'\"
'\" Copyright (c) 1993-1997 Bell Labs Innovations for Lucent Technologies
'\" Copyright (c) 1997 Sun Microsystems, Inc.
'\" Copyright (c) 2000 Scriptics Corporation.
'\" Copyright (c) 2004-2005 Donal K. Fellows.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: namespace.n,v 1.10.2.20 2009/11/10 21:59:24 dgp Exp $
'\" RCS: @(#) $Id: namespace.n,v 1.10.2.21 2009/12/30 17:24:06 dgp Exp $
'\" 
.so man.macros
.TH namespace n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
namespace \- create and manipulate contexts for commands and variables

The \fBnamespace import\fR command only imports commands
that were declared as exported by their namespace.
The \fBnamespace export\fR command specifies what commands
may be imported by other namespaces.
If a \fBnamespace import\fR command specifies a command
that is not exported, the command is not imported.
.SH "SCOPED SCRIPTS"
.PP
The \fBnamespace code\fR command is the means by which a script may be
packaged for evaluation in a namespace other than the one in which it
was created.  It is used most often to create event handlers, Tk bindings,
and traces for evaluation in the global context.  For instance, the following
code indicates how to direct a variable trace callback into the current
code indicates how to direct a variable \fBtrace\fR callback into the current
namespace:
.PP
.CS
\fBnamespace eval\fR a {
    variable b
    proc theTraceCallback { n1 n2 op } {
        upvar 1 $n1 var
        puts "the value of $n1 has changed to $var"
        return
    }
    trace variable b w [\fBnamespace code\fR theTraceCallback]
    trace add variable b write [\fBnamespace code\fR theTraceCallback]
}
set a::b c
.CE
.PP
When executed, it prints the message:
.PP
.CS