如何使用批处理文件中if-clause中的括号转义变量？ [英] How to escape variables with parentheses inside if-clause in a batch file?

问题描述

运行此批处理文件

  @echo off 
设置a =某些值（括号内）
如果1 == 1（
设置PATH =％a％
）
  

给里面是意外的。错误

如何逃避 a 变量以避免此错误

解决方案

您可以使用两种不同的方式

使用设置的扩展语法与引号设置var = content将设置var与内容，
内容被引用，所以特殊字符没有问题，它使用的内容，直到最后一个报价（没有报价本身）

  @echo off 
设置a =一些值（括号内）
如果1 == 1（
设置PATH =％a％
）
  

使用延迟扩展（如shf301的答案），但也将该值转移到主范围。

  @echo off 
 setlocal en abledelayedexpansion 
设置a =某些值（$括号内）
如果1 == 1（
设置localScope_PATH =！a！
 rem现在将其传输到全局范围
 FOR / Fdelims =%% A in（！localScope_PATH！）DO（
 endlocal 
 setpath = %% A
）
） 
  

在这种情况下，扩展集语法不是必需的，我仅使用它来避免隐藏的空格

编辑：
我可以将其与setlocal EnableDelayedExpansion结合使用！而不是％懒惰评估变量的值？当我试过我得到）！在这个时候是意想不到的。

你可以，但它是有争议的，因为

  @echo off 
 Setlocal EnableDelayedExpansion 
设置a =一些值（括号内）
如果1 == 1（
设置PATH =！a ：^）= ^^^）！ 
设置路径
）
  

然后，您的路径在 c code code code code code code code $ c $ $ b

要了解扩展的工作原理，您可以阅读 SO：Windows Command Interpreter（CMD.EXE）如何解析脚本？

EDIT2：路径更多的问题（含引号）

根据此问题当路径包含引号时，可能会出现括号中的另一个问题。

示例

path = C：\程序文件（x86）; C：\程序文件（x86）\Skype

没有必要在这里使用引号，但这会破坏扩展的 SET synt斧头，如现在设置newPath =％路径％展开为

  setnewPath =C：\Program Files（x86）; C：\Program Files（x86）\Skype
  

现在至少有一个括号不在引号内，可以打破命令块。

但是你可以简单地删除所有的引号路径变量，如上所述，这里不需要引号。

  setnewPath =％path：=％
  

Running this batch file

@echo off
set a=some value with (parentheses) inside
if 1 == 1 (
    set PATH=%a%
)

gives inside was unexpected at this time. error.

How to escape a variable to avoid this error?

解决方案

You can use two different ways

Use the extended syntax of set with quotes set "var=content" will set var with content, content is quoted so special characters aren't problematic and it uses the content till the last quote (without the quote itself)

@echo off
set a=some value with (parentheses) inside
if 1 == 1 (
    set "PATH=%a%"
)

Use delayed expansion (like the answer of shf301) but also transfer the value to the main scope.

@echo off
setlocal enabledelayedexpansion
set a=some value with (parentheses) inside
if 1 == 1 (
    set "localScope_PATH=!a!"
    rem now transfer it to the global scope
    FOR /F "delims=" %%A in ("!localScope_PATH!") DO (
       endlocal
       set "path=%%A"
    )
)

In this case the extended set-syntax is not necessary, I used it only to avoid hidden spaces at the line end.

EDIT: Can I combine this with setlocal EnableDelayedExpansion and using ! instead of % to lazy evaluate variable's value? When I tried I got )! was unexpected at this time.

You can, but it's contra productive, as

@echo off
Setlocal EnableDelayedExpansion
set a=some value with (parentheses) inside
if 1 == 1 (
    set PATH=!a:^)=^^^)!
    set path
)

Then your path contains carets in front of the ) like C:\programs (x86^)

To understand how expansion works you can read SO:How does the Windows Command Interpreter (CMD.EXE) parse scripts?

EDIT2: More problems with the path (containing quotes)
According to this question there can occour another problem with parenthesis when the path contains quotes.

Sample
path="C:\Program Files (x86)";C:\Program Files (x86)\Skype

This is allowed, even it's not necessary to use quotes here, but this destroys the extended SET syntax, as now set "newPath=%path%" expands to

set "newPath="C:\Program Files (x86)";C:\Program Files (x86)\Skype"

Now at least one parenthesis is not inside quotes and is able to break a command block.

But you can simply remove all quotes from the path variable, as said, quotes aren't necessary here.

set "newPath=%path:"=%"

这篇关于如何使用批处理文件中if-clause中的括号转义变量？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！