Add support for JSON output

main.go

@@ -29,13 +29,13 @@ func parseArguments() {
 	mailqCommandPtr := flag.String("mailqCommand", "mailq", "Command to use for getting mailq output")
 	mailqCommandArgsPtr := flag.String("mailqCommandArgs", "", "Optional arguments to pass to mailqCommand")
 	interactivePtr := flag.Bool("interactive", false, "Set to true for shell mode")
-	machineFormatPtr := flag.Bool("machineFormat", false, "Set to true to get output suitable for cut/awk/...")
+	outputFormatPtr := flag.String("outputFormat", "human", "Available output formats: \"human\", \"machine\", \"json\"")
 	usePagerPtr := flag.Bool("usePager", true, "Use pager to display output?")
 	flag.Parse()
 	settings["mailqCommand"] = *mailqCommandPtr
 	settings["mailqCommandArgs"] = *mailqCommandArgsPtr
 	settings["interactive"] = strconv.FormatBool(*interactivePtr)
-	settings["machineFormat"] = strconv.FormatBool(*machineFormatPtr)
+	settings["outputFormat"] = *outputFormatPtr
 	settings["usePager"] = strconv.FormatBool(*usePagerPtr)
 }
 
@@ -63,10 +63,12 @@ func showQueue() {
 }
 
 func printQueue(queue parser.MailQ, writer io.Writer) {
-	if settings["machineFormat"] == "true" {
-		queue.PrintMachineReadable(writer)
-	} else {
+	if settings["outputFormat"] == "human" {
 		queue.PrintHumanReadable(writer)
+	} else if settings["outputFormat"] == "machine" {
+		queue.PrintMachineReadable(writer)
+	} else if settings["outputFormat"] == "json" {
+		queue.PrintJSON(writer)
 	}
 }
 

parser/parser.go

@@ -2,6 +2,7 @@ package parser
 
 import (
 	"bufio"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -76,6 +77,15 @@ func (queue MailQ) PrintHumanReadable(writer io.Writer) {
 	}
 }
 
+func (queue MailQ) PrintJSON(writer io.Writer) {
+	bytes, err := json.Marshal(queue)
+	if err != nil {
+		fmt.Fprintf(writer, "Error encoding queue to JSON: %s\n", err.Error())
+	} else {
+		fmt.Fprintf(writer, "%s", bytes)
+	}
+}
+
 func ParseMailQ(dataSource io.Reader) (MailQ, error) {
 	const dateFormat = "2006 Mon Jan _2 15:04:05"
 	var messageIdStart = regexp.MustCompile("^[0-9A-Za-z]+[*!]? ")