---
name: "Sisimai::RFC1894"
section: "3pm"
platform: "linux"
package: "libsisimai-perl"
version: "5.3.0-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Sisimai::RFC1894"
---

# Sisimai::RFC1894(3pm)

DSN field defined in RFC3464 (obsoletes RFC1894)

## NAME

Sisimai::RFC1894 - DSN field defined in RFC3464 (obsoletes RFC1894)

## SYNOPSIS

```
    use Sisimai::RFC1894;
    print Sisimai::RFC1894->match('From: Nyaan <kijitora@libsisimai.org>'); # 0
    print Sisimai::RFC1894->match('Reporting-MTA: DNS; mx.libsisimai.org'); # 1
    print Sisimai::RFC1894->match('Final-Recipient: RFC822; cat@nyaan.jp'); # 2
    my $v = Sisimai::RFC1894->field('Reporting-MTA: DNS; mx.nyaan.jp');
    my $r = Sisimai::RFC1894->field('Status: 5.1.1 (user unknown)');
    print Data::Dumper::Dumper $v;  # ['reporting-mta', 'dns', 'mx.nyaan.org', 'host', ''];
    print Data::Dumper::Dumper $r;  # ['status', '', '5.1.1', 'stat', 'user unknown'];
```

## DESCRIPTION

`"Sisimai::RFC1894"` provide methods for checking or getting DSN fields

## CLASS METHODS

### "match(String)"

`match()` method checks the argument includes the field defined in RFC3464 or not

```
    print Sisimai::RFC1894->match('From: Nyaan <kijitora@libsisimai.org>'); # 0
    print Sisimai::RFC1894->match('Reporting-MTA: DNS; mx.libsisimai.org'); # 1
    print Sisimai::RFC1894->match('Final-Recipient: RFC822; cat@nyaan.jp'); # 2
```

### "label(String)"

`label()` method returns a lower cased field name such as `"diagnostic-code"` from the given email header or the delivery status field.

```
    print Sisimai::RFC1894->label('Remote-MTA: DNS; mx.nyaan.jp');  # remote-mta
    print Sisimai::RFC1894->field('Status: 5.1.1');                 # status
    print Sisimai::RFC1894->field('Subject: Nyaan');                # subject
    print Sisimai::RFC1894->field('');                              # undef
```

### "field(String)"

`field()` method returns the splited values as an array reference from the given string including DSN fields defined in RFC3464.

```
    my $v = Sisimai::RFC1894->field('Remote-MTA: DNS; mx.nyaan.jp');
    my $r = Sisimai::RFC1894->field('Status: 5.1.1');
    print Data::Dumper::Dumper $v;  # ['remote-mta', 'dns', 'mx.nyaan.org', 'host'];
    print Data::Dumper::Dumper $r;  # ['status', '', '5.1.1', 'stat'];
```

## AUTHOR

azumakuniyuki

## COPYRIGHT

Copyright (C) 2018-2025 azumakuniyuki, All rights reserved.

## LICENSE

This software is distributed under The BSD 2-Clause License.