blocks|key|693442|text|ls命令有一个按时间排序的参数-t。然后你可以用head+-1抓取第一个(最新的)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|693443|ls+-t+b2*+%7C+head+-1|code-block|syntax|javascript|693444|但请注意：Why+you+shouldn't+parse+the+output+of+ls|693445|我个人的观点:只有当文件名包含有趣的字符，如空格或换行符时，解析ls才是危险的。如果您可以保证文件名不会包含有趣的字符，那么解析ls是非常安全的。|693446|如果您正在开发一个脚本，该脚本将在许多不同的情况下由许多人在多个系统上运行，那么我强烈建议您不要解析ls。|693447|下面是如何“正确”做这件事：How+can+I+find+the+latest+(newest,+earliest,+oldest)+file+in+a+directory?|693448|unset+-v+latest
for+file+in+"$dir"/*;+do
++[[+$file+-nt+$latest+]]+&&+latest=$file
done|693449|entityMap|0|LINK|mutability|MUTABLE|url|http://mywiki.wooledge.org/ParsingLs|1|http://mywiki.wooledge.org/BashFAQ/003^0|0|2|F|2|O|7|0|0|5|14|0|0|W|2|1S|2|0|1E|2|0|E|21|1|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1C|8|@]|D|@$9|1D|A|1E|1|1F]]|E|$]]|$1|M|3|N|5|6|7|1G|8|@$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]]|D|@]|E|$]]|$1|O|3|P|5|6|7|1L|8|@$9|1M|A|1N|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1O|8|@]|D|@$9|1P|A|1Q|1|1R]]|E|$]]|$1|S|3|T|5|H|7|1S|8|@]|D|@]|E|$I|J]]|$1|U|3|-4|5|6|7|1T|8|@]|D|@]|E|$]]]|V|$W|$5|X|Y|Z|E|$10|11]]|12|$5|X|Y|Z|E|$10|13]]]]

The <code>ls</code> command has a parameter <code>-t</code> to sort by time. You can then grab the first (newest) with <code>head -1</code>.

<pre><code>ls -t b2* | head -1
</code></pre>

But beware: <a href="http://mywiki.wooledge.org/ParsingLs" rel="noreferrer">Why you shouldn't parse the output of ls</a>

My personal opinion: parsing <code>ls</code> is only dangerous when the filenames can contain funny characters like spaces or newlines. If you can guarantee that the filenames will not contain funny characters then parsing <code>ls</code> is quite safe.

If you are developing a script which is meant to be run by many people on many systems in many different situations then I very much do recommend to not parse <code>ls</code>.

Here is how to do it "right": <a href="http://mywiki.wooledge.org/BashFAQ/003" rel="noreferrer">How can I find the latest (newest, earliest, oldest) file in a directory?</a>

<pre><code>unset -v latest
for file in "$dir"/*; do
 [[ $file -nt $latest ]] &amp;&amp; latest=$file
done
</code></pre>

blocks|key|909582|text|不常见的文件名(例如包含有效\n字符的文件)可能会对这种解析造成严重影响。下面是在Perl中实现这一点的方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|909583|perl+-le+'@sorted+=+map+{$_->[0]}+
++++++++++++++++++++sort+{$a->[1]+<=>+$b->[1]}+
++++++++++++++++++++map+{[$_,+-M+$_]}+
++++++++++++++++++++@ARGV;
++++++++++print+$sorted[0]
'+b2*|code-block|syntax|javascript|909584|这是那里使用的Schwartzian+transform。|909585|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Schwartzian_transform^0|E|2|0|0|7|L|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

Unusual filenames (such as a file containing the valid <code>\n</code> character can wreak havoc with this kind of parsing. Here's a way to do it in Perl:

<pre><code>perl -le '@sorted = map {$_-&gt;[0]} 
 sort {$a-&gt;[1] &lt;=&gt; $b-&gt;[1]} 
 map {[$_, -M $_]} 
 @ARGV;
 print $sorted[0]
' b2*
</code></pre>

That's a <a href="http://en.wikipedia.org/wiki/Schwartzian_transform" rel="nofollow">Schwartzian transform</a> used there.

blocks|key|909638|text|这是所需Bash函数的可能实现：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|909639|#+Print+the+newest+file,+if+any,+matching+the+given+pattern
#+Example+usage:
#+++newest_matching_file+'b2*'
#+WARNING:+Files+whose+names+begin+with+a+dot+will+not+be+checked
function+newest_matching_file
{
++++#+Use+${1-}+instead+of+$1+in+case+'nounset'+is+set
++++local+-r+glob_pattern=${1-}

++++if+((+$#+!=+1+))+;+then
++++++++echo+'usage:+newest_matching_file+GLOB_PATTERN'+>&2
++++++++return+1
++++fi

++++#+To+avoid+printing+garbage+if+no+files+match+the+pattern,+set
++++#+'nullglob'+if+necessary
++++local+-i+need_to_unset_nullglob=0
++++if+[[+":$BASHOPTS:"+!=+*:nullglob:*+]]+;+then
++++++++shopt+-s+nullglob
++++++++need_to_unset_nullglob=1
++++fi

++++newest_file=
++++for+file+in+$glob_pattern+;+do
++++++++[[+-z+$newest_file+%7C%7C+$file+-nt+$newest_file+]]+\
++++++++++++&&+newest_file=$file
++++done

++++#+To+avoid+unexpected+behaviour+elsewhere,+unset+nullglob+if+it+was
++++#+set+by+this+function
++++((+need_to_unset_nullglob+))+&&+shopt+-u+nullglob

++++#+Use+printf+instead+of+echo+in+case+the+file+name+begins+with+'-'
++++[[+-n+$newest_file+]]+&&+printf+'%25s\n'+"$newest_file"

++++return+0
}|code-block|syntax|javascript|909640|它只使用Bash内置，并且应该处理名称中包含换行符或其他不常见字符的文件。|909641|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

This is a possible implementation of the required Bash function:

<pre><code># Print the newest file, if any, matching the given pattern
# Example usage:
# newest_matching_file 'b2*'
# WARNING: Files whose names begin with a dot will not be checked
function newest_matching_file
{
 # Use ${1-} instead of $1 in case 'nounset' is set
 local -r glob_pattern=${1-}

 if (( $# != 1 )) ; then
 echo 'usage: newest_matching_file GLOB_PATTERN' &gt;&amp;2
 return 1
 fi

 # To avoid printing garbage if no files match the pattern, set
 # 'nullglob' if necessary
 local -i need_to_unset_nullglob=0
 if [[ ":$BASHOPTS:" != *:nullglob:* ]] ; then
 shopt -s nullglob
 need_to_unset_nullglob=1
 fi

 newest_file=
 for file in $glob_pattern ; do
 [[ -z $newest_file || $file -nt $newest_file ]] \
 &amp;&amp; newest_file=$file
 done

 # To avoid unexpected behaviour elsewhere, unset nullglob if it was
 # set by this function
 (( need_to_unset_nullglob )) &amp;&amp; shopt -u nullglob

 # Use printf instead of echo in case the file name begins with '-'
 [[ -n $newest_file ]] &amp;&amp; printf '%s\n' "$newest_file"

 return 0
}
</code></pre>

It uses only Bash builtins, and should handle files whose names contain newlines or other unusual characters.

blocks|key|909660|text|有一种更有效的方法来实现这一点。考虑以下命令：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|909661|find+.+-cmin+1+-name+"b2*"|code-block|syntax|javascript|909662|此命令使用通配符搜索"b2*“查找恰好一分钟前生成的最新文件。如果你想要最近两天的文件，最好使用下面的命令：|909663|find+.+-mtime+2+-name+"b2*"|909664|".“表示当前目录。希望这能有所帮助。|909665|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

There is a much more efficient way of achieving this. Consider the following command:

<pre><code>find . -cmin 1 -name "b2*"
</code></pre>

This command finds the latest file produced exactly one minute ago with the wildcard search on "b2*". If you want files from the last two days then you'll be better off using the command below:

<pre><code>find . -mtime 2 -name "b2*"
</code></pre>

The "." represents the current directory. 
Hope this helps.

blocks|key|693622|text|你可以使用带有文件全局的stat和在前面添加文件时间的装饰-排序-取消装饰：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|693623|$+stat+-f+"%25m%25t%25N"+b2*+%7C+sort+-rn+%7C+head+-1+%7C+cut+-f2-|code-block|syntax|javascript|693624|entityMap^0|C|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

You can use <code>stat</code> with a file glob and a decorate-sort-undecorate with the file time added on the front:

<pre><code>$ stat -f "%m%t%N" b2* | sort -rn | head -1 | cut -f2-
</code></pre>

In Bash, I would like to create a function that returns the filename of the newest file that matches a certain pattern. For example, I have a directory of files like:

<pre><code>Directory/
 a1.1_5_1
 a1.2_1_4
 b2.1_0
 b2.2_3_4
 b2.3_2_0
</code></pre>

I want the newest file that starts with 'b2'. How do I do this in bash? I need to have this in my <code>~/.bash_profile</code> script.

Bash function to find newest file matching pattern

Perl

在Bash中，我想创建一个函数来返回与特定模式匹配的最新文件的文件名。例如，我有一个包含如下文件的目录：Directory/   a1.1_5_1   a1.2_1_4   b2.1_0   b2.2_3_4   b2.3_2_0我想要以'b2‘开头的最新文件。我如何在bash中做到这一点？我需要将它放在我的~/.ba...

问用于查找最新文件匹配模式的Bash函数
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