What's a good way to rename all special characters collected in a form to be replaced with an underscore?
Here's an example of the special characters to be replaced:
[.!,;:##$%^&*|()?/\\\<>] space tab CR NL
I am tying into a piece of software that is downloaded by a user, and in that software, the renaming convention is to replace any of the characters listed above with an underscore. And for my web based application to work properly, it needs to collect some information in a form field that is named exactly as the user put it in the software, and have the naming convention work right. So when the mp3 file gets uploaded, and the ajax call checks for a file, it will match exactly, thus tripping off the rest of the functionality.
You're almost there already:
$str = "Zebo's [Test]";
echo preg_replace("~['.!,;:##$%^&*|()?/\\<> \t\r\n\[\]]~", "_", $str);
Output: Zebo_s__Test_
Edited to include [, ], and ' properly - didn't realize you meant that you wanted to replace those.
By the way... You say you want to replace "all special characters," and that your list above is just an "example." You may want to do something broader, like this:
preg_replace("~[^A-Za-z0-9]~", "_", $str);
This would also catch characters like the backtick and other special characters, such as:
`îõ§¶þäô
You can use:
$repl = preg_replace('~[.!,;:##$%^&*|()?/\\\<>]~', '_', $str);
Related
I'm trying to match files of the following structure in PHP.
Input:
filename.ext1
filename.ext1.ext2
filename.ext3.ext2.ext1
filename.ext4.ext2.ext1.ext4
file name with spaces and no way of knowing how long.ext1
file name with spaces and no way of knowing how long.ext1.ext2
file name with spaces and no way of knowing how long.ext2.ext1.ext3
file name with spaces and no way of knowing how long.ext3.ext1.ext4.ext3
Output:
filename
filename
filename
filename
file name with spaces and no way of knowing how long
file name with spaces and no way of knowing how long
file name with spaces and no way of knowing how long
file name with spaces and no way of knowing how long
What I've already attempted (doesn't work of course and I already understand why):
^(?P<basename>.*)(\.ext4)|(\.ext3)|(\.ext2)|(\.ext1).*$
I'd like to extract the base name of the file and basically strip all extensions, because there's no way of knowing in which order they may appear. I've tried several solutions presented here but they did not work for me. The extensions could be anything alphanumeric of any length.
I'm fairly new to regular expressions and am confused that apparently you cannot simply search forward to the first dot and remove it including everything that comes after.
To learn, I'd also love to see how to do the reverse and just match all the extensions including the first dot.
Update:
I didn't think about file names that contain dots. So obviously my thinking regarding "searching forward" is flawed. Does anyone have a solution for the case
file name with spaces and no. way of knowing how long.ext3.ext1.ext4.ext3
or even
file name with spaces and no way of knowing.how.long.ext3.ext1.ext4.ext3
The latter one would quite possibly only work when certain extensions are given. So please assume ext1-4 are given but are in an unpredictable sequence.
Quick and dirty:
preg_replace("/\.(ext1|ext2|ext3|ext4)/i", "", $filename)
There's no need to use regular expressions for this; PHP has the buildin function basename() for that
Does something simple like this works for you....
^[^.]*
Basically it just matches string before first dot.
This regex should work for you:
^.+?(?=\.[^.]*$)
Online Demo: http://regex101.com/r/uT2oK5
This will find file names before very last dot only. See all the examples included in the link.
am confused that apparently you cannot simply search forward to the first dot and remove it including everything that comes after.
Since regexes are read from left to right, looking for a single dot will lead you straight to the first dot. That said, you would thus be able to use:
preg_replace("/\..*/", "", $filename);
.* matches any characters except newlines.
If the filename has dots, this obviously won't work, since part of the filename will then be removed.
As per update, if you have the specific extensions, you can use something like this:
preg_replace("/(?:\.ext[1-4])+$/m", "", $filename);
regex101 demo
In a broader perspective, you could use something like this if you have an array of extensions at your disposition:
$exts = array(".ext1", ".ext2", ".ext3", ".ext4");
$result = preg_replace("/(?:". preg_quote(join("|",$exts)) .")+$/m", "", $filename);
.*(?=\.)
Try this? Will match all before the last dot even if theres a dot in the file name
This is easy with just plain old php functions. No need for fancy regex.
$name = substr($filename, 0, strpos($filename, '.'));
This won't work for filenames which have a . like your updated example, however in order to achieve this you would likely need to know in advance the extensions which you are likely to encounter.
Something I have noticed on the StackOverflow website:
If you visit the URL of a question on StackOverflow.com:
"https://stackoverflow.com/questions/10721603"
The website adds the name of the question to the end of the URL, so it turns into:
"https://stackoverflow.com/questions/10721603/grid-background-image-using-imagebrush"
This is great, I understand that this makes the URL more meaningful and is probably good as a technique for SEO.
What I wanted to Achieve after seeing this Implementation on StackOverflow
I wish to implement the same thing with my website. I am happy using a header() 301 redirect in order to achieve this, but I am attempting to come up with a tight script that will do the trick.
My Code so Far
Please see it working by clicking here
// Set the title of the page article (This could be from the database). Trimming any spaces either side
$original_name = trim(' How to get file creation & modification date/times in Python with-dash?');
// Replace any characters that are not A-Za-z0-9 or a dash with a space
$replace_strange_characters = preg_replace('/[^\da-z-]/i', " ", $original_name);
// Replace any spaces (or multiple spaces) with a single dash to make it URL friendly
$replace_spaces = preg_replace("/([ ]{1,})/", "-", $replace_strange_characters);
// Remove any trailing slashes
$removed_dashes = preg_replace("/^([\-]{0,})|([\-]{2,})|([\-]{0,})$/", "", $replace_spaces);
// Show the finished name on the screen
print_r($removed_dashes);
The Problem
I have created this code and it works fine by the looks of things, it makes the string URL friendly and readable to the human eye. However, it I would like to see if it is possible to simplify or "tightened it up" a bit... as I feel my code is probably over complicated.
It is not so much that I want it put onto one line, because I could do that by nesting the functions into one another, but I feel that there might be an overall simpler way of achieving it - I am looking for ideas.
In summary, the code achieves the following:
Removes any "strange" characters and replaces them with a space
Replaces any spaces with a dash to make it URL friendly
Returns a string without any spaces, with words separated with dashes and has no trailing spaces or dashes
String is readable (Doesn't contain percentage signs and + symbols like simply using urlencode()
Thanks for your help!
Potential Solutions
I found out whilst writing this that article, that I am looking for what is known as a URL 'slug' and they are indeed useful for SEO.
I found this library on Google code which appears to work well in the first instance.
There is also a notable question on this on SO which can be found here, which has other examples.
I tried to play with preg like you did. However it gets more and more complicated when you start looking at foreign languages.
What I ended up doing was simply trimming the title, and using urlencode
$url_slug = urlencode($title);
Also I had to add those:
$title = str_replace('/','',$title); //Apache doesn't like this character even encoded
$title = str_replace('\\','',$title); //Apache doesn't like this character even encoded
There are also 3rd party libraries such as: http://cubiq.org/the-perfect-php-clean-url-generator
Indeed, you can do that:
$original_name = ' How to get file creation & modification date/times in Python with-dash?';
$result = preg_replace('~[^a-z0-9]++~i', '-', $original_name);
$result = trim($result, '-');
To deal with other alphabets you can use this pattern instead:
~\P{Xan}++~u
or
~[^\pL\pN]++~u
I am working with this daily data feed. To my surprise, one the fields didn't look right after it was in MySQL. (I have no control over who provides the feed.)
So I did a mysqldump and discovered the zip code and the city for this record contained a non-printing char. It displayed it in 'vi' as this:
<200e>
I'm working in PHP and I parse this data and put it into the MySQL database. I have used the trim function on this, but that doesn't get rid of it. The problem is, if you do a query on a zipcode in the MySQL database, it doesn't find the record with the non-printing character.
I'd like the clean this up before it's put into the MySQL database.
What can I do in PHP? At first I thought regular expression to only allow a-z,A-Z, and 0-9, but that's not good for addresses. Addresses use periods, commas, hyphens and perhaps other things I'm not thinking of at the moment.
What's the best approach? I don't know what it's called to define it exactly other than printing characters should only be allowed. Is there another PHP function like trim that does this job? Or regular expression? If so, I'd like an example. Thanks!
I have looked into using the PHP function, and saw this posted at PHP.NET:
<?php
$a = "\tcafé\n";
//This will remove the tab and the line break
echo filter_var($a, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW);
//This will remove the é.
echo filter_var($a, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH);
?>
While using FILTER_FLAG_STRIP_HIGH does indeed strip out the <200e> I mentioned seen in 'vi', I'm concerned that it would strip out the letter's accent in a name such as André.
Maybe a regular expression is the solution?
You can use PHP filters: http://www.php.net/manual/en/function.filter-var.php
I would recommend on using the FILTER_SANITIZE_STRING filter, or anything that fits what you need.
I think you could use this little regex replace:
preg_replace( '/[^[:print:]]+/', '', $your_value);
It basically strip out all non-printing characters from $your_value
I tried this:
<?php
$string = "\tabcde éç ÉäÄéöÖüÜß.,!-\n";
$string = preg_replace('/[^a-z0-9\!\.\, \-éâëïüÿçêîôûéäöüß]/iu', '', $string);
print "[$string]";
It gave:
[abcde éç ÉäÄéöÖüÜß.,!-]
Add all the special characters, you need into the regexp.
If you work in English and do not need to support unicode characters, then allow just [\x20-\x7E]
...and remove all others:
$s = preg_replace('/[^\x20-\x7E]+/', '', $s);
I am inserting Alias field for my db called $alias
how do I code (I am using php for mysql insert)
to remove all spaces and replace space with "-" (trying to change it to "weburl format" ie removing spaces)
Thanks
Here's the method I use to santize strings for SEF urls:
$slug = trim(strtolower($value));
$slug = preg_replace('/[^a-z0-9 _-]/', '', $slug);
return preg_replace('/\s+/', '-', $slug);
Feel free to add additional allowed characters to the first regex.
Please note that this is NOT Unicode or even full ISO-8891 safe, well, it is, but it'll drop anything that isn't a-z. That is, you may need to normalize the string beforehand (i.e., replace accented characters with their closes ASCII equivalent.) There's a number of SO questions and answers dealing with this that I've seen before, but I can't find them at the moment. I'll edit them in here if I stumble upon any.
For just removing spaces, you want the str_replace method. However, when working with URLs, you might want to consider the urlencode and rawurlencode methods as well.
I rewrite URLs to include the title of user generated travelblogs.
I do this for both readability of URLs and SEO purposes.
http://www.example.com/gallery/280-Gorges_du_Todra/
The first integer is the id, the rest is for us humans (but is irrelevant for requesting the resource).
Now people can write titles containing any UTF-8 character, but most are not allowed in the URL.
My audience is generally English speaking, but since they travel, they like to include names like
Aït Ben Haddou
What is the proper way to translate this for displaying in an URL using PHP on linux.
So far I've seen several solutions:
just strip all non allowed characters, replace spaces
this has strange results:
'Aït Ben Haddou' → /gallery/280-At_Ben_Haddou/
Not really helpfull.
just strip all non allowed characters, replace spaces, leave charcode (stackoverflow.com) most likely because of the 'regex-hammer' used
this gives strange results:
'tést tést' → /questions/0000/t233st-t233st
translate to 'nearest equivalent'
'Aït Ben Haddou' → /gallery/280-Ait_Ben_Haddou/
But this goes wrong for german; for example 'ü' should be transliterated 'ue'.
For me, as a Dutch person, the 3rd result 'looks' the best.
I'm quite sure however that (1) many people will have a different opinion and (2) it is just plain wrong in the german example.
Another problem with the 3rd option is: how to find all possible characters that can be converted to a 7bit equivalent?
So the question is:
what, in your opinion, is the most desirable result. (within tech-limits)
How to technically solve it. (reach the desired result) with PHP.
Ultimately, you're going to have to give up on the idea of "correct", for this problem. Translating the string, no matter how you do it, destroys accuracy in the name of compatibility and readability. All three options are equally compatible, but #1 and #2 suffer in terms of readability. So just run with it and go for whatever looks best — option #3.
Yes, the translations are wrong for German, but unless you start requiring your users to specify what language their titles are in (and restricting them to only one), you're not going to solve that problem without far more effort than it's worth. (For example, running each word in the title through dictionaries for each known language and translating that word's diacritics according to the rules of its language would work, but it's excessive.)
Alternatively, if German is a higher concern than other languages, make your translation always use the German version when one exists: ä→ae, ë→e, ï→i, ö→oe, ü→ue.
Edit:
Oh, and as for the actual method, I'd translate the special cases, if any, via str_replace, then use iconv for the rest:
$text = str_replace(array("ä", "ö", "ü", "ß"), array("ae", "oe", "ue", "ss"), $text);
$text = iconv('UTF-8', 'US-ASCII//TRANSLIT', $text);
To me the third is most readable.
You could use a little dictionary e.g. ï -> i and ü -> ue to specify how you'd like various charcaters to be translated.
As an interesting side note, on SO nothing seems to really matter after the ID -- this is a link to this page:
How to handle diacritics (accents) when rewriting 'pretty URLs'
Obviously the motivation is to allow title changes without breaking links, and you may want to consider that feature as well.
Nice topic, I had the same problem a while ago.
Here's how I fixed it:
function title2url($string=null){
// return if empty
if(empty($string)) return false;
// replace spaces by "-"
// convert accents to html entities
$string=htmlentities(utf8_decode(str_replace(' ', '-', $string)));
// remove the accent from the letter
$string=preg_replace(array('#&([a-zA-Z]){1,2}(acute|grave|circ|tilde|uml|ring|elig|zlig|slash|cedil|strok|lig){1};#', '#&[euro]{1};#'), array('${1}', 'E'), $string);
// now, everything but alphanumeric and -_ can be removed
// aso remove double dashes
$string=preg_replace(array('#[^a-zA-Z0-9\-_]#', '#[\-]{2,}#'), array('', '-'), html_entity_decode($string));
}
Here's how my function works:
Convert it to html entities
Strip the accents
Remove all remaining weird chars
Now people can write titles containing any UTF-8 character, but most are not allowed in the URL.
On the contrary, most are allowed. See for example Wikipedia's URLs - things like http://en.wikipedia.org/wiki/Café (aka http://en.wikipedia.org/wiki/Caf%C3%A9) display nicely - even if StackOverflow's highlighter doesn't pick them out correctly :-)
The trick is reading them reliably across any hosting environment; there are problems with CGI and Windows servers, particularly IIS, for example.
This is a good function:
function friendlyURL($string) {
setlocale(LC_CTYPE, 'en_US.UTF8');
$string = iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', $string);
$string = str_replace(' ', '-', $string);
$string = preg_replace('/\\s+/', '-', $string);
$string = strtolower($string);
return $string;
}