Added shell string encoder (@sh) #1526

pkg/yqlib/encoder_sh.go

@@ -0,0 +1,44 @@
+package yqlib
+
+import (
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+
+	yaml "gopkg.in/yaml.v3"
+)
+
+var pattern = regexp.MustCompile(`[^\w@%+=:,./-]`)
+
+type shEncoder struct {
+}
+
+func NewShEncoder() Encoder {
+	return &shEncoder{}
+}
+
+func (e *shEncoder) CanHandleAliases() bool {
+	return false
+}
+
+func (e *shEncoder) PrintDocumentSeparator(writer io.Writer) error {
+	return nil
+}
+
+func (e *shEncoder) PrintLeadingContent(writer io.Writer, content string) error {
+	return nil
+}
+
+func (e *shEncoder) Encode(writer io.Writer, originalNode *yaml.Node) error {
+	node := unwrapDoc(originalNode)
+	if guessTagFromCustomType(node) != "!!str" {
+		return fmt.Errorf("cannot encode %v as URI, can only operate on strings. Please first pipe through another encoding operator to convert the value to a string", node.Tag)
+	}
+
+	value := originalNode.Value
+	if pattern.MatchString(value) {
+		value = "'" + strings.ReplaceAll(value, "'", "\\'") + "'"
+	}
+	return writeString(writer, value)
+}