在`的delims`选择逃避双引号'为/ F` [英] Escaping double-quote in `delims` option of `for /F`
问题描述
我有一点麻烦的批处理脚本,需要一个出配置文件的解析值到一个变量。
I'm having a bit of trouble with a batch script which needs to parse a value out of an config file into a variable.
适当匿名,该文件的相关行看起来像
Suitably anonymised, the relevant line of the file looks like
<?define ProductShortName="Foo" ?>
我要设置为富
的变量。字符串 ProductShortName
是唯一的,足以获得与 FINDSTR
行,但后来我不得不提取价值。正确的做法似乎是 FOR / F
,但所有的下列给出错误的:
I want to set a variable to Foo
. The string ProductShortName
is unique enough to get the line with findstr
, but then I have to extract the value. The correct approach seems to be for /F
, but all of the following give errors:
for /F "delims=^" usebackq" %%G in (`findstr /L "ProductShortName" "%~dp0Installer\Branding.wxi"`)
for /F "delims="" usebackq" %%G in (`findstr /L "ProductShortName" "%~dp0Installer\Branding.wxi"`)
for /F "delims=\" usebackq" %%G in (`findstr /L "ProductShortName" "%~dp0Installer\Branding.wxi"`)
for /F 'delims=^" usebackq' %%G in (`findstr /L "ProductShortName" "%~dp0Installer\Branding.wxi"`)
for /F 'delims=" usebackq' %%G in (`findstr /L "ProductShortName" "%~dp0Installer\Branding.wxi"`)
for /F "delims=" usebackq" %%G in (`findstr /L "ProductShortName" "%~dp0Installer\Branding.wxi"`)
主要是沿着线
usebackq" %G in (`findstr /L "ProductShortName" "C:\foo\bar\Installer\Branding.wxi"`) was unexpected at this time.
什么是逃避它分裂的字符串的正确方法?
推荐答案
您可以使用双引号作为分隔符语法如下:
You can use the double quotation mark as a delimiter with syntax like:
FOR /F delims^=^"^ tokens^=2 %G IN ('echo I "want" a "pony"') DO @ECHO %G
在命令行中运行,使用标记^ = 2
应该给你希望
和4令牌获取你一匹小马。
When run on the command line, using tokens^=2
should give you want
, and 4 tokens gets you a pony.
应用这一技术去你原来的问题,这应该在批处理文件中工作:
Applying the technique to your original question, this should work in your batch file:
FOR /F delims^=^"^ tokens^=2 %%G IN ('FINDSTR /L "ProductShortName" "data.txt"')
详细信息
I'm no expert on quirks of the command line parser, but it may help to think of the usual "delims=blah tokens=blah"
as a single, combined argument passed to FOR. The caret escaping trick in delims^=blah^ tokens^=blah
bypasses the need for enclosing quotes while still treating the sequence as a single argument. I've used a bit of creative analogy here, and the effect isn't universal across the shell. E.g. you can't do dir C:^\Program^ Files
(which makes sense since ^
is a valid filename character).
测试用例
有足够转义,您可以快速检查你的原始样本在命令行上:
With sufficient escaping, you can quickly check your original sample on the command line:
FOR /F delims^=^"^ tokens^=2 %G IN ('echo ^^^<?define ProductShortName="Foo" ?^^^>') DO @ECHO %G
其他玩这个可能要创建一个文件的 testcases.txt
blah blah "red"
blah "green" blah
How about a "white" "unicorn"?
和运行是这样的:
FOR /F delims^=^"^ tokens^=2 %G IN (testcases.txt) DO @ECHO %G
检查结果的各种投入。在这种情况下,应产生
to check results for a variety of inputs. In this case it should yield:
red
green
white
最后一个例子:
FOR /F delims^=^"^ tokens^=2 %G IN ('FINDSTR /L "unicorn" "testcases.txt"') ^
DO @ECHO The unicorn is %G.
最后,注意我测试这是Windows Server 2003上完成的。
Finally, note my testing for this was done on Windows Server 2003.
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