if [ $# \> 1 ]; then echo usage $0 [field] >&1; exit 1; fi
if [ $# = 1 ]; then FIELD=$1; else FIELD=1; fi
process N '
my $branch = $row['`expr $FIELD - 1`'];
$branch =~ s/\.([^\.]+)$//;
my $revision = $1;
$branch =~ s/\.0$/.$revision/ and $revision = "";
unshift @row, $branch, $revision;
'