Myregextester.com is the premier online regular expressions tester that allows visitors to construct, test, and optimize regular expressions.

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URL SOURCE:	FILE SOURCE:

• MATCH PATTERN:
• REPLACE PATTERN:

MATCH PATTERN:

\r?\n\r?\n(?!((?!<pre>).)*</pre>)

REPLACEMENT PATTERN:

</p><p>

OPERATION:

i x

m s

SHOW MATCH ARRAY:

EXPLAIN:

PHP ASP

VB.NET C#.NET

Java JS

match match all replace split

DELIM: / # @ ~

HIGHLIGHT MATCHES:

GEN SAMPLES:

Save example     TOOLS:     CHARSET: Optimize Character Set NUMRANGE: Generate Number Range Pattern PASSWORD: Generate Password Pattern  WORD LIST: Generate Word List Pattern      FROM: TO:

• CAPTCHA VERIFICATION:

CAPTCHA VERIFICATION:

CAPTCHA verification required to save examples.  What is CAPTCHA?

Enter the characters from the above CAPTCHA Image:

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• PASSWORD RESTRICTIONS:

PASSWORD RESTRICTIONS:

Allow only these characters:  (any character) [  ]

At Least  Total Characters

No More Than   Total Characters

At Least  Lowercase Characters (a-z)

At Least  Uppercase Characters (A-Z)

At Least  Numeric Characters (0-9)

At Least  Special Characters in [^a-zA-Z0-9] [  ]

Disallow sequential alphanumeric sequences of 2 3 4 5 6 7 8 9 10 or more (i.e. 123... abc... ABC...)

Disallow repeating characters of 2 3 4 5 6 7 8 9 10 or more (i.e. 11... aa... AA... %%...)

• WORD LIST:

WORD LIST:

• SOURCE TEXT:
• HIGHLIGHTED MATCHES:
• RESULTS:

SOURCE TEXT:

asdfsedf asdfja asdf asdf a sdf asdf aasdf ds asdfsdafsad <pre>aa sdfasd asdfasd asdfa asdfsad</pre>

HIGHLIGHTED MATCHES:

Select All (to copy etc.)

CAPTURE GROUPS 

0

asdfsedf


asdfja asdf asdf 
a sdf 


asdf aasdf ds

asdfsdafsad


<pre>aa sdfasd
asdfasd

asdfa


asdfsad</pre>

RESULTS:

Select All (to copy etc.)

Execution Time(sec.):
0.000068

Raw Match Pattern:
\r?\n\r?\n(?!((?!<pre>).)*</pre>)

Raw Replace Pattern:
</p><p>

PHP Code Example: 
<?php
$sourcestring="your source string";
echo preg_replace('#\r?\n\r?\n(?!((?!<pre>).)*</pre>)#ms','</p><p>',$sourcestring);
?>
 
$sourcestring after replacement:
asdfsedf</p><p>
asdfja asdf asdf
a sdf </p><p>
asdf aasdf ds</p><p>asdfsdafsad</p><p>
<pre>aa sdfasd
asdfasd

asdfa


asdfsad</pre>