Implement printing mailqueue in table, restructuring

main.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"strconv"
+	"text/tabwriter"
 )
 
 import (
@@ -41,6 +42,21 @@ func interactiveShell() {
 }
 
 func showQueue() {
+	entries, err := fetchQueueEntries()
+	if err != nil {
+		fmt.Printf("Could not fetch queue entries: %s\n", err.Error())
+		os.Exit(1)
+	}
+	pagerReader, pagerWriter := io.Pipe()
+	pagerDone := make(chan bool)
+	go launchPager(pagerReader, pagerDone)
+	printQueueEntries(entries, pagerWriter)
+	pagerWriter.Close()
+	// Wait for pager to be closed before continuing the main program
+	<-pagerDone
+}
+
+func fetchQueueEntries() ([]parser.QEntry, error) {
 	var entries []parser.QEntry
 	var err error
 	if settings["mailqCommandArgs"] == "" {
@@ -48,24 +64,22 @@ func showQueue() {
 	} else {
 		entries, err = readFromCmd(exec.Command(settings["mailqCommand"], settings["mailqCommandArgs"]))
 	}
-	if err != nil {
+	return entries, err
-		fmt.Printf("Error reading: %s\n", err.Error())
+}
-		os.Exit(1)
+
-	}
+func printQueueEntries(entries []parser.QEntry, writer io.Writer) {
-	reader, writer := io.Pipe()
+	tabWriter := tabwriter.NewWriter(writer, 0, 2, 1, ' ', tabwriter.TabIndent)
-	pagerDone := make(chan bool)
+	fmt.Fprintf(tabWriter, "%s\t%s\t%s\t%s\t%s\t%s\n", "Date", "Id", "Size", "Sender", "#", "First Recipient")
-	go launchPager(reader, pagerDone)
 	for _, entry := range entries {
-		_, writeError := fmt.Fprintf(writer, "%s\n", entry.String())
+		_, writeError := fmt.Fprintf(tabWriter, "%s\t%s\t%d\t%s\t{%d}\t%s\n", entry.Date, entry.Id, entry.Size, entry.Sender, len(entry.Recipients), entry.Recipients[0])
 		if writeError != nil {
 			// A writeError is expected once the reader was closed
 			// This happens when the pager application got terminated
+			fmt.Printf("Error writing!: %s\n", writeError.Error())
 			break
 		}
 	}
-	writer.Close()
+	tabWriter.Flush()
-	// Wait for pager to be closed before continuing the main program
-	<-pagerDone
 }
 
 func launchPager(reader *io.PipeReader, pagerDone chan<- bool) {

parser/parser.go

@@ -12,35 +12,35 @@ import (
 )
 
 type QEntry struct {
-	id         string
+	Id         string
-	status     string
+	Status     string
-	date       time.Time
+	Date       time.Time
-	size       int
+	Size       int
-	sender     string
+	Sender     string
-	recipients []string
+	Recipients []string
-	reason     string
+	Reason     string
 }
 
 const sortableDateFormat = "2006-01-02 15:04:05"
 
 func (m QEntry) ShortString() string {
-	return fmt.Sprintf("[%s] %s <%s> -> %d recipients (%d bytes)", m.date.Format(sortableDateFormat), m.id, m.sender, len(m.recipients), m.size)
+	return fmt.Sprintf("[%s] %s <%s> -> %d recipients (%d bytes)", m.Date.Format(sortableDateFormat), m.Id, m.Sender, len(m.Recipients), m.Size)
 }
 
 func (m QEntry) String() string {
     var recipientSuffix string
-    if len(m.recipients) > 1 {
+    if len(m.Recipients) > 1 {
         recipientSuffix = ",..."
     }
-	return fmt.Sprintf("[%s] %s <%s> -> {%d}<%s>%s (%s, %d bytes)", m.date.Format(sortableDateFormat), m.id, m.sender, len(m.recipients), m.recipients[0], recipientSuffix, m.status, m.size)
+	return fmt.Sprintf("[%s] %s <%s> -> {%d}<%s>%s (%s, %d bytes)", m.Date.Format(sortableDateFormat), m.Id, m.Sender, len(m.Recipients), m.Recipients[0], recipientSuffix, m.Status, m.Size)
 }
 
 func (m QEntry) DetailedString() string {
     var reasonStr string
-    if m.reason == "" {
+    if m.Reason == "" {
         reasonStr = "-/-"
     }
-    return fmt.Sprintf("Id: %s\nDate: %s\nStatus: %s\nReason: %s\nSize: %d\nSender: %s\nRecipients: %s", m.id, m.date.Format(sortableDateFormat), m.status, reasonStr, m.size, m.sender, strings.Join(m.recipients, ", "))
+    return fmt.Sprintf("Id: %s\nDate: %s\nStatus: %s\nReason: %s\nSize: %d\nSender: %s\nRecipients: %s", m.Id, m.Date.Format(sortableDateFormat), m.Status, reasonStr, m.Size, m.Sender, strings.Join(m.Recipients, ", "))
 }
 
 func ParseMailQ(dataSource io.Reader) ([]QEntry, error) {
@@ -71,26 +71,26 @@ func ParseMailQ(dataSource io.Reader) ([]QEntry, error) {
 			// Handle line starting next mail in queue
 			messageId := fields[0]
 			if strings.HasSuffix(messageId, "*") {
-				currentMail.status = "active"
+				currentMail.Status = "active"
 			} else if strings.HasSuffix(messageId, "!") {
-				currentMail.status = "hold"
+				currentMail.Status = "hold"
 			} else {
-				currentMail.status = "deferred"
+				currentMail.Status = "deferred"
 			}
 			dateString := strconv.Itoa(time.Now().Year()) + " " + strings.Join(fields[2:6], " ")
 			mailDate, _ := time.Parse(dateFormat, dateString)
-			currentMail.id = strings.TrimRight(messageId, "*!")
+			currentMail.Id = strings.TrimRight(messageId, "*!")
-			currentMail.size, _ = strconv.Atoi(fields[1])
+			currentMail.Size, _ = strconv.Atoi(fields[1])
-			currentMail.date = mailDate
+			currentMail.Date = mailDate
-			currentMail.sender = fields[6]
+			currentMail.Sender = fields[6]
 			continue
 		} else if strings.HasPrefix(line, "(") && strings.HasSuffix(line, ")") {
 			// Handle reason for deferred status (if deferred at all, may be missing)
-			currentMail.reason = strings.Trim(strings.TrimSpace(line), "()")
+			currentMail.Reason = strings.Trim(strings.TrimSpace(line), "()")
 			continue
 		} else if len(fields) == 1 {
 			// Handle line with one of the mail recipients
-			currentMail.recipients = append(currentMail.recipients, fields[0])
+			currentMail.Recipients = append(currentMail.Recipients, fields[0])
 			continue
 		} else if len(fields) == 0 {
 			// If the next line is empty, make sure to push current mail to list