commandline session
$true $true $? $echo $? 0 $false $echo $? 1 $echo $? 0 $echo $? 0 $false ; true $echo $? 0 $true ; false ; echo $? 1 $true ; false ; echo $? 1 $true ; false ; echo $? 1 $true ; false ; echo $? ; echo $? 1 0 $true ; false ; echo $? ; echo $? 1 0 $echo $? 0 $echo $@ $echo $@ $tru true truncate trust $true $echo $@ $echo @ @ $