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User Contributed Notes 2 notes

marcus at synchromedia dot co dot uk
16 years ago
I can't find any real documentation on the quoted-printable-encode stream filter, but I've gathered info from several places. It seems there are 4 options that can be passed in the param array as in my other note on this subject:

line-length: integer, simply sets line length before a soft break is inserted
line-break-chars: Which char or chars to consider as a line break - note that "\r\n" will only match CRLF, not CR or LF, so make sure it matches your content.
binary: boolean, hex encodes all control chars, including spaces and line breaks, but leaves alphanumerics untouched
force-encode-first: Forcibly hex-encodes the first char on each line, even if it's alphanumeric. This is useful for avoiding corruption in some incompetent mail servers, like Exchange.
marcus at synchromedia dot co dot uk
17 years ago
As this article says, there is no quoted_printable_encode function() in PHP:

However there is a stream filter for quoted printable encoding. Here's an example function that produces output suitable for email and doesn't explicitly use external files (though it might do for strings over 2Mb due to the nature of the temp stream type):

function quoted_printable_encode($string) {
$fp = fopen('php://temp/', 'r+');
$params = array('line-length' => 70, 'line-break-chars' => "\r\n");
stream_filter_append($fp, 'convert.quoted-printable-encode', STREAM_FILTER_READ, $params);
fputs($fp, $string);

quoted_printable_encode(str_repeat("hello there ", 50)." a=1\r\n")."\n";

The filter needs to be restricted to STREAM_FILTER_READ because by default it will get filtered both going into and out of the stream, and will thus get encoded twice.

It should be much faster than using a PHP implementation of the same thing, though note that this will only work in PHP 5.1+.
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