[Emacs-diffs] Changes to emacs/lispref/processes.texi

[Richard M. Stallman]

Index: emacs/lispref/processes.texi
diff -c emacs/lispref/processes.texi:1.32 emacs/lispref/processes.texi:1.33
*** emacs/lispref/processes.texi:1.32   Mon Sep  1 11:45:41 2003
--- emacs/lispref/processes.texi        Fri Sep 19 10:42:17 2003
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*** 48,53 ****
--- 48,57 ----
  * Query Before Exit::        Whether to query if exiting will kill a process.
  * Transaction Queues::             Transaction-based communication with 
subprocesses.
  * Network::                  Opening network connections.
+ * Network Servers::          Network servers let Emacs accept net connections.
+ * Datagrams::
+ * Low-Level Network::        Lower-level but more general function
+                                to create connections and servers.
  @end menu
  
  @node Subprocess Creation
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*** 376,381 ****
--- 380,392 ----
  @end smallexample
  @end defun
  
+ @defun call-process-shell-command command &optional infile destination 
display &rest args
+ This function executes the shell command @var{command} synchronously
+ in separate process.  The final arguments @var{args} are additional
+ arguments to add at the end of @var{command}.  The other arguments
+ are handled as in @code{call-process}.
+ @end defun
+ 
  @defun shell-command-to-string command
  This function executes @var{command} (a string) as a shell command,
  then returns the command's output as a string.
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*** 539,548 ****
    Several functions return information about processes.
  @code{list-processes} is provided for interactive use.
  
! @deffn Command list-processes
  This command displays a listing of all living processes.  In addition,
  it finally deletes any process whose status was @samp{Exited} or
  @samp{Signaled}.  It returns @code{nil}.
  @end deffn
  
  @defun process-list
--- 550,562 ----
    Several functions return information about processes.
  @code{list-processes} is provided for interactive use.
  
! @deffn Command list-processes &optional query-only
  This command displays a listing of all living processes.  In addition,
  it finally deletes any process whose status was @samp{Exited} or
  @samp{Signaled}.  It returns @code{nil}.
+ 
+ If @var{query-only} is address@hidden then it lists only processes
+ whose query flag is address@hidden  @xref{Query Before Exit}.
  @end deffn
  
  @defun process-list
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*** 594,605 ****
  This function returns the name of @var{process}.
  @end defun
  
- @defun process-contact process
- This function returns @code{t} for an ordinary child process, and
- @code{(@var{hostname} @var{service})} for a net connection
- (@pxref{Network}).
- @end defun
- 
  @defun process-status process-name
  This function returns the status of @var{process-name} as a symbol.
  The argument @var{process-name} must be a process, a buffer, a
--- 608,613 ----
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*** 622,627 ****
--- 630,641 ----
  for a network connection that is closed.  Once a connection
  is closed, you cannot reopen it, though you might be able to open
  a new connection to the same place.
+ @item connect
+ for a non-blocking connection that is waiting to complete.
+ @item failed
+ for a non-blocking connection that has failed to complete.
+ @item listen
+ for a network server that is listening.
  @item nil
  if @var{process-name} is not the name of an existing process.
  @end table
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*** 679,684 ****
--- 693,719 ----
  input.
  @end defun
  
+   Every process also has a property list that you can use to store
+ miscellaneous values associated with the process.
+ 
+ @defun process-get process propname
+ This function returns the value of the @var{propname} property
+ of @var{process}.
+ @end defun
+ 
+ @defun process-put process propname value
+ This function sets the value of the @var{propname} property
+ of @var{process} to @var{value}.
+ @end defun
+ 
+ @defun process-plist process
+ This function returns the process plist of @var{process}.
+ @end defun
+ 
+ @defun set-process-plist process plist
+ This function sets the process plist of @var{process} to @var{plist}.
+ @end defun
+ 
  @node Input to Processes
  @section Sending Input to Processes
  @cindex process input
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*** 859,868 ****
  @end defun
  
  @c Emacs 19 feature
! @defun signal-process pid signal
! This function sends a signal to process @var{pid}, which need not be
! a child of Emacs.  The argument @var{signal} specifies which signal
! to send; it should be an integer.
  @end defun
  
  @node Output from Processes
--- 894,905 ----
  @end defun
  
  @c Emacs 19 feature
! @defun signal-process process signal
! This function sends a signal to process @var{process}.  The argument
! @var{signal} specifies which signal to send; it should be an integer.
! 
! You can specify the target process by its process @sc{id}; that allows
! you to send signals to processes that are not children of Emacs.
  @end defun
  
  @node Output from Processes
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*** 1437,1460 ****
  @cindex network connection
  @cindex TCP
  
!   Emacs Lisp programs can open TCP network connections to other processes on
! the same machine or other machines.  A network connection is handled by Lisp
! much like a subprocess, and is represented by a process object.
! However, the process you are communicating with is not a child of the
! Emacs process, so you can't kill it or send it signals.  All you can do
! is send and receive data.  @code{delete-process} closes the connection,
! but does not kill the process at the other end; that process must decide
! what to do about closure of the connection.
  
    You can distinguish process objects representing network connections
! from those representing subprocesses with the @code{process-status}
! function.  It always returns either @code{open} or @code{closed} for a
! network connection, and it never returns either of those values for a
! real subprocess.  @xref{Process Information}.
  
  @defun open-network-stream name buffer-or-name host service
! This function opens a TCP connection for a service to a host.  It
! returns a process object to represent the connection.
  
  The @var{name} argument specifies the name for the process object.  It
  is modified as necessary to make it unique.
--- 1474,1519 ----
  @cindex network connection
  @cindex TCP
  
!   Emacs Lisp programs can open TCP and datagram network connections to
! other processes on the same machine or other machines.  A network
! connection is handled by Lisp much like a subprocess, and is
! represented by a process object.  However, the process you are
! communicating with is not a child of the Emacs process, so it has no
! process @sc{id}, and you can't kill it or send it signals.  All you
! can do is send and receive data.  @code{delete-process} closes the
! connection, but does not kill the program at the other end; that
! program must decide what to do about closure of the connection.
! 
!   Lisp programs can listen for connections by creating network
! servers.  A network server is also represented by a kind of process
! object, but unlike a network connection, the network server never
! transfers data itself.  When it receives a connection request, it
! creates a new network connection to represent the connection just
! made.  (The network connection inherits certain information, including
! the process plist, from the server.)  The network server then goes
! back to listening for more connection requests.
  
    You can distinguish process objects representing network connections
! and servers from those representing subprocesses with the
! @code{process-status} function.  The possible status values for
! network connections are @code{open}, @code{closed}, @code{connect},
! and @code{failed}.  For a network server, the status is always
! @code{listen}.  None of those values is possible for a real
! subprocess.  @xref{Process Information}.
! 
!   You can stop and resume operation of a network processes by calling
! @code{stop-process} and @code{continue-process}.  For a server
! process, being stopped means not accepting new connections.  (Up to 5
! connection requests will be queued for when you resume the server;
! this limit is imposed by the operating system.)  For a network
! connection, being stopped means not processing input (any arriving
! input waits until you resume the connection).  You can use the
! function @code{process-command} to determine whether a network
! connection or server is stopped; a address@hidden value means yes.
  
  @defun open-network-stream name buffer-or-name host service
! This function opens a TCP connection, and returns a process object
! that represents the connection.
  
  The @var{name} argument specifies the name for the process object.  It
  is modified as necessary to make it unique.
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*** 1470,1475 ****
--- 1529,1899 ----
  a defined network service (a string) or a port number (an integer).
  @end defun
  
+ @defun open-network-stream-nowait name buffer-or-name host service &optional 
sentinel filter
+ This function opens a TCP connection, like @code{open-network-stream},
+ but it returns immediately without waiting for the request to be
+ accepted or rejected by the remote server.  When the request is
+ subsequently accepted or rejected, the process's sentinel function
+ will be called with a string that starts with @code{"open"} (on
+ success) or @code{"failed"} (on error).
+ 
+ Some systems do not support non-blocking connections; on those
+ systems, @code{open-network-stream-nowait} returns @code{nil}
+ and does nothing.
+ 
+ The optional arguments @var{sentinel} and @var{filter} specify the
+ sentinel and filter functions for this network connection.  It is
+ useful to specify them when opening the connection, because they will
+ be used later asynchronously.  The other arguments mean the same as in
+ @code{open-network-stream}.
+ @end defun
+ 
+ @defun process-contact process &optional key
+ This function returns information about how a network process was set
+ up.  For a connection, when @var{key} is @code{nil}, it returns
+ @code{(@var{hostname} @var{service})} which specifies what you
+ connected to.
+ 
+ If @var{key} is @code{t}, the value is the complete status information
+ for the connection or server; that is, the list of keywords and values
+ specified in @code{make-network-process}, except that some of the
+ values represent the current status instead of what you specified:
+ 
+ @table @code
+ @item :buffer
+ The associated value is the process buffer.
+ @item :filter
+ The associated value is the process filter function.
+ @item :sentinel
+ The associated value is the process filter function.
+ @item :remote
+ In a connection, this is the address in internal format of the remote peer.
+ @item :local
+ The local address, in internal format.
+ @item :service
+ In a server, if you specified @code{t} for @var{service},
+ this value is the actual port number.
+ @end table
+ 
+ @code{:local} and @code{:remote} are included even if they were not
+ specified explicitly in @code{make-network-process}.
+ 
+ If @var{key} is a keyword, the function returns the value corresponding
+ to that keyword.
+ 
+ For an ordinary child process, this function always returns @code{t}.
+ @end defun
+ 
+ @node Network Servers
+ @section Network Servers
+ 
+   You create a server by calling @code{make-network-process} with
+ @code{:server t}.  The server will listen for connection requests from
+ clients.  When it accepts a client connection request, that creates a
+ new network connection, itself a process object, with the following
+ parameters:
+ 
+ @itemize @bullet
+ @item
+ The connection's process name is constructed by concatenating the
+ server process' @var{name} with a client identification string.  The
+ client identification string for an IPv4 connection looks like
+ @samp{<@address@hidden@address@hidden:@var{p}>}.  Otherwise, it is a
+ unique number in brackets, as in @samp{<@var{nnn>}}.  The number
+ is unique for each connection in the Emacs session.
+ 
+ @item
+ If the server's filter is address@hidden, the connection process does
+ not get a separate process buffer; otherwise, Emacs creates a bew
+ buffer for the purpose.  The buffer name is the server's buffer name
+ or process name, concatenated with the client identification string.
+ 
+ The server's process buffer value is never used directly by Emacs, but
+ it is passed to the log function, which can log connections by
+ inserting text there.
+ 
+ @item
+ The communication type and the process filter and sentinel are
+ inherited from those of the server.  The server never directly
+ uses its filter and sentinel; their sole purpose is to initialize
+ connections made to the server.
+ 
+ @item
+ The connection's process contact info is set according to the client's
+ addressing information (typically an IP address and a port number).
+ This information is associated with the @code{process-contact}
+ keywords @code{:host}, @code{:service}, @code{:remote}.
+ 
+ @item
+ The connection's local address is set up according to the port
+ number used for the connection.
+ 
+ @item
+ The client process' plist is initialized from the server's plist.
+ @end itemize
+ 
+ @defun open-network-stream-server name buffer-or-name service &optional 
sentinel filter
+ Create a network server process for a TCP service.
+ It returns nil if server processes are not supported; otherwise,
+ it returns a subprocess-object to represent the server.
+ 
+ When a client connects to the specified service, Emacs creates a new
+ subprocess to handle the new connection, and then calls its sentinel
+ function (which it has inherited from the server).
+ 
+ The optional arguments @var{sentinel} and @var{filter} specify the
+ sentinel and filter functions for the server.  It is useful to specify
+ them now, because they will be used later asynchronously when the
+ server receives a connection request.  The three arguments @var{name},
+ @var{buffer-or-name} and @var{service} mean the same thing as in
+ @code{open-network-stream}, but @var{service} can be @code{t}
+ meaning ask the system to allocate an unused port to listen on.
+ @end defun
+ 
+ @node Datagrams
+ @section Datagrams 
+ @cindex datagrams
+ 
+   A datagram connection communicates with individual packets
+ rather than streams of data.  Each call to @code{process-send}
+ sends one datagram packet, and each datagram received results
+ in one call to the filter function.
+ 
+   The datagram connection doesn't have to talk with the same remote
+ peer all the time.  It has a @dfn{remote peer address} which specifies
+ where to send datagrams to.  Each time an incoming datagram is passed
+ to the filter function, the peer address is set to the address that
+ datagram came from; that way, if the filter function sends a datagram,
+ it will go back to that place.  You can specify the remote peer
+ address when you create the datagram connection using the
+ @code{:remote} keyword.  You can change it later on by calling
+ @code{set-process-datagram-address}.
+ 
+ @defun process-datagram-address process
+ If @var{process} is a datagram connection or server, this function
+ returns its remote peer address.
+ @end defun
+ 
+ @defun set-process-datagram-address process address
+ If @var{process} is a datagram connection or server, this function
+ sets its remote peer address to @var{address}.
+ @end defun
+ 
+ @node Low-Level Network
+ @section Low-Level Network Access
+ 
+    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.
+ 
+ @defun make-network-process &rest args
+ This function creates a network connection or server and returns the
+ process object that represents it.  The arguments @var{args} are a
+ list of keyword/argument pairs.  Omitting a keyword is always
+ equivalent to specifying it with value @code{nil}, except for
+ @code{:coding} and @code{:filter-multibyte}.  Here are the meaningful
+ keywords:
+ 
+ @table @asis
+ @item :name name
+ Use the string @var{name} as the process name.  It is modified if
+ necessary to make it unique.
+ 
+ @item :type @var{type}
+ Specify the communication type.  A value of @code{nil} specifies a
+ stream connection (the default); @code{datagram} specifies a datagram
+ connection.  Both connections and servers can be of either type.
+ 
+ @item :server @var{server-flag}
+ If @var{server-flag} is address@hidden, create a server.  Otherwise,
+ create a connection.
+ 
+ @item :host @var{host}
+ Specify the host to connect to.  @var{host} should be a host name or
+ internet address, as a string, or the symbol @code{local} to specify
+ the local host.  If you specify @var{host} for a server, it must
+ specify a valid address for the local host, and only clients
+ connecting to that address will be accepted.
+ 
+ @item :service @var{service}
+ @var{service} specifies a port number to connect to, or, for a server,
+ the port number to listen on.  It should be a service name that
+ translates to a port number, or an integer specifying the port number
+ directly.  For a server, it can also be @code{t}, which means to let
+ the system select an unused port number.
+ 
+ @item :family @var{family}
+ @var{family} specifies the address (and protocol) family for
+ communication.  @code{nil} stands for IPv4.  @code{local} specifies a
+ Unix socket, in which case @var{host} is ignored.
+ 
+ @item :local @var{local-address}
+ For a server process, @var{local-address} is the address to listen on.
+ It overrides @var{family}, @var{host} and @var{service}, and you
+ may as well not specify them.
+ 
+ @item :remote @var{remote-address}
+ For a connection, @var{remote-address} is the address to connect to.
+ It overrides @var{family}, @var{host} and @var{service}, and you
+ may as well not specify them.
+ 
+ For a datagram server, @var{remote-address} specifies the initial
+ setting of the remote datagram address.
+ 
+ The format of @var{local-address} or @var{remote-address} depends on
+ the address family:
+ 
+ @itemize -
+ @item
+ An IPv4 address is represented as a vector of integers @address@hidden
+ @var{b} @var{c} @var{d} @var{p}]} corresponding to numeric IP address
+ @address@hidden@address@hidden and port number @var{p}.
+ 
+ @item
+ A local address is represented as a string which specifies the address
+ in the local address space.
+ 
+ @item
+ An ``unsupported family'' address is represented by a cons
+ @code{(@var{f} . @var{av})}, where @var{f} is the family number and
+ @var{av} is a vector specifying the socket address using with one
+ element per address data byte.  Do not rely on this format in portable
+ code, as it may depend on implementation defined constants, data
+ sizes, and data structure alignment.
+ @end itemize
+ 
+ @item :nowait @var{bool}
+ If @var{bool} is address@hidden for a stream connection, return
+ without waiting for the connection to complete.  When the connection
+ succeeds or fails, Emacs will call the sentinel function, with a
+ second argument matching @code{"open"} (if successful) or
+ @code{"failed"}.  The default is to block, so that
+ @code{make-network-process} does not return until the connection
+ has succeeded or failed.
+ 
+ @item :stop @var{stopped}
+ Start the network connection or server in the `stopped' state if
+ @var{stopped} is address@hidden
+ 
+ @item :buffer @var{buffer}
+ Use @var{buffer} as the process buffer.
+ 
+ @item :coding @var{coding}
+ Use @var{coding} as the coding system for this process.  To specify
+ different coding systems for decoding data from the connection and for
+ encoding data sent to it, specify @code{(@var{decoding} .
+ @var{encoding})} for @var{coding}.
+ 
+ If you don't specify this keyword at all, the default
+ is to determine the coding systemx from the data.
+ 
+ @item :options @var{options}
+ Set the specified options for the network process.  See
+ @code{set-network-process-options} for details.
+ 
+ @item :noquery @var{query-flag}
+ Initialize the process query flag to @var{query-flag}.
+ 
+ @item :filter @var{filter}
+ Initialize the process filter to @var{filter}.
+ 
+ @item :filter-multibyte @var{bool}
+ If @var{bool} is address@hidden, strings given to the process filter
+ are multibyte, otherwise they are unibyte.  If you don't specify this
+ keyword at all, the default is that the strings are multibyte if
+ @code{default-enable-multibyte-characters} is address@hidden
+ 
+ @item :sentinel @var{sentinel}
+ Initialize the process sentinel to @var{sentinel}.
+ 
+ @item :log @var{log}
+ Initialize the log function of a server process to @var{log}.  The log
+ function is called each time the server accepts a network connection
+ from a client.  The arguments passed to the log function are
+ @var{server}, @var{connection}, and @var{message}, where @var{server}
+ is the server process, @var{connection} is the new process for the
+ connection, and @var{message} is a string describing what has
+ happened.
+ 
+ @item :plist @var{plist}
+ Initialize the process plist to @var{plist}.
+ @end table
+ 
+ The original argument list, modified with the actual connection
+ information, is available via the `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 @address@hidden @var{b}
+ @var{c} @var{d} @var{p}]} represents an IP address
+ @address@hidden@address@hidden and port number @var{p}.
+ @code{format-network-address} converts that to the string
+ @code{"@address@hidden@address@hidden:@var{p}"}.
+ 
+ If @var{omit-port} is address@hidden, the value does not include
+ the port number.
+ @end defun
+ 
+   To test for the availability of a given network feature, use
+ @code{featurep} like this:
+ 
+ @example
+ (featurep 'make-network-process '(@var{keyword} @var{value}))
+ @end example 
+ 
+ @noindent
+ The result is @code{t} if it works to specify @var{keyword} with value
+ @var{value} in @code{make-network-process}.  Here are some of the
+ @address@hidden pairs you can test in this way.
+ 
+ @table @code
+ @item (:nowait t)
+ address@hidden if non-blocking connect is supported.
+ @item (:type datagram)
+ address@hidden if datagrams are supported.
+ @item (:family local)
+ address@hidden if local (aka ``UNIX domain'') sockets are supported.
+ @item (:service t)
+ address@hidden if the system can select the port for a server.
+ @item (:options bindtodevice)
+ @itemx (:options broadcast)
+ @itemx (:options dontroute)
+ @itemx (:options keepalive)
+ @itemx (:options linger)
+ @itemx (:options oobinline)
+ @itemx (:options priority)
+ @itemx (:options reuseaddr)
+ That particular socket option is supported.
+ @end table
+ 
  @ignore
     arch-tag: ba9da253-e65f-4e7f-b727-08fba0a1df7a
  @end ignore
+