iconv_mime_encode

(PHP 5)

iconv_mime_encode --  Composes a MIME header field

Description

string iconv_mime_encode ( string field_name, string field_value [, array preferences])

Composes and returns a string that represents a valid MIME header field, which looks like the following:
Subject: =?ISO-8859-1?Q?Pr=FCfung_f=FCr?= Entwerfen von einer MIME kopfzeile
In the above example, "Subject" is the field name and the portion that begins with "=?ISO-8859-1?..." is the field value.

You can control the behaviour of iconv_mime_encode() by specifying an associative array that contains configuration items to the optional third parameter preferences. The items supported by iconv_mime_encode() are listed below. Note that item names are treated case-sensitive.

Table 1. Configuration items supported by iconv_mime_encode()

ItemTypeDescriptionDefault valueExample
schemeboolean Specifies the method to encode a field value by. The value of this item may be either "B" or "Q", where "B" stands for base64 encoding scheme and "Q" stands for quoted-printable encoding scheme. BB
input-charsetstring Specifies the character set in which the first parameter field_name and the second parameter field_value are presented. If not given, iconv_mime_encode() assumes those parameters are presented to it in the iconv.internal_charset ini setting. iconv.internal_charset ISO-8859-1
output-charsetstring Specifies the character set to use to compose the MIME header. If not given, the same value as input-charset will be used. the same value as input-charset UTF-8
line-lengthinteger Specifies the maximum length of the header lines. The resulting header is "folded" to a set of multiple lines in case the resulting header field would be longer than the value of this parameter, according to RFC2822 - Internet Message Format. If not given, the length will be limited to 76 characters. 76996
line-break-charsstring Specifies the sequence of characters to append to each line as an end-of-line sign when "folding" is performed on a long header field. If not given, this defaults to "\r\n" (CR LF). Note that this parameter is always treated as an ASCII string regardless of the value of input-charset. \r\n\n

Example 1. iconv_mime_encode() example:

<?php
$preferences
= array(
    
"input-charset" => "ISO-8859-1",
    
"output-charset" => "UTF-8",
    
"line-length" => 76,
    
"line-break-chars" => "\n"
);
$preferences["scheme"] = "Q";
// This yields "Subject: =?UTF-8?Q?Pr=C3=BCfung_Pr=C3=BCfung?="
echo iconv_mime_encode("Subject", "Prüfung Prüfung", $preferences);

$preferences["scheme"] = "B";
// This yields "Subject: =?UTF-8?B?UHLDvGZ1bmcgUHLDvGZ1bmc=?="
echo iconv_mime_encode("Subject", "Prüfung Prüfung", $preferences);
?>

See also imap_binary(), mb_encode_mimeheader() and imap_8bit().