global(3tcl) Tcl Built-In Commands global(3tcl)
______________________________________________________________________________
NAME
global - Access global variables
SYNOPSIS
global ?varname ...?
______________________________________________________________________________
DESCRIPTION
This command has no effect unless executed in the context of a proc
body. If the global command is executed in the context of a proc body,
it creates local variables linked to the corresponding global variables
(though these linked variables, like those created by upvar, are not
included in the list returned by info locals).
If varname contains namespace qualifiers, the local variable's name is
the unqualified name of the global variable, as determined by the name-
space tail command.
varname is always treated as the name of a variable, not an array ele-
ment. An error is returned if the name looks like an array element,
such as a(b).
EXAMPLES
This procedure sets the namespace variable ::a::x
proc reset {} {
global a::x
set x 0
}
This procedure accumulates the strings passed to it in a global buffer,
separated by newlines. It is useful for situations when you want to
build a message piece-by-piece (as if with puts) but send that full
message in a single piece (e.g. over a connection opened with socket or
as part of a counted HTTP response).
proc accum {string} {
global accumulator
append accumulator $string \n
}
SEE ALSO
namespace(3tcl), upvar(3tcl), variable(3tcl)
KEYWORDS
global, namespace, procedure, variable
Tcl global(3tcl)
Generated by dwww version 1.14 on Thu Jan 23 00:14:33 CET 2025.