Esthetic How To Reverse Quotes - php

Okay I am almost done with my project finally and im not sure how secure it really is but its a jumping off point and will see if the site ever gets any traffic if so many ill pay to have someone fix some things other wise it can wait while I keep learning but long story short I have it outputing a file
And I am having a bit of trouble with it.
here is my code
file_put_contents('DONE.html', '<html><?php include('config.php'); </html>');
But as im sure you can see my issue is that since this whole string is put into ' quotes it dosnt read the config.php correctly because it thinks it should be out of quotes how do I fix this cause I have a ton of ' And " that need to be added to this and im not sure how to make my php script out put quotes.

Quote characters in strings delimited by the same character should be escaped with a reverse solidus / backslash character.
file_put_contents('DONE.html', '<html><?php include(\'config.php\'); </html>');

There are a few ways to achieve what you want to do:
file_put_contents('DONE.html', "<html><?php include('config.php'); </html>");
file_put_contents('DONE.html', '<html><?php include("config.php"); </html>');
file_put_contents('DONE.html', "<html><?php include(\"config.php\"); </html>");
You basically alternate between single and double quotes, or escape (with backslash ) the double quotes within double quotes so it doesn't close the previous one.
Anyway I think what you want to do is kind of strange. Instead of adding the include into that file, why don't you just include the config.php directly? what happens if you change the config.php's name or path? You would have to change it from all the files, why don't just:
<?php
include("config.php");
include("DONE.html");
?>

Related

Double backslash in front of local URL

Is there a way to navigate to a file on a local location which uses a double backslash at the start like this: \192.168.1.1\folder\file.xml ?
I have tried several ways like this:
file_get_contents("\\192.168.1.1\folder\file.xml");
fopen("\\192.168.1.1\folder\file.xml", '');
But it keeps failing to open the file. while navigating to it locally seems to work.
you need a backslash to escape every backslash (a backslash is the escape char in coding)
So you would have:
$addr = "\\\\192.168.1.1\\folder\\file.xml";
#Craig B - Beat me to the answer by few seconds, you should use double double
"\\\\192.168.1.1\\folder\\file.xml"

PHP echo returning blank value

So I am trying to link using data I got from a function but it keeps giving me a blank value for ID. Here's my code for what I'm trying to print
<h3 style="text-align: center;">Seller: <?php $sellername =
getNameFromListingID(); $id = getIDByUsername($sellername); echo "".$sellername."";?></h3>
The functions work properly, I have tried printing both of them and it works. They're in a file called getinfo.php, which I have
Include 'getinfo.php';
At the top of my document.
The link with the name works but I always get seller.php?id=, with no value after. Any clue as to why?
You're ending the href attribute too early.
<a href=\"seller.php?id=".$id."\">
This will put the $id inside the href attribute, where it belongs.
Use single quotes in PHP, it's a good practice to get into, and it's also slightly (a teeny tiny bit) faster for PHP to process. Why? Because, when you use double quotes, you're telling PHP that your string contains variables that may need to be evaluated.
So in truth, you don't even need the quotes around variables here.
echo "$sellername";
But doing it like this would be following a best practice.
And now you don't need to escape \" double quotes that HTML uses.
echo ''.$sellername.'';
Caution: It's also a very good idea to escape special characters in anything you're outputting into HTML markup. That avoids the potential for an XSS vulnerability. See: htmlspecialchars()
echo ''.htmlspecialchars($sellername).'';

PHP: literal \n rather than new line

I have a php var which, when echoed, writes a JS function into the source of a page. The function loops through a CSV and so it has the following line within it:
$str="var lines = data.split('\n');";
At the present time, when echoed, I get this 'correct' JS written into the source:
var lines = data.split('
');
Instead, I want to echo the literal string \n into the source of the page.
Can anyone point me in the right direction? Thanks.
Escape the slash.
"\\n"
So that it is treated as a slash instead of an escape character.
Try this:
$str="var lines = data.split('\\n');";
you can escape \ like this: \\.
But I would put the whole JS functionality into a .js file, include that from the generated HTML, and call the specific function when needed. And generate a minimalistic js code, like var config = {....} if I have to communicate some page related information.
You almost never need dynamically generated JS code. It's a lot harder to read and you're wasting CPU and network bandwidth...
Either the solutions in the earlier answers, or invert the quotes by using single quotes as the PHP string delimiter:
$str='var lines = data.split("\n");';
Or escape the inner quotes, if you want to keep single quotes for javascript as well when using single quotes as the PHP string delimiter.
$str='var lines = data.split(\'\n\');';
See the docs on quoted strings in PHP as well about how single quoted strings and double quoted strings behave differently.

What is <<<_END?

I'm new to PHP and don't understand what the point of <<<_END is. Could someone please explain when this should be used? I've looked at various examples and they all seem to have HTML embedded within them. But I can use HTML without the <<<_END tags, so why should I use them? I tried searching the manual, but I keep finding the end() method for arrays.
It's the start of a heredoc. you can do:
$data = <<< _END
You can write anything you want in between the start and end
_END;
_END can be just about anything. You could put EOF or STUFF. as long as you use the same thing at the start and the finish.
This signifies the beginning of a heredoc (a multi-line string that allows you to use quotation marks in the middle, unescaped) that ends when you encounter the _END
It can be useful to define HTML in one of these if the goal is to assign it to a variable or pass it to a function rather than printing it to the web server immediately.
That syntax is called heredoc
<<<_END
some text
_END
Basically, it's a way of writing a string without worrying about escaping quotes and so on.
As you've mentioned, it doesn't really provide a lot of benefit over other string formats - although, it does mean you can write a block of HTML without escaping out of PHP with ?>
It also isn't too popular as its use generally goes against the practice of seperating content from logic by embedding the content in the middle of your script.
Does this help? http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc
It allows you to echo out a block of text (just the same as with echo "words";), but without using the beginning/ending quotes, and without having to escape contained double quotes. Read the manual link above for more detail.
It's a heredoc. It's just a way of defining a string.

PHP 'addslashes' not behaving as expected

This has been driving be crazy, but I can't seem to find an answer. We run a technical knowledge base that will sometimes include Windows samba paths for mapping to network drives.
For example: \\servername\sharename
When we include paths that have two backslashes followed by each other, they are not escaped properly when running 'addslashes'. My expected results would be "\\\\servername\\sharename", however it returns "\\servername\\sharename". Obviously, when running 'stripslashes' later on, the double backslash prefix is only a single slash. I've also tried using a str_replace("\\", "\", $variable); however it returns "\servername\sharename" when I would expect "\\servername\sharename".
So with addslashes, it ignores the first set of double-backslashes and with str_replace it changes the double-backslashes into a single, encoded backslash.
We need to run addslashes and stripslashes for database insertion; using pg_escape_string won't work in our specific case.
This is running on PHP 5.3.1 on Apache.
EDIT: Example Code
$variable = 'In the box labeled Folder type: \\servername\sharename';
echo addslashes($variable);
This returns: In the box labeled Folder type: \\servername\\sharename
EDIT: Example Code #2
$variable = 'In the box labeled Folder type: \\servername\sharename';
echo str_replace('\\', '\', $variable);
This returns: In the box labeled Folder type: \servername\sharename
I'd also like to state that using a single quotes or double-quotes does not give me different results (as you would expect). Using either or both give me the same exact results.
Does anyone have any suggestions on what I can possibly do?
I think I know where is a problem. Just try to run this one:
echo addslashes('\\servername\sharename');
And this one
echo addslashes('\\\\servername\sharename');
PHP escapes double slashes even with single quotes, because it is used to escape single quote.
Ran a test on the problem you described, and the only way I could get the behavior you desired was to couple a conditional with a regex and anticipate the double slashes at the start.
$str = '\\servername\sharename';
if(substr($str,0,1) == '\\'){
//String starts with double backslashes, let's append an escape one.
//Exclaimation used for demonstration purposes.
$str = '\\'.$str;
echo addslashes(preg_replace('#\\\\\\\\#', '!',$str ));
}
This outputs:
!servername\\sharename
While this may not be an outright answer, it does work and illustrates a difference in how the escape character is treated by these two constructs. If used, the ! could easily be replaced with the desired characters using another regex.
This is not a problem with addslashes, it is a problem with the way you are assigning the string to your variable.
$variable = 'In the box labeled Folder type: \\servername\sharename';
echo $variable;
This returns: In the box labeled Folder type: \servername\sharename
This is because the double backslash is interpreted as an escaped backslash. Use this assignment instead.
$variable = 'In the box labeled Folder type: \\\\servername\\sharename';
I've determined, with more testing, that it indeed is with how PHP is handling hard-coded strings. Since hard-coded strings are not what I'm interested in (I was just using them for testing/this example), I created a form with a single text box and a submit button. addslashes would correctly escape the POST'ed data this way.
Doing even more research, I determined that the issue I was experiencing was with how PostgreSQL accepts escaped data. Upon inserting data into a PostgreSQL database, it will remove any escape characters it is given when it actually places the data in the table. Therefore, stripslashes is not required to remove escape characters when pulling the data back out.
This problem stemmed from code migration from PHP 4.1 (with Magic Quotes on) to PHP 5.3 (with Magic Quotes deprecated). In the existing system (PHP4), I don't think we were aware that Magic Quotes were on. Therefore, all POST data was being escaped already and then we were escaping that data again with addslashes before inserting. When it got inserted into PostgreSQL, it would strip one set of slashes and leave the other, therefore requiring us to stripslashes on the way out. Now, with Magic Quotes off, we escape with addslashes but are not required to use stripslashes on the way out.
It was very hard to organize and determine exactly where the problem lay, so I know this answer is a little off to my original question. I do, however, thank everyone who contributed. Having other people sound off on their ideas always helps to make you think on avenues you may not have on your own.

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