#! /usr/bin/perl

use strict;
use lib "/opt/vyatta/share/perl5/";
use Sys::Syslog qw(:standard :macros);
use XorpConfigParser;

sub xorp_write {
    my ($INFILE, $OUTFILE) = @_;

    # parse config input file
    my $xcp = new XorpConfigParser();
    $xcp->parse($INFILE);

    # write config output file
    open (my $out, '>', $OUTFILE)
    or die "Can't open $OUTFILE : $!";

    select $out;
    $xcp->output(0);
    select STDOUT;
    close $out;
}

die "xorp-write needs two args: input_file output_file"
    unless ($#ARGV == 1);

xorp_write(@ARGV);
exit 0;

└──> diff -C 2 example.config xorped.config
*** example.config      2024-05-12 19:26:59.377107781 -0500
--- xorped.config       2024-05-12 19:36:30.562143990 -0500
***************
*** 7,12 ****
          address 192.168.0.1/24
          hw-id 52:54:00:c1:df:f9
!         vif 2 {
!         }
          vif 800 {
              address 192.168.1.1/24
--- 7,11 ----
          address 192.168.0.1/24
          hw-id 52:54:00:c1:df:f9
!         vif 2
          vif 800 {
              address 192.168.1.1/24
***************
*** 16,21 ****
          }
      }
!     loopback lo {
!     }
  }
  service {
--- 15,19 ----
          }
      }
!     loopback lo
  }
  service {
***************

In [1]: from vyos.configtree import ConfigTree

In [2]: with open('./example.config') as f:
   ...:     example_config_str = f.read()
   ...: 

In [3]: example_ct = ConfigTree(example_config_str)

In [4]: example_vif = example_ct.get_subtree(['interfaces', 'ethernet', 'eth1', 'vif'], with_node=True)

In [5]: print(example_vif.to_string())
vif 2 {
}
vif 800 {
    address "192.168.1.1/24"
}
vif 801 {
    address "192.168.2.1/24"
}

In [6]: with open('./xorped.config') as f:
   ...:     xorped_config_str = f.read()
   ...: 

In [7]: xorped_ct = ConfigTree(xorped_config_str)

In [8]: xorped_vif = xorped_ct.get_subtree(['interfaces', 'ethernet', 'eth1', 'vif'], with_node=True)

In [9]: print(xorped_vif.to_string())
vif {
    800 {
        address "192.168.1.1/24"
    }
    801 {
        address "192.168.2.1/24"
    }
}