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execute javascript from php

Sorry for this beginner question, I never used js server-side before.
here is my problem:
I have some javascript downloaded from a remote page (it's encrypted, I can't convert it to php), I need to execute it and read its output.
How can I do it? I'm thinking about something like this:
shell_exec('nodejs code...')
but how to pass the code? It's quite long, about 10 lines of javascript.
Another way would be to store the js to a file and run nodejs script.js, but that would be a useless and slow disk IO...

Important caveat about using exec/shell_exec
I feel the need to prepend a caveat about security to this answer. Always be careful when using exec or shell_exec. You almost always should not be taking data over the network to inject into a shell command for security reasons. Writing the script to a file would be much safer because there is no risk of command injection. If you are confident that this approach is required then I strongly advise you to.
Use the PHP function escapeshellcmd which will try to escape shell control characters.
Really ask yourself how much you trust the source? And how much you trust their security?
Having said that. Here's my original answer to the question as asked:
It sounds like the missing piece for your puzzle is the -e parameter for node. This will allow you to pass a script as part of the command invocation.
E.g.
C:\Users\Cmonahan>node -e "console.log('hello world');"
hello world
You can then use PHP exec or shell exec to get the output.
More information:
PHP shell_exec() vs exec()
Node CLI documentation
Edit: Regarding passing multiline arguments to the command line. This can be a bit of a minefield. For example: It depends on whether it is a Unix-like or Windows environment and then, if Unix-like, what shell is parsing the command.
See for example:
Windows: How to specify multiline command on command prompt?
End of line (new line) escapes in bash
I would recommend just making sure the argument is a single line. In the case of JS you can try minification first, which typically strips out all newlines, and see if that works for you.
Here's a popular PHP based minifier https://github.com/mrclay/minify I believe you should be able to install via composer.

dont know am not that at home with php, with isnt it true that php serves html files to the user at home, so why would it be any different from using a javascript file in a normal html page?
cant you just use:<script src="myscripts.js"></script>"
or <script>"with here your script"</script>
in the file that need to load this javascript?

Pass innerText value of a page to Chrome extension without opening the page

I've been looking all over for this, and I think the problem is that I inherently suck at programming or scripting of any sort, and I don't know the right words to use...
Basically: I want to make a Chrome extension that reads the the innerText value from the ticketing system at the place I work with. As an example...
<span class="infomsg">Tickets Found [<span id="tickets_count">5</span>]</span>
The goal would be for the extension to display the text "5" over the icon.
What's the best way to do this? I've tried configuring the background.html page with an iframe with the URL with the ticket count as the source, but then I run into the cross-domain scripting issue. document.getElementById("tickets_count").innerHTML can't use a specified URL, as near as I've found.
I'm sure I haven't described it very well at all - totally floundering here, to be honest...let me know what I can clarify, and I'll edit my post.
Thanks!

It depends on whether the page you're looking at is static (e.g. the server sends you HTML with this information already in it) or dynamic (e.g. some JavaScript on the page requests additional information and then adds this to the page).
If it's static, you can use XHR to request the page and find the string you need in the "raw" HTML response. You can't use getElementById in that case - you'll need to find a way to find the string yourself.
If it's dynamic, that won't work. An iframe-in-the-background approach is valid - but you can't access the contents of the iframe. Instead, you should inject a content script in that page and request the information you need.
I understand it's a broad answer - but your question is also quite broad.

tracking a javascript found in pagesource

ive tried everything i cud to figure this out, but i cannot track a piece of javascript in a webpage
so, just to give you some context even though my problem is not related to just this scenario. it depends on a much bigger spectrum.
Anyway, im developing on sugarCRM and im trying to edit the default onclick behavior of a slot in calendar module (you dont need to understand this to help me, so please keep reading). when i click on a slot, a modal dialog window opens that lets me log a meeting or a call.
So i tracked down the javascript behind this. ive used firebug and chrome, and they both give a list of all the JS files that are being used on a given webpage
for example i search for "SUGAR.collection" and firebug tells me its located in a file named "sugar_field_grp.js?v=FVh1Z-v5nA6bYov7-aFFqQ" i can see this piece of code resides in sugar_field_grp.js,
but the code im trying to change resides in "index.php?module=Calendar&action=index&parentTab=Activities", firebug actually tells me this is the file that has the javascript i want to change.
I can also right click view page source and i can see that piece of code inside the script tag. so considering this piece of code doesnt reside in a JS file, i cannot change it, its generated at runtime (i think) but there must be some source, there must be a file thats telling sugarCRM to generate this code
tl;dr how to track down a piece of javascript code that resides on pagesource and theres no JS file specified by firebug or chrome save for index.php (this file doesnt have that javascript either)
i know its been a long post
thanks for reading

Learn how to search for strings in files on disk on your machine.
On Linux, MacOS and most unixen the go-to tool for this is grep. This applies to any programming language you work with. For your case simply cd into the directory of your source code and do:
grep -r SUGAR.collection .
If you're using git as your source control tool then git grep is much faster.
On Windows there are various GUI tools you can use to search for text in files. Just google: grep for windows.
If you're using an IDE then just your IDE's find-in-files functionality.

To track down specific code using Chrome / Webkit go through the following two steps:
Client:
1. Search all static text sources
Open the Dev Panel using CTRL + SHIFT + I
Hit CTRL + SHIFT + F for a global search dialog to pop up
Right next to it you can set pretty printing of the JS code to on: button { }
Enter your search term or terms using regular expressions
Optional: Decide if you need a case insensitive search which has a greater searchspace and takes longer
Example:
2. Search the dynamic user-DOM contents
Go to the Tab 'Elements' hit CTRL + F.
Enter your search term (This will also search iframes, svg's etc... within the parent DOM)
3. Recommended:
Cross-reference the results of step 1. and step 2.
If a given string is present in both the DOM and the static sources, then you can assume that the content is not programmatically created on the client-side.
Server:
Many projects perform a media bundling step prior to content-delivery. They pack web-resources into the main file (e.g. index.php) to save HTTP roundtrips.
Use sourcemaps / and or search the entire codebase for a salient static string or a salient keyword near the static string to locate the original source files.
Searching files:
Locally, I generally use the rapid index, and heuristic search of JetBrain's IDE's (IDEA, PHPStorm,...) and Sublime. The grep-command tool can definitely not compete here in terms of performance. On Windows I additionally use Totalcommander and its archive/regex finding abilities.
When quickly looking up code on the server you may use something like:
grep -r -C10 --color=always 'keyword1|keyword2' htdocs/ | less -R
which will also provide you with line-context. two caveats: you may want to filter out binaries first and symlinks outside the scope will be ignored.

Send Javascript code to browser

Is there a way to send javascript commands to an open web running in a browser from the shell?
Let's say I have stackoverflow.com open with Chrome. Well, I'd like to send something like
alert('hi!');
from the shell, with something similar to the following:
$ send -t Chrome -w "stackoverflow.com" -c "alert('hi!')"
I was wondering this, because if I can write alert('hi!') on the javascript console of Chrome, I should be able to do the same with a call somewhere, right?
I've seen node.js but I think is not possible with that, please, let me know if I'm wrong.
I know the question could seem weird but I'm curious, thanks in advance :)

You can send JavaScript to Firefox through the jssh extension.
http://www.croczilla.com/bits_and_pieces/jssh/
This is what the Watir testing framework uses to automate Firefox.
I don't know of an equivalent for Chrome.

For IE seems like you can use good old VBScript: http://www.autohotkey.com/forum/topic7642.html
Worked for me just fine now with IE8. :)
Edit: to open this very question and alert JS value have this code as .vbs file and run it:
Dim oIE
Set oIE = CreateObject("InternetExplorer.Application")
oIE.Visible = 1
oIE.Navigate "http://stackoverflow.com/questions/4992552/send-javascript-code-to-browser/4992812"
Do While (oIE.Busy)
Wscript.Sleep 10
Loop
oIE.Navigate "javascript:alert(fkey);"

I think it is possible if you write and install some browser addon that would receive your signal, and do the job. Interesting question, ill be tracking it.

It is entirely up to the browser to provide this sort of functionality. In fact, the form of your problem isn't specific even to browsers:
I was wondering this, because if I can [provide some sort of input] to [a program] to make it [do something], I should be able to do the same with a call somewhere, right?
Some programs do indeed provide hooks for scripting, but if they don't, you're out of luck. There is certainly no guarantee that if you can do something via the GUI, then you can trigger the same action from a command line call.
Now the fact that most browsers provide some sort of plugin architecture, makes it much more likely that such a plugin exists that will listen for external input in this way, if this functionality is missing in the base product.
However, this is still going to be very specific to the particular model and even version of the browser you want to control - so if it's something you wanted to release into the wild, you'll need to be very specific with your requirements.

You can send arbitrary code to browser through the address bar! For example in AutoHotKey style，
send F6 //focus the address bar
send ctrl+v //given that your code is in clipboard
send enter
Now there is another question. Can we get the return value of the inject code? The answer is YES!
Assign your return value to document.title, and retrieve the window title from your application.
If the return value is too long (eg. a JSON format string), do the trick that
document.title='calculating...';
document.title=returnValue.subString(0,20);
sleep(10);
document.title=returnValue.subString(20,40);
sleep(10);
document.title=returnValue.subString(40,60);
...
document.title='finished';
Hope it works.

Help me to understand <script src="some.js?param1=one;param2=two" />

I observed chunks like below sometimes on web pages. So i am curious to know what this really does? or why its written in such a way?
<script src="somefile.js?param1=one&param2=two" />
i can only make out following few intentions behind it
Its not page URL (i mean .aspx/.php/.jsp etc.) so its not hacking kind of code where user can add code like this to pass data without getting users attention as its tag which does not render on UI OR implementing old type of AJAX alternative
This kind of URL param are useful if user do not wish the JS file (any other resource like image) to get cached. This can be quick way to manage caching
But i am unable to figure out following
Looks like page URL parameters but are these parameters anyway readable in JavaScript file and have some additional utility?
Do these parameters have any extra role to play here ?
What are the other possible practical scenarios where code like this can be/is used?
So please provide some inputs related with the same
Thanks,

Running Non-JS Code within .js Extensions
In cases like this, that source .js file might (given proper server-configurations) actually have PHP/.NET code within it, which can read those appended values.
As you said, Avoiding Cache...
Additionally, people will at times append a random string at the end of their referenced elements to avoid loading cached data.

The URL having '.js' means nothing. It could still be handled by a server-side script like an ASP or PHP.

Either the javascript file is not static (it is generated by the server based on the parameters in its querystring)
OR
In the JavaScript file itself, you can have it check its own querystring parameters (not just that of the page, but that of the javascript source url).
OR
(This doesn't exactly match your scenario, but) you can also add parameters at the end of image and script urls as a way of versioning. The version with the url="somescript.js?V=3" will be cached by the user until the page then changes and the url is not="somescript.js?V=4". The file will be replaced by the version on the server no matter what the browser setting may be.
My guess (without looking at this specific case) is that the javascript file is reading its own querystring. I have done this, and its very helpful.

Looks like page URL parameters but are these parameters anyway readable in JavaScript file and have some additional utility?
Yes you can read them in JavaScript, Scriptaculous uses that approach for loading modules, eg:
<script type="text/javascript" src="scriptaculous.js?load=effects,dragdrop">
</script>
Do these parameters have any extra role to play here ?
What are the other possible practical scenarios where code like this can be/is used?
That can be also used for server-side script joining and minifying, of course using some url rewriting technique to have the .js extension, and as you say, it's a common technique to add timestamp parameters to break the browser cache.

It can be used for three different reasons:
1) To generate the JavaScript file in the server depending on the parameters;
2) To avoid caching;
3) To pass parameters to JavaScript itself

An example of this in practice would be a server side handler for somefile.js that uses the parameters (names of other scripts) to determine which scripts are actually required and combine/minify them, returning them as a single somefile.js script file.