blocks|key|1096715|text|您的特殊问题是，在开头大括号之后需要空白，例如(适当地引用并使用所有参数)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1096716|lsr()+{+ls+-rt+"$@";+}|code-block|syntax|javascript|1096717|但是，您也可能需要考虑别名，因为这是命令开始时的替换：|1096718|alias+lsr='ls+-rt'|1096719|毕竟，有多少系统为您提供了非常方便的“长ls"，包括：|1096720|alias+ll='ls+-al'|1096721|您只需要确保在需要的特定情况下(例如在.bashrc中用于交互式shell)，或者在脚本本身开始时提供的文件中(并确保别名使用shopt+-s+expand_aliases进行扩展)就会出现这种情况。这是两种可能性，但毫无疑问还有其他的可能性。|offset|length|style|CODE|1096722|entityMap^0|0|0|0|0|0|0|J|7|1R|N|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]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|12|8|@$Q|13|R|14|S|T]|$Q|15|R|16|S|T]]|9|@]|A|$]]|$1|U|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|V|$]]

Your particular problem is that you need white space after the opening brace, such as (quoting properly and using all arguments as well)

<pre><code>lsr() { ls -rt "$@"; }
</code></pre>

But you may also want to consider an alias since this is substitution at the start of the command:

<pre><code>alias lsr='ls -rt'
</code></pre>

This is, after all, how many systems give you the very handy "long ls", with something like:

<pre><code>alias ll='ls -al'
</code></pre>

You'll just need to make sure this is present in something that's called for specific cases as needed, such as in <code>.bashrc</code> for interactive shells, or in a file sourced at the start of your script itself (and ensuring aliases are expanded with <code>shopt -s expand_aliases</code>). Those are two possibilities but there are no doubt others.

blocks|key|1094609|text|在{之后添加空格|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1094610|lsr+()+{+ls+-rt+$1;}|1094611|entityMap^0|1|1|0|0|K|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

add whitespace after <code>{</code>

<code>lsr () { ls -rt $1;}</code>

blocks|key|1384230|text|会不会是第一个"{“之后的空白？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1384231|#+bash+--version
GNU+bash,+version+4.3.42(1)-release+(i686-pc-linux-gnu)
Copyright+(C)+2013+Free+Software+Foundation,+Inc.
License+GPLv3%2B:+GNU+GPL+version+3+or+later+<http://gnu.org/licenses/gpl.html>

This+is+free+software;+you+are+free+to+change+and+redistribute+it.
There+is+NO+WARRANTY,+to+the+extent+permitted+by+law.
#
#+touch+a
#+touch+b
#+touch+c
#+ls+-rt
a++b++c
#+ls+-t
c++b++a
#
#+lsr()+{ls+-rt;}
bash:+syntax+error+near+unexpected+token+`{ls'
#+lsr()+{+ls+-rt;}
#+lsr
a++b++c|code-block|syntax|javascript|1384232|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|$]]

Could it be the missing space after the first "{" ?

<pre><code># bash --version
GNU bash, version 4.3.42(1)-release (i686-pc-linux-gnu)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later &lt;http://gnu.org/licenses/gpl.html&gt;

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
#
# touch a
# touch b
# touch c
# ls -rt
a b c
# ls -t
c b a
#
# lsr() {ls -rt;}
bash: syntax error near unexpected token `{ls'
# lsr() { ls -rt;}
# lsr
a b c
</code></pre>

blocks|key|1384355|text|如前所述，为了使函数定义工作，必须在{+后面加上空格。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|CODE|entityRanges|data|1384356|shellcheck.net是一个很好的语法检查shell代码站点，会发现这个问题的。|1384357|lsr+()+{ls+-rt+$1;}
++++++++%5E--+SC1054:+You+need+a+space+after+the+'{'.
+++++++++++++++%5E--+SC2086:+Double+quote+to+prevent+globbing+and+word+splitting.|code-block|syntax|javascript|1384358|正如您所看到的，它不仅发现了问题，而且还为双引号$1提供了一个有用的建议，从而使参数与带有嵌入空格的文件名和glob字符一起工作。|1384359|至于，为什么需要之后的空格：|1384360|{+是所谓的+shell关键字的实例，而不是所谓的+shell元字符+%7C++&+;+(+)+<+>+space+tab**.**。|1384361|Metacharacters+分离词在解析过程中，关键词do+|1384362|在当前的情况下，{ls中的{ls不能被识别为一个ls关键字，因为它不能被识别为一个单独的单词，因为它的后面紧跟着ls。|1384363|因此，Bash会看到单个单词{ls，这在这个位置上是出乎意料的，并且非常适合报告syntax+error+near+unexpected+token+'{ls'。|1384364|请注意，结束的}不需要前面的空格(尽管您可能想要添加它以实现视觉对称)，因为它前面有元字符;，根据定义，元字符;被认为是“自己的东西”，从而隐式地导致}被识别为自己的单词。|1384365|注意:由于关闭的}与ls命令位于同一行，所以必须用控制操作符;终止ls命令-否则，}将被解释为ls的另一个参数。|1384366|entityMap|0|LINK|mutability|MUTABLE|url|http://shellcheck.net/^0|I|1|K|6|I|1|0|Y|8|0|E|0|0|0|O|2|0|2|C|0|0|1|2|4|7|I|Q|8|Z|Q|0|1|Z|O|0|0|E|F|F|0|0|1N|8|3|D|3|O|2|1K|2|0|0|29|E|3|14|14|0|0|2E|7|1|19|1|1J|1|23|1|0|0|1K|8|1|A|2|U|1|X|2|15|1|1B|2|0^^$0|@$1|2|3|4|5|6|7|1B|8|@$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]|$9|1G|A|1H|B|D]]|E|@]|F|$]]|$1|G|3|H|5|6|7|1I|8|@$9|1J|A|1K|B|C]]|E|@$9|1L|A|1M|1|1N]]|F|$]]|$1|I|3|J|5|K|7|1O|8|@]|E|@]|F|$L|M]]|$1|N|3|O|5|6|7|1P|8|@$9|1Q|A|1R|B|D]]|E|@]|F|$]]|$1|P|3|Q|5|6|7|1S|8|@$9|1T|A|1U|B|C]]|E|@]|F|$]]|$1|R|3|S|5|6|7|1V|8|@$9|1W|A|1X|B|C]|$9|1Y|A|1Z|B|C]|$9|20|A|21|B|C]|$9|22|A|23|B|C]|$9|24|A|25|B|C]|$9|26|A|27|B|D]|$9|28|A|29|B|D]]|E|@]|F|$]]|$1|T|3|U|5|6|7|2A|8|@$9|2B|A|2C|B|C]|$9|2D|A|2E|B|C]]|E|@]|F|$]]|$1|V|3|W|5|6|7|2F|8|@$9|2G|A|2H|B|C]|$9|2I|A|2J|B|D]|$9|2K|A|2L|B|D]|$9|2M|A|2N|B|D]|$9|2O|A|2P|B|D]]|E|@]|F|$]]|$1|X|3|Y|5|6|7|2Q|8|@$9|2R|A|2S|B|C]|$9|2T|A|2U|B|D]|$9|2V|A|2W|B|D]]|E|@]|F|$]]|$1|Z|3|10|5|6|7|2X|8|@$9|2Y|A|2Z|B|C]|$9|30|A|31|B|D]|$9|32|A|33|B|D]|$9|34|A|35|B|D]|$9|36|A|37|B|D]]|E|@]|F|$]]|$1|11|3|12|5|6|7|38|8|@$9|39|A|3A|B|C]|$9|3B|A|3C|B|D]|$9|3D|A|3E|B|D]|$9|3F|A|3G|B|D]|$9|3H|A|3I|B|D]|$9|3J|A|3K|B|D]|$9|3L|A|3M|B|D]]|E|@]|F|$]]|$1|13|3|-4|5|6|7|3N|8|@]|E|@]|F|$]]]|14|$15|$5|16|17|18|F|$19|1A]]]]

As has been noted, the <code>{</code> must be followed by whitespace for the function definition to work.

<a href="http://shellcheck.net" rel="nofollow noreferrer">shellcheck.net</a> is a great site for syntax-checking shell code, which would have caught the problem:

<pre><code>lsr () {ls -rt $1;}
 ^-- SC1054: You need a space after the '{'.
 ^-- SC2086: Double quote to prevent globbing and word splitting.
</code></pre>

As you can see, it not only found the problem, but also provided a helpful suggestion to double-quote <code>$1</code>, so as to make the argument work with filenames with embedded spaces and glob characters too.

As for why the whitespace after <code>{</code> is needed:

<code>{</code> is an instance of a so-called shell keyword, as opposed to the so-called shell metacharacters <code>| &amp; ; ( ) &lt; &gt; space tab</code>.

Metacharacters separate words during parsing, keywords do not.

In the case at hand, the <code>{</code> in <code>{ls</code> is not recognized as a shell keyword, because it isn't recognized as a separate word due to immediately being followed by <code>ls</code>.

Bash therefore sees single word <code>{ls</code>, which is unexpected at this position, and fittingly reports <code>syntax error near unexpected token '{ls'</code>.

Note that the closing <code>}</code> does not need preceding whitespace (even though you may want to add it for visual symmetry), because it is preceded by metacharacter <code>;</code>, which is by definition recognized as its "own thing", and thus implicitly causes the <code>}</code> to be recognized as its own word.

On a related note: Since the closing <code>}</code> is on the same line as the <code>ls</code> command, the <code>ls</code> command must be terminated with control operator <code>;</code> - otherwise, the <code>}</code> would be interpreted as another argument to <code>ls</code>.

I want to make a shortcut function for <code>ls -rt</code>, but the <code>-rt</code> is not accepted by Unix in my definition. Why didn't this work? What is the solution?

<pre><code>lsr () {ls -rt $1;}
</code></pre>

Why doesn't this bash function work?

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。

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我想为ls -rt创建一个快捷函数，但是在我的定义中，-rt是不被Unix接受的。为什么这不起作用？解决办法是什么？lsr () {ls -rt $1;}

问为什么这个bash函数不能工作？
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问为什么这个bash函数不能工作？
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