nish [OPTIONS] [-s
              local-schema-file] -c
            connection-file
          You can specify the absolute or relative path to the connections
            file with the -c flag or --connection-file, in
            a NISH rc file or in an environment variable; see NISH rc files. In this case, the
              nish command can be entered without this argument. Arguments
            defined in the NISH rc file or using the environment variable must
            be supported in the current mode of operation. If an argument for another mode of
            operation is defined, the NISH client fails and returns an error.
          Note:  If the path to the connections file is missing or incorrect,
            the NISH application starts without available nodes. The output of the command shows
            that the connections file is missing.
          The local schema file contains the details of the locally defined
            NISH MD-CLI schema; see Local schema file.  For information about the other options, see Command options.
          In the following example, the locally defined schema file is
            absent and the connections file  is present in the same directory
            as the nish command:
          
            [root@server ~]# nish -c connections-demo
           
          When the path to the connections file is present and correct and
            no local schema file is defined, NISH starts with a minimal
            built-in MD-CLI schema. This schema defines a number of standard commands and some
            MD-CLI branches. The following output shows an example:
          Starting nish application...
Reading local schema...
[==============================================================================]
[]
root@#
 connections           + Configuration of all devices.
 environment           + Enter the environment configuration context
 Global commands:
 back                  - Move back one or more levels
 delete                - Delete an element from the candidate datastore
 exec                  - Execute commands from a file
 exit                  - Return to the previous working context or to →
the operational root
 history               - Show the most recently entered commands
 logout                - Exit the CLI session
 pwc                   - Show the present working context
 top                   - Move to the top level of the context
 tree                  - Show the command tree under the present working context