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common sense > what does brackets mean?

admin 11月 13, 2020 0

Intro : The types of brackets.

<> : angle brackets.
[] : square brackets.
() : round brackets, called parentheses.
{} : curly brackets.

Usage Message : brackets are commonly used like this.

<> : positional arguments.
- Usage : my_program <host> <port>
[] : optional argument(s).
() : required arguments by default. (explicit).
{} : required argument from mutually exclusive arguments.

Example

Usage: program [-aDde] [-f | -g] [-n number] [-b b_arg | -c c_arg] req1 req2 [opt1 [opt2]]

options w/o operands: a, D, d, e.
exclusive options : f, g with vertical bar.
options with operands : n.
required arguments : req1, req2.

Reference