Creating the Subcommands to Manage Hosts
Learn how to create subcommands to manage the hosts list.
We'll cover the following
Overview
The business logic for the hosts list is ready, so let’s write the code to manage
the hosts list under the hosts
subcommand. These commands are: add
to add a new host to the list, delete
to delete a host from the list, and list
to print all hosts in the list.
These subcommands all require a file to save and load the hosts to. Before including these commands, we make a change to the root command to add a persistent flag --hosts-file
, allowing the user to specify the name of the file they want to use to save the hosts to. A persistent flag makes it available to the
command and all subcommands under that command. By adding this flag to the root command, we make it global, which makes sense in this case because all the subcommands under hosts
and later the scan
subcommand
require it.
Updating the root.go
file
To add the persistent flag, we edit the file cmd/root.go
and then add the following
line to the init()
function:
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