send(1T) Tk Built-In Commands send(1T)______________________________________________________________________________NAMEsend - Execute a command in a different application
SYNOPSISsend ?options? app cmd ?arg arg ...?
_________________________________________________________________DESCRIPTION
This command arranges for cmd (and args) to be executed in the applica‐
tion named by app. It returns the result or error from that command
execution. App may be the name of any application whose main window is
on the display containing the sender's main window; it need not be
within the same process. If no arg arguments are present, then the
command to be executed is contained entirely within the cmd argument.
If one or more args are present, they are concatenated to form the com‐
mand to be executed, just as for the eval command.
If the initial arguments of the command begin with ``-'' they are
treated as options. The following options are currently defined:
-async Requests asynchronous invocation. In this case the send command
will complete immediately without waiting for cmd to complete in
the target application; no result will be available and errors
in the sent command will be ignored. If the target application
is in the same process as the sending application then the
-async option is ignored.
-displayof pathName
Specifies that the target application's main window is on the
display of the window given by pathName, instead of the display
containing the application's main window.
-- Serves no purpose except to terminate the list of options. This
option is needed only if app could contain a leading ``-'' char‐
acter.
APPLICATION NAMES
The name of an application is set initially from the name of the pro‐
gram or script that created the application. You can query and change
the name of an application with the tk appname command.
DISABLING SENDS
If the send command is removed from an application (e.g. with the com‐
mand rename send {}) then the application will not respond to incoming
send requests anymore, nor will it be able to issue outgoing requests.
Communication can be reenabled by invoking the tk appname command.
SECURITY
The send command is potentially a serious security loophole. On Unix,
any application that can connect to your X server can send scripts to
your applications. These incoming scripts can use Tcl to read and
write your files and invoke subprocesses under your name. Host-based
access control such as that provided by xhost is particularly insecure,
since it allows anyone with an account on particular hosts to connect
to your server, and if disabled it allows anyone anywhere to connect to
your server. In order to provide at least a small amount of security,
Tk checks the access control being used by the server and rejects
incoming sends unless (a) xhost-style access control is enabled (i.e.
only certain hosts can establish connections) and (b) the list of
enabled hosts is empty. This means that applications cannot connect to
your server unless they use some other form of authorization such as
that provide by xauth. Under Windows, send is currently disabled. │
Most of the functionality is provided by the dde command instead.
EXAMPLE
This script fragment can be used to make an application that only runs
once on a particular display.
if {[tk appname FoobarApp] ne "FoobarApp"} {
send-async FoobarApp RemoteStart $argv
exit
}
# The command that will be called remotely, which raises
# the application main window and opens the requested files
proc RemoteStart args {
raise .
foreach filename $args {
OpenFile $filename
}
}
KEYWORDS
application, dde, name, remote execution, security, send │
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Availability │ runtime/tk-8 │
├────────────────────┼─────────────────┤
│Interface Stability │ Uncommitted │
└────────────────────┴─────────────────┘
NOTES
Source for Tk is available on http://opensolaris.org.
Tk 4.0 send(1T)
