I am trying to work out the optimal way to replace all PHP variables within a string of code with a call to an array instead as shown below.
E.g. source code string
$random_var_name + $random_var_name2 * $diff_var_name3
Transformed into
$varArray["random_var_name"] + $varArray["random_var_name2"] * $varArray["diff_var_name3"]
I had thought that preg_replace() was the optimal solution, but the difficulty comes with the need to perform the replacement with a sub-part of the search pattern.
Perhaps it is better to just retrieve all the variables with a preg_match, edit/wrap them, then perform a single str_replace() for each variable?
However this is probably considerably slower.
The following regex should do what you're asking:
preg_replace('/\$([a-zA-Z_0-9]+)/', '$varArray["$1"]', $input_string);
In order to avoid to change $var['foo'] to $varArray["var"]['foo'] you have to check there're no [ character after the variable name. For this use a negative look-ahead:
$string = preg_replace('/\$(\w+)(?![\w\[])/', '$varArray["$1"]', $string);
Related
I think I need to use the preg_replace function but not sure exactly how to type in the patterns I want to find and replace. Basically, I want to replace this:
: u"x"x",
with this:
: u"x'x",
x means that any characters can go there. But I don't know how to write the x in PHP.
Thank you!
Edit: basically, I want to replace that middle double-quote with a single-quote. And I'll be searching through a big JSON file to do it. Probably should have said this at the start.
You could use this regular expression:
$result = preg_replace('#(: u".*?)"(.*?")#', "$1'$2", $string);
im having an issue with preg_match_all. I have this string:
$product_req = "ACTIVE-6,CATEGORY-ACTIVE-8,CATEGORY-ACTIVE-4,ACTIVE-9";
I need to get the numbers preceded by "ACTIVE-" but not by "CATEGORY-ACTIVE-", so in this case the result should be 6,9. I used the statement below:
preg_match_all("/ACTIVE-(\d+)/", $product_req, $this_act);
However this will return all the numbers because all of them are in fact preceded by "ACTIVE-" but thats not what i meant because i need to leave out those preceded by "CATEGORY-ACTIVE-". How can i configure preg_match_all to do it? Or maybe there is some other function that can do the job?
EDIT:
I tried this:
preg_match_all("/CATEGORY-ACTIVE-(\d+)/", $product_req, $this_cat_act);
preg_match_all("/ACTIVE-(\d+)/", $product_req, $this_act);
$act_cat = str_replace($this_cat_act[1],"",$this_act[1]);
it kinda works, but i guess there is a better and cleaner way to do it. Besides the output is kinda weird too.
Thank you.
I've got a problem with regexp function, preg_replace(), in PHP.
I want to get viewstate from html's input, but it doesn't work properly.
This code:
$viewstate = preg_replace('/^(.*)(<input\s+id="__VIEWSTATE"\s+type="hidden"\s+value=")(.*[^"])("\s+name="__VIEWSTATE">)(.*)$/u','^\${3}$',$html);
Returns this:
%0D%0A%0D%0A%3C%21DOCTYPE+html+PUBLIC+%22-%2F%2FW3C%2F%2FDTD+XHTML+1.0+Transitional%2F%2FEN%22+%22http%3A%2F%2Fwww.w3.org%2FTR%2Fxhtml1%2FDTD%2Fxhtml1-transitional.dtd%22%3E%0D%0A%0D%0A%3Chtml+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1999%2Fxhtml%22+%3E%0D%0A%3Chead%3E%3Ctitle%3E%0D%0A%09Strava.cz%0D%0A%3C%2Ftitle%3E%3Clink+rel%3D%22shortcut+icon%22+href%3D%22..%2FGrafika%2Ffavicon.ico%22+type%3D%22image%2Fx-icon%22+%2F%3E%3Clink+rel%3D%22stylesheet%22+type%3D%22text%2Fcss%22+media%3D%22screen%22+href%3D%22..%2FStyly%2FZaklad.css%22+%2F%3E%0D%0A++++%3Cstyle+type%3D%22text%2Fcss%22%3E%0D%0A++++++++.style1%0D%0A++++++++%7B%0D%0A++++++++++++width%3A+47px%3B%0D%0A++++++++%7D%0D%0A++++++++.style2%0D%0A++++++++%7B%0D%0A++++++++++++width%3A+64px%3B%0D%0A++++++++%7D%0D%0A++++%3C%2Fstyle%3E%0D%0A%0D%0A%3Cscript+type%3D%22text%2Fjavascript%22%3E%0D%0A%0D%0A++var+_gaq+%3D+_gaq+%7C%7C+%5B%5D%3B%0D%0A++_gaq.push%28%5B
EDIT: Sorry, I left this question for a long time. Finally I used DOMDocument.
To be sure i'd split this match into two phases:
Find the relevant input element
Get the value
Because you cannot be certain what the attributes order in the element will be.
if(preg_match('/<input[^>]+name="__VIEWSTATE"[^>]*>/i', $input, $match))
$value = preg_replace('/.*value="([^"]*)".*/i', '$1', $match[0]);
And, of course, always consider DOM and DOMXpath over regex for parsing html/xml.
You should only capture when you're planning on using the data. So most () are obsolete in that regexp pattern. Not a cause for failure but I thought I'd mention it.
Instead of using [^"] to mark that you don't want that character you could use the non-greedy modifier - ?. This makes sure the pattern is matching as little as it can. Since you have name="__VIEWSTATE" following the value this should be safe.
Let's put this in practice and simplify the pattern some. This works as you want:
'/.*<input\s+id="__VIEWSTATE"\s+type="hidden"\s+value="(.+?)"\s+name="__VIEWSTATE">.*/'
I would strongly recommend checking out an alternative to regexp for DOM operations. This makes certain your code works also if the attributes changes order. Plus it's so much nicer to work with.
The main mistake was the use of funciton preg_replace, witch returns the subject - neither the matched pattern nor the replacement. Thank you for your ideas and for the recommendation of DOMDocument. m93a
http://www.php.net/manual/en/function.preg-replace.php#refsect1-function.preg-replace-returnvalues
I got a string in which I replace all occurrences of [CODE]...[/CODE]. With preg_replace_callback can I call a function which handles the content of those tags. But how can I manipulate all string which are around those occurrences?
Example:
$str = "Hello, I am a string with [CODE]some code[/CODE] in it";
Now, with preg_replace_callback I manipulate the content of [CODE], in this case some code. But I'd like for all other text in this string, so Hello, I am a string with and in it to do something different. How could I do this the best way?
Thank you for you help!
Flo
It'd be simpler if I could see the regex, but the gist is that I think you want capture groups.
You should be able to access those regions separately by placing them into parenthesis-wrapped groups. Each section will be available to your callback. So (crudely) something like /(.*)(\[CODE\].*\[/CODE\])(.*)/ should pass an array of matches to your callback
I'm looking for a regex that will scan a document to match a function call, and return the value of the first parameter (a string literal) only.
The function call could look like any of the following:
MyFunction("MyStringArg");
MyFunction("MyStringArg", true);
MyFunction("MyStringArg", true, true);
I'm currently using:
$pattern = '/Use\s*\(\s*"(.*?)\"\s*\)\s*;/';
This pattern will only match the first form, however.
Thanks in advance for your help!
Update
I was able to solve my problem with:
$pattern = '/Use\s*\(\s*"(.*?)\"/';
Thanks Justin!
~Scott
If you only care about the value of the first parameter, you can just chop off the end of the regex:
$pattern = '/Use\s*\(\s*"(.*?)\"/';
However, you should understand that this (or any pure-regex solution for this problem) will not be perfect, and there will be some possible cases it handles incorrectly. In this case, you'll get false positives, and escaped quotes (\") will break it.
You can ignore escaped quotes by complicating it a bit:
$pattern = '/Use\s*\(\s*"(.*?)(?!<(?:\\\\)*\\)\"/';
This ignores " characters inside the quoted string if they have an odd number of backslashes in front of them.
However, the false-postives issue can't be helped without introducing false-negatives, and vice versa. This is because PHP is an irregular language, so it can't be parsed with "pure" regex, and even modern regex engines that allow recursion are going to need some pretty complex code to do a really thorough job at this.
All I'm saying is, if you're planning a one-off job to quickly scrape through some PHP you wrote yourself, regex is probably fine. If you're looking for something robust and open-ended that will do this on arbitrary PHP code, you need some kind of reflection or PHP parser.
This might be slightly simpler, though will only work if you have double quotes and not single quotes:
$pattern = /Use\s*[^\"]*\"([^\"]*)\"/