mailq-inspector/parser/parser.go

87 lines
2.7 KiB
Go

package parser
import (
"bufio"
"errors"
"fmt"
"regexp"
"strconv"
"strings"
"time"
)
type Entry struct {
id string
status string
date time.Time
size int
sender string
recipients []string
reason string
}
func (m Entry) String() string {
return fmt.Sprintf("ID: %s, Status: %s, Size: %d bytes, Sender: %s, Recipients: %d", m.id, m.status, m.size, m.sender, len(m.recipients))
}
func ParseMailQ(scanner *bufio.Scanner) ([]Entry, error) {
const dateFormat = "2006 Mon Jan _2 15:04:05"
var messageIdStart = regexp.MustCompile("^[0-9A-Za-z]+[*!]? ")
scanner.Scan()
line := scanner.Text()
if strings.HasPrefix(line, "Mail queue is empty") {
// If mail queue is empty, there is nothing to do
return nil, errors.New(line)
} else if strings.HasPrefix(line, "-Queue ID-") == false {
// Abort if input does not look like output from mailq(1)
return nil, errors.New("Sorry, this does not look like output from mailq(1).")
}
var currentMail Entry
var queueEntries []Entry
for scanner.Scan() {
// Read input line by line
line := scanner.Text()
fields := strings.Fields(line)
if strings.HasPrefix(line, "--") {
// Handle the summary line at the end of mailq output
break
} else if messageIdStart.MatchString(line) {
// Handle line starting next mail in queue
messageId := fields[0]
if strings.HasSuffix(messageId, "*") {
currentMail.status = "active"
} else if strings.HasSuffix(messageId, "!") {
currentMail.status = "hold"
} else {
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.size, _ = strconv.Atoi(fields[1])
currentMail.date = mailDate
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), "()")
continue
} else if len(fields) == 1 {
// Handle line with one of the mail recipients
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
// and create a new struct for the next mail to process
queueEntries = append(queueEntries, currentMail)
currentMail = Entry{}
}
}
if scanner.Err() != nil {
// If the scanner failed, let our caller know.
return nil, errors.New("Something went wrong with reading from stdin. Sorry!")
}
return queueEntries, nil
}