racket/collects/net/doc.txt
Robby Findler 2488c15f91 ,
svn: r386
2005-07-16 14:14:52 +00:00

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The `net' collection contains libraries that provide access to the
following _Internet_ (quasi-)protocols:
URL parsing
CGI backends
sendmail
SMTP
NNTP
POP-3
IMAP
Mail header reading and writing
DNS
==========================================================================
_URL_ posting, _web clients_, _WWW_
==========================================================================
To load directly: (require (lib "url.ss" "net"))
Module files: _url.ss_ - provides the procedures documented below
_url-unit.ss_ - provides unit net:url@
_url-sig.ss_ - provides signature net:url^
_url-struct.ss_ - provides the url and path/param structs
ABSTRACT -------------------------------------------------------------
The url package helps programmers use URIs as specified in RFC 2396:
http://www.ietf.org/rfc/rfc2396.txt
TYPES ----------------------------------------------------------------
> url
struct url (scheme user host port path fragment)
scheme : string or #f
user : string or #f
host : string or #f
port : number or #f
path : (listof (union string path/param))
query : (listof (cons symbol string))
fragment : string or #f
The basic structure for all URLs.
http://sky@www.cs.brown.edu:801/cgi-bin/finger;xyz?name=shriram;host=nw#top
{-1} {2} {----3---------} {4}{---5---------} {6} {----7-------------} {8}
1 = scheme, 2 = user, 3 = host, 4 = port,
5 = path, 6 = param, 7 = query, 8 = fragment
If the scheme is "file", then the path is a platform-dependent
string assumed to have been constructed using build-path. The library
does, however, check for the presence of a fragment designator and, if
there is one, separates it from the rest of the path. For non-"file"
schemes, the path is a URL path as defined in the standard.
If a path segment has a parameter, it is represented with
an instance of the path/param struct. Otherwise, it is
just represented as a string.
The strings inside the fields user, path, query, and fragment are
represented directly as Scheme strings, ie without
url-syntax-specific quoting. The procedures `string->url' and
`url->string' translate things like %20 into spaces and back again.
By default, query associations are parsed with either ";" or "&" as
a separator, and they are generated with ";" as a separator. The
`current-alist-separator-mode' parameter for "uri-codec.ss" adjusts
this default.
An empty string at the end of the list of paths
corresponds to a url that ends in a slash. For example,
this url: http://www.drscheme.org/a/ has a path field
'("a" "") and this url: http://www.drscheme.org/a
has a path field '("a").
> path/param
A pair of strings, accessible with _path/param-path_ and
path/param-params_ that joins a path segment with its
params in a url. The function _path/param?_ recognizes
such pairs.
> pure-port
A pure port is one from which the MIME headers have been removed, so
that what remains is purely the first content fragment.
> impure-port
An impure port is one that still has its MIME headers. Contrast
with a pure-port.
PROCEDURES -----------------------------------------------------------
> unixpath->path
This procedure, which used to be provided by this library, is no
longer supported.
> (string->url string) -> url
Parses the url specified by the string into a url struct. The
`string->url' procedure uses `form-urlencoded->alist' when parsing
the query, so it is sensitive to the `current-alist-separator-mode'
parameter for determining the association separator.
> (combine-url/relative url string) -> url
Given a base URL and a relative path, combines the two and returns a
new URL as per the URL combination specification. Call the
arguments base and relative. They are combined according to the
following rules (applied in order until one matches):
- If either argument is an empty URL, the result is the other
argument.
- If relative sports a scheme, then the result is relative.
- If the base has scheme "file", the procedure uses the special rule
specified below.
- If relative specifies a host, then the result is relative.
Failing the above, relative inherit's base's host and port. Then:
- If the path of relative begins with a "/", the result is relative.
- If the path of relative is empty, then relative inherits base's
params and query, and the result is relative.
- Otherwise base and relative are combined as per the standard
specification of merging and normalization.
On combining "file" schemes:
If the base has scheme "file", relative is treated as a
slash-separated path (unless it contains an empty path --- only
params, queries, and fragments --- in which case the path is not
used). These path fragments are combined using build-path, starting
with the base's path. Three path segments are special: ".."
corresponds to an 'up directive to build-path, while "." and ""
correspond to 'same. As a consequence, if relative begins with "/",
this does not make it an absolute URL: the leading slash is treated
as if the initial segment is "", so this has no effect, and base's
path remains the base path of the result. If base refers to a
directory, relative is indexed from that directory; if base refers
to a file, relative is indexed from the directory containing the
file. Note that if base does not refer to an actual directory that
exists on the filesystem, then it must syntactically be a directory
as understood by split-path.
The above algorithm tests for the presence of a directory to
correctly combine paths. As a result, it can raise any exception
raised by directory-exists?. None of these exceptions is trapped by
the procedure; consumers must be prepared for them.
> (netscape/string->url string) -> url
Turns a string into a URL, applying (what appear to be) Netscape's
conventions on automatically specifying the scheme: a string
starting with a slash gets the scheme "file", while all others get
the scheme "http".
> (url->string url) -> string
Generates a string corresponding to the contents of the url struct.
The `url->string' procedure uses `alist->form-urlencoded' when
formatting the query, so it it sensitive to the
`current-alist-separator-mode' parameter for determining the
association separator. In particular, the default is to separate
associations with ";" (based on modern recommendations) instead of
"&".
> (decode-some-url-parts url) -> url
This procedure, which used to be provided by this library, is no
longer supported or necessary. A `url' struct not contains properly
decoded information.
> (get-pure-port url [list-of-strings]) -> input-port
Takes a URL and returns a pure port corresponding to it. Writes the
optional RFC 822 header-line strings to the server. For the "file"
scheme, uses open-input-file, does not handle exceptions, and
ignores the optional strings.
> (post-pure-port url post-byte-string [list-of-strings]) -> input-port
Like `get-pure-port', but issues a POST request (instead of a GET
request) to a web server using the given post data byte string.
> (get-impure-port url [list-of-strings]) -> input-port
Takes a URL and returns an impure port corresponding to it. Writes
the optional RFC 822 header-line strings to the server. There are
no impure ports with scheme "file".
> (post-impure-port url post-byte-string [list-of-strings]) -> input-port
Like `get-impure-port', but issues a POST request (instead of a GET
request) to a web server using the given post data string.
> (display-pure-port input-port) -> void
Writes the output of a pure port. For debugging purposes.
> (purify-port input-port) -> string
Purifies a port, returning the MIME headers, plus a leading line
for the form
HTTP/<vers> <code> <message>
where <vers> is something like 1.0 or 1.1, <code> is an exact
integer for the response code, and <message> is arbitrary text
without a return or newline.
The "head.ss" library provides procedures, such as `extract-field,
for manipulating the header.
Since web server sometimes return mis-formatted replies,
`purify-port' is liberal in what it accepts as a header. as a
result, the result string may be ill formed, but it will either be
the empty string, or it will be a string matching the following
regexp:
#rx"^HTTP/.*?((\r\n\r\n)|(\n\n)|(\r\r))"
> (call/input-url url url->port-proc port->X-proc [list-of-strings]) -> X
First argument is the URL to open. Second is a procedure that takes
a URL and turns it into a (pure or impure) port. The third takes
the (pure or impure) port and handles its contents. The optional
fourth argument is a set of strings to send to the server. The result
of `call/input-url' is the result of the third argument procedure.
> (current-proxy-servers) -> (list (list scheme string port-number) ...)
> (current-proxy-servers server-mapping) -> void
The `current-proxy-server' parameter determines a mapping of proxy
servers used for connections. The mapping is of the form
(list (list proxiable-scheme server-string port-number) ...)
where, currently, the only proxiable scheme is "http". An omitted
mapping indicates that no proxy should be used. The default mapping
is the empty list (i.e., no proxies).
PRAGMATICS -----------------------------------------------------------
_web documents_
To access the text of a document from the Web, first obtain its URL
as a string; convert this into a url structure using string->url;
then open the document using get-pure-port or get-impure-port,
depending on whether or not you wish to examine its MIME headers.
At this point you have a regular input port with which to process
the document like any other file. Note that currently the only
supported protocol is "http". The "news" protocol is not supported
directly by this library, but the news library in this collection
can be used to read NNTP documents.
EXAMPLE --------------------------------------------------------------
(require (lib "url.ss" "net"))
(define url:cs (string->url "http://www.cs.rice.edu/"))
(define (test url)
(call/input-url url get-pure-port display-pure-port))
(test url:cs)
UNITS ----------------------------------------------------------------
The _url-sig.ss_ module exports the _net:url^_ signature which
contains the names documented above. the _url-unit.ss_ module exports
_url@_, a unit that imports net:tcp^ (see "tcp-sig.ss", below) and
exports the names in net:url^.
==========================================================================
_URL viewing_
==========================================================================
To load a module for accessing a Web _browser_ either
(require (lib "external.ss" "browser"))
or
(require (lib "sendurl.ss" "net"))
The version in "browser" will prompt the user for a browser preference
if not already set. The version in "sendurl.ss" lacks this capability,
but does not depend on MrEd's graphical toolbox.
These modules define one main function:
> (send-url str [separate-window? #t]) -
opens the url in a platform-specific manner,
sending a message to the local browser to display the url named
by `str'. The separate-window? parameter determines
if the browser creates a new window to display the url
or not.
Under Windows, `send-url' uses the registry to get a
browser-launching command line. The registry can be read only from
MrEd (i.e., not MzScheme).
Under Mac OS, `send-url' uses the URL apple event library.
Under Unix, `send-url' uses the value of a the _external-browser_
parameter to select a browser. The parameter is initialized to the
value of the _'external-browser preference_, which can be either
'opera, 'galeon, 'netscape, 'mozilla, 'dillo, #f, or a pair of
strings. If #f, `send-url' uses the first of these browsers found
in the path. If the parameter is a pair of strings, then the first
string, the url requested, followed by the second string is
interpreted as a command line used to launch a browser. If the
preferred or default browser can't be launched, `send-url'
fails. See the file.ss library for details on setting preferences.
> (browser-preference? v) -> bool
return #t if v is a valid browser preference
==========================================================================
_CGI_ backends, _WWW_
==========================================================================
To load directly: (require (lib "cgi.ss" "net"))
Module files: _cgi.ss_ - provides the procedures documented below
_cgi-unit.ss_ - provides unit net:cgi@
_cgi-sig.ss_ - provides signature net:cgi^
ABSTRACT -------------------------------------------------------------
The cgi package helps programmers write scripts that follow the Common
Gateway Interface (CGI/1.1) protocol of the World-Wide Web:
http://hoohoo.ncsa.uiuc.edu/cgi/
INTERACTIONS ---------------------------------------------------------
The CGI library expects to be run in a certain context as defined by
the CGI standard. This means, for instance, that certain environment
variables will be bound. Unfortunately, not all CGI environments
provide this. For instance, the FastCGI library, despite its name,
does not bind the environment variables required of the standard.
Users of FastCGI will need to bind REQUEST_METHOD and possibly also
QUERY_STRING to successfully employ the CGI library. The FastCGI
library ought to provide a way to extract the values bound to these
variables; the user can then put these into the CGI program's
environment using PLT Scheme's `putenv' function.
TYPES ----------------------------------------------------------------
binding:
A binding is an association of a form item with its value. Some form
items (such as checkboxes) may correspond to multiple bindings. A
binding is a tag-string pair, where a tag is a symbol or a string.
bindings:
A list of `binding's.
html-string:
A text string that has been escaped according to HTML conventions.
EXCEPTIONS -----------------------------------------------------------
> cgi-error
struct cgi-error ()
cgi-error is a super-structure for all exceptions thrown by this
library.
> incomplete-%-suffix
struct (incomplete-%-suffix cgi-error) (chars)
chars : list of chars
Used when a % in a query is followed by an incomplete suffix. The
characters of the suffix -- excluding the "%" -- are provided by the
exception.
> invalid-%-suffix
struct (invalid-%-suffix cgi-error) (char)
char : char
Used when the character immediately following a % in a query is
invalid.
PROCEDURES -----------------------------------------------------------
> (get-bindings) -> bindings
> (get-bindings/post) -> bindings
> (get-bindings/get) -> bindings
Returns the bindings that corresponding to the options specified by
the user. The /post and /get forms work only when POST and GET
forms are used, respectively, while get-bindings determines the kind
of form that was used and invokes the appropriate function.
> (extract-bindings symbol-or-string bindings) -> list of strings
Given a key and a set of bindings, extract-bindings determines which
ones correspond to a given key. There may be zero, one, or many
associations for a given key.
> (extract-binding/single symbol-or-string bindings) -> string
Given a key and a set of bindings, extract-binding/single ensures
that the key has exactly one association, and returns it.
> (output-http-headers) -> void
Outputs all the http headers needed for a normal html response.
Only call this function if you are not using generate-html-output
or generate-error-output.
> (generate-html-output html-string list-of-html-strings [color color color color color]) -> void
The first argument is the title. The second is a list of strings
that consist of the body. The last five arguments are each strings
representing a HTML color; in order, they represent the color of the
text, the background, un-visited links, visited links, and a link
being selected.
> (string->html string) -> html-string
Converts a string into an html-string by applying the appropriate
HTML quoting conventions.
> (generate-link-text string html-string) -> html-string
Takes a string representing a URL, a html-string for the anchor
text, and generates HTML corresponding to an anchor.
> (generate-error-output list-of-html-strings) -> <exit>
The procedure takes a series of strings representing the body,
prints them with the subject line "Internal error", and forces the
script to exit.
> (get-cgi-method) -> string
Returns either "GET" or "POST". Always returns a string when
invoked inside a CGI script. Unpredictable otherwise.
> (bindings-as-html bindings) -> list of html-strings
Converts a set of bindings into a list of html-string's. Useful for
debugging.
==========================================================================
_sending mail_, _sendmail_
==========================================================================
To load directly: (require (lib "sendmail.ss" "net"))
Module files: _sendmail.ss_ - provides the procedures documented below
_sendmail-unit.ss_ - provides unit net:sendmail@
_sendmail-sig.ss_ - provides signature net:sendmail^
ABSTRACT -------------------------------------------------------------
The sendmail package helps programmers write programs that need to
send electronic mail messages. The package assumes the existence of a
conformant sendmail program on the local system; see also the SMTP
package, below (and, in most cases, use it instead).
TYPES ----------------------------------------------------------------
All strings used in mail messages are assumed to conform to their
corresponding SMTP specifications, except as noted otherwise.
EXCEPTIONS -----------------------------------------------------------
> no-mail-recipients
struct (no-mail-recipients exn) ()
Raised when no mail recipients were specified.
PROCEDURES -----------------------------------------------------------
> (send-mail-message/port from-string subject-string to-list-of-strings cc-list-of-strings bcc-list-of-string) -> output-port
The first argument is the header for the sender, the second is the
subject line, the third a list of To: recipients, the fourth a list
of CC: recipients, and the fifth a list of BCC: recipients. The
optional sixth argument is used for other mail headers, which must
be specified completely formatted.
The return value is an output port into which the client must write
the message. Clients are urged to use close-output-port on the
return value as soon as the necessary text has been written, so that
the sendmail process can complete.
The sender can hold any value, though of course spoofing should be
used with care.
> (send-mail-message from-string subject-string to-list-of-strings cc-list-of-strings bcc-list-of-string body-list-of-strings [extra-headers-list-of-strings]) -> void
The arguments are the same as that for send-mail-message/port except
that there is one extra input, the list of strings corresponding to
the mail message (followed by the optional additional headers, if
present). There is no interesting return value.
Lines that contain a single period do not need to be quoted.
==========================================================================
_sending mail_, _SMTP_
==========================================================================
To load directly: (require (lib "smtp.ss" "net"))
Module files: _smtp.ss_ - provides the procedures documented below
_smtp-unit.ss_ - provides unit net:smtp@
_smtp-sig.ss_ - provides signature net:smtp^
ABSTRACT -------------------------------------------------------------
The SMTP package helps programmers write programs that need to send
electronic mail messages using SMTP. The client must provide the
address of an SMTP server; in contrast, the mail package (see above)
uses a pre-configured sendmail on the local system.
TYPES ----------------------------------------------------------------
The head package defines the format of a `header' string, which is
used by `send-smtp-message'. The head package also provides
utilities to verify the formatting of a mail address. The procedures
of the SMTP package assume that the given string arguments are
well-formed.
EXCEPTIONS -----------------------------------------------------------
Communication errors are signaled via exn:fail structure instances.
PROCEDURES -----------------------------------------------------------
> (smtp-send-message server-string from-string to-list-of-strings header
message-list-of-strings/bytes [port]) -> void
The first argument is the IP address of the SMTP server. The
`from-string' argument specifies the mail address of the sender, and
`to-listof-strings' is a list of recipient addresses (including
"To", "CC", and "BCC" recipients). The `header' argument is the
complete message header, which should already include "From", "To",
and "CC" fields consistent with the given sender and recipients.
the `message-list-of-strings/bytes' argument is the body of the
message, where each string or byte string in the list corresponds to
a single line of message text; no string in
`message-list-of-strings' should contain a carriage return or
newline characters. The optional `port' argument specifies the IP
port to use in contacting the SMTP server; the default is 25.
See the head package for utilities that construct a message headers
and validate mail address strings.
> (smtp-sending-end-of-message [proc])
Parameter that determines a send-done procedure to be called after
`smtp-send-message' has completely sent the message. Before the
send-done procedure is called, breaking the thread that is executing
`smtp-send-message' cancels the send. After the send-done procedure
is called, breaking may or may not cancel the send (and probably
won't).
==========================================================================
_NNTP_, _newsgroups_
==========================================================================
To load directly: (require (lib "nntp.ss" "net"))
Module files: _nntp.ss_ - provides the procedures documented below
_nntp-unit.ss_ - provides unit net:nntp@
_nntp-sig.ss_ - provides signature net:nntp^
ABSTRACT -------------------------------------------------------------
The nntp package helps programmers access Usenet groups via the NNTP
protocols:
http://www.ietf.org/rfc/rfc0977.txt
TYPES ----------------------------------------------------------------
> communicator
struct communicator (sender receiver server port)
sender : oport
receiver : iport
server : string
port : number
Once a connection to a Usenet server has been established, its state
is stored in a communicator, and other procedures take communicators
as an argument.
> message-index
A number or string (the number is common, but a string is useful for
specifying the entire Message-ID).
> desired
A regular expression that matches against a Usenet header.
EXCEPTIONS -----------------------------------------------------------
> nntp
struct (nntp exn) ()
The super-struct of all subsequent exceptions.
> unexpected-response
struct (unexpected-response nntp) (code text)
code : number
text : string
Thrown whenever an unexpected response code is received. The text
holds the response text sent by the server.
> bad-status-line
struct (bad-status-line nntp) (line)
line : string
Mal-formed status lines.
> premature-close
struct (premature-close nntp) (communicator)
communicator : communicator
Thrown when a remote server closes its connection unexpectedly.
> bad-newsgroup-line
struct (bad-newsgroup-line nntp) (line)
line : string
When the newsgroup line is improperly formatted.
> non-existent-group
struct (non-existent-group nntp) (group)
group : string
When the server does not recognize the name of the requested group.
> article-not-in-group
struct (article-not-in-group nntp) (article)
article : number
When an article is outside the server's range for that group.
> no-group-selected
struct (no-group-selected nntp) ()
When an article operation is used before a group has been selected.
> article-not-found
struct (article-not-found nntp) (article)
article : number
When the server is unable to locate the article.
> authentication-rejected
struct (authentication-rejected nntp) ()
When the server reject an authentication attempt.
PROCEDURES -----------------------------------------------------------
> (connect-to-server server-string [port-number]) -> communicator
Connects to the name server. The second argument, if provided, must
be a port number; otherwise the default NNTP port is used.
> (disconnect-from-server communicator) -> void
Disconnects a communicator.
> (open-news-group communicator newsgroup-string) -> three values: number number number
The second argument is the name of a newsgroup. The returned values
are the total number of articles in that group, the first available
article, and the last available article.
> (authenticate-user communicator username password) -> void
Tries to authenticate a user. This is using the original authinfo command
(uses cleartext). The password argument is ignored if the server does not
ask for it.
> (head-of-message communicator message-index) -> list of strings
Given a message number, returns its headers.
> (body-of-message communicator message-index) -> list of strings
Given a message number, returns the body of the message.
> (newnews-since communicator message-index) -> list of strings
Implements the NEWNEWS command (often disabled on servers).
> (generic-message-command communicator message-index) -> list of strings
Useful primitive for implementing head-of-message, body-of-message
and other similar commands.
> (make-desired-header tag-string) -> desired
Takes the header's tag and returns a desired regexp for that header.
> (extract-desired-headers list-of-header-strings list-of-desireds) -> list of strings
Given a list of headers and of desired's, returns the header lines
that match any of the desired's.
==========================================================================
_POP-3_, _reading mail_
==========================================================================
To load directly: (require (lib "pop3.ss" "net"))
Module files: _pop3.ss_ - provides the procedures documented below
_pop3-unit.ss_ - provides unit net:pop3@
_pop3-sig.ss_ - provides signature net:pop3^
ABSTRACT -------------------------------------------------------------
Implements RFC 1939, Post Office Protocol - Version 3, Myers & Rose.
http://www.ietf.org/rfc/rfc1939.txt
TYPES ----------------------------------------------------------------
> communicator
struct communicator (sender receiver server port state)
sender : oport
receiver : iport
server : string
port : number
state : symbol = (disconnected, authorization, transaction)
Once a connection to a POP-3 server has been established, its state
is stored in a communicator, and other procedures take communicators
as an argument.
> desired
A regular expression that matches against a mail header.
EXCEPTIONS -----------------------------------------------------------
> pop3
struct (pop3 exn) ()
The super-struct used for all other package exceptions.
> cannot-connect
struct (cannot-connect pop3) ()
When a connection to a server cannot be established.
> username-rejected
struct (username-rejected pop3) ()
If the username is rejected.
> password-rejected
struct (password-rejected pop3) ()
If the password is rejected.
> not-ready-for-transaction
struct (not-ready-for-transaction pop3) (communicator)
communicator : communicator
When the communicator is not in transaction mode.
> not-given-headers
struct (not-given-headers pop3) (communicator message)
communicator : communicator
message : number
When the server does not respond with headers for a message as
requested.
> illegal-message-number
struct (illegal-message-number pop3) (communicator message)
communicator : communicator
message : number
When the user specifies an illegal message number.
> cannot-delete-message
struct (cannot-delete-message exn) (communicator message)
communicator : communicator
message : number
When the server is unable to delete a message.
> disconnect-not-quiet
struct (disconnect-not-quiet pop3) (communicator)
communicator : communicator
When the server does not gracefully disconnect.
> malformed-server-response
struct (malformed-server-response pop3) (communicator)
communicator : communicator
When the server produces a mal-formed response.
PROCEDURES -----------------------------------------------------------
> (connect-to-server server-string [port-number]) -> communicator
Connects to a server. Uses the default port number if none is
provided.
> (disconnect-from-server communicator) -> void
Disconnects from as server. Sets the communicator state to
disconnected.
> (authenticate/plain-text user-string passwd-string communicator) -> void
Takes a username and password string and, if successful, changes the
communicator's state to transaction.
> (get-mailbox-status communicator) -> two values: count-number octet-number
Returns the number of messages and the number of octets.
> (get-message/complete communicator message-number) -> two lists of strings
Given a message number, returns a list of headers and list of
strings for the body.
> (get-message/headers communicator message-number) -> list of strings
Given a message number, returns the list of headers.
> (get-message/body communicator message-number) -> list of strings
Given a message number, returns the list of strings for the body.
> (delete-message communicator message-number) -> void
Deletes the specified message.
> (get-unique-id/single communicator message-number) -> string
Gets the server's unique id for a particular message.
> (get-unique-id/all communicator) -> list of (cons message-number id-string)
Gets a list of unique id's from the server for all the messages in
the mailbox.
> (make-desired-header tag-string) -> desired
Takes the header's tag and returns a desired regexp for that header.
> (extract-desired-headers list-of-strings list-of-desireds) -> list of strings
Given a list of headers and of desired's, returns the header lines
that match any of the desired's.
EXAMPLE --------------------------------------------------------------
> (require (lib "pop3.ss" "net"))
> (define c (connect-to-server "cs.rice.edu"))
> (authenticate/plain-text "scheme" "********" c)
> (get-mailbox-status c)
196
816400
> (get-message/headers c 100)
("Date: Thu, 6 Nov 1997 12:34:18 -0600 (CST)"
"Message-Id: <199711061834.MAA11961@new-world.cs.rice.edu>"
"From: Shriram Krishnamurthi <shriram@cs.rice.edu>"
...
"Status: RO")
> (get-message/complete c 100)
("Date: Thu, 6 Nov 1997 12:34:18 -0600 (CST)"
"Message-Id: <199711061834.MAA11961@new-world.cs.rice.edu>"
"From: Shriram Krishnamurthi <shriram@cs.rice.edu>"
...
"Status: RO")
("some body" "text" "goes" "." "here" "." "")
> (get-unique-id/single c 205)
no message numbered 205 available for unique id
> (list-tail (get-unique-id/all c) 194)
((195 . "e24d13c7ef050000") (196 . "3ad2767070050000"))
> (get-unique-id/single c 196)
"3ad2767070050000"
> (disconnect-from-server c)
==========================================================================
_IMAP_, _reading mail_
==========================================================================
To load directly: (require (lib "imap.ss" "net"))
Module files: _imap.ss_ - provides the procedures documented below
_imap-unit.ss_ - provides unit net:imap@
_imap-sig.ss_ - provides signature net:imap^
ABSTRACT -------------------------------------------------------------
Implements portions of client-side RFC 2060, Internet Message Access
Protocol - Version 4rev1, Crispin
http://www.ietf.org/rfc/rfc2060.txt
TYPES ----------------------------------------------------------------
> imap
An opaque record representing an IMAP connection.
> imap-flag
A symbol, but generally not a convenient one to use within a Scheme
program. The `imap-flag->symbol' and `symbol->imap-flag' procedures
convert IMAP flags to convenient symbols and vice-versa.
EXCEPTIONS -----------------------------------------------------------
Communication errors are signaled via exn:fail structure instances.
PROCEDURES -----------------------------------------------------------
- - - - - - Connecting and selecting mailboxes - - - - -
> (imap-connect server-string username-str/bytes password-str/bytes mailbox-str/bytes)
-> three values: imap, message count, recent message count
Establishes an IMAP connection to the given server using the given
username and password, and selects the specified mailbox. The second
and third return values indicate the total number of messages in the
mailbox and the number of recent messages (i.e., messages received
since the mailbox was last selected), respectively.
See also `imap-port-number', below.
A user's primary mailbox is always called "INBOX". (Capitalization
doesn't matter for that keyword.)
Updated message-count and recent-count values are available through
`imap-messages' and `imap-recent'. See also `imap-new?' and
`imap-reset-new!'.
> (imap-port-number [k])
A parameter that determines the server port number. The initial
value is 143.
> (imap-connect* in-port out-port username-str/bytes password-str/bytes mailbox-str/bytes)
-> three values: imap, message count, recent message count
Like `imap-connect', but given input and output ports instead of a
server address.
> (imap-disconnect imap) -> void
Closes an IMAP connection. The close may fail due to a communication
error.
> (imap-force-disconnect imap) -> void
Closes an IMAP connection forcefully (i.e., without send a close
message to the server). A forced disconnect never fails.
> (imap-reselect imap mailbox-str/bytes)
-> two values: message count and recent message count
De-selects the mailbox currently selected by the connection and
selects the specified mailbox, returning the total and recent
message counts for the new mailbox. Expunge and message-state
information is removed.
Do not use this procedure to poll a mailbox to see whether there are
any new messages. Use `imap-noop', `imap-new?', and
`imap-reset-new?' instead.
> (imap-examine imap mailbox-str/bytes)
-> two values: message count and recent message count
Like `imap-reselect', but the mailbox is selected as read-only.
- - - - - - Selected mailbox state - - - - -
> (imap-noop imap mailbox-str/bytes)
-> two values: message count and recent message count
Sends a "no-op" message to the server, typically to keep the session
alive. As for many commands, the server may report message-state
updates or expunges.
The return information is the same as for `imap-reselect'.
> (imap-poll imap) -> void
Does not send a request to the server, but checks for asynchronous
messages from the server that update the message count, to report
expunges, etc.
> (imap-messages imap) -> number
Returns the number of messages in the selected mailbox. The server
can update this count during most any interaction.
This operation does not communicate with the server. It merely
reports the result of previous communication.
> (imap-recent imap) -> number
Returns the number of "recent" messages in the currently selected
mailbox, as most recently reported by the server. The server can
update this count during most any interaction.
This operation does not communicate with the server. It merely
reports the result of previous communication.
> (imap-unseen imap) -> number-or-false
Returns the number of "unseen" messages in the currently selected
mailbox, as most recently reported by the server. The server can
update this count during most any interaction. Old IMAP servers
might not report this value, in which case the result is #f.
This operation does not communicate with the server. It merely
reports the result of previous communication.
> (imap-uidnext imap) -> number-or-false
Returns the predicted next uid for a message in the currently
selected mailbox, as most recently reported by the server. The
server can update this count during most any interaction. Old IMAP
servers might not report this value, in which case the result is #f.
This operation does not communicate with the server. It merely
reports the result of previous communication.
> (imap-uidvalidity imap) -> number-or-false
Returns an id number that changes when all uids become invalid. The
server *cannot* update this number during a session. Old IMAP
servers might not report this value, in which case the result is #f.
This operation does not communicate with the server. It merely
reports the result of previous communication.
> (imap-new? imap) -> boolean
Returns #t if the server has reported an increase in the message
count for the currently mailbox since the last call to
`imap-reset-new!'. Selecting a mailbox implicitly calls
`imap-reset-new!'.
This operation does not communicate with the server. It merely
reports the result of previous communication.
> (imap-reset-new! imap) -> void
Resets the new flag for the session; see `imap-new?', above.
This operation does not communicate with the server.
> (imap-get-expunges imap) -> msg-num-list
Returns pending expunge notifications from the server for the
selected mailbox in terms of message positions (not uids), and
clears the pending notifications. The result list is sorted,
ascending.
This operation does not communicate with the server. It merely
reports the result of previous communication.
The server can notify the client of newly deleted messages during
most other commands, but not asynchronously between
commands. Furthermore, the server cannot report new deletions during
`imap-get-messages' or `imap-store' operations.
Before calling any IMAP operation that works in terms of message
numbers, pending expunge notifications must be handled by calling
`imap-get-expunges'.
> (imap-pending-expunges? imap) -> boolean
Returns #f if `imap-get-expunges' would return an empty list, #t
otherwise.
> (imap-get-updates imap) -> list of (cons msg-num assoc-list)
Returns information must like `imap-get-messages', but includes
information reported asynchronously by the server (e.g., to notify a
client with some other client changes a message attribute). Instead
of reporting specific requested information for specific messages,
the result is associates message positions to field-value
association lists. The result list is sorted by message position,
ascending.
This operation does not communicate with the server; it merely
reports the result of previous communication. It also clears the
update information from the connection after reporting it.
When a server reports information that supersedes old reported
information for a message, or if the server reports that a message
has been deleted, then old information for the message is
dropped. Similarly, if `imap-get-messages' is used to explicitly
obtain information, any redundant (or out-of-date) information is
dropped.
A client need not use `imap-get-updates' ever, but accumulated
information for the connection consumes space.
> (imap-pending-updates? imap) -> boolean
Returns #f if `imap-get-updates' would return an empty list, #t
otherwise.
- - - - - - Manipulating messages - - - - -
> (imap-get-messages imap msg-num-list field-list)
-> list of field-value lists
Downloads information for a set of messages. The `msg-num-list'
argument specifies a set of messages by their message positions (not
their uids). The `field-list' argument specifies the type of
information to download for each message. The available fields are:
* 'uid - value is an integer
* 'header - value is a header (string; see the head package)
* 'body - value is a byte string (with CRLF-separated lines)
* 'flags - value is a list of imap flags
The return value is a list of entry items in parallel to
`msg-num-list'. Each entry is itself a list containing value items
in parallel to `field-list'.
Pending expunges must be handled before calling this function; see
`imap-get-expunges'.
Example:
(imap-get-message imap '(1 3 5) '(uid header))
; => ((107 #"From: larry@stooges.com ...")
(110 #"From: moe@stooges.com ...")
(112 #"From: curly@stooges.com ..."))
> (imap-flag->symbol imap-flag) -> symbol
> (symbol->imap-flag symbol) -> imap-flag
An imap flag is a symbol, but it is generally not a convenient one
to use within a Scheme program, because it usually starts with a
backslash and flag comparisons are case-insensitive. The
`imap-flag->symbol' and `symbol->imap-flag' procedures convert IMAP
flags to convenient symbols and vice-versa:
symbol imap flag
------ ----------
'seen '|\Seen| \
'answered '|\Answered| |
'flagged '|\Flagged| > message flags
'deleted '|\Deleted| |
'draft '|\Draft| |
'recent '|\Recent| /
'noinferiors '|\Noinferiors| \
'noselect '|\Noselect| |
'marked '|\Marked| > mailbox flags
'unmarked '|\Unmarked| |
'hasnochildren '|\HasNoChildren| |
'haschildren '|\HasChildren| /
`imap-flag->symbol' and `symbol->imap-flag' act like the identity
function when any other symbol/flag is provided.
> (imap-store imap mode msg-num-list imap-flags) -> void
Sets flags for a set of messages. The mode argument specifies how
flags are set:
* '+ - add the given flags to each message
* '- - remove the given flags from each message
* '! - set each message's flags to the given set
The `msg-num-list' argument specifies a set of messages by their
message positions (not their uids). The `flags' argument specifies
the imap flags to add/remove/install.
Pending expunges must be handled before calling this function; see
`imap-get-expunges'. The server will not report back message-state
changes (so they will not show up through `imap-get-updates').
Example:
(imap-store imap '+ '(1 2 3) (list (symbol->imap-flag 'deleted)))
; marks the first three messages to be deleted
(imap-expunge imap)
; permanently removes the first three messages (and possibly others)
; from the currently-selected mailbox
> (imap-expunge imap) -> void
Purges every message currently marked with the '|\Deleted| flag from
the mailbox.
- - - - - - Querying and changing (other) mailboxes - - - - -
> (imap-copy imap msg-num-list dest-mailbox-str/bytes) -> void
Copies the specified messages from the currently selected mailbox to
the specified mailbox.
Pending expunges must be handled before calling this function; see
`imap-get-expunges'.
> (imap-append imap mailbox-string message-str/bytes) -> void
Adds a new message (containing message-string) to the given mailbox
> (imap-status imap mailbox-str/bytes status-symbol-list)
-> list of status values
Requests information about a mailbox from the server, typically
*not* the currently selected mailbox.
The status-symbol-list specifies the request, and the return value
includes one value for each symbol in status-symbol-list. The
allowed status symbols are:
'messages - number of messages
'recent - number of recent messages
'unseen - number of unseen messages
'uidnext - uid for next received message
'uidvalidity - id that changes when all uids are changed
Use `imap-messages' to get the message count for the currently
selected mailbox, etc. Use `imap-new?' and `imap-reset-new!' to
detect when new messages are available in the currently selected
mailbox.
> (imap-mailbox-exists? imap mailbox-str/bytes) -> bool
Returns #t if the specified mailbox exists, #f otherwise.
> (imap-create-mailbox imap mailbox-str/bytes) -> void
Creates the specified mailbox. (It must not exist already.)
> (imap-list-child-mailboxes imap mailbox-str/bytes [delimiter-str/bytes])
-> list of mailbox-info lists
Returns information about sub-mailboxes of the given mailbox. If
mailbox-string is #f, information about all top-level mailboxes is
returned. The optional `delimiter-string' is determined
automatically (via `imap-get-hierarchy-delimiter') if it is not
provided.
The return value is a list of mailbox-information lists. Each
mailbox-information list contains two items:
* a list of imap flags for the mailbox
* the mailbox's name
> (imap-get-hierarchy-delimiter imap) -> bytes
Returns the server-specific string that is used as a separator in
mailbox path names.
> (imap-mailbox-flags imap mailbox-str/bytes)
-> list of imap flags
Returns a list of imap flags for the given mailbox.
==========================================================================
_mime headers_, _mail headers_, _http headers_
==========================================================================
To load directly: (require (lib "head.ss" "net"))
Module files: _head.ss_ - provides the procedures documented below
_head-unit.ss_ - provides unit net:head@
_head-sig.ss_ - provides signature net:head^
ABSTRACT -------------------------------------------------------------
Implements utilities for RFC 822 headers and mail addresses.
TYPES ----------------------------------------------------------------
> header
A string that is an RFC-882-compliant header. A header string
contains a series of CRLF-delimited fields, and ends with two CRLFs
(the first one terminates the last field, and the second terminates
the header).
PROCEDURES -----------------------------------------------------------
> empty-header
A string corresponding to the empty header, useful for building up
headers with `insert-field' and `append-headers'.
> (validate-header candidate-header-string) -> void
If the format of `candidate-header-string' matches RFC 822, void is
returned, otherwise an exception is raised.
> (extract-field field-string header) -> string or #f
Returns the header content for the specified field, or #f if the
field is not in the header. `field-string' should not end with ":",
and it is used case-insensitively. The returned string will not
contain the field name, color separator, of CRLF terminator for the
field; however, if the field spans multiple lines, the CRLFs
separating the lines will be intact.
Example:
(extract-field "TO" (insert-field "to" "me@localhost" empty-header))
; => "me@localhost"
> (extract-all-fields header) -> (list (cons string string))
Returns an association-list version of the header; the case of the
field names is preserved, as well as the order and duplicate uses of
a field name.
> (remove-field field-string header) -> header
Creates a new header by removing the specified field from `header'
(or the first instance of the field, if it occurs multiple
times). If the field is not in `header', then the return value is
`header'.
> (insert-field field-string value-string header) -> header
Creates a new header by prefixing the given header with the given
field-value pair. `value-string' should not contain a terminating
CRLF, but a multi-line value (perhaps created with
`data-lines->data') may contain separator CRLFs.
> (replace-field field-string value-string header) -> header
Replaces or inserts the given field. If value-string is #f, then
the field is simply removed.
> (append-headers a-header another-header) -> header
> (standard-message-header from-string to-list-of-strings cc-list-of-strings bcc-list-of-strings subject-string) -> header
Creates a standard mail header given the sender, various lists of
recipients, a subject, and the current date. (The BCC recipients do
not actually appear in the header, but they're accepted anyway to
complete the abstraction.)
> (data-lines->data list-of-strings) -> string
Merges multiple lines for a single field value into one string,
adding CRLF-TAB separators.
> (extract-addresses string kind) -> list of strings or
list of list of strings
Parses `string' as a list of comma-delimited mail addresses, raising
an exception if the list is ill-formed. This procedure can be used
for single-address strings, in which case the returned list should
contain only one address.
The `kind' argument specifies which portion of an address should be
returned:
* 'name - the free-form name in the address, or the address
itself if no name is available:
"John Doe <doe@localhost>" => "Jon Doe"
"doe@localhost (Johnny Doe)" => "Johnny Doe"
"doe@localhost" => "doe@localhost"
* 'address - just the mailing address, without any free-form
names:
"Jon Doe <doe@localhost>" => "doe@localhost"
"doe@localhost (Johnny Doe)" => "doe@localhost"
"doe@localhost" => "doe@localhost"
* 'full - the full address, essentially as it appears in the
input, but normalized:
"Jon Doe < doe@localhost >" => "Jon Doe <doe@localhost>"
" doe@localhost (Johnny Doe)" => "doe@localhost (Johnny Doe)"
"doe@localhost" => "doe@localhost"
* 'all - a list containing each of the three possibilities:
free-form name, address, and full address (in that
order)
Example:
(extract-addresses " \"Doe, John\" <doe@localhost>, john" 'address)
; => ("doe@localhost" "john")
> (assemble-address-field list-of-address-strings) -> string
Creates a header field value from a list of addresses. The addresses
are comma-separated, and possibly broken into multiple lines.
==========================================================================
_DNS_, _domain name service_
==========================================================================
To load directly: (require (lib "dns.ss" "net"))
Module files: _dns.ss_ - provides the procedures documented below
_dns-unit.ss_ - provides unit net:dns@
_dns-sig.ss_ - provides signature net:dns^
ABSTRACT -------------------------------------------------------------
Implements part of a DNS client, based on RFC 1035. The name cache
does not properly time out entries, however.
Thanks to Eduardo Cavazos and Jason Crowe for repairs and
improvements.
PROCEDURES -----------------------------------------------------------
> (dns-get-address nameserver-string address-string) -> address-string
Consults the specified nameserver (normally a numerical address like
"128.42.1.30") to obtain a numerical address for the given Internet
address.
The query record sent to the DNS server includes the "recursive"
bit, but `dns-get-address' also implements a recursive search itself
in case the server does not provide this optional feature.
> (dns-get-name nameserver-string address-string) -> address-string
Consults the specified nameserver (normally a numerical address like
"128.42.1.30") to obtain a name for the given numerical address.
> (dns-get-mail-exchanger nameserver-string address-string) -> address-string
Consults the specified nameserver to obtain the address for a mail
exchanger the given mail host address. For example, the mail
exchanger for "ollie.cs.rice.edu" is currently "cs.rice.edu".
> (dns-find-nameserver) -> address-string or #f
Attempts to find the address of a nameserver on the present system.
Under Unix, this procedure parses /etc/resolv.conf to extract the
first nameserver address. Under Windows, it runs "nslookup.exe".
==========================================================================
_MIME support__
==========================================================================
To load directly: (require (lib "mime.ss" "net"))
Module files: _mime.ss_ - provides the procedures documented below
_mime-unit.ss_ - provides unit net:mime@
imports net:base64^ from "base64-sig.ss"
and net:qp^ from "qp-sig.ss"
_mime-sig.ss_ - provides signature net:mime^
ABSTRACT -------------------------------------------------------------
Author: Francisco Solsona <solsona@acm.org>
MIME stands for Multipurpose Internet Mail Extensions. the mime
library provides support for MIME as described in: rfc2045 through
rfc2049.
This library is supposed to be used by PLT Scheme applications, or
libraries to make the MIME-aware. For instance, MUAs, (Fast)CGI
libraries to support multipart/form-data extensions, etc.
EXCEPTIONS -----------------------------------------------------------
unexpected-termination
This exception is raised when eof is reached while parsing the
headers of a MIME entity. And it usually means, that the message
does not conform to rfc2045, and friends. It has a message
parameter, `msg', that gives exact information on the problem:
unexpected-termination-msg.
missing-multipart-boundary-parameter
A multipart type is signaled, but no `boundary' parameter is
given, also an error on the producer end of the message.
malformed-multipart-entity
Similar to `unexpected-termination', but it is used only while
scanning parts of a multipart message.
empty-mechanism
No transport encoding mechanism was provided with the
Content-Transfer-Encoding field.
empty-type
No type specified for Content-Type, or incorrectly formated.
empty-subtype
No subtype specified for Content-Type, or incorrectly formated.
empty-disposition-type
No type specified for the Content-Disposition field, or incorrectly
formated.
mime-error
A catch-all exception.
PROCEDURES -----------------------------------------------------------
> (mime-analyze message)
Message must conform to the RFC 2045, 2046, 2047, 2048, and 2049.
This is basically the only function provided by the MIME support
library. It returns a `message' structure, having the following
fields: version, entity, and fields.
> (message-version message-struct)
the value of the MIME-version header. It has a default 1.0 value
when message does not contain a MIME-version header.
> (message-entity message-struct)
another structure, `entity'. According to rfc2045, and entity
refers to the MIME-defined header fields and contents of either a
message or one of the parts in the body of a multipart entity.
See below, for the fields of an entity-structure. All the
MIME-headers, parts (sub-entities), and/or contents of message are
stored into this structure.
> (message-fields message-struct)
a list of all non-MIME headers in message. If message is an
rfc822, for instance, this list could contain 'From', 'Subject',
etc.
struct entity
-------------
These kind of structure contains all the headers, parameters, and
contents of a given entity, and its parts (sub-entities). These
are the fields of the entity structure:
type, subtype, charset, encoding, disposition, params, id,
description, other, fields, parts, body, close.
> (entity-type entity-struct)
In rfc822 BNF extension:
type := discrete-type | composite-type
discrete-type := "text" / "image" / "audio" / "video" /
"application" / extension-token
composite-type := "message" / "multipart" / extension-token
extension-token := ietf-token / x-token
ietf-token := <An extension token defined by a standards-track
RFC and registered with IANA.>
x-token := <The two characters "X-" or "x-" followed, with no
intervening white space, by any token>
In English, it returns one of the symbols: text, image, audio,
video, application, an ietf-extension, and x-token, or a local
extension (not recommended by the way.)
> (entity-subtype entity-struct)
subtype := extension-token / iana-token
Also a symbol, it depends on the value of type. Quoting RFC 1700:
Type Subtype Description Reference
---- ------- ----------- ---------
text plain [RFC1521,NSB]
richtext [RFC1521,NSB]
tab-separated-values [Paul Lindner]
multipart mixed [RFC1521,NSB]
alternative [RFC1521,NSB]
digest [RFC1521,NSB]
parallel [RFC1521,NSB]
appledouble [MacMime,Patrik Faltstrom]
header-set [Dave Crocker]
message rfc822 [RFC1521,NSB]
partial [RFC1521,NSB]
external-body [RFC1521,NSB]
news [RFC 1036, Henry Spencer]
application octet-stream [RFC1521,NSB]
postscript [RFC1521,NSB]
oda [RFC1521,NSB]
atomicmail [atomicmail,NSB]
andrew-inset [andrew-inset,NSB]
slate [slate,terry crowley]
wita [Wang Info Transfer,Larry Campbell]
dec-dx [Digital Doc Trans, Larry Campbell]
dca-rft [IBM Doc Content Arch, Larry Campbell]
activemessage [Ehud Shapiro]
rtf [Paul Lindner]
applefile [MacMime,Patrik Faltstrom]
mac-binhex40 [MacMime,Patrik Faltstrom]
news-message-id [RFC1036, Henry Spencer]
news-transmission [RFC1036, Henry Spencer]
wordperfect5.1 [Paul Lindner]
pdf [Paul Lindner]
zip [Paul Lindner]
macwriteii [Paul Lindner]
msword [Paul Lindner]
remote-printing [RFC1486,MTR]
image jpeg [RFC1521,NSB]
gif [RFC1521,NSB]
ief Image Exchange Format [RFC1314]
tiff Tag Image File Format [MTR]
audio basic [RFC1521,NSB]
video mpeg [RFC1521,NSB]
quicktime [Paul Lindner]
> (entity-charset entity-struct)
The value of the `charset' parameter of the Content-Type header.
By default, the symbol: us-ascii.
> (entity-encoding entity-struct)
The value of the Content-Transfer-Encoding header, one of the
symbols: 7bit, 8bit, binary, quoted-printable, base64. If no
Content-Transfer-Encoding header is given, message should be 7bit,
thus, 7bit is the default value of this field.
> (entity-disposition entity-struct)
This one is a litter bit complex, so it is yet another structure.
These `disposition' structures represent the value of the
Content-Disposition header, as defined in rfc2183:
disposition := "Content-Disposition" ":"
disposition-type
*(";" disposition-parm)
disposition structs have the following fields: type, filename,
creation, modification, read, size, and params. Only type is
required.
> (disposition-type disposition-struct)
disposition-type := 'inline / 'attachment / extension-token
> (disposition-filename disposition-struct)
string representing the `filename' parameter of the
Content-Disposition header.
> (disposition-creation disposition-struct)
string representing the `creation-date' parameter, which must
follow this BNF grammar:
date-time = [ day "," ] date time ; dd mm yy
; hh:mm:ss zzz
day = "Mon" / "Tue" / "Wed" / "Thu"
/ "Fri" / "Sat" / "Sun"
date = 1*2DIGIT month 2DIGIT ; day month year
; e.g. 20 Jun 82
month = "Jan" / "Feb" / "Mar" / "Apr"
/ "May" / "Jun" / "Jul" / "Aug"
/ "Sep" / "Oct" / "Nov" / "Dec"
time = hour zone ; ANSI and Military
hour = 2DIGIT ":" 2DIGIT [":" 2DIGIT]
; 00:00:00 - 23:59:59
zone = "UT" / "GMT" ; Universal Time
; North American : UT
/ "EST" / "EDT" ; Eastern: - 5/ - 4
/ "CST" / "CDT" ; Central: - 6/ - 5
/ "MST" / "MDT" ; Mountain: - 7/ - 6
/ "PST" / "PDT" ; Pacific: - 8/ - 7
/ 1ALPHA ; Military: Z = UT;
; A:-1; (J not used)
; M:-12; N:+1; Y:+12
/ ( ("+" / "-") 4DIGIT ) ; Local differential
> (disposition-modification disposition-struct)
String representing the `modification-date' parameter, it has the
same syntax as `disposition-creation'.
> (disposition-read disposition-struct)
String representing the `read-date' parameter, it has the same
syntax as `disposition-creation'.
> (disposition-size disposition-struct)
Number representing the `size' parameter (the size of the file).
> (disposition-params disposition-struct)
List of extra parameters (non-standard) following the
Content-Disposition header.
> (entity-params entity-struct)
List of `parameters' given with all the MIME headers above. Each
of these parameters is a pair of the form: (parameter-name . value)
> (entity-id entity-struct)
The value of the Content-Id header.
> (entity-description entity-struct)
The value of the Content-description header.
> (entity-other entity-struct)
MIME extension fields (non-standard) they all start with
"Content-".
> (entity-fields entity-struct)
A list of all non-MIME headers.
> (entity-parts entity-struct)
A list of `message'-structs see above. Each entry represents a
part of the current MIME entity (only multipart, or message
entities can have parts).
> (entity-body entity-struct)
A procedure that consumes an output port and writes the message
body into the port, properly decoded (e.g. if body was
quoted-printable encoded, then the body is written already
quoted-printable decoded.). If type is multipart, or message,
clearly no bytes are written to port. The procedure only works
once (since the encoded body is pulled from a stream).
==========================================================================
_Base 64 Encoding_, _base64_
==========================================================================
To load directly: (require (lib "base64.ss" "net"))
Module files: _base64.ss_ - provides the procedures documented below
_base64-unit.ss_ - provides unit net:base64@
_base64-sig.ss_ - provides signature net:base64^
ABSTRACT -------------------------------------------------------------
Implements Base 64 (mime-standard) encoder and decoder.
PROCEDURES -----------------------------------------------------------
> (base64-encode bytes) -> bytes
Consumes a byte string and returns its Base 64 encoding as a new
byte string. The returned string is broken into 72-byte lines
separated by CRLF combinations, and always ends with a CRLF
combination unless the input is empty.
> (base64-decode bytes) -> bytes
Consumes a byte string and returns its Base 64 decoding as a new
byte string.
> (base64-encode-stream input-port output-port [newline-bytes]) -> void
Reads bytes from `input-port' and writes the encoded result to
`output-port', breaking the output into 72-character lines separated
by `newline-bytes, and ending with `newline-bytes unless the
input stream is empty. The default `newline-bytes contains just a
newline (not CRLF). The procedure returns when it encounters an
end-of-file from `input-port'.
> (base64-decode-stream input-port output-port) -> void
Reads a Base 64 encoding from `input-port' and writes the decoded
result to `output-port'. The procedure returns when it encounters an
end-of-file or Base 64 terminator (=) from `input-port'.
==========================================================================
_Quoted Printable Encoding_, _qp__
==========================================================================
To load directly: (require (lib "qp.ss" "net"))
Module files: _qp.ss_ - provides the procedures documented below
_qp-unit.ss_ - provides unit net:qp@
_qp-sig.ss_ - provides signature net:qp^
ABSTRACT -------------------------------------------------------------
Author: Francisco Solsona <solsona@acm.org>
Implements Quoted Printable (mime-standard) encoder and decoder. As
proposed by the rfc2045 section 6.7.
EXCEPTIONS -----------------------------------------------------------
qp-wrong-input
This exception is raised when input to any of the qp-procedures (see
below) is neither a string, nor an input port.
qp-wrong-line-size
If the length of a supposedly quoted-printable line is longer than
76 this exception is raised.
qp-error
is a catch all exception.
PROCEDURES -----------------------------------------------------------
> (qp-encode string) -> string
Consumes a string and returns its quoted printable representation as
a new string. The encoded string uses "\r\n" where necessary to
create shorter lines.
> (qp-decode string) -> string
Consumes a string and returns its un-quoted printable representation
as a new string. Non-soft linebreaks are preserved in whatever form
they exist (CR, LR, or CRLF) in the input string.
> (qp-encode-stream input output [newline-string]) -> void
Reads characters from `input' and writes the quoted printable
encoded result to `output'.
The `newline-string' argument is used for soft line-breaks (after
"="). The default `newline-string' is #"\n", though it should
probably be #"\r\n" instead.
Other linebreaks are preserved in whatever form they exist (CR, LR,
or CRLF) in the input stream.
> (qp-decode-stream input output) -> void
Reads characters from `input' and writes de-quoted-printable result
to `output'. Non-soft linebreaks are preserved in whatever form
they exist (CR, LR, or CRLF) in the input stream.
==========================================================================
_FTP client_
==========================================================================
To load directly: (require (lib "ftp.ss" "net"))
Module files: _ftp.ss_ - provides the procedures documented below
_ftp-unit.ss_ - provides unit net:ftp@
_ftp-sig.ss_ - provides signature net:ftp^
ABSTRACT -------------------------------------------------------------
Author: Micah Flatt <mflatt@elephant-ear.com>
Implements FTP client actions.
PROCEDURES -----------------------------------------------------------
> (ftp-establish-connection server-host-string server-port-k user-string passwd-string)
Establishes an FTP connection with the given server using the
supplied username and password. The result is an opaque `ftp-conn'
structure representing the connection.
The username and password strings are encoded to bytes using the
current locale's encoding.
> (ftp-close-connection ftp-conn)
Closes an FTP connection.
> (ftp-cd ftp-conn new-dir-string)
Changes the current directory on the FTP server to `new-dir-string'.
The `new-dir-string' is not interpreted at all, but simply passed on
to the server (encoded using the current locale's encoding). It must
not contain a newline.
> (ftp-directory-list ftp-conn)
Returns a list of files and directories in the current directory of
the server, assuming that the server provides directory information
in the quasi-standard Unix format.
Each file or directory is represented by a list of three
strings. The first string is either "-", "d", or "l", depending on
whether the items is a file, directory, or link, respectively. The
second item is the file's date; to convert this value to seconds
consistent with `file-seconds', pass the date string to
`ftp-make-file-seconds', below. The third string is the name of the
file or directory.
All strings are decoded from bytes using the current locale's
encoding.
> (ftp-make-file-seconds ftp-date-string)
Takes a date string produced by `ftp-directory-list' and converts it
to seconds.
> (ftp-download-file ftp-conn local-directory-path filename-string)
Downloads `filename-string' from the server's current directory and
puts it in `local-directory-path' using the same name. If the file
already exists in the local directory, it is replaced, but only
after the transfer succeeds (i.e., the file is first downloaded to a
temporary file, then moved into place on success).
==========================================================================
_TCP redirect_
==========================================================================
The "tcp-redirect.ss" library provides an function to generate a unit
with the signature net:tcp^ that redirects certain port numbers to
intra-process listeners that do not actually use TCP. The net:tcp^
signature is imported, for example, by the url@ unit of "url-unit.ss".
Module file: _tcp-redirect.ss_ - provides the `tcp-redirect-function
_tcp-sig.ss_ - defines _net:tcp^_, which contains the
following:
tcp-abandon-port
tcp-accept
tcp-accept-ready?
tcp-addresses
tcp-close
tcp-connect
tcp-connect/enable-break
tcp-listen
tcp-listener?
_tcp-unit.ss_ - defines _tcp@_ which implements
net:tcp^ using the MzScheme functions of
the same name
ssl-tcp-unit.ss - see below
PROCEDURES -----------------------------------------------------------
> (tcp-redirect port-number-list)
Returns a unit that implements net:tcp^ (from "tcp-sig.ss"). For
port numbers not listed in `port-number-list', the unit's
implementations are the MzScheme implementations.
For the port numbers listed in `port-number-list', and for
connections to "127.0.0.1", the unit's implementation does not use
TCP connections, but instead uses internal buffered channels. Such
channels behave exactly as TCP listeners and ports.
==========================================================================
_SSL redirect__
==========================================================================
The _ssl-tcp-unit.ss_ library provides `make-ssl-tcp@', which returns
a unit that implements net:tcp^ from "tcp-sig.ss"
PROCEDURES -----------------------------------------------------------
> (make-ssl-tcp@
server-cert-file server-key-file server-root-cert-files
server-suggest-auth-file
client-cert-file client-key-file client-root-cert-files)
Returns a unit that implements net:tcp^ using the SSL functions from
(lib "mzssl.ss" "openssl"). The arguments to `make-ssl-tcp@' control
the certificates and keys uses by server and client connections:
`server-cert-file' - a PEM file for a server's certificate; #f means
no certificate (which is unlikely to work with any SSL client)
`server-key-file' - a private key PEM to go with `server-cert-file';
#f means no key (which is likely renders a certificate useless)
`server-root-cert-files' - a list of PEM files for trusted root
certificates; #f disables verification of peer client certificates
`server-suggest-auth-file' - PEM file for root certificates to be
suggested to peer clients that must supply certificates
`client-cert-file' - a PEM file for a client's certificate; #f means
no certificate (usually fine)
`client-key-file' - a private key PEM to go with `client-cert-file';
#f means no key (which is likely renders a certificate useless)
`client-root-cert-files' - a list of PEM files for trusted root
certificates; #f disables verification of peer server certificates
==========================================================================
_cookies_, HTTP _State Management_
==========================================================================
To load directly: (require (lib "cookie.ss" "net"))
Module files: _cookie.ss_ - provides the procedures documented below
_cookie-unit.ss_ - provides unit net:cookie@
_cookie-sig.ss_ - provides signature net:cookie^
ABSTRACT -------------------------------------------------------------
The cookie package helps programmers use cookies as specified in RFC
2109 HTTP State Management Mechanism, aka HTTP cookies:
http://www.w3.org/Protocols/rfc2109/rfc2109
EXCEPTIONS -----------------------------------------------------------
> cookie-error
struct (cookie-error exn) ()
All errors are signaled by raising a cookie-error
TYPES ----------------------------------------------------------------
> cookie
The opaque structure that represents a cookie
PROCEDURES -----------------------------------------------------------
> (set-cookie name value)
: String String -> cookie
Creates a new cookie, with default values for required fields:
> (cookie:add-comment cookie comment)
: cookie String -> cookie
> (cookie:add-domain cookie domain)
: cookie String -> cookie
> (cookie:add-max-age cookie seconds)
: cookie Nat -> cookie
> (cookie:add-path cookie path)
: cookie String -> cookie
> (cookie:secure cookie secure?)
: cookie Boolean -> cookie
> (cookie:version cookie version)
: cookie Nat -> cookie
These procedures all modify the fields of an existing cookie. The
modification is destructive, and the modified cookie is returned.
`domain' must match a prefix of the request-URI.
`seconds' should be a non-negative natural number representing the
number of seconds you want the client to retain the cookie.
`version' is a required field; the library defaults to the only
known incarnation of HTTP cookies: 1.
> (print-cookie cookie)
: cookie-structure -> String
Printing a cookie obtains the string that represents the cookie you
formed with the procedures above.
Empty fields will not appear in the output except when there is a
required default. Currently only the Version is always added.
> (get-cookie name cookies)
: String String -> (listof String)
Returns a list with all the values (strings) associated with name.
> (get-cookie/single name cookies)
: String String -> (U String #f)
Returns the `first' value string associated to name, or #f if no
association is found.
The method used to obtain the `Cookie' header depends on the web
server. It may be an environment variable (CGI), or you may have to
read it from the `input port' (FastCGI), or maybe it comes in an
`initial-request' structure, etc. The above two procedures can be
used to extract fields from a `Cookie' header.
EXAMPLES -------------------------------------------------------------
> Creating a cookie
(let ((c (cookie:add-max-age
(cookie:add-path
(set-cookie "foo" "bar")
"/servlets")
3600)))
(print-cookie c))
=>
"foo=bar; Max-Age=3600; Path=/servlets; Version=1"
To use this output in a "regular" CGI, instead of the last line you
would use:
(display (format "Set-Cookie: ~a" (print-cookie c)))
and to use with the PLT Web Server, you would use:
(make-response/full code message (current-seconds) mime
`((Set-Cookie . ,(print-cookie c)))
body)
> Parsing a cookie
Imagine your Cookie header looks like this:
(cookies . "test2=2; test3=3; xfcTheme=theme6; xfcTheme=theme2")
Then, to get the values of the xfcTheme cookie, you would use:
(get-cookie "xfcTheme" cookies)
=> ("theme6" "theme2")
(get-cookie/single "xfcTheme" cookies)
=> "theme6"
If you try to get a cookie that simply is not there, you will get:
(get-cookie/single "foo" cookies)
=> #f
(get-cookie "foo" cookies)
=> ()
Note that not having a cookie is normally not an error. Most clients
won't have a cookie set then first arrive at your site.
==========================================================================
_URL encoding_, _URL decoding_, _application/x-www-form-urlencoded_
==========================================================================
To load directly: (require (lib "uri-codec.ss" "net"))
Module files: _uri-codec.ss_ - provides the procedures documented below
_uri-codec-unit.ss_ - provides unit net:uri-codec@
_uri-codec-sig.ss_ - provides signature net:uri-codec^
ABSTRACT -------------------------------------------------------------
The module provides functions to encode and decode strings using
the URI encoding rules given in RFC 2396, and to encode and decode
name/value pairs using the application/x-www-form-urlencoded
mimetype given the in HTML 4.0 specification. There are minor
differences between the two encodings.
The URI encoding uses allows a few characters to be represented `as
is': a-Z, A-Z, 0-9, -, _, ., !, ~, *, ', ( and ). The remaining
characters are encoded as %xx, where xx is the hex representation
of the integer value of the character (where the mapping
character<->integer is determined by US-ASCII if the integer is
<128).
The encoding, inline with RFC 2396's recommendation, represents a
character as is, if possible. The decoding allows any characters
to be represented by their hex values, and allows characters to be
incorrectly represented `as is'.
The rules for the application/x-www-form-urlencoded mimetype given
in the HTML 4.0 spec are:
1. Control names and values are escaped. Space characters are
replaced by `+', and then reserved characters are escaped as
described in [RFC1738], section 2.2: Non-alphanumeric characters
are replaced by `%HH', a percent sign and two hexadecimal digits
representing the ASCII code of the character. Line breaks are
represented as "CR LF" pairs (i.e., `%0D%0A').
2. The control names/values are listed in the order they appear in
the document. The name is separated from the value by `=' and
name/value pairs are separated from each other by either `;' or `&'.
When encoding, `;' is used as the separator by default. When
decoding, both `;' and `&' are parsed as separators by default.
NB: RFC 2396 supersedes RFC 1738.
This differs slightly from the straight encoding in RFC 2396 in
that `+' is allowed, and represents a space. We follow this
convention, encoding a space as `+' and decoding `+' as a space.
There appear to be some brain-dead decoders on the web, so we also
encode `!', `~', `'', `(' and ')' using their hex representation.
This is the same choice as made by the Java URLEncoder.
TYPES ----------------------------------------------------------------
> alist
(list-of (cons symbol string)) Represents decoded name/value pairs
PROCEDURES -----------------------------------------------------------
> (uri-encode string)
: String -> String
Encode a string using the URI encoding rules
> (uri-decode string)
: String -> String
Decode a string encoded using the URI encoding rules
> (form-urlencoded-encode string)
: String -> String
Encode a string using the application/x-www-form-urlencoded encoding
rules. (This string contains no non-ASCII characters, of course.)
> (form-urlencoded-decode string)
: String -> String
Decode a string encoded using the application/x-www-form-urlencoded
encoding rules.
> (alist->form-urlencoded alist)
: alist -> String
Encode an alist of key/value pairs using the
application/x-www-form-urlencoded encoding rules.
The `separator-mode-sym' argument must be either 'amp or 'semi to
select the separator. The default is 'semi.
> (form-urlencoded->alist string [separator-mode-sym])
: String -> alist
Decode a string encoded using the application/x-www-form-urlencoded
encoding rules into an alist of key/value pairs. All keys are
downcased for conversion to symbols.
The `separator-mode-sym' argument must be either 'amp, 'semi, or
'both to select the separator. The default is 'both.
> (current-alist-separator-mode)
> (current-alist-separator-mode mode-sym)
A parameter that determines the separator used/recognized between
alist pairs in `form-urlencoded->alist', `alist->form-urlencoded',
`url->string', and `string->url'. The possible mode symbols are
'amp, 'semi, and 'amp-or-semi.
The default value is 'amp-or-semi, which means that both "&" and ";"
are treated as separators when parsing, and ";" is used as a
separator when encoding. The other modes use/recognize only of the
separators.
Examples for '((name . "shriram") (host "nw")):
Mode Parse Generate
------ -------------------- --------------------
'amp name=shriram&host=nw name=shriram&host=nw
'semi name=shriram;host=nw name=shriram;host=nw
'amp-or-semi name=shriram&host=nw name=shriram;host=nw
or
name=shriram;host=nw