global(n)

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NAME

       global - Access global variables

SYNOPSIS

       global varname ?varname ...?
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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
       (and therefore these variables are listed 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
       namespace tail command.

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(n), upvar(n), variable(n)

KEYWORDS

       global, namespace, procedure, variable

Tcl                                                                  global(n)