'\"'\" Copyright (c) 1990-1994 The Regents of the University of California.'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.'\"'\" See the file "license.terms" for information on usage and redistribution'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.'\" '\" SCCS: @(#) send.n 1.18 96/08/27 13:21:47'\" .so man.macros.TH send n 4.0 Tk "Tk Built-In Commands".BS'\" Note:  do not modify the .SH NAME line immediately below!.SH NAMEsend \- Execute a command in a different application.SH SYNOPSIS\fBsend ?\fIoptions\fR? \fIapp cmd \fR?\fIarg arg ...\fR?.BE.SH DESCRIPTION.PPThis command arranges for \fIcmd\fR (and \fIarg\fRs) to be executed in theapplication named by \fIapp\fR.  It returns the result orerror from that command execution.\fIApp\fR may be the name of any application whose main window ison the display containing the sender's main window;  it need notbe within the same process.If no \fIarg\fR arguments are present, then the command to be executed iscontained entirely within the \fIcmd\fR argument.  If one ormore \fIarg\fRs are present, they are concatenated to form thecommand to be executed, just as for the \fBeval\fR command..PPIf the initial arguments of the command begin with ``\-''they are treated as options.  The following options arecurrently defined:.TP\fB\-async\fRRequests asynchronous invocation.  In this case the \fBsend\fRcommand will complete immediately without waiting for \fIcmd\fRto complete in the target application;  no result will be availableand errors in the sent command will be ignored.If the target application is in the same process as the sendingapplication then the \fB\-async\fR option is ignored..TP\fB\-displayof\fR \fIpathName\fRSpecifies that the target application's main window is on the displayof the window given by \fIpathName\fR, instead of the display containingthe application's main window..TP\fB\-\|\-\fRServes no purpose except to terminate the list of options.  Thisoption is needed only if \fIapp\fR could contain a leading ``\-''character..SH "APPLICATION NAMES".PPThe name of an application is set initially from the name of theprogram or script that created the application.You can query and change the name of an application with the\fBtk appname\fR command..SH "DISABLING SENDS".PPIf the \fBsend\fR command is removed from an application (e.g.with the command \fBrename send {}\fR) then the applicationwill not respond to incoming send requests anymore,  nor will itbe able to issue outgoing requests.Communication can be reenabled by invoking the \fBtk appname\fRcommand..SH SECURITY.PPThe \fBsend\fR command is potentially a serious security loophole,since any application that can connect to your X server can sendscripts to your applications.These incoming scripts can use Tcl to read andwrite your files and invoke subprocesses under your name.Host-based access control such as that provided by \fBxhost\fRis particularly insecure, since it allows anyone with an accounton particular hosts to connect to your server, and if disabled itallows anyone anywhere to connect to your server.In order to provide at least a small amount ofsecurity, Tk checks the access control being used by the serverand rejects incoming sends unless (a) \fBxhost\fR-style access controlis enabled (i.e. only certain hosts can establish connections) and (b) thelist of enabled hosts is empty.This means that applications cannot connect to your server unlessthey use some other form of authorizationsuch as that provide by \fBxauth\fR..SH KEYWORDSapplication, name, remote execution, security, send