Here is my regex to exclude special character other then allowing few like (-,%,:,#). I want to allow / also but getting issue
return preg_replace('/[^a-zA-Z0-9_ %\[\]\.\(\)%:#&-]/s', '', $string);
this works fine for listed special character, but
return preg_replace('/[^a-zA-Z0-9_ %\[\]\.\(\)%\\:&-]/s', '', $string);
does not filter l chracter to.
Here is the link to test:
http://ideone.com/WxR0ka
where it does not allow \\ in url. I want to dispaly URL as usual
You're making a mistake in entering http:// by http:\\ also your regex needs to include / in exclusion list. This should work:
function clean($string) {
// Replaces all spaces with hyphens.
$string = str_replace(' ', '-', $string);
// Removes special chars.
return preg_replace('~[^\w %\[\].()%\\:#&/-]~', '', $string);
}
$d = clean("this was http://nice readlly n'ice 'test for#me to") ;
echo $d; // this-was-http://nice-readlly-nice-test-for#me-to
Working Demo
Related
I have the following string:
$thetextstring = "jjfnj 948"
At the end I want to have:
echo $thetextstring; // should print jjf-nj948
So basically what am trying to do is to join the separated string then separate the first 3 letters with a -.
So far I have
$string = trim(preg_replace('/s+/', ' ', $thetextstring));
$result = explode(" ", $thetextstring);
$newstring = implode('', $result);
print_r($newstring);
I have been able to join the words, but how do I add the separator after the first 3 letters?
Use a regex with preg_replace function, this would be a one-liner:
^.{3}\K([^\s]*) *
Breakdown:
^ # Assert start of string
.{3} # Match 3 characters
\K # Reset match
([^\s]*) * # Capture everything up to space character(s) then try to match them
PHP code:
echo preg_replace('~^.{3}\K([^\s]*) *~', '-$1', 'jjfnj 948');
PHP live demo
Without knowing more about how your strings can vary, this is working solution for your task:
Pattern:
~([a-z]{2}) ~ // 2 letters (contained in capture group1) followed by a space
Replace:
-$1
Demo Link
Code: (Demo)
$thetextstring = "jjfnj 948";
echo preg_replace('~([a-z]{2}) ~','-$1',$thetextstring);
Output:
jjf-nj948
Note this pattern can easily be expanded to include characters beyond lowercase letters that precede the space. ~(\S{2}) ~
You can use str_replace to remove the unwanted space:
$newString = str_replace(' ', '', $thetextstring);
$newString:
jjfnj948
And then preg_replace to put in the dash:
$final = preg_replace('/^([a-z]{3})/', '\1-', $newString);
The meaning of this regex instruction is:
from the beginning of the line: ^
capture three a-z characters: ([a-z]{3})
replace this match with itself followed by a dash: \1-
$final:
jjf-nj948
$thetextstring = "jjfnj 948";
// replace all spaces with nothing
$thetextstring = str_replace(" ", "", $thetextstring);
// insert a dash after the third character
$thetextstring = substr_replace($thetextstring, "-", 3, 0);
echo $thetextstring;
This gives the requested jjf-nj948
You proceeding is correct. For the last step, which consists in inserting a - after the third character, you can use the substr_replace function as follows:
$thetextstring = 'jjfnj 948';
$string = trim(preg_replace('/\s+/', ' ', $thetextstring));
$result = explode(' ', $thetextstring);
$newstring = substr_replace(implode('', $result), '-', 3, false);
If you are confident enough that your string will always have the same format (characters followed by a whitespace followed by numbers), you can also reduce your computations and simplify your code as follows:
$thetextstring = 'jjfnj 948';
$newstring = substr_replace(str_replace(' ', '', $thetextstring), '-', 3, false);
Visit this link for a working demo.
Oldschool without regex
$test = "jjfnj 948";
$test = str_replace(" ", "", $test); // strip all spaces from string
echo substr($test, 0, 3)."-".substr($test, 3); // isolate first three chars, add hyphen, and concat all characters after the first three
I'm making a function that that detect and remove all trailing special characters from string. It can convert strings like :
"hello-world"
"hello-world/"
"hello-world--"
"hello-world/%--+..."
into "hello-world".
anyone knows the trick without writing a lot of codes?
Just for fun
[^a-z\s]+
Regex demo
Explanation:
[^x]: One character that is not x sample
\s: "whitespace character": space, tab, newline, carriage return, vertical tab sample
+: One or more sample
PHP:
$re = "/[^a-z\\s]+/i";
$str = "Hello world\nhello world/\nhello world--\nhellow world/%--+...";
$subst = "";
$result = preg_replace($re, $subst, $str);
try this
$string = preg_replace('/[^A-Za-z0-9\-]/', '', $string); // Removes special chars.
or escape apostraphe from string
preg_replace('/[^A-Za-z0-9\-\']/', '', $string); // escape apostraphe
You could use a regex like this, depending on your definition of "special characters":
function clean_string($input) {
return preg_replace('/\W+$/', '', $input);
}
It replaces any characters that are not a word character (\W) at the end of the string $ with nothing. \W will match [^a-zA-Z0-9_], so anything that is not a letter, digit, or underscore will get replaced. To specify which characters are special chars, use a regex like this, where you put all your special chars within the [] brackets:
function clean_string($input) {
return preg_replace('/[\/%.+-]+$/', '', $input);
}
This one is what you are looking for. :
([^\n\w\d \"]*)$
It removes anything that is not from the alphabet, a number, a space and a new line.
Just call it like this :
preg_replace('/([^\n\w\s]*)$/', '', $string);
I am working with a slug function and I dont fully understand some of it and was looking for some help on explaining.
My first question is about this line in my slug function $string = preg_replace('# +#', '-', $string); Now I understand that this replaces all spaces with a '-'. What I don't understand is what the + sign is in there for which comes after the white space in between the #.
Which leads to my next problem. I want a trim function that will get rid of spaces but only the spaces after they enter the value. For example someone accidentally entered "Arizona " with two spaces after the a and it destroyed the pages linked to Arizona.
So after all my rambling I basically want to figure out how I can use a trim to get rid of accidental spaces but still have the preg_replace insert '-' in between words.
ex.. "Sun City West " = "sun-city-west"
This is my full slug function-
function getSlug($string){
if(isset($string) && $string <> ""){
$string = strtolower($string);
//var_dump($string); echo "<br>";
$string = preg_replace('#[^\w ]+#', '', $string);
//var_dump($string); echo "<br>";
$string = preg_replace('# +#', '-', $string);
}
return $string;
}
You can try this:
function getSlug($string) {
return preg_replace('#\s+#', '-', trim($string));
}
It first trims extra spaces at the beginning and end of the string, and then replaces all the other with the - character.
Here your regex is:
#\s+#
which is:
# = regex delimiter
\s = any space character
+ = match the previous character or group one or more times
# = regex delimiter again
so the regex here means: "match any sequence of one or more whitespace character"
The + means at least one of the preceding character, so it matches one or more spaces. The # signs are one of the ways of marking the start and end of a regular expression's pattern block.
For a trim function, PHP handily provides trim() which removes all leading and trailing whitespace.
Ok so I am taking a string, querying a database and then must provide a URL back to the page. There are multiple special characters in the input and I am stripping all special characters and spaces out using the following code and replacing with HTML "%25" so that my legacy system correctly searches for the value needed. What I need to do however is cut down the number of "%25" that show up.
My current code would replace something like
"Hello. / there Wilbur" with "Hello%25%25%25%25there%25Wilbur"
but I would like it to return
"Hello%25there%25Wilbur"
replacing multiples of the "%25" with only one instance
$string = str_replace(' ', '-', $string); // Replaces all spaces with hyphens.
return preg_replace('/[^A-Za-z0-9]/', '%25', $string); // Replaces special chars.
Just add a + after selecting a non-alphanumeric character.
$string = "Hello. / there Wilbur";
$string = str_replace(' ', '-', $string);
// Just add a '+'. It will remove one or more consecutive instances of illegal
// characters with '%25'
return preg_replace('/[^A-Za-z0-9]+/', '%25', $string);
Sample input: Hello. / there Wilbur
Sample output: Hello%25there%25Wilbur
This will work:
while (strpos('%25%25', $str) !== false)
$str = str_replace('%25%25', '%25', $str);
Or using a regexp:
preg_replace('#((?:\%25){2,})#', '%25', $string_to_replace_in)
No looping using a while, so the more consecutive '%25', the faster preg_replace is against a while.
Cf PHP doc:
http://fr2.php.net/manual/en/function.preg-replace.php
I would like to sanitize a string in to a URL so this is what I basically need:
Everything must be removed except alphanumeric characters and spaces and dashed.
Spaces should be converter into dashes.
Eg.
This, is the URL!
must return
this-is-the-url
function slug($z){
$z = strtolower($z);
$z = preg_replace('/[^a-z0-9 -]+/', '', $z);
$z = str_replace(' ', '-', $z);
return trim($z, '-');
}
First strip unwanted characters
$new_string = preg_replace("/[^a-zA-Z0-9\s]/", "", $string);
Then changes spaces for unserscores
$url = preg_replace('/\s/', '-', $new_string);
Finally encode it ready for use
$new_url = urlencode($url);
The OP is not explicitly describing all of the attributes of a slug, but this is what I am gathering from the intent.
My interpretation of a perfect, valid, condensed slug aligns with this post: https://wordpress.stackexchange.com/questions/149191/slug-formatting-acceptable-characters#:~:text=However%2C%20we%20can%20summarise%20the,or%20end%20with%20a%20hyphen.
I find none of the earlier posted answers to achieve this consistently (and I'm not even stretching the scope of the question to include multi-byte characters).
convert all characters to lowercase
replace all sequences of one or more non-alphanumeric characters to a single hyphen.
trim the leading and trailing hyphens from the string.
I recommend the following one-liner which doesn't bother declaring single-use variables:
return trim(preg_replace('/[^a-z0-9]+/', '-', strtolower($string)), '-');
I have also prepared a demonstration which highlights what I consider to be inaccuracies in the other answers. (Demo)
'This, is - - the URL!' input
'this-is-the-url' expected
'this-is-----the-url' SilentGhost
'this-is-the-url' mario
'This-is---the-URL' Rooneyl
'This-is-the-URL' AbhishekGoel
'This, is - - the URL!' HelloHack
'This, is - - the URL!' DenisMatafonov
'This,-is-----the-URL!' AdeelRazaAzeemi
'this-is-the-url' mickmackusa
---
'Mork & Mindy' input
'mork-mindy' expected
'mork--mindy' SilentGhost
'mork-mindy' mario
'Mork--Mindy' Rooneyl
'Mork-Mindy' AbhishekGoel
'Mork & Mindy' HelloHack
'Mork & Mindy' DenisMatafonov
'Mork-&-Mindy' AdeelRazaAzeemi
'mork-mindy' mickmackusa
---
'What the_underscore ?!?' input
'what-the-underscore' expected
'what-theunderscore' SilentGhost
'what-the_underscore' mario
'What-theunderscore-' Rooneyl
'What-theunderscore-' AbhishekGoel
'What the_underscore ?!?' HelloHack
'What the_underscore ?!?' DenisMatafonov
'What-the_underscore-?!?' AdeelRazaAzeemi
'what-the-underscore' mickmackusa
This will do it in a Unix shell (I just tried it on my MacOS):
$ tr -cs A-Za-z '-' < infile.txt > outfile.txt
I got the idea from a blog post on More Shell, Less Egg
Try This
function clean($string) {
$string = str_replace(' ', '-', $string); // Replaces all spaces with hyphens.
$string = preg_replace('/[^A-Za-z0-9\-]/', '', $string); // Removes special chars.
return preg_replace('/-+/', '-', $string); // Replaces multiple hyphens with single one.
}
Usage:
echo clean('a|"bc!#£de^&$f g');
Will output: abcdef-g
source : https://stackoverflow.com/a/14114419/2439715
Using intl transliterator is a good option because with it you can easily handle complicated cases with a single set of rules. I added custom rules to illustrate how it can be flexible and how you can keep a maximum of meaningful informations. Feel free to remove them and to add your own rules.
$strings = [
'This, is - - the URL!',
'Holmes & Yoyo',
'L’Œil de démon',
'How to win 1000€?',
'€, $ ＆ other currency symbols',
'Und die Katze fraß alle mäuse.',
'Белите рози на София',
'പോണ്ടിച്ചേരി സൂര്യനു കീഴിൽ',
];
$rules = <<<'RULES'
# Transliteration
:: Any-Latin ; :: Latin-Ascii ;
# examples of custom replacements
'&' > ' and ' ;
[^0-9][01]? { € > ' euro' ; € > ' euros' ;
[^0-9][01]? { '$' > ' dollar' ; '$' > ' dollars' ;
:: Null ;
# slugify
[^[:alnum:]&[:ascii:]]+ > '-' ;
:: Lower ;
# trim
[$] { '-' > &Remove() ;
'-' } [$] > &Remove() ;
RULES;
$tsl = Transliterator::createFromRules($rules, Transliterator::FORWARD);
$results = array_map(fn($s) => $tsl->transliterate($s), $strings);
print_r($results);
demo
Unfortunately, the PHP manual is totally empty about ICU transformations but you can find informations about them here.
All previous asnwers deal with url, but in case some one will need to sanitize string for login (e.g.) and keep it as text, here is you go:
function sanitizeText($str) {
$withSpecCharacters = htmlspecialchars($str);
$splitted_str = str_split($str);
$result = '';
foreach ($splitted_str as $letter){
if (strpos($withSpecCharacters, $letter) !== false) {
$result .= $letter;
}
}
return $result;
}
echo sanitizeText('ОРРииыфвсси ajvnsakjvnHB "&nvsp;\n" <script>alert()</script>');
//ОРРииыфвсси ajvnsakjvnHB &nvsp;\n scriptalert()/script
//No injections possible, all info at max keeped
function isolate($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
You should use the slugify package and not reinvent the wheel ;)
https://github.com/cocur/slugify
The following will replace spaces with dashes.
$str = str_replace(' ', '-', $str);
Then the following statement will remove everything except alphanumeric characters and dashed. (didn't have spaces because in previous step we had replaced them with dashes.
// Char representation 0 - 9 A- Z a- z -
$str = preg_replace('/[^\x30-\x39\x41-\x5A\x61-\x7A\x2D]/', '', $str);
Which is equivalent to
$str = preg_replace('/[^0-9A-Za-z-]+/', '', $str);
FYI: To remove all special characters from a string use
$str = preg_replace('/[^\x20-\x7E]/', '', $str);
\x20 is hexadecimal for space that is start of Acsii charecter and \x7E is tilde. As accordingly to wikipedia https://en.wikipedia.org/wiki/ASCII#Printable_characters
FYI: look into the Hex Column for the interval 20-7E
Printable characters
Codes 20hex to 7Ehex, known as the printable characters, represent letters, digits, punctuation marks, and a few miscellaneous symbols. There are 95 printable characters in total.