批处理文件：变量中的变量(Batch file: Variable within a variable)

批处理文件：变量中的变量(Batch file: Variable within a variable)

我有一个复杂的字符串，我正在尝试解析。 我有一个简短的子程序来细化两个特定字符的索引，我需要在它们之间的字符串。 所以问题是：如何在另一个变量的字符串操作中使用变量？

这是一些示例代码：

@ECHO off set start=2 set end=5 set str=Hello World echo %str:~2,5% echo %str:~%start%,%end%%

如何获取第二个回波以显示第一个回波显示的内容？ （现在第二个回声只显示我想要的东西，它会崩溃）

I have a complex string I'm trying to parse. I have a short subroutine to fine the index of two specific characters, and I need the string in between. So the question is: How do I use variables inside string manipulation of another variable?

Here's some sample code:

@ECHO off set start=2 set end=5 set str=Hello World echo %str:~2,5% echo %str:~%start%,%end%%

How do I get the second echo to display what the first echo displays? (right now second echo is just showing what I want, it'll crash as is)

最满意答案

@ECHO off set start=2 set end=5 set str=Hello World setlocal enableDelayedExpansion echo %str:~2,5% echo !str:~%start%,%end%! endlocal

或（最坏的方式）

@ECHO off set start=2 set end=5 set str=Hello World echo %str:~2,5% call echo %%str:~%start%,%end%%%

或（如果开始和结束定义以及子字符串都在括号上下文中，则可以使用）

@ECHO off set start=2 set end=5 set str=Hello World echo %str:~2,5% setlocal enableDelayedExpansion for /f "tokens=1,2" %%a in ("%start% %end%") do echo !str:~%%a,%%b! endlocal

或者（也是一种糟糕的方式）

@ECHO off set start=2 set end=5 set str=Hello World call :substr "%str%" %start% %end% goto :eof :substr setlocal enableDelayedExpansion set "_str=%~1" echo !_str:~%2,%3! rem without delayedExpansion rem call echo %%_str:~%2,%3%% endlocal goto :eof @ECHO off set start=2 set end=5 set str=Hello World setlocal enableDelayedExpansion echo %str:~2,5% echo !str:~%start%,%end%! endlocal

or (the worst way)

@ECHO off set start=2 set end=5 set str=Hello World echo %str:~2,5% call echo %%str:~%start%,%end%%%

or (can be used if start and end definition and the substringing are all in brackets context)

@ECHO off set start=2 set end=5 set str=Hello World echo %str:~2,5% setlocal enableDelayedExpansion for /f "tokens=1,2" %%a in ("%start% %end%") do echo !str:~%%a,%%b! endlocal

or (also a bad way)

@ECHO off set start=2 set end=5 set str=Hello World call :substr "%str%" %start% %end% goto :eof :substr setlocal enableDelayedExpansion set "_str=%~1" echo !_str:~%2,%3! rem without delayedExpansion rem call echo %%_str:~%2,%3%% endlocal goto :eof