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标题: [文本处理] [已解决]批处理里面括号也需要转义吗？ [打印本页]

作者: bingxing8000 时间: 2011-9-13 10:06 标题: [已解决]批处理里面括号也需要转义吗？

在这段代码里，括号不转义的话，就会一闪而过

@echo off
(echo # This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
echo #
echo # This file contains the mappings of IP addresses to host names. Each   
echo # entry should be kept on an individual line. The IP address should
echo # be placed in the first column followed by the corresponding host name.  
echo # The IP address and the host name should be separated by at least one
echo # space.
echo #
echo # Additionally, comments ^(such as these^) may be inserted on individual
echo # lines or following the machine name denoted by a '#' symbol. 
echo # For example:
echo # 
echo #      102.54.94.97     rhino.acme.com          # source server 
echo #       38.25.63.10     x.acme.com              # x client host
echo 127.0.0.1 localhost ) >E:\1.txt
pause >nul
复制代码

以下代码中括号又不用转义

echo (dsfdf(sdfsdf)) >>e:\1.txt
复制代码

为什么会这样呢？

作者: CrLf 时间: 2011-9-13 11:08

因为未转义的括号会造成语块的错误划分，除 for 和 if 外（可以把这两个命令看成特殊的带有条件语句的语块，这解释虽不准确，但可以帮助理解…），所有命令中出现的括号都必须转义，因为它们只是命令参数的一部分，而非语块的划分符。

作者: ArdentMan 时间: 2011-9-13 11:23

我理解括号同其他特殊字符一样具有特殊的作用
所以在命令中用到括号就要跟其他特殊字符一样先进行转义
使之先成为普通字符（预处理前）
当cmd预处理时会去掉所有的转义符还原特殊字符原来的作用
从而使得命令正常进行~~~

作者: bingxing8000 时间: 2011-9-13 11:44

回复 2# CrLf

谢谢了。
针对我碰到的这个情况，应该是这样的：如下代码
(echo # Additionally, comments (such as these) may be inserted on individual)>>e:\1.txt
批处理应该是把(echo # Additionally, comments (such as these)看成是一个完整的括号，然后就出错退出了。所以需要转义。

作者: Hello123World 时间: 2011-9-14 18:20

按照2楼的说法，其实就是批处理语法太混乱，( 只跟最近的一个 ) 相结合。——但是for的嵌套 () 为什么没出现这种规律？

所以代码这么修改也行：

@echo off
(echo # This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
echo #
echo # This file contains the mappings of IP addresses to host names. Each   
echo # entry should be kept on an individual line. The IP address should
echo # be placed in the first column followed by the corresponding host name.  
echo # The IP address and the host name should be separated by at least one
echo # space.
echo #
echo # Additionally, comments (such as these^) may be inserted on individual
echo # lines or following the machine name denoted by a '#' symbol. 
echo # For example:
echo # 
echo #      102.54.94.97     rhino.acme.com          # source server 
echo #       38.25.63.10     x.acme.com              # x client host
echo 127.0.0.1 localhost ) >11.txt
pause >nul
复制代码

echo # Additionally, comments (such as these^) may be inserted on individual

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