blocks|key|252137|text|您可以尝试使用awk：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|252138|awk+'/blah/{getline;+print}'+logfile|code-block|syntax|javascript|252139|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 try with awk:

<pre><code>awk '/blah/{getline; print}' logfile
</code></pre>

blocks|key|3151962|text|如果您想坚持使用grep：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3151963|grep+-A1+'blah'+logfile+%7C+grep+-v+"blah"|code-block|syntax|javascript|3151964|或者使用sed：|3151965|sed+-n+'/blah/{n;p;}'+logfile|3151966|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|$]]

If you want to stick to grep:
<pre><code>grep -A1 'blah' logfile | grep -v &quot;blah&quot;
</code></pre>
or alternatively with sed:
<pre><code>sed -n '/blah/{n;p;}' logfile
</code></pre>

blocks|key|2937636|text|派平是你的朋友。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2937637|使用grep+-A1显示匹配后的下一行，然后通过管道将结果传递给tail，并且只抓取1行。|offset|length|style|CODE|2937638|cat+logs/info.log+%7C+grep+"term"+-A1+%7C+tail+-n+1|code-block|syntax|javascript|2937639|entityMap^0|0|2|8|W|4|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@$D|Q|E|R|F|G]|$D|S|E|T|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|U|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

Piping is your friend...

Use <code>grep -A1</code> to show the next line after a match, then pipe the result to <code>tail</code> and only grab 1 line, 

<pre><code>cat logs/info.log | grep "term" -A1 | tail -n 1
</code></pre>

blocks|key|257163|text|来自raim的很好的回答，对我非常有用。将其扩展到打印模式后的第7行是很简单的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|257164|awk+-v+lines=7+'/blah/+{for(i=lines;i;--i)getline;+print+$0+}'+logfile|code-block|syntax|javascript|257165|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|$]]

Great answer from raim, was very useful for me. It is trivial to extend this to print e.g. line 7 after the pattern

<pre><code>awk -v lines=7 '/blah/ {for(i=lines;i;--i)getline; print $0 }' logfile
</code></pre>

blocks|key|257258|text|到目前为止，对于这个问题已经有了很多很好的答案，但我仍然错过了一个不使用getline的awk。因为，in+general，没有必要使用getline，所以我会选择：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|257259|awk+'+f+&&+NR==f%2B1;+/blah/+{f=NR}'+file++#all+matches+after+"blah"|code-block|syntax|javascript|257260|或|257261|awk+'/blah/+{f=NR}+f+&&+NR==f%2B1'+file+++#matches+after+"blah"+not+being+also+"blah"|257262|逻辑总是存储"blah“所在的行，然后打印一行之后的行。|257263|测试|257264|示例文件：|257265|$+cat+a
0
blah1
1
2
3
blah2
4
5
6
blah3
blah4
7|257266|获取"blah“之后的所有行。这将打印另一个"blah“，如果它出现在第一个”blah“之后。|257267|$+awk+'f&&NR==f%2B1;+/blah/+{f=NR}'+a
1
4
blah4
7|257268|获取"blah“之后的所有行，如果它们本身不包含"blah”。|257269|$+awk+'/blah/+{f=NR}+f+&&+NR==f%2B1'+a
1
4
7|257270|entityMap|0|LINK|mutability|MUTABLE|url|http://awk.freeshell.org/AllAboutGetline^0|10|7|18|3|1W|7|1F|A|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@$9|1J|A|1K|1|1L]]|E|$]]|$1|F|3|G|5|H|7|1M|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1N|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1O|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1P|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1Q|8|@]|D|@]|E|$]]|$1|S|3|T|5|6|7|1R|8|@]|D|@]|E|$]]|$1|U|3|V|5|H|7|1S|8|@]|D|@]|E|$I|J]]|$1|W|3|X|5|6|7|1T|8|@]|D|@]|E|$]]|$1|Y|3|Z|5|H|7|1U|8|@]|D|@]|E|$I|J]]|$1|10|3|11|5|6|7|1V|8|@]|D|@]|E|$]]|$1|12|3|13|5|H|7|1W|8|@]|D|@]|E|$I|J]]|$1|14|3|-4|5|6|7|1X|8|@]|D|@]|E|$]]]|15|$16|$5|17|18|19|E|$1A|1B]]]]

Many good answers have been given to this question so far, but I still miss one with <code>awk</code> not using <code>getline</code>. Since, <a href="http://awk.freeshell.org/AllAboutGetline" rel="noreferrer">in general</a>, it is not necessary to use <code>getline</code>, I would go for:
<pre><code>awk ' f &amp;&amp; NR==f+1; /blah/ {f=NR}' file #all matches after &quot;blah&quot;
</code></pre>
or
<pre><code>awk '/blah/ {f=NR} f &amp;&amp; NR==f+1' file #matches after &quot;blah&quot; not being also &quot;blah&quot;
</code></pre>
The logic always consists in storing the line where &quot;blah&quot; is found and then printing those lines that are one line after.
<h3>Test</h3>
Sample file:
<pre><code>$ cat a
0
blah1
1
2
3
blah2
4
5
6
blah3
blah4
7
</code></pre>
Get all the lines after &quot;blah&quot;. This prints another &quot;blah&quot; if it appears after the first one.
<pre><code>$ awk 'f&amp;&amp;NR==f+1; /blah/ {f=NR}' a
1
4
blah4
7
</code></pre>
Get all the lines after &quot;blah&quot; if they do not contain &quot;blah&quot; themselves.
<pre><code>$ awk '/blah/ {f=NR} f &amp;&amp; NR==f+1' a
1
4
7
</code></pre>

blocks|key|257146|text|如果接下来几行从不包含'blah'，您可以使用以下命令对其进行过滤：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|257147|grep+-A1+blah+logfile+%7C+grep+-v+blah|code-block|syntax|javascript|257148|不需要使用cat+logfile+%7C+...。|offset|length|style|CODE|257149|entityMap^0|0|0|5|H|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]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

If that next lines never contain 'blah', you can filter them with:

<pre><code>grep -A1 blah logfile | grep -v blah
</code></pre>

The use of <code>cat logfile | ...</code> is not needed.

blocks|key|252141|text|我不知道使用grep有什么方法可以做到这一点，但是可以使用awk来实现相同的结果：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|252142|awk+'/blah/+{getline;print}'+<+logfile|code-block|syntax|javascript|252143|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|$]]

I don't know of any way to do this with grep, but it is possible to use awk to achieve the same result:

<pre><code>awk '/blah/ {getline;print}' &lt; logfile
</code></pre>

blocks|key|257202|text|总的来说，我同意您在这里对grep的要求很高，另一种工具可能是更好的解决方案。但在嵌入式环境中，我可能不希望仅使用sed或awk来完成此任务。我发现以下解决方案是有效的(只要它们不是连续的匹配)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|257203|grep+-A1+AT\%2BCSQ+wvdial.out+%7C+grep+-v+AT\%2BCSQ|code-block|syntax|javascript|257204|基本上，匹配它们，为每个匹配添加一行上下文，然后通过原始模式的反向匹配来剥离这些内容。当然，这意味着您可以假设您的模式不会出现在“下一行”中。|257205|entityMap^0|1L|3|1P|3|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

In general, I agree you're asking a lot of grep here, and that another tool may be the better solution. But in an embedded environment, I may not want to have <code>sed</code> or <code>awk</code> just to do this. I found the following solution works (as long as they're not contiguous matches):

<pre><code>grep -A1 AT\+CSQ wvdial.out | grep -v AT\+CSQ
</code></pre>

Basically, match them, appending 1 line of context for each match, and then pipe that through an inverse match of your original pattern to strip those out. This of course means you can assume that your pattern doesn't show up in the "next" line.

blocks|key|253941|text|perl单行警报|type|unstyled|depth|inlineStyleRanges|entityRanges|data|253942|只是为了好玩。匹配后仅打印一行|253943|perl+-lne+'$next+=+($.%2B1)+if+/match/;+$.+==+$next+&&+print'+data.txt|code-block|syntax|javascript|253944|更有趣的是...匹配后打印下10行|253945|perl+-lne+'push+@nexts,+(($.%2B1)..($.%2B10))+if+/match/;+$.+~~+@nexts+&&+print'+data.txt|253946|虽然有点作弊，因为实际上有两个命令|253947|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

perl one-liner alert
just for fun... print only one line after match
<pre><code>perl -lne '$next = ($.+1) if /match/; $. == $next &amp;&amp; print' data.txt
</code></pre>
even more fun... print the next ten lines after match
<pre><code>perl -lne 'push @nexts, (($.+1)..($.+10)) if /match/; $. ~~ @nexts &amp;&amp; print' data.txt
</code></pre>
kinda cheating though since there's actually two commands

blocks|key|256065|text|看起来你用错了工具。Grep并没有那么复杂，我认为你应该使用awk来完成这项工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|256066|awk+'/blah/+{+getline;+print+$0+}'+logfile|offset|length|style|CODE|256067|如果你遇到任何问题，请让我知道，我认为它很值得学习一点awk，它是一个很棒的工具:)|256068|附注：这个例子没有赢得“无用的cat奖”;)+http://porkmail.org/era/unix/award.html|256069|entityMap|0|LINK|mutability|MUTABLE|url|http://porkmail.org/era/unix/award.html^0|0|0|16|0|0|N|13|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@$D|V|E|W|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Y|8|@]|9|@$D|Z|E|10|1|11]]|A|$]]|$1|L|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|S]]]]

It looks like you're using the wrong tool there. Grep isn't that sophisticated, I think you want to step up to awk as the tool for the job:

<code>awk '/blah/ { getline; print $0 }' logfile</code>

If you get any problems let me know, I think its well worth learning a bit of awk, its a great tool :)

p.s. This example doesn't win a 'useless use of cat award' ;)
<a href="http://porkmail.org/era/unix/award.html" rel="nofollow">http://porkmail.org/era/unix/award.html</a>

blocks|key|256203|text|您可以使用grep，然后采用跳转形式的行：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|256204|grep+-A1+'blah'+logfile+%7C+awk+'NR%253==2'|offset|length|style|CODE|256205|也可以在匹配后取n行，例如：|256206|seq+100+%7C+grep+-A3+.2+%7C+awk+'NR%255==4'|256207|15|256208|25|256209|35|256210|45|256211|55|256212|65|256213|75|256214|85|256215|95|256216|解释-|256217|在这里，我们希望grep所有*2的行，然后取它后面的3行，即*5。|256218|seq+100+%7C+grep+-A3+.2将为您提供：|256219|12|256220|13|256221|14|256222|256223|--|256224|22|256225|23|256226|24|256227|256228|256229|..。|256230|模(NR%255)中的数字是grep添加的行数(这里是由标志-A3添加的3行)，%2B2个额外的行，因为您有当前匹配的行以及grep添加的--行。|256231|entityMap^0|0|0|13|0|0|0|11|0|0|0|0|0|0|0|0|0|0|0|0|0|L|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1X|8|@$D|1Y|E|1Z|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|20|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|21|8|@$D|22|E|23|F|G]]|9|@]|A|$]]|$1|L|3|M|5|6|7|24|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|25|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|26|8|@]|9|@]|A|$]]|$1|R|3|S|5|6|7|27|8|@]|9|@]|A|$]]|$1|T|3|U|5|6|7|28|8|@]|9|@]|A|$]]|$1|V|3|W|5|6|7|29|8|@]|9|@]|A|$]]|$1|X|3|Y|5|6|7|2A|8|@]|9|@]|A|$]]|$1|Z|3|10|5|6|7|2B|8|@]|9|@]|A|$]]|$1|11|3|12|5|6|7|2C|8|@]|9|@]|A|$]]|$1|13|3|14|5|6|7|2D|8|@]|9|@]|A|$]]|$1|15|3|16|5|6|7|2E|8|@]|9|@]|A|$]]|$1|17|3|18|5|6|7|2F|8|@$D|2G|E|2H|F|G]]|9|@]|A|$]]|$1|19|3|1A|5|6|7|2I|8|@]|9|@]|A|$]]|$1|1B|3|1C|5|6|7|2J|8|@]|9|@]|A|$]]|$1|1D|3|1E|5|6|7|2K|8|@]|9|@]|A|$]]|$1|1F|3|M|5|6|7|2L|8|@]|9|@]|A|$]]|$1|1G|3|1H|5|6|7|2M|8|@]|9|@]|A|$]]|$1|1I|3|1J|5|6|7|2N|8|@]|9|@]|A|$]]|$1|1K|3|1L|5|6|7|2O|8|@]|9|@]|A|$]]|$1|1M|3|1N|5|6|7|2P|8|@]|9|@]|A|$]]|$1|1O|3|O|5|6|7|2Q|8|@]|9|@]|A|$]]|$1|1P|3|1H|5|6|7|2R|8|@]|9|@]|A|$]]|$1|1Q|3|1R|5|6|7|2S|8|@]|9|@]|A|$]]|$1|1S|3|1T|5|6|7|2T|8|@]|9|@]|A|$]]|$1|1U|3|-4|5|6|7|2U|8|@]|9|@]|A|$]]]|1V|$]]

you can use grep, then take lines in jumps: 
<code>grep -A1 'blah' logfile | awk 'NR%3==2'</code> 
 
you can also take n lines after match, for example: 
<code>seq 100 | grep -A3 .2 | awk 'NR%5==4'</code> 
15 
25 
35 
45 
55 
65 
75 
85 
95 
explanation - 
here we want to grep all lines that are *2 and take 3 lines after it, which is *5. 
<code>seq 100 | grep -A3 .2</code> will give you: 
12 
13 
14 
15 
-- 
22 
23 
24 
25 
-- 
... 
the number in the modulo (NR%5) is the added rows by grep (here it's 3 by the flag -A3), +2 extra lines because you have current matching line and also the -- line that the grep is adding.

blocks|key|256199|text|grep+/+-n+/%7C尾部模式2%7C头部模式1|type|unstyled|depth|inlineStyleRanges|entityRanges|data|256200|先尾部2，然后尾部最后一个，以在匹配后恰好获得第一行。|256201|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

grep /Pattern/ | tail -n 2 | head -n 1 

Tail first 2 and then head last one to get exactly first line after match.

<pre><code>grep -A1 'blah' logfile
</code></pre>

Thanks to this command for every line that has 'blah' in it, I get the output of the line that contains 'blah' and the next line that follows in the logfile. It might be a simple one but I can't find a way to omit the line that has 'blah' and only show next line in the output.

How to show only next line after the matched one?

日志文件

grep -A1 'blah' logfile多亏了这个命令，对于每一行中包含'blah‘的行，我得到了包含'blah’的那一行的输出，以及日志文件中接下来的一行的输出。这可能很简单，但我找不到一种方法来省略输出中包含'blah‘和“ next line”的行。

问如何只显示匹配行之后的下一行？
EN

回答 12

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问如何只显示匹配行之后的下一行？EN

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问如何只显示匹配行之后的下一行？
EN