set myresponse [exec -keepnewline bash -c {for i in $log.*; do
$command $params $i
done}]
Or, assuming you want $i to be related to "for i" and $log,$command,
and $params to be your tcl variables
set myresponse [exec -keepnewline bash -c "for i in $log.*; do
$command $params $i
done"]
