blocks|key|3371369|text|将IGNORECASE+=+1;添加到awk命令的开头，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3371370|bash-3.2$+echo+"Create"+%7C+awk+'/%5Ecreate/;'
bash-3.2$+echo+"Create"+%7C+awk+'IGNORECASE+=+1;/%5Ecreate/;'
Create|code-block|syntax|javascript|3371371|entityMap^0|1|F|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|$]]

Add <code>IGNORECASE = 1;</code> to the beginning of your awk command like so:

<pre><code>bash-3.2$ echo "Create" | awk '/^create/;'
bash-3.2$ echo "Create" | awk 'IGNORECASE = 1;/^create/;'
Create
</code></pre>

blocks|key|4971661|text|下面的行将执行OR测试，而不是AND测试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4971662|echo+-e+"Create\nAny+text"+%7C+awk+'IGNORECASE+=+1;/%5Ecreate/;'
Create
Create
Any+text|code-block|syntax|javascript|4971663|BEGIN这个特殊的单词解决了这个问题：|4971664|echo+-e+"Create\nAny+text"+%7C+awk+'BEGIN{IGNORECASE+=+1}/%5Ecreate/;'
Create|4971665|希望这能有所帮助。|4971666|塞巴斯蒂安。|4971667|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

The following line executes an OR test instead of an AND :

<pre><code>echo -e "Create\nAny text" | awk 'IGNORECASE = 1;/^create/;'
Create
Create
Any text
</code></pre>

The BEGIN special word solved the problem :

<pre><code>echo -e "Create\nAny text" | awk 'BEGIN{IGNORECASE = 1}/^create/;'
Create
</code></pre>

Hope this helps.

Sebastien.

blocks|key|4971637|text|对于那些使用IGNORECASE标志无用的旧awk的用户：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4971638|选项1|BOLD|4971639|echo+"CreAte"+%7C+awk+'/%5E[Cc][Rr][Ee][Aa][Tt][Ee]/'|code-block|syntax|javascript|4971640|选项2+(感谢@mwfearnley)|4971641|echo+"CreAte"+%7C+awk+'tolower($0)+~+/%5Ecreate/'|4971642|entityMap^0|6|A|M|3|0|0|3|0|0|0|3|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]|$9|W|A|X|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Y|8|@$9|Z|A|10|B|H]]|D|@]|E|$]]|$1|I|3|J|5|K|7|11|8|@]|D|@]|E|$L|M]]|$1|N|3|O|5|6|7|12|8|@$9|13|A|14|B|H]]|D|@]|E|$]]|$1|P|3|Q|5|K|7|15|8|@]|D|@]|E|$L|M]]|$1|R|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|S|$]]

For those who have an old <code>awk</code> where the <code>IGNORECASE</code> flag is useless:

Option 1 

<pre><code>echo "CreAte" | awk '/^[Cc][Rr][Ee][Aa][Tt][Ee]/'
</code></pre>

Option 2 (thanks @mwfearnley)

<pre><code>echo "CreAte" | awk 'tolower($0) ~ /^create/'
</code></pre>

blocks|key|3371495|text|这有点晚了，但two+answers对这个问题(包括公认的答案)提到了做awk+'IGNORECASE=1;...'+-即将IGNORECASE=1作为条件，而不是块中的语句。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3371496|这不应该这样做。它确实将变量设置为预期的，但它也(意外地)将其计算为布尔表达式，返回true。|3371497|没有块的true条件将导致始终打印该行。如果它恰好与以下模式匹配，则还将再次打印它。|3371498|公认的答案可能是awk+'{IGNORECASE=1}+...'，它在每行文本上设置IGNORECASE变量。通过使用BEGIN条件只分配一次，可以进一步改进这一点。但更清晰的解决方案是使用-v标志在脚本逻辑之外设置参数：|3371499|awk+-v+IGNORECASE=1+'/(\<%5Ecreate\>%7C\<%5Ealter\>%7C\<%5Edrop\>)/,+/;/'|code-block|syntax|javascript|3371500|注意，IGNORECASE是特定于gawk的。对于非gawk特定的方法，GNU+Awk+User's+Guide建议在模式匹配中使用tolower：|3371501|awk+'(tolower($0)+~+/(\<%5Ecreate\>%7C\<%5Ealter\>%7C\<%5Edrop\>)/),+/;/'|3371502|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/5228938/446106|1|https://stackoverflow.com/a/34132156/446106|2|https://www.gnu.org/software/gawk/manual/html_node/Case_002dsensitivity.html^0|10|M|1Q|C|7|3|0|B|7|1|0|0|0|8|O|16|A|1N|5|2N|2|0|0|3|A|1U|7|10|K|2|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@$9|1B|A|1C|1|1D]|$9|1E|A|1F|1|1G]]|E|$]]|$1|F|3|G|5|6|7|1H|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|1I|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|1J|8|@$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]|$9|1Q|A|1R|B|C]]|D|@]|E|$]]|$1|L|3|M|5|N|7|1S|8|@]|D|@]|E|$O|P]]|$1|Q|3|R|5|6|7|1T|8|@$9|1U|A|1V|B|C]|$9|1W|A|1X|B|C]]|D|@$9|1Y|A|1Z|1|20]]|E|$]]|$1|S|3|T|5|N|7|21|8|@]|D|@]|E|$O|P]]|$1|U|3|-4|5|6|7|22|8|@]|D|@]|E|$]]]|V|$W|$5|X|Y|Z|E|$10|11]]|12|$5|X|Y|Z|E|$10|13]]|14|$5|X|Y|Z|E|$10|15]]]]

This is a bit late, but <a href="https://stackoverflow.com/a/5228938/446106">two</a> <a href="https://stackoverflow.com/a/34132156/446106">answers</a> to this question (including the accepted answer) mention doing <code>awk 'IGNORECASE=1;...'</code> - i.e. putting <code>IGNORECASE=1</code> as a condition, instead of a statement in a block.

This should not be done. It does set the variable as intended, but it also (as unintended) evaluates it as a boolean expression, returning true.

A true condition without a block will cause the line to always be printed. If it happens to match the following pattern, it will also be printed a second time.

What the accepted answer probably meant was <code>awk '{IGNORECASE=1} ...'</code>, which sets the <code>IGNORECASE</code> variable on each line of text. This can be further improved by using the <code>BEGIN</code> condition to assign it only once. But a cleaner solution is to use the <code>-v</code> flag to set the parameter outside of the script logic:

<pre><code>awk -v IGNORECASE=1 '/(\&lt;^create\&gt;|\&lt;^alter\&gt;|\&lt;^drop\&gt;)/, /;/'
</code></pre>

Note that <code>IGNORECASE</code> is specific to gawk. For a non gawk-specific method, the <a href="https://www.gnu.org/software/gawk/manual/html_node/Case_002dsensitivity.html" rel="nofollow noreferrer">GNU Awk User's Guide</a> suggests using <code>tolower</code> in a pattern match:

<pre><code>awk '(tolower($0) ~ /(\&lt;^create\&gt;|\&lt;^alter\&gt;|\&lt;^drop\&gt;)/), /;/'
</code></pre>

The following command is working as expected. 

<pre><code># some command | awk '/(\&lt;^create\&gt;|\&lt;^alter\&gt;|\&lt;^drop\&gt;)/,/;/' 
create table todel1 (id int) max_rows=2
/*!*/;
alter table todel1 engine=InnoDB
/*!*/;
create database common
/*!*/;
create database rules
/*!*/;
</code></pre>

But it matches only the lower case "create", "alter" etc. I want to use IGNORECASE switch in the awk statement so that it will return all instances of the search term.

ignorecase in AWK

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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下面的命令可以正常工作。# some command | awk '/(\<^create\>|\<^alter\>|\<^drop\>)/,/;/' create table todel1 (id int) max_rows=2/*!*/;alter table todel1 engine=InnoDB/*!*/;create database common/*!*/;create databa

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