set f [open $database_fn r]
if {[string compare [db_getsl $f] $database_header]} { error "$l ?" }
if {([db_getsl $f])+0 != $rows} { error "wrong h ?" }
set f [open $database_fn r]
if {[string compare [db_getsl $f] $database_header]} { error "$l ?" }
if {([db_getsl $f])+0 != $rows} { error "wrong h ?" }