writing to files

Anon

I want to log each visitors IP address and time of visit into a file. Does PHP handle flocking?

Here is my code for writing

if ($file=fopen("visitor.log", "a")) {
fputs($file, "$visitorinfo\n");
}

Please tell me if that will write the $visitorinfo into the file?

Also tell me if filelocking is needed and does PHP automatically do or do I have to add some code to it. If it needs it, can you add the neccessary code!

Please respond as soon as possible!

Thanks in advance!

Anon

Yep. That code will do it. There is a Php file locking function...

You can use the following code:

if ($file=fopen("visitor.log", "a")) {
flock($file, 2);
fputs($file, "$visitorinfo\n");
}

Anon

Yep. That code will do it. There is a Php file locking function...

You can use the following code:

if ($file=fopen("visitor.log", "a")) {
flock($file, 2);
fputs($file, "$visitorinfo\n");
}

Anon

What happens if another flock() command has been right before another call to it? Does the one call wait for it to be unlocked?

I have a counter function which is writing the current visitor count and logging IP address of visitors. However, I'm NOT locking the file right now. I would assume I would have to to avoid concurrent read/writes.

Anon

What do you mean.

If you have a program that writes to two files.

It will write them in the order your wrote the script.

If two people access the site, the first person will be listed first and then the second.

Anon

Sorry, maybe I was unclear.

I have a script that writes to ONE file. What happens when the script is execute simultaneously by 2 or more people? Do I need to worry about locking?

Anon

Yes you do or the file and/or server will be screwed up and data may be lost.

I wasn't sure if PHP does it automatically or not so I asked the question, but yes you should lock your files.

In this post, someone showed an example.