blocks|key|3787763|text|尝试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3787764|zero=0;

if+[[+$depth+-eq+$zero+]];+then
++echo+"false";
++exit;
fi|code-block|syntax|javascript|3787765|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: 

<pre><code>zero=0;

if [[ $depth -eq $zero ]]; then
 echo "false";
 exit;
fi
</code></pre>

blocks|key|1676782|text|双括号((+...+))用于算术运算。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1676783|双方括号[[+...+]]可用于比较和检查数字(仅支持整数)，运算符如下：|1676784|·+NUM1+-eq+NUM2+returns+true+if+NUM1+and+NUM2+are+numerically+equal.

·+NUM1+-ne+NUM2+returns+true+if+NUM1+and+NUM2+are+not+numerically+equal.

·+NUM1+-gt+NUM2+returns+true+if+NUM1+is+greater+than+NUM2.

·+NUM1+-ge+NUM2+returns+true+if+NUM1+is+greater+than+or+equal+to+NUM2.

·+NUM1+-lt+NUM2+returns+true+if+NUM1+is+less+than+NUM2.

·+NUM1+-le+NUM2+returns+true+if+NUM1+is+less+than+or+equal+to+NUM2.|code-block|syntax|javascript|1676785|例如|1676786|if+[[+$age+>+21+]]+#+bad,+>+is+a+string+comparison+operator

if+[+$age+>+21+]+#+bad,+>+is+a+redirection+operator

if+[[+$age+-gt+21+]]+#+okay,+but+fails+if+$age+is+not+numeric

if+((+$age+>+21+))+#+best,+$+on+age+is+optional|1676787|entityMap^0|3|9|0|4|9|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|Z|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

Double parenthesis <code>(( ... ))</code> is used for arithmetic operations.

Double square brackets <code>[[ ... ]]</code> can be used to compare and examine numbers (only integers are supported), with the following operators:

<pre><code>· NUM1 -eq NUM2 returns true if NUM1 and NUM2 are numerically equal.

· NUM1 -ne NUM2 returns true if NUM1 and NUM2 are not numerically equal.

· NUM1 -gt NUM2 returns true if NUM1 is greater than NUM2.

· NUM1 -ge NUM2 returns true if NUM1 is greater than or equal to NUM2.

· NUM1 -lt NUM2 returns true if NUM1 is less than NUM2.

· NUM1 -le NUM2 returns true if NUM1 is less than or equal to NUM2.
</code></pre>

For example

<pre><code>if [[ $age &gt; 21 ]] # bad, &gt; is a string comparison operator

if [ $age &gt; 21 ] # bad, &gt; is a redirection operator

if [[ $age -gt 21 ]] # okay, but fails if $age is not numeric

if (( $age &gt; 21 )) # best, $ on age is optional
</code></pre>

blocks|key|5205601|text|您可以尝试这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5205602|:+${depth?"Error+Message"}+##+when+your+depth+variable+is+not+even+declared+or+is+unset.|code-block|syntax|javascript|5205603|注意:这里只是depth之后的?。|offset|length|style|CODE|5205604|或|5205605|:+${depth:?"Error+Message"}+##+when+your+depth+variable+is+declared+but+is+null+like:+"depth=".+|5205606|注意:这里是depth之后的:?。|5205607|在这里，如果发现变量depth为null，它将打印错误消息，然后退出。|5205608|entityMap^0|0|0|7|5|F|1|0|0|0|6|5|E|2|0|A|5|G|4|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]|$I|11|J|12|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|15|8|@$I|16|J|17|K|L]|$I|18|J|19|K|L]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1A|8|@$I|1B|J|1C|K|L]|$I|1D|J|1E|K|L]]|9|@]|A|$]]|$1|U|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|V|$]]

You can try this:

<pre><code>: ${depth?"Error Message"} ## when your depth variable is not even declared or is unset.
</code></pre>

NOTE: Here it's just <code>?</code> after <code>depth</code>.

or

<pre><code>: ${depth:?"Error Message"} ## when your depth variable is declared but is null like: "depth=". 
</code></pre>

NOTE: Here it's <code>:?</code> after <code>depth</code>.

Here if the variable <code>depth</code> is found <code>null</code> it will print the error message and then exit.

blocks|key|1676830|text|具体来说：((depth))。通过示例，下面的代码打印1。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1676831|declare+-i+x=0
((x))+&&+echo+$x

x=1
((x))+&&+echo+$x|code-block|syntax|javascript|1676832|entityMap^0|5|9|R|1|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Specifically: <code>((depth))</code>. By example, the following prints <code>1</code>.

<pre><code>declare -i x=0
((x)) &amp;&amp; echo $x

x=1
((x)) &amp;&amp; echo $x
</code></pre>

blocks|key|5205637|text|您还可以使用此格式并使用比较运算符，如'==‘'<=’|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5205638|++if+((+$total+==+0+));+then
++++++echo+"No+results+for+${1}"
++++++return
++fi|code-block|syntax|javascript|5205639|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|$]]

you can also use this format and use comparison operators like '==' '&lt;='

<pre><code> if (( $total == 0 )); then
 echo "No results for ${1}"
 return
 fi
</code></pre>

I have a bash variable depth and I would like to test if it equals 0. In case yes, I want to stop executing of script. So far I have:

<pre><code>zero=0;

if [ $depth -eq $zero ]; then
 echo "false";
 exit;
fi
</code></pre>

Unfortunately, this leads to:

<pre><code> [: -eq: unary operator expected
</code></pre>

(might be a bit inaccurate due to translation)

Please, how can I modify my script to get it working?

Check if bash variable equals 0

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

我有一个bash变量depth，我想测试它是否等于0。如果是，我想停止执行脚本。到目前为止，我有：zero=0;if [ $depth -eq $zero ]; then    echo "false";    exit;fi不幸的是，这会导致： [: -eq: unary operator expected(由于翻译...

问检查bash变量是否等于0
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

问检查bash变量是否等于0EN