"tail"ing a file in PHP

[Anon]

I've been thumbing through here for a while and can't find exactly what I want. Though, I have made quick progress from one post that gave me the code (slight modified) below. Basically, what I want to do is similar to the "tail -f" unix command. The following does this:

$returnString = system("tail -f ./temp.txt");

Although, it doesn't format a text file properly. Minor annoyance as I seem to recall a way around that. I guess my question is, is this the best way to go about doing this? Is there already a function or something that will do this for me? (I didn't see one, but may have searched for the wrong thing).

Thanks.

[Anon]

I haven't tested this, but is the format incorrect because of missing <BR>'s? If so, use
$returnString = nl2br(system("tail -f ./temp.txt"));

This will only correct the problem if you are echoing the $returnString to an html page

[Anon]

To be honest, the only line I had in my .php file was the one I pasted here. 🙂 It was simply a test to see how I could make things work. Using the line you suggested doesn't seem to work either. Really I don't even need the variable (Which I assigned and didn't even use). The following line does the same as before, although the text is still not formatted correctly. (no <br> tags)

echo nl2br(system("tail -f ./temp.txt"));

My guess is that the system() call is messing it up, it perhaps never exists that function so it can execute the nl2br function. My backup for this is there are lots of left over processes kicking around my box. It doesn't shut itself off.

[Anon]

I'm a little unclear what the -f is supposed to do for you in this case. Doesn't it cause tail to run "forever" so it can continue to display the end of the file as it (potentially) grows by another app appending data to it?

[Anon]

That is exactly what it is supposed to do. The reason behind all this is that I have quite a few log files that I need access to all the time. Its becoming a pain to log into each server and type "tail -f filename.txt" each time. I had a vision of a nice web page that I could simply click on the name of the file and it would start displaying in a web page in real time. Meaning, as soon as there is a change in the file, I would like to see it on my web page display. I certainly can't be the first person to think of this, though I can't find where anyone else has done it in any language.

[Anon]

It's the continuous display that's the problem. Wouldn't it be good enough to click on the link and get a static snapshot of the tail of the file at that moment? If you liked, you could embed a meta refresh in the page so it re-tails the file every n seconds. But HTML and HTTP simply weren't designed for long-lived connections.

[Anon]

Thats what I'm finding with this. I was hoping that it could stream the file somehow. Like a realtime Real Media file of a news broadcast or something. Perhaps there is another way of going about this. I'm certainly the first to say my way isn't always best.

[Anon]

Like a realtime Real Media file

Don't get led astray by the fact that your browser can launch such a thing. There's a server at the sending end and a client at the receiving end, and neither of them speak http nor send data in html format. But sure, if you wanted to write a streaming-data server and client, you could certainly launch it from your browser, too. Say! Isn't that sort of what Pointcast was all about?

[Anon]

Well, the real media thing was just an example really. At any rate, I've decided to quit messing with it and just do the following:

$output = tail -n 50 ./temp2.txt;
echo "<pre>$output</pre>";

Throw a meta refresh (thanks) at the beginning and deal with that. At least it doesn't make IE make that stupid clicking sound when it refreshes, whish is surprising.

[Anon]

At least it doesn't make IE make that stupid clicking sound when it refreshes

Hey! Figure out a way to cure that, and you can retire early.

[Anon]

I have seen tail -f outputted to an HTML file in real time, but using Perl. I too am looking for a way to do this in PHP to view our log files in real-time.

So, I know that HTML/HTTP can do this, but not how to reproduce this in PHP.

Any ideas anybody?

[Anon]

I've accomplished this however I can only get it to work in IE.

you can get my script at:
http://216.147.67.63/Downloads/Files/PHPTail.php.gz