lassign list var ?var...?
Assign successive elements of a list to specified
variables. If there are more variable names than
fields, the remaining variables are set to the
empty string. If there are more elements than
variables, a list of the unassigned elements is
returned.
For example,
lassign {dave 100 200 {Dave Foo}} name uid gid longName
Assigns name to ``dave'', uid to ``100'', gid to
``200'', and longName to ``Dave Foo''.
This command is provided by Extended Tcl.