set data {12 3.45 1.665 345}
set RE {(?:^|[^0-9.])(\d+)(?!\.?\d)}
set matches [regexp -all -inline -- $RE $data]
foreach {- group1} $matches {
puts "$group1"
}
c2V0IGRhdGEgezEyICAzLjQ1IDEuNjY1IDM0NX0Kc2V0IFJFIHsoPzpefFteMC05Ll0pKFxkKykoPyFcLj9cZCl9CnNldCBtYXRjaGVzIFtyZWdleHAgLWFsbCAtaW5saW5lIC0tICRSRSAkZGF0YV0KZm9yZWFjaCB7LSBncm91cDF9ICRtYXRjaGVzIHsKICAgcHV0cyAiJGdyb3VwMSIKfQoK