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diff --git a/Doc/lib/librfc822.tex b/Doc/lib/librfc822.tex new file mode 100644 index 0000000..43a5cea --- /dev/null +++ b/Doc/lib/librfc822.tex @@ -0,0 +1,108 @@ +\section{Built-in module \sectcode{rfc822}} +\stmodindex{rfc822} + +This module defines a class, \code{Message}, which represents a +collection of ``email headers'' as defined by the Internet standard +RFC 822. It is used in various contexts, usually to read such headers +from a file. + +A \code{Message} instance is instantiated with an open file object as +parameter. Instantiation reads headers from the file up to a blank +line and stores them in the instance; after instantiation, the file is +positioned directly after the blank line that terminates the headers. + +Input lines as read from the file may either be terminated by CR-LF or +by a single linefeed; a terminating CR-LF is replaced by a single +linefeed before the line is stored. + +All header matching is done independent of upper or lower case; +e.g. \code{m['From']}, \code{m['from']} and \code{m['FROM']} all yield +the same result. + +A \code{Message} instance has the following methods: + +\begin{funcdesc}{rewindbody}{} +Seek to the start of the message body. This only works if the file +object is seekable. +\end{funcdesc} + +\begin{funcdesc}{getallmatchingheaders}{name} +Return a list of lines consisting of all headers whose header matches +\var{name}, if any. Each physical line, whether it is a continuation +line or not, is a separate list item. Return the empty list if no +header matches \var{name}. +\end{funcdesc} + +\begin{funcdesc}{getfirstmatchingheader}{name} +Return a list of lines comprising the first header matching +\var{name}, and its continuation line(s), if any. Return \code{None} +if there is no header matching \var{name}. +\end{funcdesc} + +\begin{funcdesc}{getrawheader}{name} +Return a single string consisting of the text after the colon in the +first header matching \var{name}. This includes leading whitespace, +the trailing linefeed, and internal linefeeds and whitespace if there +any continuation line(s) were present. Return \code{None} if there is +no header matching \var{name}. +\end{funcdesc} + +\begin{funcdesc}{getheader}{name} +Like \code{getrawheader(\var{name})}, but strip leading and trailing +whitespace (but not internal whitespace). +\end{funcdesc} + +\begin{funcdesc}{getaddr}{name} +Return a pair (full name, email address) parsed from the string +returned by \code{getheader(\var{name})}. If no header matching +\var{name} exists, return \code{None, None}; otherwise both the full +name and the address are (possibly empty )strings. + +Example: if \code{m}'s first \code{From} header contains the string +\code{'guido@cwi.nl (Guido van Rossum)'}, then +\code{m.getaddr('From')} will yield the pair +\code{('Guido van Rossum', 'guido\@cwi.nl')}. +If the header contained +\code{'Guido van Rossum <guido\@cwi.nl>'} instead, it would yield the +exact same result. +\end{funcdesc} + +\begin{funcdesc}{getaddrlist}{name} +This is similar to \code{getaddr(\var{list})}, but parses a header +containing a list of email addresses (e.g. a \code{To} header) and +returns a list of (full name, email address) pairs (even if there was +only one address in the header). If there is no header matching +\var{name}, return an empty list. + +XXX The current version of this function is not really correct. It +yields bogus results if a full name contains a comma. +\end{funcdesc} + +\begin{funcdesc}{getdate}{name} +Retrieve a header using \code{getheader} and parse it into a 9-tuple +compatible with \code{time.kmtime()}. If there is no header matching +\var{name}, or it is unparsable, return \code{None}. + +Date parsing appears to be a black art, and not all mailers adhere to +the standard. While it has been tested and found correct on a large +collection of email from many sources, it is still possible that this +function may occasionally yield an incorrect result. +\end{funcdesc} + +\code{Message} instances also support a read-only mapping interface. +In particular: \code{m[name]} is the same as \code{m.getheader(name)}; +and \code{len(m)}, \code{m.has_key(name)}, \code{m.keys()}, +\code{m.values()} and \code{m.items()} act as expected (and +consistently). + +Finally, \code{Message} instances have two public instance variables: + +\begin{datadesc}{headers} +A list containing the entire set of header lines, in the order in +which they were read. Each line contains a trailing newline. The +blank line terminating the headers is not contained in the list. +\end{datadesc} + +\begin{datadesc}{fp} +The file object passed at instantiation time. +\end{datadesc} |