regex101: PCRE (Legacy) Match Workspace

1st Alternative(?:\<\!\-\-(?:(?!\-\-\>)\r\n?|\n|.)*?-\-\>)

Non-Capturing Group(?:\<\!\-\-(?:(?!\-\-\>)\r\n?|\n|.)*?-\-\>)

\<the literal < (60₁₀ / 74₈ / 3C₁₆)

\!the literal ! (33₁₀ / 41₈ / 21₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:(?!\-\-\>)\r\n?|\n|.)*?

*?repeats the group contents below any number of times:

1st Alternative(?!\-\-\>)\r\n?

Negative Lookahead(?!\-\-\>)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\>the literal > (62₁₀ / 76₈ / 3E₁₆)

\ra carriage return (ASCII 13)

\n?optionally matches a line-feed (newline) character (ASCII 10)

2nd Alternative\n

\na line-feed (newline) character (ASCII 10)

3rd Alternative.

.any character

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

\>the literal > (62₁₀ / 76₈ / 3E₁₆)

2nd Alternative(?:<(\S+)\s+(?=.*>)|(?<=[=\s])\G)(?:((?:(?!\s|=).)*)\s*?=\s*?[\"']?((?:(?<=\")(?:(?<=\\)\"|[^\"])*|(?<=')(?:(?<=\\)'|[^'])*)|(?:(?!\"|')(?:(?!\/>|>|\s).)+))[\"']?\s*)

Non-Capturing Group(?:<(\S+)\s+(?=.*>)|(?<=[=\s])\G)

1st Alternative<(\S+)\s+(?=.*>)

<the literal < (60₁₀ / 74₈ / 3C₁₆)

Group 1(\S+)

\S+any non-whitespace character, repeated at least once

\s+any whitespace character, repeated at least once

Positive Lookahead(?=.*>)

.*any character, repeated any number of times

>the literal > (62₁₀ / 76₈ / 3E₁₆)

2nd Alternative(?<=[=\s])\G

Positive Lookbehind(?<=[=\s])

Character Class[=\s]

=the literal = (61₁₀ / 75₈ / 3D₁₆)

\sany whitespace character

\Gstart of current search

Non-Capturing Group(?:((?:(?!\s|=).)*)\s*?=\s*?[\"']?((?:(?<=\")(?:(?<=\\)\"|[^\"])*|(?<=')(?:(?<=\\)'|[^'])*)|(?:(?!\"|')(?:(?!\/>|>|\s).)+))[\"']?\s*)

Group 2((?:(?!\s|=).)*)

Non-Capturing Group(?:(?!\s|=).)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\s|=)

1st Alternative\s

\sany whitespace character

2nd Alternative=

=the literal = (61₁₀ / 75₈ / 3D₁₆)

.any character

\s*?any whitespace character, repeated any number of times

=the literal = (61₁₀ / 75₈ / 3D₁₆)

\s*?any whitespace character, repeated any number of times

Character Class[\"']?

?matches at most one character from the set below:

\"the literal " (34₁₀ / 42₈ / 22₁₆)

'the literal ' (39₁₀ / 47₈ / 27₁₆)

Group 3((?:(?<=\")(?:(?<=\\)\"|[^\"])*|(?<=')(?:(?<=\\)'|[^'])*)|(?:(?!\"|')(?:(?!\/>|>|\s).)+))

1st Alternative(?:(?<=\")(?:(?<=\\)\"|[^\"])*|(?<=')(?:(?<=\\)'|[^'])*)

Non-Capturing Group(?:(?<=\")(?:(?<=\\)\"|[^\"])*|(?<=')(?:(?<=\\)'|[^'])*)

1st Alternative(?<=\")(?:(?<=\\)\"|[^\"])*

2nd Alternative(?<=')(?:(?<=\\)'|[^'])*

2nd Alternative(?:(?!\"|')(?:(?!\/>|>|\s).)+)

Character Class[\"']?

\s*any whitespace character, repeated any number of times

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

s modifier: single line. Allows a dot to match line terminators

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

25 tokens

Regular Expression

(?:\<\!\-\-(?:(?!\-\-\>)\r\n?|\n|.)*?-\-\>)|(?:<(\S+)\s+(?=.*>)|(?<=[=\s])\G)(?:((?:(?!\s|=).)*)\s*?=\s*?[\"']?((?:(?<=\")(?:(?<=\\)\"|[^\"])*|(?<=')(?:(?<=\\)'|[^'])*)|(?:(?!\"|')(?:(?!\/>|>|\s).)+))[\"']?\s*)

New

In this case, $url will indeed contain http://example.com/whatever.jpg. But what happens when you start getting HTML like this:

<img src='http://example.com/whatever.jpg'>
or

<img src=http://example.com/whatever.jpg>
or

<img border=0 src="http://example.com/whatever.jpg">
or

<img
    src="http://example.com/whatever.jpg">
or you start getting false positives from

<!-- // commented out
<img src="http://example.com/outdated.png">
-->



<asd ASD=asd>

<!-- // commented out <img src="http://example.com/outdated.png"> -->

No quotes:
<iframe src=test.html target=xyz></iframe>
Self-closing tag:
<a href=test.html target=xyz/>
Self closing tag with a space before closure:
<a href=test.html target=xyz />
Double quotes:
<a href="test.html" target="xyz">
Single quotes:
<a href='test.html' target='xyz'>
Escaping double quotes:
<a href="test.html?val=1" title="\"No rules exist\" Andre Breton's quote">
Escaping single quotes (also with spaces between equals signs):
<a href = "test.html?val=1" title = 'Charlie\'s Angels'>
Tag without opening (ignore attributes):
a href = "test.html?val=1" title='Charlie\'s Angels'>
Tag without closure (ignore attributes):
<a href = "test.html?val=1" title='Charlie\'s Angels'