日志

syntax conventions

已有 384 次阅读| 2016-4-2 13:06 |个人分类:杂谈

symbol	meaning	example
\|	Vertical bars(CR-bars) separate possible choices for a single argument. They take precedence over any other operators.	command argument1 \| argument2
[]	Brackets denote optional arguments. When used tihe OR-bars,they enclose a list of choices. You can choose one argument from the list.	command [argument1 \| argument2]
{}	Brace are used with OR-bars and enclose a list choices.You must choose one argument from the list.	command {argument1 \| argument2}
…	Three dots(…) indicate that you can repeate the previous argument. If they are used with brackets,you can specify zero or more argments. If the are used without brackets,you must specify at least one argument,but you can specify more.	argment … sepcify at least one [argument]… you can specify zero or more.