Web Development

Maybe I am missing something...

My knowledge of PHP is near >NIL: but why open a file for read ONLY!

If you want it to delete the file on write then why not have it "w+" ...

He doesn't do anything to the file contents but read them.

Deleting the file is controlled by the permissions on the directory.

Corona688 -

Thanks.

On the mark.

Can we now make the C program and PHP script talk to each other w/o deleting the file?

It does not delete the file. I suspect it never created it in the first place. A web server has write-access to nearly nothing, and this is intentional. I'm still unsure what the point is of creating a file at all.

Try writing to /tmp/ instead of /var/www.

Corona688 -

Thanks.

The only way way [maybe there are easier ones] I know of talking to a COM port is thru C.

Definitely created. If I run the C program as a stand alone, the file is created and I can read it. Moreover, I know the weight and the correct weight is written to the file.

I will try /temp/ when I get home tonight. [I am assuming you are stating that a temp file is not deleted.]

Can you please suggest some books that will help me and give me facts that you note above.

Thanks again, and I will keep you posted.

I know for a fact that an ordinary webserver cannot and should not write files to /var/www/. That would be a security hole large enough to drop the moon through, with Jupiter and Sirius for change. It's blocked on purpose, to limit the damage a program bug -- or an outright hacking attempt -- can do. When it's blocked, an attacker can't drop malicious programs there even if they try.

It blocks it by running it as a different user. This is why you had to chmod 666 the device file, too. You have access to the device -- the webserver does not. This isn't related to the owner of the program at all, any more than ls would run as root just because root owns it.

There are a few very specific and tightly controlled places your web server is allowed to write, /tmp/ is the main one. Not /temp/, /tmp/. Please give it a try.

Corona688 -

Will try your suggestion when I get home tonight.

Thanks ever so much. I appreciate your patience and courtesy.

As I stated in the previous post, any ideas on books?
I really do not totally understand what you said in your post. It is my job to dig it out of the appropriate books.