blocks|key|3732852|text|你应该用反斜杠逃避它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3732853|$+./script.sh+arg1+\"\"|code-block|syntax|javascript|3732854|可进行测试，例如在回波上：|3732855|$+echo+\"\"
""|3732856|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You shall escape it using backslash

<pre><code>$ ./script.sh arg1 \"\"
</code></pre>

Can be tested e.g. on echo:

<pre><code>$ echo \"\"
""
</code></pre>

blocks|key|3732885|text|用反斜杠或单引号将它们转义。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3732886|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Escape them with backslashes or put them in single quotes.

blocks|key|3732939|text|您还可以将它们放入单引号中，以获得它们的字面值，例如：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3732940|++]$+echo+'""'
++""|code-block|syntax|javascript|3732941|例如，在脚本中：|3732942|+++]#+cat+a.bash
+++++#!/bin/bash++++++++
+++++echo+a$1b

++]$+./a.sh+'""'
++a""b

++]$+./a.sh+""
++ab|3732943|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You can also put them inside a single quote to have their literal values, e.g. : 

<pre><code> ]$ echo '""'
 ""
</code></pre>

For example, in a script:

<pre><code> ]# cat a.bash
 #!/bin/bash 
 echo a$1b

 ]$ ./a.sh '""'
 a""b

 ]$ ./a.sh ""
 ab
</code></pre>

blocks|key|919415|text|补充Kaz's+helpful+explanation|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|919416|如果您将"$@"+传递给，则+空的参数将被传递，太了。|style|BOLD|CODE|919417|#!/bin/bash

/home/myapp+"$@"|code-block|syntax|javascript|919418|通过"$@"传递的原始参数与传入的参数完全相同-即使是作为空字符串传递的参数(例如，''、""或"$someVar"传递，其中变量someVar未设置或包含空字符串)。|919419|919420|如果可能存在，则多个参数()|919421|#!/bin/bash

#+Copy+the+(up+to)+first+2+arguments+-+whether+they're+empty+strings+or+not+-
#+to+a+separate+array.
firstTwo=("${@:1:2}")+
shift;+shift++#+Remove+the+first+2+arguments+from+the+arguments+array.

#+Invoke+the+app+with+the+(up+to)+first+2+arguments+stored+in+the+new+array.
/home/myapp+"${firstTwo[@]}"

#+Process+the+remaining+arguments,+if+any.
for+a;+do
++echo+"remaining:+[$a]"
done|919422|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/23306094/45375^0|2|P|0|0|4|4|9|5|F|A|4|4|0|0|2|4|16|2|19|2|1C|A|1T|7|0|0|6|7|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@$A|13|B|14|1|15]]|C|$]]|$1|D|3|E|5|6|7|16|8|@$A|17|B|18|F|G]|$A|19|B|1A|F|G]|$A|1B|B|1C|F|G]|$A|1D|B|1E|F|H]]|9|@]|C|$]]|$1|I|3|J|5|K|7|1F|8|@]|9|@]|C|$L|M]]|$1|N|3|O|5|6|7|1G|8|@$A|1H|B|1I|F|H]|$A|1J|B|1K|F|H]|$A|1L|B|1M|F|H]|$A|1N|B|1O|F|H]|$A|1P|B|1Q|F|H]]|9|@]|C|$]]|$1|P|3|-4|5|6|7|1R|8|@]|9|@]|C|$]]|$1|Q|3|R|5|6|7|1S|8|@$A|1T|B|1U|F|G]]|9|@]|C|$]]|$1|S|3|T|5|K|7|1V|8|@]|9|@]|C|$L|M]]|$1|U|3|-4|5|6|7|1W|8|@]|9|@]|C|$]]]|V|$W|$5|X|Y|Z|C|$10|11]]]]

To complement <a href="https://stackoverflow.com/a/23306094/45375">Kaz's helpful explanation</a>: 
If you pass <code>"$@"</code> through, empty arguments will be passed through, too:

<pre><code>#!/bin/bash

/home/myapp "$@"
</code></pre>

Passing through <code>"$@"</code> preserves the original arguments exactly as passed in - even arguments passed as empty strings (passed as, e.g., <code>''</code> or <code>""</code> or <code>"$someVar"</code>, where variable <code>someVar</code> is unset or contains an empty string).

<hr>

In case there can be more than 2 arguments:

<pre><code>#!/bin/bash

# Copy the (up to) first 2 arguments - whether they're empty strings or not -
# to a separate array.
firstTwo=("${@:1:2}") 
shift; shift # Remove the first 2 arguments from the arguments array.

# Invoke the app with the (up to) first 2 arguments stored in the new array.
/home/myapp "${firstTwo[@]}"

# Process the remaining arguments, if any.
for a; do
 echo "remaining: [$a]"
done
</code></pre>

blocks|key|3733002|text|您正在正确地将空字符串参数传递给脚本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3733003|是脚本搞砸了它：|3733004|#!/bin/bash
/home/myapp+$1+$2|code-block|syntax|javascript|3733005|这个脚本并不能保护$1和$2的扩展不受分字的影响。这意味着如果$1和$2包含多个单词，它们就会变成单独的参数，如果它们中的任何一个扩展到零，它们就会消失。|offset|length|style|CODE|3733006|这应该是：|3733007|#!/bin/bash
/home/myapp+"$1"+"$2"|3733008|通常，您可以让脚本将其所有参数传递给被调用的程序，如下所示：|3733009|/home/myapp+"$@"|3733010|引号只是shell语法；它们不是参数数据本身的一部分。当您在shell中输入program+""时，在操作系统级别上，程序会收到一个空C语言字符串:指向空字节的指针。没有引号。|3733011|您可以传递参数""+(由两个双引号组成的两个字符字符串)，但这不是一个空参数。一种方法是，例如，'""'：用单引号包装它。|3733012|这样做的唯一原因是当您在元级别上操作shell语法时:传递shell脚本源代码的片段，比如引用的令牌，空的或其他的。shell有一个名为eval的命令，它将源代码作为参数(或多个参数)并计算它。|3733013|empty_shell_string_syntax='""'++++#+this+variable+holds+the+characters+""

eval+empty_var=$empty_shell_string_syntax+++#+empty_var+gets+set+to+empty+string|3733014|在调用eval之前，命令行要进行扩展。该展开移除语法$empty_shell_string_sytnax，并将其替换为内容、字符""。然后eval获得字符串empty_var=""。它计算这一点，因此empty_var被设置为空字符串，正如语法所示。|3733015|entityMap^0|0|0|0|9|2|C|2|V|2|Y|2|0|0|0|0|0|12|A|0|7|2|1C|4|0|1W|4|0|0|3|4|Q|Q|1S|2|26|C|2S|9|0^^$0|@$1|2|3|4|5|6|7|18|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|19|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1A|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|1B|8|@$K|1C|L|1D|M|N]|$K|1E|L|1F|M|N]|$K|1G|L|1H|M|N]|$K|1I|L|1J|M|N]]|9|@]|A|$]]|$1|O|3|P|5|6|7|1K|8|@]|9|@]|A|$]]|$1|Q|3|R|5|F|7|1L|8|@]|9|@]|A|$G|H]]|$1|S|3|T|5|6|7|1M|8|@]|9|@]|A|$]]|$1|U|3|V|5|F|7|1N|8|@]|9|@]|A|$G|H]]|$1|W|3|X|5|6|7|1O|8|@$K|1P|L|1Q|M|N]]|9|@]|A|$]]|$1|Y|3|Z|5|6|7|1R|8|@$K|1S|L|1T|M|N]|$K|1U|L|1V|M|N]]|9|@]|A|$]]|$1|10|3|11|5|6|7|1W|8|@$K|1X|L|1Y|M|N]]|9|@]|A|$]]|$1|12|3|13|5|F|7|1Z|8|@]|9|@]|A|$G|H]]|$1|14|3|15|5|6|7|20|8|@$K|21|L|22|M|N]|$K|23|L|24|M|N]|$K|25|L|26|M|N]|$K|27|L|28|M|N]|$K|29|L|2A|M|N]]|9|@]|A|$]]|$1|16|3|-4|5|6|7|2B|8|@]|9|@]|A|$]]]|17|$]]

You are correctly passing an empty string argument to the script.

It is the script that is messing it up:

<pre><code>#!/bin/bash
/home/myapp $1 $2
</code></pre>

The script is not protecting the expansion of <code>$1</code> and <code>$2</code> from word-splitting. This means that if <code>$1</code> and <code>$2</code> contain multiple words, those turn into individual arguments, and if either of them expand to nothing, they simply disappear.

This should be:

<pre><code>#!/bin/bash
/home/myapp "$1" "$2"
</code></pre>

In general, you can make your script pass all of its arguments to the invoked program, like this:

<pre><code>/home/myapp "$@"
</code></pre>

The quotes are just shell syntax; they are not part of the argument data itself. When you type <code>program ""</code> into the shell, at the operating system level, the program receives an empty C language string: a pointer to a null byte. There are no quotes.

You can pass the argument <code>""</code> (a two-character string made of two double quotes) but that is not an empty argument. A way to do that is, for instance, <code>'""'</code>: wrap it in single quotes.

The only reason to do things like that is when you're manipulating shell syntax at a meta-level: passing around pieces of shell script source code, such as quoted tokens, empty or otherwise. The shell has a command called <code>eval</code> which takes source code as an argument (or multiple arguments) and evaluates it.

<pre><code>empty_shell_string_syntax='""' # this variable holds the characters ""

eval empty_var=$empty_shell_string_syntax # empty_var gets set to empty string
</code></pre>

before <code>eval</code> is invoked, the command line is subject to expansion. That expansion removes the syntax <code>$empty_shell_string_sytnax</code> and replaces it with the contents, the characters <code>""</code>. So then eval gets the string <code>empty_var=""</code>. It evaluates this, and so <code>empty_var</code> is set to the empty string, as the syntax indicates.

blocks|key|3733034|text|试试这个：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3733035|cmd=yourcomand;
n=0;+for+a+in+"$@";+do+n=$((n+%2B1));+cmd="$cmd+\${$n%2B\"\$$n\"}";+done
eval+$cmd|code-block|syntax|javascript|3733036|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Try this:

<pre><code>cmd=yourcomand;
n=0; for a in "$@"; do n=$((n +1)); cmd="$cmd \${$n+\"\$$n\"}"; done
eval $cmd
</code></pre>

I'm trying to write a script that will accept as additional arguments on the command line an empty string with double quotes. I want the script to pass those arguments along with the double quoted empty string if that is provided, but instead the command interpreter seems to interpret such an argument as an empty string and strips away the quotes. Is there any way to do this? 

As a simple example I would have in the file script.sh:

<pre><code>#!/bin/bash
/home/myapp $1 $2
</code></pre>

If I run at the prompt:

<pre><code>$ ./script.sh arg1 ""
</code></pre>

The script just executes <code>"/home/myapp arg1"</code>, but misses/ignores the second argument <code>("")</code>. I want it to preserve this empty string and instead execute: <code>/home/myapp arg1 ""</code>

How do I pass an empty string with double quotes to a bash script?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我正在尝试编写一个脚本，它将在命令行中接受带有双引号的空字符串作为附加参数。我希望脚本将这些参数与双引号空字符串一起传递，但命令解释器似乎将这种参数解释为空字符串，并删除引号。有办法这样做吗？作为一个简单的例子，我将在文件script.sh中获得：#!/bin/bash/home/myapp $1 $2如果我按提示运行...

问如何将带有双引号的空字符串传递给bash脚本？
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何将带有双引号的空字符串传递给bash脚本？EN