@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2005
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2002, 2003,
+@c 2004, 2005 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/processes
@node Processes, Display, Abbrevs, Top
* Datagrams:: UDP network connections.
* Low-Level Network:: Lower-level but more general function
to create connections and servers.
+* Misc Network:: Additional relevant functions for network connections.
* Byte Packing:: Using bindat to pack and unpack binary data.
@end menu
(shell-quote-argument "foo > bar")
@result{} "foo\\ \\>\\ bar"
-;; @r{This example shows the behavior on MS-DOS and MS-Windows systems.}
+;; @r{This example shows the behavior on MS-DOS and MS-Windows.}
(shell-quote-argument "foo > bar")
@result{} "\"foo > bar\""
@end example
Quitting is normally inhibited within a filter function---otherwise,
the effect of typing @kbd{C-g} at command level or to quit a user
-command would be unpredictable. If you want to permit quitting inside a
-filter function, bind @code{inhibit-quit} to @code{nil}.
-@xref{Quitting}.
+command would be unpredictable. If you want to permit quitting inside
+a filter function, bind @code{inhibit-quit} to @code{nil}. In most
+cases, the right way to do this is with the macro
+@code{with-local-quit}. @xref{Quitting}.
If an error happens during execution of a filter function, it is
caught automatically, so that it doesn't stop the execution of whatever
termination will always run the sentinel exactly once. This is
because the process status can't change again after termination.
- Quitting is normally inhibited within a sentinel---otherwise, the
-effect of typing @kbd{C-g} at command level or to quit a user command
-would be unpredictable. If you want to permit quitting inside a
-sentinel, bind @code{inhibit-quit} to @code{nil}. @xref{Quitting}.
+ Emacs explicitly checks for output from the process before running
+the process sentinel. Once the sentinel runs due to process
+termination, no further output can arrive from the process.
A sentinel that writes the output into the buffer of the process
should check whether the buffer is still alive. If it tries to insert
into a dead buffer, it will get an error. If the buffer is dead,
@code{(buffer-name (process-buffer @var{process}))} returns @code{nil}.
+ Quitting is normally inhibited within a sentinel---otherwise, the
+effect of typing @kbd{C-g} at command level or to quit a user command
+would be unpredictable. If you want to permit quitting inside a
+sentinel, bind @code{inhibit-quit} to @code{nil}. In most cases, the
+right way to do this is with the macro @code{with-local-quit}.
+@xref{Quitting}.
+
If an error happens during execution of a sentinel, it is caught
automatically, so that it doesn't stop the execution of whatever
programs was running when the sentinel was started. However, if
process, being stopped means not accepting new connections. (Up to 5
connection requests will be queued for when you resume the server; you
can increase this limit, unless it is imposed by the operating
-systems.) For a network stream connection, being stopped means not
+system.) For a network stream connection, being stopped means not
processing input (any arriving input waits until you resume the
connection). For a datagram connection, some number of packets may be
queued but input may be lost. You can use the function
@node Low-Level Network
@section Low-Level Network Access
+ You can also create network connections by operating at a lower
+level that that of @code{open-network-stream}, using
+@code{make-network-process}.
+
+@menu
+* Make Network:: Using @code{make-network-process}.
+* Network Options:: Further control over network connections.
+* Network Feature Testing:: Determining which network features work on
+ the machine you are using.
+@end menu
+
+@node Make Network
+@subsection @code{make-network-process}
+
The basic function for creating network connections and network
servers is @code{make-network-process}. It can do either of those
jobs, depending on the arguments you give it.
Initialize the process plist to @var{plist}.
@end table
-The following network options can be specified for the network
-process. Except for @code{:reuseaddr}, you can set or modify these
-options later using @code{set-network-process-option}.
+The original argument list, modified with the actual connection
+information, is available via the @code{process-contact} function.
+@end defun
+
+@node Network Options
+@subsection Network Options
-For a server process, the options specified with
+ The following network options can be specified when you create a
+network process. Except for @code{:reuseaddr}, you can also set or
+modify these options later, using @code{set-network-process-option}.
+
+ For a server process, the options specified with
@code{make-network-process} are not inherited by the client
connections, so you will need to set the necessary options for each
-child connection as they are created.
+child connection as it is created.
@table @asis
@item :bindtodevice @var{device-name}
may be a period of time after the last use of that port (by any
process on the host), where it is not possible to make a new server on
that port.
-
@end table
-The original argument list, modified with the actual connection
-information, is available via the @code{process-contact} function.
-@end defun
-
@defun set-network-process-option process option value
This function sets or modifies a network option for network process
@var{process}. See @code{make-network-process} for details of options
@code{process-contact} function.
@end defun
-@defun network-interface-list
-This function returns a list describing the network interfaces
-of the machine you are using. The value is an alist whose
-elements have the form @code{(@var{name} . @var{address})}.
-@var{address} has the same form as the @var{local-address}
-and @var{remote-address} arguments to @code{make-network-process}.
-@end defun
-
-@defun network-interface-info ifname
-This function returns information about the network interface named
-@var{ifname}. The value is a list of the form
-@code{(@var{addr} @var{bcast} @var{netmask} @var{hwaddr} @var{flags})}.
-
-@table @var
-@item addr
-The internet protocol address.
-@item bcast
-The broadcast address.
-@item netmask
-The network mask.
-@item hwaddr
-The layer 2 address (Ethernet MAC address, for instance).
-@item flags
-The current flags of the interface.
-@end table
-@end defun
-
-@defun format-network-address address &optional omit-port
-This function converts the Lisp representation of a network address to
-a string. For example, a five-element vector @code{[@var{a} @var{b}
-@var{c} @var{d} @var{p}]} represents an IP address
-@var{a}.@var{b}.@var{c}.@var{d} and port number @var{p}.
-@code{format-network-address} converts that to the string
-@code{"@var{a}.@var{b}.@var{c}.@var{d}:@var{p}"}.
-
-If @var{omit-port} is non-@code{nil}, the value does not include
-the port number.
-@end defun
+@node Network Feature Testing
+@subsection Testing Availability of Network Features
To test for the availability of a given network feature, use
@code{featurep} like this:
(featurep 'make-network-process '@var{keyword})
@end example
-Here are some of the option @var{keyword}s you can test in
-this way.
+@noindent
+Here are some of the options you can test in this way.
@table @code
@item :bindtodevice
@code{make-network-process} and @code{set-network-process-option}.
@end table
+@node Misc Network
+@section Misc Network Facilities
+
+ These additional functions are useful for creating and operating
+on network connections.
+
+@defun network-interface-list
+This function returns a list describing the network interfaces
+of the machine you are using. The value is an alist whose
+elements have the form @code{(@var{name} . @var{address})}.
+@var{address} has the same form as the @var{local-address}
+and @var{remote-address} arguments to @code{make-network-process}.
+@end defun
+
+@defun network-interface-info ifname
+This function returns information about the network interface named
+@var{ifname}. The value is a list of the form
+@code{(@var{addr} @var{bcast} @var{netmask} @var{hwaddr} @var{flags})}.
+
+@table @var
+@item addr
+The internet protocol address.
+@item bcast
+The broadcast address.
+@item netmask
+The network mask.
+@item hwaddr
+The layer 2 address (Ethernet MAC address, for instance).
+@item flags
+The current flags of the interface.
+@end table
+@end defun
+
+@defun format-network-address address &optional omit-port
+This function converts the Lisp representation of a network address to
+a string. For example, a five-element vector @code{[@var{a} @var{b}
+@var{c} @var{d} @var{p}]} represents an IP address
+@var{a}.@var{b}.@var{c}.@var{d} and port number @var{p}.
+@code{format-network-address} converts that to the string
+@code{"@var{a}.@var{b}.@var{c}.@var{d}:@var{p}"}.
+
+If @var{omit-port} is non-@code{nil}, the value does not include
+the port number.
+@end defun
+
@node Byte Packing
@section Packing and Unpacking Byte Arrays
To control unpacking and packing, you write a @dfn{data layout
specification}, a special nested list describing named and typed
-@dfn{fields}. This specification conrtols length of each field to be
+@dfn{fields}. This specification controls length of each field to be
processed, and how to pack or unpack it.
@cindex endianness
Here is a complete example of byte unpacking and packing:
- @lisp
+@lisp
(defvar fcookie-index-spec
'((:version u32)
(:count u32)
(buffer-string))))
(sel (random (bindat-get-field info :count)))
(beg (cdar (bindat-get-field info :offset sel)))
- (end (or (cdar (bindat-get-field info :offset (1+ sel)))
+ (end (or (cdar (bindat-get-field info
+ :offset (1+ sel)))
(nth 7 (file-attributes cookies)))))
- (switch-to-buffer (get-buffer-create
- (format "*Fortune Cookie: %s*"
- (file-name-nondirectory cookies))))
+ (switch-to-buffer
+ (get-buffer-create
+ (format "*Fortune Cookie: %s*"
+ (file-name-nondirectory cookies))))
(erase-buffer)
- (insert-file-contents-literally cookies nil beg (- end 3))))
+ (insert-file-contents-literally
+ cookies nil beg (- end 3))))
(defun fcookie-create-index (cookies &optional index delim)
"Scan file COOKIES, and write out its index file.
offsets (cons (1- p) offsets))))
(with-temp-buffer
(set-buffer-multibyte nil)
- (insert (string-make-unibyte
- (bindat-pack
- fcookie-index-spec
- `((:version . 2)
- (:count . ,count)
- (:longest . ,max)
- (:shortest . ,min)
- (:flags . 0)
- (:delim . ,delim)
- (:offset . ,(mapcar (lambda (o)
- (list (cons :foo o)))
- (nreverse offsets)))))))
+ (insert
+ (string-make-unibyte
+ (bindat-pack
+ fcookie-index-spec
+ `((:version . 2)
+ (:count . ,count)
+ (:longest . ,max)
+ (:shortest . ,min)
+ (:flags . 0)
+ (:delim . ,delim)
+ (:offset . ,(mapcar (lambda (o)
+ (list (cons :foo o)))
+ (nreverse offsets)))))))
(let ((coding-system-for-write 'raw-text-unix))
(write-file (or index (concat cookies ".dat")))))))
@end lisp
The corresponding decoded structure:
@lisp
-(setq decoded-structure (bindat-unpack packet-spec binary-data))
+(setq decoded (bindat-unpack packet-spec binary-data))
@result{}
((header
(dest-ip . [192 168 1 100])
Fetching data from this structure:
@lisp
-(bindat-get-field decoded-structure 'item 1 'id)
+(bindat-get-field decoded 'item 1 'id)
@result{} "BCDEFG"
@end lisp
HCoop / bpt / emacs.git / blobdiff