[cmd] Notation for "mandatory" and "optional" parameters in "help shell_cmd" output

Adarsh Babu Kalepalli learn2kab at gmail.com
Sun Mar 1 14:31:26 CET 2020


When we type "help shell_command" at u-boot console.
The syntax for the command usage is displayed.

In most of the cases I noticed parameters enclosed in '[]' or/and '<>'
or just the sub-command string is provided.

>From the help of most of the commands, and on using them I observed that
parameters enclosed in
                -'[]' could be optional
                -'<>' could be mandatory

In some cases, the mandatory parameters were not enclosed in "<>" .
For ex.
            env ask name [message] [size] - ask for environment variable
            env edit name - edit environment variable
            env exists name - tests for existence of variable

in the above case "name" seems to be a mandatory parameter.

Could you please let me know the notation we follow to indicate the
mandatory and optional input parameters for shell commands in their syntax
(displayed through help) ??


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