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So this is my first time posting a question on this website and as a programmer I'm ashamed I didn't create an account sooner, this website has gotten me through a lot lol, anyways enough about that, I need some help.
I am creating a system where users can post their own little statuses, update their status, share, etc. I need help creating folders for #hashtags based on the hashtag the user has in his posted status.
So an example would be: "Hello world #firstpost #helloworld", the code would have to exclude everything in that sentence except for any and all hashtags, and it would then create the folders for all the hashtags that are in the users post, in this case it's going to create the folders firstpost and helloworld (if they don't already exist).
Can I create the folders using a modified version of this or at least something better/similar/related?
$foldername = $_POST["status_posting"];
mkdir('../hashtag/' . $foldername, 0755);
for ($i = 0; $i < 1; $i++) {
mkdir('../users/' . $foldername, 0755);
}
Thank you for your guys help in advance.

You can use a regular expression to capture the hashtags, then use mkdir() to create the directories. You can use file_exists() to check if a file exists (or not !).
I would use the following expression: #(\S{1,}). This expression looks for a #, then starts capturing any non white-space character (/S), from once to infinite times ({1,}).
<?php
$input = "Hello world #firstpost #helloworld";
preg_match_all("/#(\S{1,})/", $input, $matches);
foreach($matches[1] as $match){
if (!file_exists('../hashtag/' . $match)) {
mkdir('../hashtag/' . $match, 0755, true);
}
}

I'd php explode() the message, check each item if it contains a #, if so mkdir the item's name minus the #. Possibly not the most efficient way to do it.
$foldername = explode(" ", $_POST["status_posting"]);
foreach($foldername as $string){
if(strpos($string, '#') !== FALSE){
//Make dir!
mkdir('../hashtag/' . ltrim($string, "#"), 0755, true);
}
}
The true at the end of mkdir allows for recursive file path creation. For instance, if the hashtag folder has not been created yet, it will create that too.
After doing some research, since "#" can be found without using regex, it's much more efficient to use strpos() and explode(). preg_match() vs strpos() speed is shown below.
no. strings 1 2 3 10 100 1000 10000
strpos() 0.01 ms 0.02 ms 0.04 ms 0.2 ms 0.9 ms 2.6 ms 25.6 ms
preg_match() 0.2 ms 0.2 ms 0.3 ms 0.47 ms 0.95 ms 7.4 ms 72.2 ms
Though you do have to factor in explode() time, the php forum states that explode() should be used when regex power is not required, for reasons we can see above. I would be interested in seeing the two answers code put head to head as it would be quite interesting to know for sure.