PHPMailer::encodeHeader( string $str, string $position = 'text' ): string

Description

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$strstring

The header value to encode

$positionstringoptional

What context the string will be used inDefault: 'text'

Return value

string

Performance profile

How much work a call to PHPMailer::encodeHeader() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Trivial

Touches nothing outside its own arguments.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

15–92

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 164.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

• regexregular expression over the whole inputpreg_match_all()called directly

What one call costs · 10 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost PHPMailer::encodeHeader() can have, taken from its control-flow graph on PHP 8.5.

Uses · 6

• static::normalizeBreaks()
• \PHPMailer\PHPMailer\PHPMailer::has8bitChars()
• \PHPMailer\PHPMailer\PHPMailer::hasMultiBytes()
• \PHPMailer\PHPMailer\PHPMailer::base64EncodeWrapMB()
• \PHPMailer\PHPMailer\PHPMailer::encodeQ()
• \PHPMailer\PHPMailer\PHPMailer::wrapText()

Source code

View on Trac ↗View on GitHub ↗

3723    public function encodeHeader($str, $position = 'text')3724    {3725        $position = strtolower($position);3726        if ($this->UseSMTPUTF8 && !("comment" === $position)) {3727            return trim(static::normalizeBreaks($str));3728        }3729 3730        $matchcount = 0;3731        switch (strtolower($position)) {3732            case 'phrase':3733                if (!preg_match('/[\200-\377]/', $str)) {3734                    //Can't use addslashes as we don't know the value of magic_quotes_sybase3735                    $encoded = addcslashes($str, "\0..\37\177\\\"");3736                    if (($str === $encoded) && !preg_match('/[^A-Za-z0-9!#$%&\'*+\/=?^_`{|}~ -]/', $str)) {3737                        return $encoded;3738                    }3739 3740                    return "\"$encoded\"";3741                }3742                $matchcount = preg_match_all('/[^\040\041\043-\133\135-\176]/', $str, $matches);3743                break;3744            /* @noinspection PhpMissingBreakStatementInspection */3745            case 'comment':3746                $matchcount = preg_match_all('/[()"]/', $str, $matches);3747            //fallthrough3748            case 'text':3749            default:3750                $matchcount += preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $str, $matches);3751                break;3752        }3753 3754        if ($this->has8bitChars($str)) {3755            $charset = $this->CharSet;3756        } else {3757            $charset = static::CHARSET_ASCII;3758        }3759 3760        //Q/B encoding adds 8 chars and the charset ("` =?<charset>?[QB]?<content>?=`").3761        $overhead = 8 + strlen($charset);3762 3763        if ('mail' === $this->Mailer) {3764            $maxlen = static::MAIL_MAX_LINE_LENGTH - $overhead;3765        } else {3766            $maxlen = static::MAX_LINE_LENGTH - $overhead;3767        }3768 3769        //Select the encoding that produces the shortest output and/or prevents corruption.3770        if ($matchcount > strlen($str) / 3) {3771            //More than 1/3 of the content needs encoding, use B-encode.3772            $encoding = 'B';3773        } elseif ($matchcount > 0) {3774            //Less than 1/3 of the content needs encoding, use Q-encode.3775            $encoding = 'Q';3776        } elseif (strlen($str) > $maxlen) {3777            //No encoding needed, but value exceeds max line length, use Q-encode to prevent corruption.3778            $encoding = 'Q';3779        } else {3780            //No reformatting needed3781            $encoding = false;3782        }3783 3784        switch ($encoding) {3785            case 'B':3786                if ($this->hasMultiBytes($str)) {3787                    //Use a custom function which correctly encodes and wraps long3788                    //multibyte strings without breaking lines within a character3789                    $encoded = $this->base64EncodeWrapMB($str, "\n");3790                } else {3791                    $encoded = base64_encode($str);3792                    $maxlen -= $maxlen % 4;3793                    $encoded = trim(chunk_split($encoded, $maxlen, "\n"));3794                }3795                $encoded = preg_replace('/^(.*)$/m', ' =?' . $charset . "?$encoding?\\1?=", $encoded);3796                break;3797            case 'Q':3798                $encoded = $this->encodeQ($str, $position);3799                $encoded = $this->wrapText($encoded, $maxlen, true);3800                $encoded = str_replace('=' . static::$LE, "\n", trim($encoded));3801                $encoded = preg_replace('/^(.*)$/m', ' =?' . $charset . "?$encoding?\\1?=", $encoded);3802                break;

Changelog

Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/PHPMailer/PHPMailer.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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