikefarah.gitbook.io/yq/commands/read#from-stdin)
-- [Merge](https://mikefarah.gitbook.io/yq/commands/merge) multiple yaml files with various options for [overriding](https://mikefarah.gitbook.io/yq/commands/merge#overwrite-values) and [appending](https://mikefarah.gitbook.io/yq/commands/merge#append-values-with-arrays)
-- Supports multiple documents in a single yaml file for [reading](https://mikefarah.gitbook.io/yq/commands/read#multiple-documents), [writing](https://mikefarah.gitbook.io/yq/commands/write-update#multiple-documents) and [merging](https://mikefarah.gitbook.io/yq/commands/merge#multiple-documents)
-
-## [Usage](https://mikefarah.gitbook.io/yq/)
-
-Check out the [documentation](https://mikefarah.gitbook.io/yq/) for more detailed and advanced usage.
-
-```
-Usage:
-  yq [flags]
-  yq [command]
-
-Available Commands:
-  compare     yq x [--prettyPrint/-P] dataA.yaml dataB.yaml 'b.e(name==fr*).value'
-  delete      yq d [--inplace/-i] [--doc/-d index] sample.yaml 'b.e(name==fred)'
-  help        Help about any command
-  merge       yq m [--inplace/-i] [--doc/-d index] [--overwrite/-x] [--append/-a] sample.yaml sample2.yaml
-  new         yq n [--script/-s script_file] a.b.c newValue
-  prefix      yq p [--inplace/-i] [--doc/-d index] sample.yaml a.b.c
-  read        yq r [--printMode/-p pv] sample.yaml 'b.e(name==fr*).value'
-  validate    yq v sample.yaml
-  write       yq w [--inplace/-i] [--script/-s script_file] [--doc/-d index] sample.yaml 'b.e(name==fr*).value' newValue
-
-Flags:
-  -C, --colors        print using colors
-  -h, --help          help for yq
-  -I, --indent int    sets indent level for output (default 2)
-  -P, --prettyPrint   pretty print
-  -j, --tojson        output as json. By default it prints a json document in one line, use the prettyPrint flag to print a formatted doc.
-  -v, --verbose       verbose mode
-  -V, --version       Print version information and quit
-
-Use "yq [command] --help" for more information about a command.
-```

SUMMARY.md

@@ -0,0 +1,11 @@
+# Table of contents
+
+* [Yq](README.md)
+* [Write](write-update.md)
+* [Read](read.md)
+* [Prefix](prefix.md)
+* [Delete](delete.md)
+* [Create](create.md)
+* [Convert](convert.md)
+* [Merge](merge.md)
+

cmd/compare.go

@@ -31,6 +31,8 @@ yq x -d1 dataA.yaml dataB.yaml 'a.b.c'
 	cmdCompare.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
 	cmdCompare.PersistentFlags().StringVarP(&printMode, "printMode", "p", "v", "print mode (v (values, default), p (paths), pv (path and value pairs)")
 	cmdCompare.PersistentFlags().StringVarP(&defaultValue, "defaultValue", "D", "", "default value printed when there are no results")
+	cmdCompare.PersistentFlags().BoolVarP(&stripComments, "stripComments", "", false, "strip comments out before comparing")
+	cmdCompare.PersistentFlags().BoolVarP(&explodeAnchors, "explodeAnchors", "X", false, "explode anchors")
 	return cmdCompare
 }
 

cmd/compare_test.go

@@ -0,0 +1,115 @@
+package cmd
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestCompareSameCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare ../examples/data1.yaml ../examples/data1.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := ``
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestCompareIgnoreCommentsCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare --stripComments ../examples/data1.yaml ../examples/data1-no-comments.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := ``
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestCompareDontIgnoreCommentsCmd(t *testing.T) {
+	forceOsExit = false
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare ../examples/data1.yaml ../examples/data1-no-comments.yaml")
+
+	expectedOutput := `-a: simple # just the best
++a: simple
+ b: [1, 2]
+ c:
+   test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestCompareExplodeAnchorsCommentsCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare --explodeAnchors ../examples/simple-anchor.yaml ../examples/simple-anchor-exploded.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := ``
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestCompareDontExplodeAnchorsCmd(t *testing.T) {
+	forceOsExit = false
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare ../examples/simple-anchor.yaml ../examples/simple-anchor-exploded.yaml")
+
+	expectedOutput := `-foo: &foo
++foo:
+   a: 1
+ foobar:
+-  !!merge <<: *foo
++  a: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestCompareDifferentCmd(t *testing.T) {
+	forceOsExit = false
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare ../examples/data1.yaml ../examples/data3.yaml")
+
+	expectedOutput := `-a: simple # just the best
+-b: [1, 2]
++a: "simple" # just the best
++b: [1, 3]
+ c:
+   test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestComparePrettyCmd(t *testing.T) {
+	forceOsExit = false
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare -P ../examples/data1.yaml ../examples/data3.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := ` a: simple # just the best
+ b:
+   - 1
+-  - 2
++  - 3
+ c:
+   test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestComparePathsCmd(t *testing.T) {
+	forceOsExit = false
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "compare -P -ppv ../examples/data1.yaml ../examples/data3.yaml **")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := ` a: simple # just the best
+ b.[0]: 1
+-b.[1]: 2
++b.[1]: 3
+ c.test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}

cmd/constant.go

@@ -9,12 +9,16 @@ var customTag = ""
 var printMode = "v"
 var printLength = false
 var unwrapScalar = true
+var customStyle = ""
+var anchorName = ""
+var makeAlias = false
 var stripComments = false
 var collectIntoArray = false
 var writeInplace = false
 var writeScript = ""
 var sourceYamlFile = ""
 var outputToJSON = false
+var exitStatus = false
 var prettyPrint = false
 var explodeAnchors = false
 var colorsEnabled = false

cmd/delete_test.go

@@ -0,0 +1,246 @@
+package cmd
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestDeleteYamlCmd(t *testing.T) {
+	content := `a: 2
+b:
+  c: things
+  d: something else
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s b.c", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `a: 2
+b:
+  d: something else
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteDeepDoesNotExistCmd(t *testing.T) {
+	content := `a: 2`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s b.c", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `a: 2
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteSplatYaml(t *testing.T) {
+	content := `a: other
+b: [3, 4]
+c:
+  toast: leave
+  test: 1
+  tell: 1
+  tasty.taco: cool
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s c.te*", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `a: other
+b: [3, 4]
+c:
+  toast: leave
+  tasty.taco: cool
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteSplatArrayYaml(t *testing.T) {
+	content := `a: 2
+b:
+ hi:
+  - thing: item1
+    name: fred
+  - thing: item2
+    name: sam
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s b.hi[*].thing", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `a: 2
+b:
+  hi:
+    - name: fred
+    - name: sam
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteDeepSplatArrayYaml(t *testing.T) {
+	content := `thing: 123
+b:
+ hi:
+  - thing: item1
+    name: fred
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s **.thing", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `b:
+  hi:
+    - name: fred
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteSplatPrefixYaml(t *testing.T) {
+	content := `a: 2
+b:
+ hi:
+   c: things
+   d: something else
+ there:
+   c: more things
+   d: more something else
+ there2:
+   c: more things also
+   d: more something else also
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s b.there*.c", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `a: 2
+b:
+  hi:
+    c: things
+    d: something else
+  there:
+    d: more something else
+  there2:
+    d: more something else also
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteYamlArrayCmd(t *testing.T) {
+	content := `- 1
+- 2
+- 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s [1]", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `- 1
+- 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteYamlArrayExpressionCmd(t *testing.T) {
+	content := `- name: fred
+- name: cat
+- name: thing
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s (name==cat)", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `- name: fred
+- name: thing
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteYamlMulti(t *testing.T) {
+	content := `apples: great
+---
+- 1
+- 2
+- 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete -d 1 %s [1]", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+
+	expectedOutput := `apples: great
+---
+- 1
+- 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestDeleteYamlMultiAllCmd(t *testing.T) {
+	content := `b:
+  c: 3
+apples: great
+---
+apples: great
+something: else
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("delete %s -d * apples", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+---
+something: else`
+	test.AssertResult(t, expectedOutput, strings.Trim(result.Output, "\n "))
+}

cmd/merge_test.go

@@ -0,0 +1,337 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestMergeCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge ../examples/data1.yaml ../examples/data2.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: simple # just the best
+b: [1, 2]
+c:
+  test: 1
+  toast: leave
+  tell: 1
+  tasty.taco: cool
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeOneFileCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge ../examples/data1.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: simple # just the best
+b: [1, 2]
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeNoAutoCreateCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge -c=false ../examples/data1.yaml ../examples/data2.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: simple # just the best
+b: [1, 2]
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeOverwriteCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge -c=false --overwrite ../examples/data1.yaml ../examples/data2.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: other # better than the original
+b: [3, 4]
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeAppendCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge --autocreate=false --append ../examples/data1.yaml ../examples/data2.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: simple # just the best
+b: [1, 2, 3, 4]
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeAppendArraysCmd(t *testing.T) {
+	content := `people:
+  - name: Barry
+    age: 21`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	mergeContent := `people:
+  - name: Roger
+    age: 44`
+	mergeFilename := test.WriteTempYamlFile(mergeContent)
+	defer test.RemoveTempYamlFile(mergeFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("merge --append -d* %s %s", filename, mergeFilename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `people:
+  - name: Barry
+    age: 21
+  - name: Roger
+    age: 44
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeOverwriteAndAppendCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge --autocreate=false --append --overwrite ../examples/data1.yaml ../examples/data2.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: other # better than the original
+b: [1, 2, 3, 4]
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeArraysCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge --append ../examples/sample_array.yaml ../examples/sample_array_2.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `[1, 2, 3, 4, 5]
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeCmd_Multi(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge -d1 ../examples/multiple_docs_small.yaml ../examples/data1.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: Easy! as one two three
+---
+another:
+  document: here
+a: simple # just the best
+b:
+  - 1
+  - 2
+c:
+  test: 1
+---
+- 1
+- 2
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeYamlMultiAllCmd(t *testing.T) {
+	content := `b:
+  c: 3
+apples: green
+---
+something: else`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	mergeContent := `apples: red
+something: good`
+	mergeFilename := test.WriteTempYamlFile(mergeContent)
+	defer test.RemoveTempYamlFile(mergeFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("merge -d* %s %s", filename, mergeFilename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+apples: green
+something: good
+---
+something: else
+apples: red
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeSpecialCharacterKeysCmd(t *testing.T) {
+	content := ``
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	mergeContent := `key[bracket]: value
+key.bracket: value
+key"value": value
+key'value': value
+`
+	mergeFilename := test.WriteTempYamlFile(mergeContent)
+	defer test.RemoveTempYamlFile(mergeFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("merge %s %s", filename, mergeFilename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	test.AssertResult(t, mergeContent, result.Output)
+}
+
+func TestMergeYamlMultiAllOverwriteCmd(t *testing.T) {
+	content := `b:
+  c: 3
+apples: green
+---
+something: else`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	mergeContent := `apples: red
+something: good`
+	mergeFilename := test.WriteTempYamlFile(mergeContent)
+	defer test.RemoveTempYamlFile(mergeFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("merge --overwrite -d* %s %s", filename, mergeFilename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+apples: red
+something: good
+---
+something: good
+apples: red
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeYamlNullMapCmd(t *testing.T) {
+	content := `b:`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	mergeContent := `b:
+  thing: a frog
+`
+	mergeFilename := test.WriteTempYamlFile(mergeContent)
+	defer test.RemoveTempYamlFile(mergeFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("merge %s %s", filename, mergeFilename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	test.AssertResult(t, mergeContent, result.Output)
+}
+
+func TestMergeCmd_Error(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to missing arg")
+	}
+	expectedOutput := `Must provide at least 1 yaml file`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestMergeCmd_ErrorUnreadableFile(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge ../examples/data1.yaml fake-unknown")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to unknown file")
+	}
+	var expectedOutput string
+	if runtime.GOOS == "windows" {
+		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
+	} else {
+		expectedOutput = `open fake-unknown: no such file or directory`
+	}
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestMergeCmd_Inplace(t *testing.T) {
+	filename := test.WriteTempYamlFile(test.ReadTempYamlFile("../examples/data1.yaml"))
+	err := os.Chmod(filename, os.FileMode(int(0666)))
+	if err != nil {
+		t.Error(err)
+	}
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("merge -i %s ../examples/data2.yaml", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	info, _ := os.Stat(filename)
+	gotOutput := test.ReadTempYamlFile(filename)
+	expectedOutput := `a: simple # just the best
+b: [1, 2]
+c:
+  test: 1
+  toast: leave
+  tell: 1
+  tasty.taco: cool
+`
+	test.AssertResult(t, expectedOutput, gotOutput)
+	test.AssertResult(t, os.FileMode(int(0666)), info.Mode())
+}
+
+func TestMergeAllowEmptyTargetCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge ../examples/empty.yaml ../examples/data1.yaml")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: simple # just the best
+b:
+  - 1
+  - 2
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestMergeAllowEmptyMergeCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "merge ../examples/data1.yaml ../examples/empty.yaml")
+	expectedOutput := `a: simple # just the best
+b: [1, 2]
+c:
+  test: 1
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}

cmd/new.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"github.com/mikefarah/yq/v3/pkg/yqlib"
+	errors "github.com/pkg/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -27,11 +28,19 @@ Note that you can give a create script to perform more sophisticated yaml. This
 	}
 	cmdNew.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for creating yaml")
 	cmdNew.PersistentFlags().StringVarP(&customTag, "tag", "t", "", "set yaml tag (e.g. !!int)")
+	cmdNew.PersistentFlags().StringVarP(&customStyle, "style", "", "", "formatting style of the value: single, double, folded, flow, literal, tagged")
+	cmdNew.PersistentFlags().StringVarP(&anchorName, "anchorName", "", "", "anchor name")
+	cmdNew.PersistentFlags().BoolVarP(&makeAlias, "makeAlias", "", false, "create an alias using the value as the anchor name")
 	return cmdNew
 }
 
 func newProperty(cmd *cobra.Command, args []string) error {
-	var updateCommands, updateCommandsError = readUpdateCommands(args, 2, "Must provide <path_to_update> <value>")
+	var badArgsMessage = "Must provide <path_to_update> <value>"
+	if len(args) != 2 {
+		return errors.New(badArgsMessage)
+	}
+
+	var updateCommands, updateCommandsError = readUpdateCommands(args, 2, badArgsMessage)
 	if updateCommandsError != nil {
 		return updateCommandsError
 	}

cmd/new_test.go

@@ -0,0 +1,101 @@
+package cmd
+
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestNewCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c 3")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestNewAnchorCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c 3 --anchorName=fred")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: &fred 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestNewAliasCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c foo --makeAlias")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: *foo
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestNewArrayCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b[0] 3")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  - 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestNewCmd_Error(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to missing arg")
+	}
+	expectedOutput := `Must provide <path_to_update> <value>`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestNewWithTaggedStyleCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c cat --tag=!!str --style=tagged")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: !!str cat
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestNewWithDoubleQuotedStyleCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c cat --style=double")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: "cat"
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestNewWithSingleQuotedStyleCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "new b.c cat --style=single")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 'cat'
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}

cmd/prefix_test.go

@@ -0,0 +1,189 @@
+package cmd
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestPrefixCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `d:
+  b:
+    c: 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestPrefixCmdArray(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s [+].d.[+]", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `- d:
+    - b:
+        c: 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestPrefixCmd_MultiLayer(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s d.e.f", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `d:
+  e:
+    f:
+      b:
+        c: 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestPrefixMultiCmd(t *testing.T) {
+	content := `b:
+  c: 3
+---
+apples: great
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s -d 1 d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+---
+d:
+  apples: great
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+func TestPrefixInvalidDocumentIndexCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s -df d", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail due to invalid path")
+	}
+	expectedOutput := `Document index f is not a integer or *: strconv.ParseInt: parsing "f": invalid syntax`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestPrefixBadDocumentIndexCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s -d 1 d", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail due to invalid path")
+	}
+	expectedOutput := `asked to process document index 1 but there are only 1 document(s)`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+func TestPrefixMultiAllCmd(t *testing.T) {
+	content := `b:
+  c: 3
+---
+apples: great
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix %s -d * d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `d:
+  b:
+    c: 3
+---
+d:
+  apples: great`
+	test.AssertResult(t, expectedOutput, strings.Trim(result.Output, "\n "))
+}
+
+func TestPrefixCmd_Error(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "prefix")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to missing arg")
+	}
+	expectedOutput := `Must provide <filename> <prefixed_path>`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestPrefixCmd_ErrorUnreadableFile(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "prefix fake-unknown a.b")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to unknown file")
+	}
+	var expectedOutput string
+	if runtime.GOOS == "windows" {
+		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
+	} else {
+		expectedOutput = `open fake-unknown: no such file or directory`
+	}
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestPrefixCmd_Inplace(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("prefix -i %s d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	gotOutput := test.ReadTempYamlFile(filename)
+	expectedOutput := `d:
+  b:
+    c: 3`
+	test.AssertResult(t, expectedOutput, strings.Trim(gotOutput, "\n "))
+}

cmd/read.go

@@ -31,6 +31,7 @@ yq r -- things.yaml '--key-starting-with-dashes.blah'
 	cmdRead.PersistentFlags().BoolVarP(&unwrapScalar, "unwrapScalar", "", true, "unwrap scalar, print the value with no quotes, colors or comments")
 	cmdRead.PersistentFlags().BoolVarP(&stripComments, "stripComments", "", false, "print yaml without any comments")
 	cmdRead.PersistentFlags().BoolVarP(&explodeAnchors, "explodeAnchors", "X", false, "explode anchors")
+	cmdRead.PersistentFlags().BoolVarP(&exitStatus, "exitStatus", "e", false, "set exit status if no matches are found")
 	return cmdRead
 }
 
@@ -50,7 +51,13 @@ func readProperty(cmd *cobra.Command, args []string) error {
 
 	matchingNodes, errorReadingStream := readYamlFile(args[0], path, updateAll, docIndexInt)
 
+	if exitStatus && len(matchingNodes) == 0 {
+		cmd.SilenceUsage = true
+		return errors.New("No matches found")
+	}
+
 	if errorReadingStream != nil {
+		cmd.SilenceUsage = true
 		return errorReadingStream
 	}
 	out := cmd.OutOrStdout()

cmd/root.go

@@ -54,8 +54,7 @@ func New() *cobra.Command {
 		createDeleteCmd(),
 		createNewCmd(),
 		createMergeCmd(),
+		createBashCompletionCmd(rootCmd),
 	)
-	rootCmd.SetOutput(os.Stdout)
-
 	return rootCmd
 }

cmd/shell_completion.go

@@ -0,0 +1,57 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var shellVariant = "bash"
+
+func createBashCompletionCmd(rootCmd *cobra.Command) *cobra.Command {
+	var completionCmd = &cobra.Command{
+		Use:   "shell-completion",
+		Short: "Generates shell completion scripts",
+		Long: `To load completion for:
+bash:
+	Run	
+	. <(yq shell-completion)
+	
+	To configure your bash shell to load completions for each session add to
+	your bashrc
+	
+	# ~/.bashrc or ~/.profile
+	. <(yq shell-completion)
+
+zsh:
+	The generated completion script should be put somewhere in your $fpath named _yq
+
+powershell:
+	Users need PowerShell version 5.0 or above, which comes with Windows 10 and 
+	can be downloaded separately for Windows 7 or 8.1. They can then write the 
+	completions to a file and source this file from their PowerShell profile, 
+	which is referenced by the $Profile environment variable.
+
+fish:
+	Save the output to a fish file and add it to your completions directory.
+
+	`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			switch shellVariant {
+			case "bash", "":
+				return rootCmd.GenBashCompletion(os.Stdout)
+			case "zsh":
+				return rootCmd.GenZshCompletion(os.Stdout)
+			case "fish":
+				return rootCmd.GenFishCompletion(os.Stdout, true)
+			case "powershell":
+				return rootCmd.GenPowerShellCompletion(os.Stdout)
+			default:
+				return fmt.Errorf("Unknown variant %v", shellVariant)
+			}
+		},
+	}
+	completionCmd.PersistentFlags().StringVarP(&shellVariant, "variation", "V", "", "shell variation: bash (default), zsh, fish, powershell")
+	return completionCmd
+}

cmd/utils.go

@@ -149,25 +149,91 @@ func writeString(writer io.Writer, txt string) error {
 	return errorWriting
 }
 
+func setIfNotThere(node *yaml.Node, key string, value *yaml.Node) {
+	for index := 0; index < len(node.Content); index = index + 2 {
+		keyNode := node.Content[index]
+		if keyNode.Value == key {
+			return
+		}
+	}
+	// need to add it to the map
+	mapEntryKey := yaml.Node{Value: key, Kind: yaml.ScalarNode}
+	node.Content = append(node.Content, &mapEntryKey)
+	node.Content = append(node.Content, value)
+}
+
+func applyAlias(node *yaml.Node, alias *yaml.Node) {
+	for index := 0; index < len(alias.Content); index = index + 2 {
+		keyNode := alias.Content[index]
+		log.Debugf("applying alias key %v", keyNode.Value)
+		valueNode := alias.Content[index+1]
+		setIfNotThere(node, keyNode.Value, valueNode)
+	}
+}
+
+func explodeNode(node *yaml.Node) error {
+	node.Anchor = ""
+	switch node.Kind {
+	case yaml.SequenceNode, yaml.DocumentNode:
+		for index, contentNode := range node.Content {
+			log.Debugf("exploding index %v", index)
+			errorInContent := explodeNode(contentNode)
+			if errorInContent != nil {
+				return errorInContent
+			}
+		}
+		return nil
+	case yaml.AliasNode:
+		log.Debugf("its an alias!")
+		node.Kind = node.Alias.Kind
+		node.Style = node.Alias.Style
+		node.Tag = node.Alias.Tag
+		node.Content = node.Alias.Content
+		node.Value = node.Alias.Value
+		node.Alias = nil
+		return nil
+	case yaml.MappingNode:
+		for index := 0; index < len(node.Content); index = index + 2 {
+			keyNode := node.Content[index]
+			valueNode := node.Content[index+1]
+			log.Debugf("traversing %v", keyNode.Value)
+			if keyNode.Value != "<<" {
+				errorInContent := explodeNode(valueNode)
+				if errorInContent != nil {
+					return errorInContent
+				}
+			} else {
+				if valueNode.Kind == yaml.SequenceNode {
+					log.Debugf("an alias merge list!")
+					for index := len(valueNode.Content) - 1; index >= 0; index = index - 1 {
+						aliasNode := valueNode.Content[index]
+						applyAlias(node, aliasNode.Alias)
+					}
+				} else {
+					log.Debugf("an alias merge!")
+					applyAlias(node, valueNode.Alias)
+				}
+				node.Content = append(node.Content[:index], node.Content[index+2:]...)
+				//replay that index, since the array is shorter now.
+				index = index - 2
+			}
+		}
+
+		return nil
+	default:
+		return nil
+	}
+}
+
 func explode(matchingNodes []*yqlib.NodeContext) error {
 	log.Debug("exploding nodes")
 	for _, nodeContext := range matchingNodes {
-		var targetNode = yaml.Node{Kind: nodeContext.Node.Kind}
+		log.Debugf("exploding %v", nodeContext.Head)
-		explodedNodes, errorRetrieving := lib.Get(nodeContext.Node, "**", true)
+		errorExplodingNode := explodeNode(nodeContext.Node)
-		if errorRetrieving != nil {
+		if errorExplodingNode != nil {
-			return errorRetrieving
+			return errorExplodingNode
-		}
-		for _, matchingNode := range explodedNodes {
-			mergePath := lib.MergePathStackToString(matchingNode.PathStack, appendFlag)
-			updateCommand := yqlib.UpdateCommand{Command: "update", Path: mergePath, Value: matchingNode.Node, Overwrite: overwriteFlag}
-			errorUpdating := lib.Update(&targetNode, updateCommand, true)
-			if errorUpdating != nil {
-				return errorUpdating
 		}
 	}
-		nodeContext.Node = &targetNode
-	}
-	log.Debug("done exploding nodes")
 	return nil
 }
 
@@ -357,6 +423,16 @@ func readAndUpdate(stdOut io.Writer, inputFile string, updateData updateDataFn)
 		if err != nil {
 			return err
 		}
+		// mkdir temp dir as some docker images does not have temp dir
+		_, err = os.Stat(os.TempDir())
+		if os.IsNotExist(err) {
+			err = os.Mkdir(os.TempDir(), 0700)
+			if err != nil {
+				return err
+			}
+		} else if err != nil {
+			return err
+		}
 		tempFile, err := ioutil.TempFile("", "temp")
 		if err != nil {
 			return err
@@ -430,15 +506,20 @@ func readUpdateCommands(args []string, expectedArgs int, badArgsMessage string)
 		log.Debug("args %v", args[expectedArgs-2])
 		updateCommands = make([]yqlib.UpdateCommand, 1)
 		updateCommands[0] = yqlib.UpdateCommand{Command: "update", Path: args[expectedArgs-2], Value: value.Content[0], Overwrite: true}
-
+	} else if len(args) == expectedArgs {
-	} else if len(args) < expectedArgs {
-		return nil, errors.New(badArgsMessage)
-	} else {
 		updateCommands = make([]yqlib.UpdateCommand, 1)
 		log.Debug("args %v", args)
 		log.Debug("path %v", args[expectedArgs-2])
 		log.Debug("Value %v", args[expectedArgs-1])
-		updateCommands[0] = yqlib.UpdateCommand{Command: "update", Path: args[expectedArgs-2], Value: valueParser.Parse(args[expectedArgs-1], customTag), Overwrite: true}
+		updateCommands[0] = yqlib.UpdateCommand{Command: "update", Path: args[expectedArgs-2], Value: valueParser.Parse(args[expectedArgs-1], customTag, customStyle, anchorName, makeAlias), Overwrite: true}
+	} else if len(args) == expectedArgs-1 {
+		// don't update the value
+		updateCommands = make([]yqlib.UpdateCommand, 1)
+		log.Debug("args %v", args)
+		log.Debug("path %v", args[expectedArgs-2])
+		updateCommands[0] = yqlib.UpdateCommand{Command: "update", Path: args[expectedArgs-2], Value: valueParser.Parse("", customTag, customStyle, anchorName, makeAlias), Overwrite: true, DontUpdateNodeValue: true}
+	} else {
+		return nil, errors.New(badArgsMessage)
 	}
 	return updateCommands, nil
 }

cmd/validate_test.go

@@ -0,0 +1,31 @@
+package cmd
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestValidateCmd(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "validate ../examples/sample.yaml b.c")
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	test.AssertResult(t, "", result.Output)
+}
+
+func TestValidateBadDataCmd(t *testing.T) {
+	content := `[!Whatever]`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("validate %s", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail")
+	}
+	expectedOutput := `yaml: line 1: did not find expected ',' or ']'`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}

cmd/version.go

@@ -11,7 +11,7 @@ var (
 	GitDescribe string
 
 	// Version is main version number that is being run at the moment.
-	Version = "3.2.2"
+	Version = "3.3.2"
 
 	// VersionPrerelease is a pre-release marker for the version. If this is "" (empty string)
 	// then it means that it is a final release. Otherwise, this is a pre-release

cmd/write.go

@@ -46,6 +46,9 @@ format is list of update commands (update or delete) like so:
 	cmdWrite.PersistentFlags().StringVarP(&sourceYamlFile, "from", "f", "", "yaml file for updating yaml (as-is)")
 	cmdWrite.PersistentFlags().StringVarP(&customTag, "tag", "t", "", "set yaml tag (e.g. !!int)")
 	cmdWrite.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
+	cmdWrite.PersistentFlags().StringVarP(&customStyle, "style", "", "", "formatting style of the value: single, double, folded, flow, literal, tagged")
+	cmdWrite.PersistentFlags().StringVarP(&anchorName, "anchorName", "", "", "anchor name")
+	cmdWrite.PersistentFlags().BoolVarP(&makeAlias, "makeAlias", "", false, "create an alias using the value as the anchor name")
 	return cmdWrite
 }
 

cmd/write_test.go

@@ -0,0 +1,593 @@
+package cmd
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/mikefarah/yq/v3/test"
+)
+
+func TestWriteCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 7
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteWithTaggedStyleCmd(t *testing.T) {
+	content := `b:
+  c: dog
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --tag=!!str --style=tagged", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: !!str cat
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteWithDoubleQuotedStyleCmd(t *testing.T) {
+	content := `b:
+  c: dog
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=double", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: "cat"
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteUpdateStyleOnlyCmd(t *testing.T) {
+	content := `b:
+  c: dog
+  d: things
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.* --style=single", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 'dog'
+  d: 'things'
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteUpdateTagOnlyCmd(t *testing.T) {
+	content := `b:
+  c: true
+  d: false
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.* --tag=!!str", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: "true"
+  d: "false"
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteWithSingleQuotedStyleCmd(t *testing.T) {
+	content := `b:
+  c: dog
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=single", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 'cat'
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteWithLiteralStyleCmd(t *testing.T) {
+	content := `b:
+  c: dog
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=literal", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: |-
+    cat
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteWithFoldedStyleCmd(t *testing.T) {
+	content := `b:
+  c: dog
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c cat --style=folded", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: >-
+    cat
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteEmptyMultiDocCmd(t *testing.T) {
+	content := `# this is empty
+---
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s c 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `c: 7
+
+# this is empty
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteSurroundingEmptyMultiDocCmd(t *testing.T) {
+	content := `---
+# empty
+---
+cat: frog
+---
+
+# empty
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d1 c 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `
+
+# empty
+---
+cat: frog
+c: 7
+---
+
+
+# empty
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteFromFileCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	source := `kittens: are cute # sure are!`
+	fromFilename := test.WriteTempYamlFile(source)
+	defer test.RemoveTempYamlFile(fromFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c -f %s", filename, fromFilename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c:
+    kittens: are cute # sure are!
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteEmptyCmd(t *testing.T) {
+	content := ``
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 7
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteAutoCreateCmd(t *testing.T) {
+	content := `applications:
+  - name: app
+    env:`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s applications[0].env.hello world", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `applications:
+  - name: app
+    env:
+      hello: world
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmdScript(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	updateScript := `- command: update
+  path: b.c
+  value: 7`
+	scriptFilename := test.WriteTempYamlFile(updateScript)
+	defer test.RemoveTempYamlFile(scriptFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write --script %s %s", scriptFilename, filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 7
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmdEmptyScript(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	updateScript := ``
+	scriptFilename := test.WriteTempYamlFile(updateScript)
+	defer test.RemoveTempYamlFile(scriptFilename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write --script %s %s", scriptFilename, filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteMultiCmd(t *testing.T) {
+	content := `b:
+  c: 3
+---
+apples: great
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d 1 apples ok", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+---
+apples: ok
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+func TestWriteInvalidDocumentIndexCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s -df apples ok", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail due to invalid path")
+	}
+	expectedOutput := `Document index f is not a integer or *: strconv.ParseInt: parsing "f": invalid syntax`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestWriteBadDocumentIndexCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d 1 apples ok", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail due to invalid path")
+	}
+	expectedOutput := `asked to process document index 1 but there are only 1 document(s)`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+func TestWriteMultiAllCmd(t *testing.T) {
+	content := `b:
+  c: 3
+---
+apples: great
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s -d * apples ok", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+apples: ok
+---
+apples: ok`
+	test.AssertResult(t, expectedOutput, strings.Trim(result.Output, "\n "))
+}
+
+func TestWriteCmd_EmptyArray(t *testing.T) {
+	content := `b: 3`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s a []", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b: 3
+a: []
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_Error(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "write")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to missing arg")
+	}
+	expectedOutput := `Must provide <filename> <path_to_update> <value>`
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestWriteCmd_ErrorUnreadableFile(t *testing.T) {
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, "write fake-unknown a.b 3")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to unknown file")
+	}
+	var expectedOutput string
+	if runtime.GOOS == "windows" {
+		expectedOutput = `open fake-unknown: The system cannot find the file specified.`
+	} else {
+		expectedOutput = `open fake-unknown: no such file or directory`
+	}
+	test.AssertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestWriteCmd_Inplace(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write -i %s b.c 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	gotOutput := test.ReadTempYamlFile(filename)
+	expectedOutput := `b:
+  c: 7`
+	test.AssertResult(t, expectedOutput, strings.Trim(gotOutput, "\n "))
+}
+
+func TestWriteCmd_InplaceError(t *testing.T) {
+	content := `b: cat
+  c: 3
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write -i %s b.c 7", filename))
+	if result.Error == nil {
+		t.Error("Expected Error to occur!")
+	}
+	gotOutput := test.ReadTempYamlFile(filename)
+	test.AssertResult(t, content, gotOutput)
+}
+
+func TestWriteCmd_Append(t *testing.T) {
+	content := `b:
+  - foo
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[+] 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  - foo
+  - 7
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_AppendInline(t *testing.T) {
+	content := `b: [foo]`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[+] 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b: [foo, 7]
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_AppendInlinePretty(t *testing.T) {
+	content := `b: [foo]`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s -P b[+] 7", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  - foo
+  - 7
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_AppendEmptyArray(t *testing.T) {
+	content := `a: 2
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[+] v", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `a: 2
+b:
+  - v
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_SplatArray(t *testing.T) {
+	content := `b:
+- c: thing
+- c: another thing
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b[*].c new", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  - c: new
+  - c: new
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_SplatMap(t *testing.T) {
+	content := `b:
+  c: thing
+  d: another thing
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.* new", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: new
+  d: new
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}
+
+func TestWriteCmd_SplatMapEmpty(t *testing.T) {
+	content := `b:
+  c: thing
+  d: another thing
+`
+	filename := test.WriteTempYamlFile(content)
+	defer test.RemoveTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := test.RunCmd(cmd, fmt.Sprintf("write %s b.c.* new", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: {}
+  d: another thing
+`
+	test.AssertResult(t, expectedOutput, result.Output)
+}

convert.md

@@ -0,0 +1,52 @@
+# Convert
+
+### Yaml to Json[¶](convert.md#yaml-to-json) <a id="yaml-to-json"></a>
+
+To convert output to json, use the --tojson \(or -j\) flag. This can only be used with the read command.
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+```
+
+then
+
+```text
+yq r -j sample.yaml b.c
+```
+
+will output
+
+```text
+{"b":{"c":2}}
+```
+
+### Json to Yaml[¶](convert.md#json-to-yaml) <a id="json-to-yaml"></a>
+
+To read in json, just pass in a json file instead of yaml, it will just work :\)
+
+e.g given a json file
+
+```text
+{"a":"Easy! as one two three","b":{"c":2,"d":[3,4]}}
+```
+
+then
+
+```text
+yq r sample.json
+```
+
+will output
+
+```text
+a: Easy! as one two three
+b:
+  c: 2
+  d:
+  - 3
+  - 4
+```
+

create.md

@@ -0,0 +1,88 @@
+# Create
+
+ Yaml files can be created using the 'new' command. This works in the same way as the write command, but you don't pass in an existing Yaml file. Currently this does not support creating multiple documents in a single yaml file.
+
+```text
+yq n <path> <new value>
+```
+
+### Creating a simple yaml file[¶](create.md#creating-a-simple-yaml-file) <a id="creating-a-simple-yaml-file"></a>
+
+```text
+yq n b.c cat
+```
+
+will output:
+
+```text
+b:
+  c: cat
+```
+
+### Creating using a create script[¶](create.md#creating-using-a-create-script) <a id="creating-using-a-create-script"></a>
+
+Create scripts follow the same format as the update scripts.
+
+Given a script create\_instructions.yaml of:
+
+```text
+b.c: 3
+b.e[+].name: Howdy Partner
+```
+
+then
+
+```text
+yq n -s create_instructions.yaml
+```
+
+will output:
+
+```text
+b:
+  c: 3
+  e:
+    - name: Howdy Partner
+```
+
+You can also pipe the instructions in:
+
+```text
+cat create_instructions.yaml | yq n -s -
+```
+
+### Keys with dots[¶](create.md#keys-with-dots) <a id="keys-with-dots"></a>
+
+When specifying a key that has a dot use key lookup indicator.
+
+```text
+b:
+  foo.bar: 7
+```
+
+```text
+yaml r sample.yaml 'b[foo.bar]'
+```
+
+```text
+yaml w sample.yaml 'b[foo.bar]' 9
+```
+
+Any valid yaml key can be specified as part of a key lookup.
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Keys \(and values\) with leading dashes[¶](create.md#keys-and-values-with-leading-dashes) <a id="keys-and-values-with-leading-dashes"></a>
+
+If a key or value has leading dashes, yq won't know that you are passing a value as opposed to a flag \(and you will get a 'bad flag syntax' error\).
+
+To fix that, you will need to tell it to stop processing flags by adding '--' after the last flag like so:
+
+```text
+yq n -t -- --key --value
+```
+
+Will result in
+
+``` --key: --value``
+

debian/changelog

@@ -1,3 +1,13 @@
+yq (3.3-0) focal; urgency=medium
+
+  * You can control string styles (quotes) using the new --style flag
+  * String values now always have quotes when outputting to json
+  * Negative array indices now traverse the array backwards
+  * Added a --stripComments flag to print yaml without any comments
+  * Bumped go to version 1.14
+
+ -- Roberto Mier Escandon <rmescandon@gmail.com>  Thu, 30 Apr 2020 20:45:44 +0200
+
 yq (3.1-2) eoan; urgency=medium
 
   * Bug fix: yq 3 was removing empty inline-style objects and arrays (#355)

debian/files

@@ -1 +0,0 @@
-yq_3.1-2_source.buildinfo devel optional

delete.md

@@ -0,0 +1,280 @@
+# Delete
+
+```text
+yq d <yaml_file> <path_to_delete>
+```
+
+### To Stdout[¶](delete.md#to-stdout) <a id="to-stdout"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+  apples: green
+```
+
+then
+
+```text
+yq d sample.yaml b.c
+```
+
+will output:
+
+```text
+b:
+  apples: green
+```
+
+### From STDIN[¶](delete.md#from-stdin) <a id="from-stdin"></a>
+
+```text
+cat sample.yaml | yq d - b.c
+```
+
+### Deleting array elements[¶](delete.md#deleting-array-elements) <a id="deleting-array-elements"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 
+    - 1
+    - 2
+    - 3
+```
+
+then
+
+```text
+yq d sample.yaml 'b.c[1]'
+```
+
+will output:
+
+```text
+b:
+  c:
+  - 1
+  - 3
+```
+
+### Deleting nodes in-place[¶](delete.md#deleting-nodes-in-place) <a id="deleting-nodes-in-place"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+  apples: green
+```
+
+then
+
+```text
+yq d -i sample.yaml b.c
+```
+
+will update the sample.yaml file so that the 'c' node is deleted
+
+### Splat[¶](delete.md#splat) <a id="splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+  item1:
+    cats: bananas
+    dogs: woof
+  item2:
+    cats: apples
+    dogs: woof2
+  thing:
+    cats: oranges
+    dogs: woof3
+```
+
+then
+
+```text
+yq d sample.yaml bob.*.cats
+```
+
+will output:
+
+```text
+---
+bob:
+  item1:
+    dogs: woof
+  item2:
+    dogs: woof2
+  thing:
+    dogs: woof3
+```
+
+### Prefix Splat[¶](delete.md#prefix-splat) <a id="prefix-splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+  item1:
+    cats: bananas
+    dogs: woof
+  item2:
+    cats: apples
+    dogs: woof2
+  thing:
+    cats: oranges
+    dogs: woof3
+```
+
+then
+
+```text
+yq d sample.yaml bob.item*.cats
+```
+
+will output:
+
+```text
+---
+bob:
+  item1:
+    dogs: woof
+  item2:
+    dogs: woof2
+  thing:
+    cats: oranges
+    dogs: woof3
+```
+
+### Array Splat[¶](delete.md#array-splat) <a id="array-splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+- cats: bananas
+  dogs: woof
+- cats: apples
+  dogs: woof2
+- cats: oranges
+  dogs: woof3
+```
+
+then
+
+```text
+yq d sample.yaml bob.[*].cats
+```
+
+will output:
+
+```text
+---
+bob:
+- dogs: woof
+- dogs: woof2
+- dogs: woof3
+```
+
+### Multiple Documents - delete from single document[¶](delete.md#multiple-documents-delete-from-single-document) <a id="multiple-documents-delete-from-single-document"></a>
+
+Given a sample.yaml file of:
+
+```text
+something: else
+field: leaveMe
+---
+b:
+  c: 2
+field: deleteMe
+```
+
+then
+
+```text
+yq w -d1 sample.yaml field
+```
+
+will output:
+
+```text
+something: else
+field: leaveMe
+---
+b:
+  c: 2
+```
+
+### Multiple Documents - delete from all documents[¶](delete.md#multiple-documents-delete-from-all-documents) <a id="multiple-documents-delete-from-all-documents"></a>
+
+Given a sample.yaml file of:
+
+```text
+something: else
+field: deleteMe
+---
+b:
+  c: 2
+field: deleteMeToo
+```
+
+then
+
+```text
+yq w -d'*' sample.yaml field
+```
+
+will output:
+
+```text
+something: else
+---
+b:
+  c: 2
+```
+
+Note that '\*' is in quotes to avoid being interpreted by your shell.
+
+### Keys with dots[¶](delete.md#keys-with-dots) <a id="keys-with-dots"></a>
+
+When specifying a key that has a dot use key lookup indicator.
+
+```text
+b:
+  foo.bar: 7
+```
+
+```text
+yaml r sample.yaml 'b[foo.bar]'
+```
+
+```text
+yaml w sample.yaml 'b[foo.bar]' 9
+```
+
+Any valid yaml key can be specified as part of a key lookup.
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Keys \(and values\) with leading dashes[¶](delete.md#keys-and-values-with-leading-dashes) <a id="keys-and-values-with-leading-dashes"></a>
+
+If a key or value has leading dashes, yq won't know that you are passing a value as opposed to a flag \(and you will get a 'bad flag syntax' error\).
+
+To fix that, you will need to tell it to stop processing flags by adding '--' after the last flag like so:
+
+```text
+yq n -t -- --key --value
+```
+
+Will result in
+
+``` --key: --value``
+

examples/data1-no-comments.yaml

@@ -0,0 +1,4 @@
+a: simple
+b: [1, 2]
+c:
+  test: 1

examples/sample2.yaml

@@ -1,2 +0,0 @@
-b:
-  c: things

examples/simple-anchor-exploded.yaml

@@ -0,0 +1,5 @@
+foo:
+  a: 1
+
+foobar: 
+  a: 1

go.mod

@@ -2,16 +2,16 @@ module github.com/mikefarah/yq/v3
 
 require (
 	github.com/fatih/color v1.9.0
-	github.com/goccy/go-yaml v1.4.3
+	github.com/goccy/go-yaml v1.7.5
 	github.com/kylelemons/godebug v1.1.0
 	github.com/mattn/go-colorable v0.1.6 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/spf13/cobra v1.0.0
 	github.com/spf13/pflag v1.0.5 // indirect
-	golang.org/x/sys v0.0.0-20200413165638-669c56c373c4 // indirect
+	golang.org/x/sys v0.0.0-20200602225109-6fdc65e7d980 // indirect
 	golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 // indirect
 	gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473
-	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c
+	gopkg.in/yaml.v3 v3.0.0-20200605160147-a5ece683394c
 )
 
 go 1.14

go.sum

@@ -29,8 +29,8 @@ github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V
 github.com/go-playground/locales v0.13.0/go.mod h1:taPMhCMXrRLJO55olJkUXHZBHCxTMfnGwq/HNwmWNS8=
 github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
-github.com/goccy/go-yaml v1.4.3 h1:+1jK1ost1TBEfWjciIMU8rciBq0poxurgS7XvLgQInM=
+github.com/goccy/go-yaml v1.7.5 h1:dWvj+p3BG11S/GlUzwzt1WZz0lhBTzTIDtmXT/ZOaPY=
-github.com/goccy/go-yaml v1.4.3/go.mod h1:PsEEJ29nIFZL07P/c8dv4P6rQkVFFXafQee85U+ERHA=
+github.com/goccy/go-yaml v1.7.5/go.mod h1:wS4gNoLalDSJxo/SpngzPQ2BN4uuZVLCmbM4S3vd4+Y=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
@@ -144,8 +144,8 @@ golang.org/x/sys v0.0.0-20191026070338-33540a1f6037 h1:YyJpGZS1sBuBCzLAR1VEpK193
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200413165638-669c56c373c4 h1:opSr2sbRXk5X5/givKrrKj9HXxFpW2sdCiP8MJSKLQY=
+golang.org/x/sys v0.0.0-20200602225109-6fdc65e7d980 h1:OjiUf46hAmXblsZdnoSXsEUSKU8r1UEzcL5RVZ4gO9Y=
-golang.org/x/sys v0.0.0-20200413165638-669c56c373c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200602225109-6fdc65e7d980/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
@@ -175,7 +175,6 @@ gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bl
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v3 v3.0.0-20191120175047-4206685974f2/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20200605160147-a5ece683394c h1:grhR+C34yXImVGp7EzNk+DTIk+323eIUWOmEevy6bDo=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200605160147-a5ece683394c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

merge.md

@@ -0,0 +1,245 @@
+# Merge
+
+ Yaml files can be merged using the 'merge' command. Each additional file merged with the first file will set values for any key not existing already or where the key has no value.
+
+```text
+yq m <yaml_file> <path>...
+```
+
+### To Stdout[¶](merge.md#to-stdout) <a id="to-stdout"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+```
+
+and data2.yaml file of:
+
+```text
+a: other
+c:
+  test: 1
+```
+
+then
+
+```text
+yq m data1.yaml data2.yaml
+```
+
+will output:
+
+```text
+a: simple
+b: [1, 2]
+c:
+  test: 1
+```
+
+### Updating files in-place[¶](merge.md#updating-files-in-place) <a id="updating-files-in-place"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+```
+
+and data2.yaml file of:
+
+```text
+a: other
+c:
+  test: 1
+```
+
+then
+
+```text
+yq m -i data1.yaml data2.yaml
+```
+
+will update the data1.yaml file so that the value of 'c' is 'test: 1'.
+
+### Overwrite values[¶](merge.md#overwrite-values) <a id="overwrite-values"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+```
+
+and data2.yaml file of:
+
+```text
+a: other
+c:
+  test: 1
+```
+
+then
+
+```text
+yq m -x data1.yaml data2.yaml
+```
+
+will output:
+
+```text
+a: other
+b: [1, 2]
+c:
+  test: 1
+```
+
+### Overwrite values with arrays[¶](merge.md#overwrite-values-with-arrays) <a id="overwrite-values-with-arrays"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+```
+
+and data3.yaml file of:
+
+```text
+b: [3, 4]
+c:
+  test: 2
+  other: true
+d: false
+```
+
+then
+
+```text
+yq m -x data1.yaml data3.yaml
+```
+
+will output:
+
+```text
+a: simple
+b: [3, 4]
+c:
+  test: 2
+  other: true
+d: false
+```
+
+Notice that 'b' does not result in the merging of the values within an array.
+
+### Append values with arrays[¶](merge.md#append-values-with-arrays) <a id="append-values-with-arrays"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+d: hi
+```
+
+and data3.yaml file of:
+
+```text
+a: something
+b: [3, 4]
+c:
+  test: 2
+  other: true
+```
+
+then
+
+```text
+yq m -a data1.yaml data3.yaml
+```
+
+will output:
+
+```text
+a: simple
+b: [1, 2, 3, 4]
+c:
+  test: 2
+  other: true
+d: hi
+```
+
+Note that the 'b' array has concatenated the values from the second data file. Also note that other map keys are not overridden \(field a\).
+
+Append cannot be used with overwrite, if both flags are given then append is ignored.
+
+### Multiple Documents - merge into single document[¶](merge.md#multiple-documents-merge-into-single-document) <a id="multiple-documents-merge-into-single-document"></a>
+
+Currently yq only has multi-document support for the _first_ document being merged into. The remaining yaml files will have their first document selected.
+
+Given a data1.yaml file of:
+
+```text
+something: else
+---
+a: simple
+b: cat
+```
+
+and data3.yaml file of:
+
+```text
+b: dog
+```
+
+then
+
+```text
+yq m -x -d1 data1.yaml data3.yaml
+```
+
+will output:
+
+```text
+something: else
+---
+a: simple
+b: dog
+```
+
+### Multiple Documents - merge into all documents[¶](merge.md#multiple-documents-merge-into-all-documents) <a id="multiple-documents-merge-into-all-documents"></a>
+
+Currently yq only has multi-document support for the _first_ document being merged into. The remaining yaml files will have their first document selected.
+
+Given a data1.yaml file of:
+
+```text
+something: else
+---
+a: simple
+b: cat
+```
+
+and data3.yaml file of:
+
+```text
+b: dog
+```
+
+then
+
+```text
+yq m -x -d'*' data1.yaml data3.yaml
+```
+
+will output:
+
+```text
+b: dog
+something: else
+---
+a: simple
+b: dog
+```
+

pkg/yqlib/data_navigator.go

@@ -24,6 +24,7 @@ func NewDataNavigator(NavigationStrategy NavigationStrategy) DataNavigator {
 func (n *navigator) Traverse(value *yaml.Node, path []interface{}) error {
 	realValue := value
 	emptyArray := make([]interface{}, 0)
+	log.Debugf("Traversing path %v", pathStackToString(path))
 	if realValue.Kind == yaml.DocumentNode {
 		log.Debugf("its a document! returning the first child")
 		return n.doTraverse(value.Content[0], "", path, emptyArray)
@@ -68,6 +69,16 @@ func (n *navigator) getOrReplace(original *yaml.Node, expectedKind yaml.Kind) *y
 
 func (n *navigator) recurse(value *yaml.Node, head interface{}, tail []interface{}, pathStack []interface{}) error {
 	log.Debug("recursing, processing %v, pathStack %v", head, pathStackToString(pathStack))
+
+	nodeContext := NewNodeContext(value, head, tail, pathStack)
+
+	if head == "**" && !n.navigationStrategy.ShouldOnlyDeeplyVisitLeaves(nodeContext) {
+		errorVisitingDeeply := n.navigationStrategy.Visit(nodeContext)
+		if errorVisitingDeeply != nil {
+			return errorVisitingDeeply
+		}
+	}
+
 	switch value.Kind {
 	case yaml.MappingNode:
 		log.Debug("its a map with %v entries", len(value.Content)/2)
@@ -85,20 +96,20 @@ func (n *navigator) recurse(value *yaml.Node, head interface{}, tail []interface
 			if head == "+" {
 				return n.appendArray(value, head, tail, pathStack)
 			} else if len(value.Content) == 0 && head == "**" {
-				return n.navigationStrategy.Visit(NewNodeContext(value, head, tail, pathStack))
+				return n.navigationStrategy.Visit(nodeContext)
 			}
 			return n.splatArray(value, head, tail, pathStack)
 		}
 	case yaml.AliasNode:
 		log.Debug("its an alias!")
 		DebugNode(value.Alias)
-		if n.navigationStrategy.FollowAlias(NewNodeContext(value, head, tail, pathStack)) {
+		if n.navigationStrategy.FollowAlias(nodeContext) {
 			log.Debug("following the alias")
 			return n.recurse(value.Alias, head, tail, pathStack)
 		}
 		return nil
 	default:
-		return n.navigationStrategy.Visit(NewNodeContext(value, head, tail, pathStack))
+		return n.navigationStrategy.Visit(nodeContext)
 	}
 }
 

pkg/yqlib/delete_navigation_strategy.go

@@ -12,15 +12,12 @@ func DeleteNavigationStrategy(pathElementToDelete interface{}) NavigationStrateg
 		followAlias: func(nodeContext NodeContext) bool {
 			return false
 		},
-		autoCreateMap: func(nodeContext NodeContext) bool {
+		shouldOnlyDeeplyVisitLeaves: func(nodeContext NodeContext) bool {
 			return false
 		},
-		shouldDeeplyTraverse: func(nodeContext NodeContext) bool {
-			return true
-		},
 		visit: func(nodeContext NodeContext) error {
 			node := nodeContext.Node
-			log.Debug("need to find and delete %v in here", pathElementToDelete)
+			log.Debug("need to find and delete %v in here (%v)", pathElementToDelete, pathStackToString(nodeContext.PathStack))
 			DebugNode(node)
 			if node.Kind == yaml.SequenceNode {
 				newContent := deleteFromArray(parser, node.Content, nodeContext.PathStack, pathElementToDelete)

pkg/yqlib/filter_matching_node_navigation_strategy.go

@@ -4,12 +4,6 @@ func FilterMatchingNodesNavigationStrategy(value string) NavigationStrategy {
 	return &NavigationStrategyImpl{
 		visitedNodes: []*NodeContext{},
 		pathParser:   NewPathParser(),
-		followAlias: func(nodeContext NodeContext) bool {
-			return true
-		},
-		autoCreateMap: func(nodeContext NodeContext) bool {
-			return false
-		},
 		visit: func(nodeContext NodeContext) error {
 			return nil
 		},

pkg/yqlib/lib.go

@@ -17,6 +17,7 @@ type UpdateCommand struct {
 	Path                string
 	Value               *yaml.Node
 	Overwrite           bool
+	DontUpdateNodeValue bool
 }
 
 func KindString(kind yaml.Kind) string {
@@ -47,7 +48,7 @@ func DebugNode(value *yaml.Node) {
 			log.Error("Error debugging node, %v", errorEncoding.Error())
 		}
 		encoder.Close()
-		log.Debug("Tag: %v, Kind: %v", value.Tag, KindString(value.Kind))
+		log.Debug("Tag: %v, Kind: %v, Anchor: %v", value.Tag, KindString(value.Kind), value.Anchor)
 		log.Debug("%v", buf.String())
 	}
 }

pkg/yqlib/navigation_strategy.go

@@ -35,6 +35,8 @@ type NavigationStrategy interface {
 	// we use it to match against the pathExpression in head.
 	ShouldTraverse(nodeContext NodeContext, nodeKey string) bool
 	ShouldDeeplyTraverse(nodeContext NodeContext) bool
+	// when deeply traversing, should we visit all matching nodes, or just leaves?
+	ShouldOnlyDeeplyVisitLeaves(NodeContext) bool
 	GetVisitedNodes() []*NodeContext
 	DebugVisitedNodes()
 	GetPathParser() PathParser
@@ -46,6 +48,7 @@ type NavigationStrategyImpl struct {
 	visit                       func(nodeContext NodeContext) error
 	shouldVisitExtraFn          func(nodeContext NodeContext) bool
 	shouldDeeplyTraverse        func(nodeContext NodeContext) bool
+	shouldOnlyDeeplyVisitLeaves func(nodeContext NodeContext) bool
 	visitedNodes                []*NodeContext
 	pathParser                  PathParser
 }
@@ -59,15 +62,32 @@ func (ns *NavigationStrategyImpl) GetVisitedNodes() []*NodeContext {
 }
 
 func (ns *NavigationStrategyImpl) FollowAlias(nodeContext NodeContext) bool {
+	if ns.followAlias != nil {
 		return ns.followAlias(nodeContext)
+	}
+	return true
 }
 
 func (ns *NavigationStrategyImpl) AutoCreateMap(nodeContext NodeContext) bool {
+	if ns.autoCreateMap != nil {
 		return ns.autoCreateMap(nodeContext)
+	}
+	return false
 }
 
 func (ns *NavigationStrategyImpl) ShouldDeeplyTraverse(nodeContext NodeContext) bool {
+	if ns.shouldDeeplyTraverse != nil {
 		return ns.shouldDeeplyTraverse(nodeContext)
+	}
+	return true
+}
+
+func (ns *NavigationStrategyImpl) ShouldOnlyDeeplyVisitLeaves(nodeContext NodeContext) bool {
+	if ns.shouldOnlyDeeplyVisitLeaves != nil {
+		return ns.shouldOnlyDeeplyVisitLeaves(nodeContext)
+	}
+	return true
+
 }
 
 func (ns *NavigationStrategyImpl) ShouldTraverse(nodeContext NodeContext, nodeKey string) bool {

pkg/yqlib/read_navigation_strategy.go

@@ -4,12 +4,6 @@ func ReadNavigationStrategy(deeplyTraverseArrays bool) NavigationStrategy {
 	return &NavigationStrategyImpl{
 		visitedNodes: []*NodeContext{},
 		pathParser:   NewPathParser(),
-		followAlias: func(nodeContext NodeContext) bool {
-			return true
-		},
-		autoCreateMap: func(nodeContext NodeContext) bool {
-			return false
-		},
 		visit: func(nodeContext NodeContext) error {
 			return nil
 		},

pkg/yqlib/update_navigation_strategy.go

@@ -10,9 +10,6 @@ func UpdateNavigationStrategy(updateCommand UpdateCommand, autoCreate bool) Navi
 		autoCreateMap: func(nodeContext NodeContext) bool {
 			return autoCreate
 		},
-		shouldDeeplyTraverse: func(nodeContext NodeContext) bool {
-			return true
-		},
 		visit: func(nodeContext NodeContext) error {
 			node := nodeContext.Node
 			changesToApply := updateCommand.Value
@@ -21,11 +18,15 @@ func UpdateNavigationStrategy(updateCommand UpdateCommand, autoCreate bool) Navi
 				DebugNode(node)
 				log.Debug("with")
 				DebugNode(changesToApply)
+				if !updateCommand.DontUpdateNodeValue {
 					node.Value = changesToApply.Value
+				}
 				node.Tag = changesToApply.Tag
 				node.Kind = changesToApply.Kind
 				node.Style = changesToApply.Style
 				node.Content = changesToApply.Content
+				node.Anchor = changesToApply.Anchor
+				node.Alias = changesToApply.Alias
 				node.HeadComment = changesToApply.HeadComment
 				node.LineComment = changesToApply.LineComment
 				node.FootComment = changesToApply.FootComment

pkg/yqlib/value_parser.go

@@ -5,7 +5,7 @@ import (
 )
 
 type ValueParser interface {
-	Parse(argument string, customTag string) *yaml.Node
+	Parse(argument string, customTag string, customStyle string, anchorName string, createAlias bool) *yaml.Node
 }
 
 type valueParser struct {
@@ -15,9 +15,32 @@ func NewValueParser() ValueParser {
 	return &valueParser{}
 }
 
-func (v *valueParser) Parse(argument string, customTag string) *yaml.Node {
+func (v *valueParser) Parse(argument string, customTag string, customStyle string, anchorName string, createAlias bool) *yaml.Node {
-	if argument == "[]" {
+	var style yaml.Style
-		return &yaml.Node{Tag: "!!seq", Kind: yaml.SequenceNode}
+	if customStyle == "tagged" {
+		style = yaml.TaggedStyle
+	} else if customStyle == "double" {
+		style = yaml.DoubleQuotedStyle
+	} else if customStyle == "single" {
+		style = yaml.SingleQuotedStyle
+	} else if customStyle == "literal" {
+		style = yaml.LiteralStyle
+	} else if customStyle == "folded" {
+		style = yaml.FoldedStyle
+	} else if customStyle == "flow" {
+		style = yaml.FlowStyle
+	} else if customStyle != "" {
+		log.Error("Unknown style %v, ignoring", customStyle)
 	}
-	return &yaml.Node{Value: argument, Tag: customTag, Kind: yaml.ScalarNode}
+	if argument == "[]" {
+		return &yaml.Node{Tag: "!!seq", Kind: yaml.SequenceNode, Style: style}
+	}
+
+	kind := yaml.ScalarNode
+
+	if createAlias {
+		kind = yaml.AliasNode
+	}
+
+	return &yaml.Node{Value: argument, Tag: customTag, Kind: kind, Style: style, Anchor: anchorName}
 }

pkg/yqlib/value_parser_test.go

@@ -7,6 +7,26 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
+var parseStyleTests = []struct {
+	customStyle   string
+	expectedStyle yaml.Style
+}{
+	{"", 0},
+	{"tagged", yaml.TaggedStyle},
+	{"double", yaml.DoubleQuotedStyle},
+	{"single", yaml.SingleQuotedStyle},
+	{"folded", yaml.FoldedStyle},
+	{"flow", yaml.FlowStyle},
+	{"literal", yaml.LiteralStyle},
+}
+
+func TestValueParserStyleTag(t *testing.T) {
+	for _, tt := range parseStyleTests {
+		actual := NewValueParser().Parse("cat", "", tt.customStyle, "", false)
+		test.AssertResultWithContext(t, tt.expectedStyle, actual.Style, tt.customStyle)
+	}
+}
+
 var parseValueTests = []struct {
 	argument        string
 	customTag       string
@@ -20,7 +40,7 @@ var parseValueTests = []struct {
 
 func TestValueParserParse(t *testing.T) {
 	for _, tt := range parseValueTests {
-		actual := NewValueParser().Parse(tt.argument, tt.customTag)
+		actual := NewValueParser().Parse(tt.argument, tt.customTag, "", "", false)
 		test.AssertResultWithContext(t, tt.argument, actual.Value, tt.testDescription)
 		test.AssertResultWithContext(t, tt.expectedTag, actual.Tag, tt.testDescription)
 		test.AssertResult(t, yaml.ScalarNode, actual.Kind)
@@ -28,7 +48,18 @@ func TestValueParserParse(t *testing.T) {
 }
 
 func TestValueParserParseEmptyArray(t *testing.T) {
-	actual := NewValueParser().Parse("[]", "")
+	actual := NewValueParser().Parse("[]", "", "", "", false)
 	test.AssertResult(t, "!!seq", actual.Tag)
 	test.AssertResult(t, yaml.SequenceNode, actual.Kind)
 }
+
+func TestValueParserParseAlias(t *testing.T) {
+	actual := NewValueParser().Parse("bob", "", "", "", true)
+	test.AssertResult(t, "bob", actual.Value)
+	test.AssertResult(t, yaml.AliasNode, actual.Kind)
+}
+
+func TestValueParserAnchorname(t *testing.T) {
+	actual := NewValueParser().Parse("caterpillar", "", "", "foo", false)
+	test.AssertResult(t, "foo", actual.Anchor)
+}

prefix.md

@@ -0,0 +1,127 @@
+# Prefix
+
+ Paths can be prefixed using the 'prefix' command. The complete yaml content will be nested inside the new prefix path.
+
+```text
+yq p <yaml_file> <path>
+```
+
+### To Stdout[¶](prefix.md#to-stdout) <a id="to-stdout"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+```
+
+then
+
+```text
+yq p data1.yaml c
+```
+
+will output:
+
+```text
+c:
+  a: simple
+  b: [1, 2]
+```
+
+### Arbitrary depth[¶](prefix.md#arbitrary-depth) <a id="arbitrary-depth"></a>
+
+Given a data1.yaml file of:
+
+```text
+a:
+  b: [1, 2]
+```
+
+then
+
+```text
+yq p data1.yaml c.d
+```
+
+will output:
+
+```text
+c:
+  d:
+    a:
+      b: [1, 2]
+```
+
+### Updating files in-place[¶](prefix.md#updating-files-in-place) <a id="updating-files-in-place"></a>
+
+Given a data1.yaml file of:
+
+```text
+a: simple
+b: [1, 2]
+```
+
+then
+
+```text
+yq p -i data1.yaml c
+```
+
+will update the data1.yaml file so that the path 'c' is prefixed to all other paths.
+
+### Multiple Documents - prefix a single document[¶](prefix.md#multiple-documents-prefix-a-single-document) <a id="multiple-documents-prefix-a-single-document"></a>
+
+Given a data1.yaml file of:
+
+```text
+something: else
+---
+a: simple
+b: cat
+```
+
+then
+
+```text
+yq p -d1 data1.yaml c
+```
+
+will output:
+
+```text
+something: else
+---
+c:
+  a: simple
+  b: cat
+```
+
+### Multiple Documents - prefix all documents[¶](prefix.md#multiple-documents-prefix-all-documents) <a id="multiple-documents-prefix-all-documents"></a>
+
+Given a data1.yaml file of:
+
+```text
+something: else
+---
+a: simple
+b: cat
+```
+
+then
+
+```text
+yq p -d'*' data1.yaml c
+```
+
+will output:
+
+```text
+c:
+  something: else
+---
+c:
+  a: simple
+  b: cat
+```
+

read.md

@@ -0,0 +1,228 @@
+# Read
+
+```text
+yq r <yaml_file|json_file> <path>
+```
+
+This command can take a json file as input too, and will output yaml unless specified to export as json \(-j\)
+
+### Basic[¶](read.md#basic) <a id="basic"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+```
+
+then
+
+```text
+yq r sample.yaml b.c
+```
+
+will output the value of '2'.
+
+### From Stdin[¶](read.md#from-stdin) <a id="from-stdin"></a>
+
+Given a sample.yaml file of:
+
+```text
+cat sample.yaml | yq r - b.c
+```
+
+will output the value of '2'.
+
+### Splat[¶](read.md#splat) <a id="splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+  item1:
+    cats: bananas
+  item2:
+    cats: apples
+  thing:
+    cats: oranges
+```
+
+then
+
+```text
+yq r sample.yaml bob.*.cats
+```
+
+will output
+
+```text
+- bananas
+- apples
+- oranges
+```
+
+### Prefix Splat[¶](read.md#prefix-splat) <a id="prefix-splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+  item1:
+    cats: bananas
+  item2:
+    cats: apples
+  thing:
+    cats: oranges
+```
+
+then
+
+```text
+yq r sample.yaml bob.item*.cats
+```
+
+will output
+
+```text
+- bananas
+- apples
+```
+
+### Multiple Documents - specify a single document[¶](read.md#multiple-documents-specify-a-single-document) <a id="multiple-documents-specify-a-single-document"></a>
+
+Given a sample.yaml file of:
+
+```text
+something: else
+---
+b:
+  c: 2
+```
+
+then
+
+```text
+yq r -d1 sample.yaml b.c
+```
+
+will output the value of '2'.
+
+### Multiple Documents - read all documents[¶](read.md#multiple-documents-read-all-documents) <a id="multiple-documents-read-all-documents"></a>
+
+Reading all documents will return the result as an array. This can be converted to json using the '-j' flag if desired.
+
+Given a sample.yaml file of:
+
+```text
+name: Fred
+age: 22
+---
+name: Stella
+age: 23
+---
+name: Android
+age: 232
+```
+
+then
+
+```text
+yq r -d'*' sample.yaml name
+```
+
+will output:
+
+```text
+- Fred
+- Stella
+- Android
+```
+
+### Arrays[¶](read.md#arrays) <a id="arrays"></a>
+
+You can give an index to access a specific element: e.g.: given a sample file of
+
+```text
+b:
+  e:
+    - name: fred
+      value: 3
+    - name: sam
+      value: 4
+```
+
+then
+
+```text
+yq r sample.yaml 'b.e[1].name'
+```
+
+will output 'sam'
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Array Splat[¶](read.md#array-splat) <a id="array-splat"></a>
+
+e.g.: given a sample file of
+
+```text
+b:
+  e:
+    - name: fred
+      value: 3
+    - name: sam
+      value: 4
+```
+
+then
+
+```text
+yq r sample.yaml 'b.e[*].name'
+```
+
+will output:
+
+```text
+- fred
+- sam
+```
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Keys with dots[¶](read.md#keys-with-dots) <a id="keys-with-dots"></a>
+
+When specifying a key that has a dot use key lookup indicator.
+
+```text
+b:
+  foo.bar: 7
+```
+
+```text
+yaml r sample.yaml 'b[foo.bar]'
+```
+
+```text
+yaml w sample.yaml 'b[foo.bar]' 9
+```
+
+Any valid yaml key can be specified as part of a key lookup.
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Keys \(and values\) with leading dashes[¶](read.md#keys-and-values-with-leading-dashes) <a id="keys-and-values-with-leading-dashes"></a>
+
+If a key or value has leading dashes, yq won't know that you are passing a value as opposed to a flag \(and you will get a 'bad flag syntax' error\).
+
+To fix that, you will need to tell it to stop processing flags by adding '--' after the last flag like so:
+
+```text
+yq n -t -- --key --value
+```
+
+Will result in
+
+``` --key: --value``
+

snap/snapcraft.yaml

@@ -1,5 +1,5 @@
 name: yq
-version: '3.2.2'
+version: '3.3.2'
 summary: A lightweight and portable command-line YAML processor
 description: |
   The aim of the project is to be the jq or sed of yaml files.

write-update.md

@@ -0,0 +1,349 @@
+# Write
+
+```text
+yq w <yaml_file> <path> <new value>
+```
+
+### To Stdout[¶](write-update.md#to-stdout) <a id="to-stdout"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+```
+
+then
+
+```text
+yq w sample.yaml b.c cat
+```
+
+will output:
+
+```text
+b:
+  c: cat
+```
+
+### From STDIN[¶](write-update.md#from-stdin) <a id="from-stdin"></a>
+
+```text
+cat sample.yaml | yq w - b.c blah
+```
+
+### Adding new fields[¶](write-update.md#adding-new-fields) <a id="adding-new-fields"></a>
+
+Any missing fields in the path will be created on the fly.
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+```
+
+then
+
+```text
+yq w sample.yaml b.d[+] "new thing"
+```
+
+will output:
+
+```text
+b:
+  c: cat
+  d:
+    - new thing
+```
+
+### Splat[¶](write-update.md#splat) <a id="splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+  item1:
+    cats: bananas
+  item2:
+    cats: apples
+  thing:
+    cats: oranges
+```
+
+then
+
+```text
+yq w sample.yaml bob.*.cats meow
+```
+
+will output:
+
+```text
+---
+bob:
+  item1:
+    cats: meow
+  item2:
+    cats: meow
+  thing:
+    cats: meow
+```
+
+### Prefix Splat[¶](write-update.md#prefix-splat) <a id="prefix-splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+  item1:
+    cats: bananas
+  item2:
+    cats: apples
+  thing:
+    cats: oranges
+```
+
+then
+
+```text
+yq w sample.yaml bob.item*.cats meow
+```
+
+will output:
+
+```text
+---
+bob:
+  item1:
+    cats: meow
+  item2:
+    cats: meow
+  thing:
+    cats: oranges
+```
+
+### Array Splat[¶](write-update.md#array-splat) <a id="array-splat"></a>
+
+Given a sample.yaml file of:
+
+```text
+---
+bob:
+- cats: bananas
+- cats: apples
+- cats: oranges
+```
+
+then
+
+```text
+yq w sample.yaml bob[*].cats meow
+```
+
+will output:
+
+```text
+---
+bob:
+- cats: meow
+- cats: meow
+- cats: meow
+```
+
+### Appending value to an array field[¶](write-update.md#appending-value-to-an-array-field) <a id="appending-value-to-an-array-field"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+  d:
+    - new thing
+    - foo thing
+```
+
+then
+
+```text
+yq w sample.yaml "b.d[+]" "bar thing"
+```
+
+will output:
+
+```text
+b:
+  c: cat
+  d:
+    - new thing
+    - foo thing
+    - bar thing
+```
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Multiple Documents - update a single document[¶](write-update.md#multiple-documents-update-a-single-document) <a id="multiple-documents-update-a-single-document"></a>
+
+Given a sample.yaml file of:
+
+```text
+something: else
+---
+b:
+  c: 2
+```
+
+then
+
+```text
+yq w -d1 sample.yaml b.c 5
+```
+
+will output:
+
+```text
+something: else
+---
+b:
+  c: 5
+```
+
+### Multiple Documents - update all documents[¶](write-update.md#multiple-documents-update-all-documents) <a id="multiple-documents-update-all-documents"></a>
+
+Given a sample.yaml file of:
+
+```text
+something: else
+---
+b:
+  c: 2
+```
+
+then
+
+```text
+yq w -d'*' sample.yaml b.c 5
+```
+
+will output:
+
+```text
+something: else
+b:
+  c: 5
+---
+b:
+  c: 5
+```
+
+Note that '\*' is in quotes to avoid being interpreted by your shell.
+
+### Updating files in-place[¶](write-update.md#updating-files-in-place) <a id="updating-files-in-place"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+```
+
+then
+
+```text
+yq w -i sample.yaml b.c cat
+```
+
+will update the sample.yaml file so that the value of 'c' is cat.
+
+### Updating multiple values with a script[¶](write-update.md#updating-multiple-values-with-a-script) <a id="updating-multiple-values-with-a-script"></a>
+
+Given a sample.yaml file of:
+
+```text
+b:
+  c: 2
+  e:
+    - name: Billy Bob
+```
+
+and a script update\_instructions.yaml of:
+
+```text
+b.c: 3
+b.e[+].name: Howdy Partner
+```
+
+then
+
+```text
+yq w -s update_instructions.yaml sample.yaml
+```
+
+will output:
+
+```text
+b:
+  c: 3
+  e:
+    - name: Howdy Partner
+```
+
+And, of course, you can pipe the instructions in using '-':
+
+```text
+cat update_instructions.yaml | yq w -s - sample.yaml
+```
+
+### Values starting with a hyphen \(or dash\)[¶](write-update.md#values-starting-with-a-hyphen-or-dash) <a id="values-starting-with-a-hyphen-or-dash"></a>
+
+The flag terminator needs to be used to stop the app from attempting to parse the subsequent arguments as flags:
+
+```text
+yq w -- my.path -3
+```
+
+will output
+
+```text
+my:
+  path: -3
+```
+
+### Keys with dots[¶](write-update.md#keys-with-dots) <a id="keys-with-dots"></a>
+
+When specifying a key that has a dot use key lookup indicator.
+
+```text
+b:
+  foo.bar: 7
+```
+
+```text
+yaml r sample.yaml 'b[foo.bar]'
+```
+
+```text
+yaml w sample.yaml 'b[foo.bar]' 9
+```
+
+Any valid yaml key can be specified as part of a key lookup.
+
+Note that the path is in quotes to avoid the square brackets being interpreted by your shell.
+
+### Keys \(and values\) with leading dashes[¶](write-update.md#keys-and-values-with-leading-dashes) <a id="keys-and-values-with-leading-dashes"></a>
+
+If a key or value has leading dashes, yq won't know that you are passing a value as opposed to a flag \(and you will get a 'bad flag syntax' error\).
+
+To fix that, you will need to tell it to stop processing flags by adding '--' after the last flag like so:
+
+```text
+yq n -t -- --key --value
+```
+
+Will result in
+
+``` --key: --value``
+

yq.go

@@ -4,14 +4,11 @@ import (
 	"os"
 
 	command "github.com/mikefarah/yq/v3/cmd"
-	logging "gopkg.in/op/go-logging.v1"
 )
 
 func main() {
 	cmd := command.New()
-	log := logging.MustGetLogger("yq")
 	if err := cmd.Execute(); err != nil {
-		log.Error(err.Error())
 		os.Exit(1)
 	}
 }