on [<modes>]list [<serial#>] [-|^]<match> { <action> }

This hook is triggered whenever the client receives server output from the LIST command. Any individual line of output can trigger the hook.

To limit output to channels with a topic:

 on ^list "*" {
    if ( [$2] ) {
       xecho -b $[$CHANNEL_NAME_WIDTH]0 $[-2]1 $2-
    }
 }