<?php
$string = "http://example.com/file/D1 http://example.com/file/D2
http://example.com/file/D3";
preg_match_all('/(https?\:\/\/)?(www\.)?example\.com\/file\/(\w+)/i', $string, $matches);
foreach($matches[3] as $value)
{
print $value;
}
?>
I want to preg match the third link and get "D3".
I dont want that it matches with the other two links. This is why it should check if the link has a whitespace at the beginning or the end.
I know that to match with whitespace the expression is \s. I tried but somehow I don't get it. :(
You can add the $ to match the end of the string like this, and it will only return the last one.
preg_match_all('/(https?\:\/\/)?(www\.)?example\.com\/file\/(\w+)$/i', $string, $matches);
Related
I am trying to detect a string inside the following pattern: [url('example')] in order to replace the value.
I thought of using a regex to get the strings inside the squared brackets and then another to get the text inside the parenthesis but I am not sure if that's the best way to do it.
//detect all strings inside brackets
preg_match_all("/\[([^\]]*)\]/", $text, $matches);
//loop though results to get the string inside the parenthesis
preg_match('#\((.*?)\)#', $match, $matches);
To match the string between the parenthesis, you might use a single pattern to get a match only:
\[url\(\K[^()]+(?=\)])
The pattern matches:
\[url\( Match [url(
\K Clear the current match buffer
[^()]+ Match 1+ chars other than ( and )
(?=\)]) Positive lookahead, assert )] to the right
See a regex demo.
For example
$re = "/\[url\(\K[^()]+(?=\)])/";
$text = "[url('example')]";
if (preg_match($re, $text, $match)) {
var_dump($match[0]);;
}
Output
string(9) "'example'"
Another option could be using a capture group. You can place the ' inside or outside the group to capture the value:
\[url\(([^()]+)\)]
See another regex demo.
For example
$re = "/\[url\(([^()]+)\)]/";
$text = "[url('example')]";
if (preg_match($re, $text, $match)) {
var_dump($match[1]);;
}
Output
string(9) "'example'"
I am getting a result as a return of a laravel console command like
Some text as: 'Nerad'
Now i tried
$regex = '/(?<=\bSome text as:\s)(?:[\w-]+)/is';
preg_match_all( $regex, $d, $matches );
but its returning empty.
my guess is something is wrong with single quotes, for this i need to change the regex..
Any guess?
Note that you get no match because the ' before Nerad is not matched, nor checked with the lookbehind.
If you need to check the context, but avoid including it into the match, in PHP regex, it can be done with a \K match reset operator:
$regex = '/\bSome text as:\s*'\K[\w-]+/i';
See the regex demo
The output array structure will be cleaner than when using a capturing group and you may check for unknown width context (lookbehind patterns are fixed width in PHP PCRE regex):
$re = '/\bSome text as:\s*\'\K[\w-]+/i';
$str = "Some text as: 'Nerad'";
if (preg_match($re, $str, $match)) {
echo $match[0];
} // => Nerad
See the PHP demo
Just come from the back and capture the word in a group. The Group 1, will have the required string.
/:\s*'(\w+)'$/
i am using php Regular expressions but i can't retrieve values that i group using ()
this is my input
<img src="http://www.example.com/image.jpg" title="title" />
i need only src value , this is my regex '"<img src=\"(.*?)\".*?\/>"'
if i can retrieve First group just like java patterns my problem is sloved
preg_match_all('"<img src=\"(.*?)\".*?\/>"', $source, $re);
print_r($re);
and it return full image tag like this <img src="http://www.example.com/image.jpg" title="title" />
To match a single string, preg_match function is enough. You don't need to go for preg_matchall function. If you want to match more number of strings then you could use preg_matchall function. And also first try to match the exact string through the pattern rather than to go for grouping. If it's impossible to match a particular string then go for grouping.
In the below, matching the exact value of src attribute is done.
You could get the value of src in two ways,
1. positive lookbehind
Regex:
(?<=src=\")[^\"]*
PHP code:(Through match_all)
<?php
$string = "<img src=\"http://www.example.com/image.jpg\" title=\"title\" />";
$regex = '~(?<=src=\")[^\"]*~';
preg_match_all($regex, $string, $matches);
print_r($matches);
?>
PHP code:(Through match)
<?php
$string = "<img src=\"http://www.example.com/image.jpg\" title=\"title\" />";
$regex = '~(?<=src=\")[^\"]*~';
if (preg_match($regex, $string, $m)) {
$yourmatch = $m[0];
echo $yourmatch;
}
?> //=> http://www.example.com/image.jpg
Explanation:
(?<=src=\") Positive look-behind is used here. So the regex engine puts the match marker just after to the src=".
[^\"]* Now it starts matching any character zero or more times but not of ". When it finds a ", it stops matching characters.
2. Using \K
Regex:
src=\"\K[^\"]*
PHP code (through match)
<?php
$string = "<img src=\"http://www.example.com/image.jpg\" title=\"title\" />";
$regex = '~src=\"\K[^\"]*~';
if (preg_match($regex, $string, $m)) {
$yourmatch = $m[0];
echo $yourmatch;
}
?> //=> http://www.example.com/image.jpg
Explanation:
\K resets the starting point of the reported match. Any previously consumed characters are no longer included in the final match.
src=\"\K So it discards the previously matched src=".
[^\"]* Matches any character zero or more times but not of "
You're using preg_match_all so that you need to pass index as well, use print_r($re[1]); to get results.
I Got It Accidently !
we can Code Like this for first Grouped
print_r($re[1]);
I am trying to make a regex that will look behind .txt and then behind the "-" and get the first digit .... in the example, it would be a 1.
$record_pattern = '/.txt.+/';
preg_match($record_pattern, $decklist, $record);
print_r($record);
.txt?n=chihoi%20%283-1%29
I want to write this as one expression but can only seem to do it as two. This is the first time working with regex's.
You can use this:
$record_pattern = '/\.txt.+-(\d)/';
Now, the first group contains what you want.
Your regex would be,
\.txt[^-]*-\K\d
You don't need for any groups. It just matches from the .txt and upto the literal -. Because of \K in our regex, it discards the previously matched characters. In our case it discards .txt?n=chihoi%20%283- string. Then it starts matching again the first digit which was just after to -
DEMO
Your PHP code would be,
<?php
$mystring = ".txt?n=chihoi%20%283-1%29";
$regex = '~\.txt[^-]*-\K\d~';
if (preg_match($regex, $mystring, $m)) {
$yourmatch = $m[0];
echo $yourmatch;
}
?> //=> 1
I want to find anything that matches
[^1] and [/^1]
Eg if the subject is like this
sometext[^1]abcdef[/^1]somemoretext[^2]12345[/^2]
I want to get back an array with abcdef and 12345 as the elements.
I read this
And I wrote this code and I am unable to advance past searching between []
<?php
$test = '[12345]';
getnumberfromstring($test);
function getnumberfromstring($text)
{
$pattern= '~(?<=\[)(.*?)(?=\])~';
$matches= array();
preg_match($pattern, $text, $matches);
var_dump($matches);
}
?>
Your test checks the string '[12345]' which does not apply for the rule of having an "opening" of [^digit] and a "closing" of [\^digit]. Also, you're using preg_match when you should be using: preg_match_all
Try this:
<?php
$test = 'sometext[^1]abcdef[/^1]somemoretext[^2]12345[/^2]';
getnumberfromstring($test);
function getnumberfromstring($text)
{
$pattern= '/(?<=\[\^\d\])(.*?)(?=\[\/\^\d\])/';
$matches= array();
preg_match_all($pattern, $text, $matches);
var_dump($matches);
}
?>
That other answer doesn't really apply to your case; your delimiters are more complex and you have to use part of the opening delimiter to match the closing one. Also, unless the numbers inside the tags are limited to one digit, you can't use a lookbehind to match the first one. You have to match the tags in the normal way and use a capturing group to extract the content. (Which is how I would have done it anyway. Lookbehind should never be the first tool you reach for.)
'~\[\^(\d+)\](.*?)\[/\^\1\]~'
The number from the opening delimiter is captured in the first group and the backreference \1 matches the same number, thus insuring that the delimiters are correctly paired. The text between the delimiters is captured in group #2.
I have tested following code in php 5.4.5:
<?php
$foo = 'sometext[^1]abcdef[/^1]somemoretext[^2]12345[/^2]';
function getnumberfromstring($text)
{
$matches= array();
# match [^1]...[/^1], [^2]...[/^2]
preg_match_all('/\[\^(\d+)\]([^\[\]]+)\[\/\^\1\]/', $text, $matches, PREG_SET_ORDER);
for($i = 0; $i < count($matches); ++$i)
printf("%s\n", $matches[$i][2]);
}
getnumberfromstring($foo);
?>
output:
abcdef
123456