Print path is more accurate than keys (i think)

Upgrade Notes

@@ -1,11 +1,55 @@
 
 # New Features
-  - Keeps comments and formatting (e.g. inline arrays)!
+  - Keeps yaml comments and formatting (string blocks are saved, number formatting is preserved, so it won't drop off trailing 0s for values like 0.10, which is important when that's a version entry )
-  - Handles anchors!
-  - Can specify yaml tags (e.g. !!int), quoting values no longer sufficient, need to specify the tag value instead.
-  - JSON output works for all commands! Yaml files with multiple documents are printed out as one JSON document per line. 
   
-# Update scripts file format has changed to be more powerful. Comments can be added, and delete commands have been introduced.
+  - Handles anchors! (doc link)
+  - Can specify yaml tags (e.g. !!int), quoting values no longer sufficient, need to specify the tag value instead.
+  - Can print out matching paths and values when splatting (doc link)
+  - JSON output works for all commands! Yaml files with multiple documents are printed out as one JSON document per line. 
+  - Deep splat (**) to match arbitrary paths, (doc link)
+
+
+# Breaking changes
+
+## Update scripts file format has changed to be more powerful. 
+Comments can be added, and delete commands have been introduced.
+
+## Reading and splatting, matching results are printed once per line.
+  e.g:
+
+```json
+parent:
+  childA: 
+    no: matches here
+  childB:
+    there: matches
+    hi: no match
+    there2: also matches
+```
+
+yq r sample.yaml 'parent.*.there*'
+
+old
+```yaml
+- null
+- - matches
+  - also matches
+```
+
+new
+```yaml
+matches
+also matches
+```
+
+and you can print the matching paths:
+
+yq r --printMode pv sample.yaml 'parent.*.there*'
+
+```yaml
+parent.childB.there: matches
+parent.childB.there2: also matches
+```
 
 # Merge command
 - New flag 'autocreates' missing entries in target by default, new flag to turn that off.

commands_test.go

@@ -96,7 +96,7 @@ func TestReadCmd(t *testing.T) {
 
 func TestReadWithKeyAndValueCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv examples/sample.yaml b.c")
+	result := test.RunCmd(cmd, "read -p pv examples/sample.yaml b.c")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -105,7 +105,7 @@ func TestReadWithKeyAndValueCmd(t *testing.T) {
 
 func TestReadArrayCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv examples/sample.yaml b.e.1.name")
+	result := test.RunCmd(cmd, "read -p pv examples/sample.yaml b.e.1.name")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -114,7 +114,7 @@ func TestReadArrayCmd(t *testing.T) {
 
 func TestReadDeepSplatCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv examples/sample.yaml b.**")
+	result := test.RunCmd(cmd, "read -p pv examples/sample.yaml b.**")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -132,7 +132,7 @@ b.e.[1].value: 4
 
 func TestReadDeepSplatWithSuffixCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv examples/sample.yaml b.**.name")
+	result := test.RunCmd(cmd, "read -p pv examples/sample.yaml b.**.name")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -144,7 +144,7 @@ b.e.[1].name: sam
 
 func TestReadWithKeyCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p k examples/sample.yaml b.c")
+	result := test.RunCmd(cmd, "read -p p examples/sample.yaml b.c")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -162,7 +162,7 @@ func TestReadAnchorsCmd(t *testing.T) {
 
 func TestReadAnchorsWithKeyAndValueCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv examples/simple-anchor.yaml foobar.a")
+	result := test.RunCmd(cmd, "read -p pv examples/simple-anchor.yaml foobar.a")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -189,7 +189,7 @@ func TestReadMergeAnchorsOverrideCmd(t *testing.T) {
 
 func TestReadMergeAnchorsPrefixMatchCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "r -p kv examples/merge-anchor.yaml foobar.th*")
+	result := test.RunCmd(cmd, "r -p pv examples/merge-anchor.yaml foobar.th*")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -271,7 +271,7 @@ func TestReadMultiCmd(t *testing.T) {
 
 func TestReadMultiWithKeyAndValueCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p vk -d 1 examples/multiple_docs.yaml another.document")
+	result := test.RunCmd(cmd, "read -p vp -d 1 examples/multiple_docs.yaml another.document")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -292,7 +292,7 @@ third document`, result.Output)
 
 func TestReadMultiAllWithKeyAndValueCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv -d* examples/multiple_docs.yaml commonKey")
+	result := test.RunCmd(cmd, "read -p pv -d* examples/multiple_docs.yaml commonKey")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -372,7 +372,7 @@ gather_facts: true
 
 func TestReadCmd_ArrayYaml_SplatWithKeyAndValueCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p kv examples/array.yaml [*]")
+	result := test.RunCmd(cmd, "read -p pv examples/array.yaml [*]")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -394,7 +394,7 @@ func TestReadCmd_ArrayYaml_SplatWithKeyAndValueCmd(t *testing.T) {
 
 func TestReadCmd_ArrayYaml_SplatWithKeyCmd(t *testing.T) {
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, "read -p k examples/array.yaml [*]")
+	result := test.RunCmd(cmd, "read -p p examples/array.yaml [*]")
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -494,7 +494,7 @@ func TestReadCmd_Verbose(t *testing.T) {
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
-	test.AssertResult(t, "2\n", result.Output)
+	test.AssertResult(t, "2", result.Output)
 }
 
 // func TestReadCmd_ToJson(t *testing.T) {
@@ -559,7 +559,7 @@ b:
 	defer test.RemoveTempYamlFile(filename)
 
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, fmt.Sprintf("read -p kv %s b.there*.c", filename))
+	result := test.RunCmd(cmd, fmt.Sprintf("read -p pv %s b.there*.c", filename))
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -587,7 +587,7 @@ b:
 	defer test.RemoveTempYamlFile(filename)
 
 	cmd := getRootCommand()
-	result := test.RunCmd(cmd, fmt.Sprintf("read -p k %s b.there*.c", filename))
+	result := test.RunCmd(cmd, fmt.Sprintf("read -p p %s b.there*.c", filename))
 	if result.Error != nil {
 		t.Error(result.Error)
 	}
@@ -871,6 +871,28 @@ func TestWriteCmdScript(t *testing.T) {
 	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

yq.go

@@ -107,7 +107,7 @@ yq r -- things.yaml --key-starting-with-dashes.blah
 		RunE: readProperty,
 	}
 	cmdRead.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
-	cmdRead.PersistentFlags().StringVarP(&printMode, "printMode", "p", "v", "print mode (v (values, default), k (keys), kv (key and value pairs)")
+	cmdRead.PersistentFlags().StringVarP(&printMode, "printMode", "p", "v", "print mode (v (values, default), p (paths), pv (path and value pairs)")
 	return cmdRead
 }
 
@@ -218,7 +218,7 @@ Note that you can give a create script to perform more sophisticated yaml. This
 `,
 		RunE: newProperty,
 	}
-	cmdNew.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for updating yaml")
+	cmdNew.PersistentFlags().StringVarP(&writeScript, "script", "s", "", "yaml script for creating yaml")
 	cmdNew.PersistentFlags().StringVarP(&customTag, "tag", "t", "", "set yaml tag (e.g. !!int)")
 	return cmdNew
 }
@@ -323,6 +323,11 @@ func appendDocument(originalMatchingNodes []*yqlib.NodeContext, dataBucket yaml.
 }
 
 func printValue(node *yaml.Node, cmd *cobra.Command) error {
+	if node.Kind == yaml.ScalarNode {
+		cmd.Print(node.Value)
+		return nil
+	}
+
 	bufferedWriter := bufio.NewWriter(cmd.OutOrStdout())
 	defer safelyFlush(bufferedWriter)
 
@@ -346,12 +351,12 @@ func printResults(matchingNodes []*yqlib.NodeContext, cmd *cobra.Command) error
 
 	for index, mappedDoc := range matchingNodes {
 		switch printMode {
-		case "k":
+		case "p":
 			cmd.Print(lib.PathStackToString(mappedDoc.PathStack))
 			if index < len(matchingNodes)-1 {
 				cmd.Print("\n")
 			}
-		case "kv", "vk":
+		case "pv", "vp":
 			// put it into a node and print that.
 			var parentNode = yaml.Node{Kind: yaml.MappingNode}
 			parentNode.Content = make([]*yaml.Node, 2)
@@ -601,9 +606,13 @@ func readUpdateCommands(args []string, expectedArgs int, badArgsMessage string)
 	var updateCommands []yqlib.UpdateCommand = make([]yqlib.UpdateCommand, 0)
 	if writeScript != "" {
 		var parsedCommands = make([]updateCommandParsed, 0)
-		if err := readData(writeScript, 0, &parsedCommands); err != nil {
+
+		err := readData(writeScript, 0, &parsedCommands)
+
+		if err != nil && err != io.EOF {
 			return nil, err
 		}
+
 		log.Debugf("Read write commands file '%v'", parsedCommands)
 		for index := range parsedCommands {
 			parsedCommand := parsedCommands[index]