nas - Create Reusable Session Scripts


 $ nas --help

  nas [options] [hostname or IP]

  -p, --personality  Device <personality> (default: "ios")
  -t, --transport    <transport> method (Serial, Telnet, default: SSH)
  -u, --username     <username> to connect as on device (default: $USER)
  -R, --record       Record session
  -P, --playback     Play back session
  -s, --script       When recording, save playback script to this <filename>
  -l, --cmdlog       NAS <file> to record commands to, or play them back from
  -e, --exit-last    Num. of output lines from last command is program exit status
  -c, --cloginrc     RANCID cloginrc <file> with device credentials
  -z, --nopassword   Do not ask for device password (if not using cloginrc)
  -o, --echo         Echo commands sent, when playing back the recorded script/cmdlog
  -M, --paging       Do not attempt to disable command output paging
  -B, --nobanner     Suppress display of any login banner received from the device
  -q, --quiet        Hide informational messages
  -v, --verbose      NCI log <level> ("debug", "notice", "info", etc)
  -V, --version      Display this program's version number
  -h, --help         Display this help text


Use this program to help write reusable Net::Appliance::Session scripts, play them back, and also to more easily connect to network devices.

  • Start a connection to a network device using CLI switches, and prompts for credentials. This is easier than writing short Perl programs.

  • Record a set of commands issued to one network device into a command log, then replay that log against other devices (-R -l <log> and -P -l <log>).

  • Record a session and produce a Perl script which when run, replays the session to the same host, or overridable to other devices (-R -s <script> and then run the script).

Once connected to the device you can enter any command and it will be run.


Please see the SYNOPSIS section and the command line help for the available options. In the future more documentation will be forthcoming, I promise. Here are some highlights:

The exit-last option can be useful for creating a session script which checks for some error condition. Assuming the last command should have no output on success, then the exit status of the script will be non-zero when there's a problem. Use this with -R to make a reuseable script.

To play a script with no output other than that returned from the device in response to sent commands, use the switch combination -Bqoz. Note that you will need to be able to login automatically, and RANCID config isn't yet supported.

If you don't provide a hostname or IP then the script goes into a loop waiting for the hostname on standard input. This way, you can pipe a list of device names to the script and it will execute the commands on each one.

In case you didn't know, the library has support for connecting to linux boxes using the -p bash setting to chose the Bash shell personality.

Getting to be a super-user is a little clunky at the moment. I need to work on that a little more. Take care that your scripts don't contain any passwords!


The methods of Net::Appliance::Session are available by using the command !s <method-name>. The best use of this is to gracefully disconnect, by issuing:

 !s close

You can also enter the command !m to see a list of available Macros. If you don't know what a Macro is, please move a long, there's nothing to see here. You run a Macro with the !m <macro-name> [params] command.





Oliver Gorwits <>


This software is copyright (c) 2017 by Oliver Gorwits.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.