类型
help set
在命令行
,你会得到一个完整的描述。在for
命令的帮助下,还会记录一些信息。所以help for
会给你更多的信息。
这是“帮助设置”命令的输出的一部分:
May also specify substrings for an expansion.
%PATH:~10,5%
would expand the PATH environment variable, and then use only the 5
characters that begin at the 11th (offset 10) character of the expanded
result. If the length is not specified, then it defaults to the
remainder of the variable value. If either number (offset or length) is
negative, then the number used is the length of the environment variable
value added to the offset or length specified.
%PATH:~-10%
would extract the last 10 characters of the PATH variable.
%PATH:~0,-2%
would extract all but the last 2 characters of the PATH variable.
谢谢!忘了帮助指令太哈哈 – user1229895 2012-04-18 07:07:52