tcl7.6 User Commands - global






NAME

     global - Access global variables


SYNOPSIS

     global varname ?varname ...?





DESCRIPTION

     This command is ignored unless  a  Tcl  procedure  is  being
     interpreted.   If so then it declares the given varname's to
     be global variables rather than local ones.  For  the  dura-
     tion  of  the current procedure (and only while executing in
     the current procedure), any reference to any of the varnames
     will refer to the global variable by the same name.

     Global variables are  found  with  respect  to  the  current  |
     namespace  context.   To  access global variables in another  |
     namespace, simply include namespace qualifiers in  the  var-  |
     name arguments.  For example,                                 |

         set x "ignored"                                           |
         set y 1                                                   |

         namespace foo {                                           |
             variable x 0                                          |
             variable y "ignored"                                  |

             proc checkx {} {                                      |
                 global x                                          |
                 return $x                                         |
             }                                                     |
             proc checky {} {                                      |
                 global ::y                                        |
                 return $y                                         |
             }                                                     |
         }                                                         |

     The command "foo::checkx" will return the value of  "foo::x"  |
     which  is  "0".   The  command "foo::checky" will return the  |
     value of "::y" which is "1".



KEYWORDS

     global, procedure, variable