I have some content that contains a token string in the form
$string_text = '[widget_abc]This is some text. This is some text, etc...';
And I want to pull all the text after the first ']' character
So the returned value I'm looking for in this example is:
This is some text. This is some text, etc...
preg_match("/^.+?\](.+)$/is" , $string_text, $match);
echo trim($match[1]);
Edit
As per author's request - added explanation:
preg_match(param1, param2, param3) is a function that allows you to match a single case scenario of a regular expression that you're looking for
param1 = "/^.+?](.+?)$/is"
"//" is what you put on the outside of your regular expression in param1
the i at the end represents case insensitive (it doesn't care if your letters are 'a' or 'A')
s - allows your script to go over multiple lines
^ - start the check from the beginning of the string
$ - go all the way to end of the string
. - represents any character
.+ - at least one or more characters of anything
.+? - at least one more more characters of anything until you reach
.+?] - at least one or more characters of anything until you reach ] (there is a backslash before ] because it represents something in regular expressions - look it up)
(.+)$ - capture everything after ] and store it as a seperate element in the array defined in param3
param2 = the string that you created.
I tried to simplify the explanations, I might be off, but I think I'm right for the most part.
The regex (?<=]).* will solve this problem if you can guarantee that there are no other square brackets on the line. In PHP the code will be:
if (preg_match('/(?<=\]).*/', $input, $group)) {
$match = $group[0];
}
This will transform [widget_abc]This is some text. This is some text, etc... into This is some text. This is some text, etc.... It matches everything that follows the ].
$output = preg_replace('/^[^\]]*\]/', '', $string_text);
Is there any particular reason why a regex is wanted here?
echo substr(strstr($string_text, ']'), 1);
A regex is definitely overkill for this instance.
Here is a nice one-liner :
list(, $result) = explode(']', $inputText, 2);
It does the job and is way less expensive than using regular expressions.
Related
I have a string that contains something like "LAB_FF, LAB_FF12" and I'm trying to use preg_replace to look for both patterns and replace them with different strings using a pattern match of;
/LAB_[0-9A-F]{2}|LAB_[0-9A-F]{4}/
So input would be
LAB_FF, LAB_FF12
and the output would need to be
DAB_FF, HAD_FF12
Problem is, for the second string, it interprets it as "LAB_FF" instead of "LAB_FF12" and so the output is
DAB_FF, DAB_FF
I've tried splitting the input line out using 2 different preg_match statements, the first looking for the {2} pattern and the second looking for the {4} pattern. This sort of works in that I can get the correct output into 2 separate strings but then can't combine the two strings to give the single amended output.
\b is word boundary. Meaning it will look at where the word ends and not only pattern match.
https://regex101.com/r/upY0gn/1
$pattern = "/\bLAB_[0-9A-F]{2}\b|\bLAB_[0-9A-F]{4}\b/";
Seeing the comment on the other answer about how to replace the string.
This is one way.
The pattern will create empty entries in the output array for each pattern that fails.
In this case one (the first).
Then it's just a matter of substr.
$re = '/(\bLAB_[0-9A-F]{2}\b)|(\bLAB_[0-9A-F]{4}\b)/';
$str = 'LAB_FF12';
preg_match($re, $str, $matches);
var_dump($matches);
$substitutes = ["", "DAB", "HAD"];
For($i=1; $i<count($matches); $i++){
If($matches[$i] != ""){
$result = $substitutes[$i] . substr($matches[$i],3);
Break;
}
}
Echo $result;
https://3v4l.org/gRvHv
You can specify exact amounts in one set of curly braces, e.g. `{2,4}.
Just tested this and seems to work:
/LAB_[0-9A-F]{2,4}/
LAB_FF, LAB_FFF, LAB_FFFF
EDIT: My mistake, that actually matches between 2 and 4. If you change the order of your selections it matches the first it comes to, e.g.
/LAB_([0-9A-F]{4}|[0-9A-F]{2})/
LAB_FF, LAB_FFFF
EDIT2: The following will match LAB_even_amount_of_characters:
/LAB_([0-9A-F]{2})+/
LAB_FF, LAB_FFFF, LAB_FFFFFF...
really struggling with this...hopefully someone can put me on the right path to a solution.
My input string is structured like this:
66-2141-A-AC107-7
I'm interested in extracting the string 'AC107' using a single regular expression. I know how to do this with other PHP string functions, but I have to do this with a regular expression.
What I need is to extract all data between the third and fourth hyphens. The structure of each section is not fixed (i.e, 66 may be 8798709 and 2141 may be 38). The presence of the number of hyphens is guaranteed (i.e., there will always be a total of four (4) hyphens).
Any help/guidance is greatly appreciated!
This will do what you need:
(?:[^-]*-){3}([^-]+)
Debuggex Demo
Explanation:
(?:[^-]*-) Look for zero or more non-hyphen characters followed by a hyphen
{3} Look for three of the blocks just described
([^-]+) Capture all the consecutive non-hyphen characters from that point forward (will automatically cut off before the next hyphen)
You can use it in PHP like this:
$str = '66-2141-A-AC107-7';
preg_match('/^(?:[^-]*-){3}([^-]+)/', $str, $matches);
echo $matches[1]; // prints AC107
This should look for anything followed by a hyphen 3 times and then in group 2 (the second set of parenthesis) it will have your value, followed by another hyphen and anything else.
/^(.*-){3}(.*)-(.*)/
You can access it by using $2. In php, it would be like this:
$string = '66-2141-A-AC107-7';
preg_match('/^(.*-){3}(.*)-(.*)/', $string, $matches);
$special_id = $matches[2];
print $special_id;
How would i use regular expressions to check for characters within the following string of text:
=== logo ===
I tried to use a regex tester but could come up with the correct expression for i've tried this:
/^[=]{3}$/
I want search within a string find where the text starts with 3 equal signs.
Find a string or any other characters within the equal signs.
Find 3 more equal signs.. ending the expression.
Thanks in advance.
Try using this regex:
/===[^=]+===/
If you want to capture the text, surround it in parentheses:
/===([^=]+)===/
Here's the fiddle: http://jsfiddle.net/jufXA/
If you might have equal signs in your text (but less than 3, obviously) you should instead match everything lazily (which is a tad slower):
/===(.+?)===/
Here's the fiddle: http://jsfiddle.net/jufXA/1/
How about as simple as...
/===(.+?)===/
For example:
$test = "here's ===something special===, like ===this=one===";
preg_match_all('/===(.+?)===/', $test, $matches);
var_dump($matches[1]);
Laziness is kinda virtue here: the regex engine won't advance past the first 'closing delimiter ==='. Without ?, however, you need to use negated character classes (but then again, what about ===something=like=this===?).
I prefer:
/([=]{3})\s*(.+?)\s*\1/.
This puts the text markup (three equal signs) in the beginning and then just uses a back reference for the end. It also trims your text of spaces, which is what you probably want.
I got the following URL
http://www.amazon.com/LEGO-Ultimate-Building-Set-Pieces/dp/B000NO9GT4/ref=sr_1_1?m=ATVPDKIKX0DER&s=toys-and-games&ie=UTF8&qid=1350518571&sr=1-1&keywords=lego
and I want to extract
B000NO9GT4
that is the asin...to now, I can get search between the string, but not in this way I require. I saw the split functin, I saw the explode. but cant find a way out...also, the urls will be different in length so I cant hardcode the length two..the only thing which make some sense in my mind is to split the string so that
http://www.amazon.com/LEGO-Ultimate-Building-Set-Pieces/dp/
become first part
and
B000NO9GT4/ref=sr_1_1?m=ATVPDKIKX0DER&s=toys-and-games&ie=UTF8&qid=1350518571&sr=1-1&keywords=lego
becomes the 2nd part , from the second part , I should extract B000NO9GT4
in the same way, i would want to get product name LEGO-Ultimate-Building-Set-Pieces from the first part
I am very bad at regex and cant find a way out..
can somebody guide me how I can do it in php?
thanks
This grabs both pieces of information that you are looking to capture:
$url = 'http://www.amazon.com/LEGO-Ultimate-Building-Set-Pieces/dp/B000NO9GT4/ref=sr_1_1?m=ATVPDKIKX0DER&s=toys-and-games&ie=UTF8&qid=1350518571&sr=1-1&keywords=lego';
$path = parse_url($url, PHP_URL_PATH);
if (preg_match('#^/([^/]+)/dp/([^/]+)/#i', $path, $matches)) {
echo "Description = {$matches[1]}<br />"
."ASIN = {$matches[2]}<br />";
}
Output:
Description = LEGO-Ultimate-Building-Set-Pieces
ASIN = B000NO9GT4
Short Explanation:
Any expressions enclosed in ( ) will be saved as a capture group. This is how we get at the data in $matches[1] and $matches[2].
The expression ([^/]+) says to match all characters EXCEPT / so in effect it captures everything in the URL between the two / separators. I use this pattern twice. The [ ] actually defines the character class which was /, the ^ in this case negates it so instead of matching / it matches everything BUT /. Another example is [a-f0-9] which would say to match the characters a,b,c,d,e,f and the numbers 0,1,2,3,4,5,6,7,8,9. [^a-f0-9] would be the opposite.
# is used as the delimiter for the expression
^ following the delimiter means match from the beginning of the string.
See www.regular-expressions.info and PCRE Pattern Syntax for more info on how regexps work.
You can try
$str = "http://www.amazon.com/LEGO-Ultimate-Building-Set-Pieces/dp/B000NO9GT4/ref=sr_1_1?m=ATVPDKIKX0DER&s=toys-and-games&ie=UTF8&qid=1350518571&sr=1-1&keywords=lego" ;
list(,$desc,,$num,) = explode("/",parse_url($str,PHP_URL_PATH));
var_dump($desc,$num);
Output
string 'LEGO-Ultimate-Building-Set-Pieces' (length=33)
string 'B000NO9GT4' (length=10)
I am trying to pull the anchor text from a link that is formatted this way:
<h3><b>File</b> : i_want_this</h3>
I want only the anchor text for the link : "i_want_this"
"variable_text" varies according to the filename so I need to ignore that.
I am using this regex:
<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>
This is matching of course the complete link.
PHP uses a pretty close version to PCRE (PERL Regex). If you want to know a lot about regex, visit perlretut.org. Also, look into Regex generators like exspresso.
For your use, know that regex is greedy. That means that when you specify that you want something, follwed by anything (any repetitions) followed by something, it will keep on going until that second something is reached.
to be more clear, what you want is this:
<a href="
any character, any number of times (regex = .* )
">
any character, any number of times (regex = .* )
</a>
beyond that, you want to capture the second group of "any character, any number of times". You can do that using what are called capture groups (capture anything inside of parenthesis as a group for reference later, also called back references).
I would also look into named subpatterns, too - with those, you can reference your choice with a human readable string rather than an array index. Syntax for those in PHP are (?P<name>pattern) where name is the name you want and pattern is the actual regex. I'll use that below.
So all that being said, here's the "lazy web" for your regex:
<?php
$str = '<h3><b>File</b> : i_want_this</h3>';
$regex = '/(<a href\=".*">)(?P<target>.*)(<\/a>)/';
preg_match($regex, $str, $matches);
print $matches['target'];
?>
//This should output "i_want_this"
Oh, and one final thought. Depending on what you are doing exactly, you may want to look into SimpleXML instead of using regex for this. This would probably require that the tags that we see are just snippits of a larger whole as SimpleXML requires well-formed XML (or XHTML).
I'm sure someone will probably have a more elegant solution, but I think this will do what you want to done.
Where:
$subject = "<h3><b>File</b> : i_want_this</h3>";
Option 1:
$pattern1 = '/(<a href=")(.*)(">)(.*)(<\/a>)/i';
preg_match($pattern1, $subject, $matches1);
print($matches1[4]);
Option 2:
$pattern2 = '()(.*)()';
ereg($pattern2, $subject, $matches2);
print($matches2[4]);
Do not use regex to parse HTML. Use a DOM parser. Specify the language you're using, too.
Since it's in a captured group and since you claim it's matching, you should be able to reference it through $1 or \1 depending on the language.
$blah = preg_match( $pattern, $subject, $matches );
print_r($matches);
The thing to remember is that regex's return everything you searched for if it matches. You need to specify that only care about the part you've surrounded in parenthesis (the anchor text). I'm not sure what language you're using the regex in, but here's an example in Ruby:
string = 'i_want_this'
data = string.match(/<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>/)
puts data # => outputs 'i_want_this'
If you specify what you want in parenthesis, you can reference it:
string = 'i_want_this'
data = string.match(/<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>/)[1]
puts data # => outputs 'i_want_this'
Perl will have you use $1 instead of [1] like this:
$string = 'i_want_this';
$string =~ m/<a href=\"\/en\/browse\/file\/variable_text\">(.*?)<\/a>/;
$data = $1;
print $data . "\n";
Hope that helps.
I'm not 100% sure if I understand what you want. This will match the content between the anchor tags. The URL must start with /en/browse/file/, but may end with anything.
#(.*?)#
I used # as a delimiter as it made it clearer. It'll also help if you put them in single quotes instead of double quotes so you don't have to escape anything at all.
If you want to limit to numbers instead, you can use:
#(.*?)#
If it should have just 5 numbers:
#(.*?)#
If it should have between 3 and 6 numbers:
#(.*?)#
If it should have more than 2 numbers:
#(.*?)#
This should work:
<a href="[^"]*">([^<]*)
this says that take EVERYTHING you find until you meet "
[^"]*
same! take everything with you till you meet <
[^<]*
The paratese around [^<]*
([^<]*)
group it! so you can collect that data in PHP! If you look in the PHP manual om preg_match you will se many fine examples there!
Good luck!
And for your concrete example:
<a href="/en/browse/file/variable_text">([^<]*)
I use
[^<]*
because in some examples...
.*?
can be extremely slow! Shoudln't use that if you can use
[^<]*
You should use the tool Expresso for creating regular expression... Pretty handy..
http://www.ultrapico.com/Expresso.htm