iconv_mime_decode_headers

(PHP 5, PHP 7, PHP 8)

iconv_mime_decode_headers — Decodes multiple MIME header fields at once

Description

iconv_mime_decode_headers(string $headers, int $mode = 0, ?string $encoding = null): array|false

Decodes multiple MIME header fields at once.

Parameters

headers

The encoded headers, as a string.

mode

mode determines the behaviour in the event iconv_mime_decode_headers() encounters a malformed MIME header field. You can specify any combination of the following bitmasks.

Bitmasks acceptable to **iconv_mime_decode_headers()**
Value	Constant	Description
1	ICONV_MIME_DECODE_STRICT	If set, the given header is decoded in full conformance with the standards defined in » RFC2047. This option is disabled by default because there are a lot of broken mail user agents that don't follow the specification and don't produce correct `MIME` headers.
2	ICONV_MIME_DECODE_CONTINUE_ON_ERROR	If set, iconv_mime_decode_headers() attempts to ignore any grammatical errors and continue to process a given header.

encoding

The optional encoding parameter specifies the character set to represent the result by. If omitted or null, iconv.internal_encoding will be used.

Return Values

Returns an associative array that holds a whole set of MIME header fields specified by headers on success, or false if an error occurs during the decoding.

Each key of the return value represents an individual field name and the corresponding element represents a field value. If more than one field of the same name are present, iconv_mime_decode_headers() automatically incorporates them into a numerically indexed array in the order of occurrence. Note that header names are not case-insensitive.

Changelog

Version	Description
8.0.0	`encoding` is nullable now.

Examples

Example #1 iconv_mime_decode_headers() example

<?php
$headers_string = <<<EOF
Subject: =?UTF-8?B?UHLDvGZ1bmcgUHLDvGZ1bmc=?=
To: example@example.com
Date: Thu, 1 Jan 1970 00:00:00 +0000
Message-Id: <example@example.com>
Received: from localhost (localhost [127.0.0.1]) by localhost
    with SMTP id example for <example@example.com>;
    Thu, 1 Jan 1970 00:00:00 +0000 (UTC)
    (envelope-from example-return-0000-example=example.com@example.com)
Received: (qmail 0 invoked by uid 65534); 1 Thu 2003 00:00:00 +0000

EOF;

$headers =  iconv_mime_decode_headers($headers_string, 0, "ISO-8859-1");
print_r($headers);
?>

The above example will output:

Array
(
    [Subject] => Prüfung Prüfung
    [To] => example@example.com
    [Date] => Thu, 1 Jan 1970 00:00:00 +0000
    [Message-Id] => <example@example.com>
    [Received] => Array
        (
            [0] => from localhost (localhost [127.0.0.1]) by localhost with SMTP id example for <example@example.com>; Thu, 1 Jan 1970 00:00:00 +0000 (UTC) (envelope-from example-return-0000-example=example.com@example.com)
            [1] => (qmail 0 invoked by uid 65534); 1 Thu 2003 00:00:00 +0000
        )

)

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User Contributed Notes 2 notes

down

phpmanual at NOSPAM dot headbank dot co dot uk ¶

29 days ago

Just in case this catches anyone else: If your headers string has any leading linebreaks, this function will reject it and return an empty array. If that might apply to your input, sanitise it with ltrim().

Trailing empty lines are tolerated/ignored.

Other quirks I noticed just now:

1. Leading whitespace (" " or "\t") in the *first* line will be included in the header's key name in the returned array. ltrim() will prevent that too.

2. Leading whitespace in any subsequent header (before the key) will cause that line to be appended to the preceding header's value, as though it were a run-on of that header.