charset
specifies the name of the character set
in which str
is represented in. The default value
is determined by the current NLS setting (mbstring.language).
mb_internal_encoding() should be set to same encoding.
transfer_encoding
transfer_encoding
specifies the scheme of MIME
encoding. It should be either "B" (Base64) or
"Q" (Quoted-Printable). Falls back to
"B" if not given.
linefeed
linefeed
specifies the EOL (end-of-line) marker
with which mb_encode_mimeheader() performs
line-folding (a » RFC term,
the act of breaking a line longer than a certain length into multiple
lines. The length is currently hard-coded to 74 characters).
Falls back to "\r\n" (CRLF) if not given.
indent
Indentation of the first line (number of characters in the header
before str
).
Возвращаемые значения
A converted version of the string represented in ASCII.
Замечание:
This function isn't designed to break lines at higher-level
contextual break points (word boundaries, etc.).
This behaviour may clutter up the original string with unexpected spaces.