Thanks to everyone who is contributing answers and improvements.  Keep
them coming! :)

    http://php.faqts.com

cheers,

Nathan


## Unanswered Questions ########################################


-------------------------------------------------------------
How can I find out what the date of the last monday was without year/month concerns?
http://www.faqts.com/knowledge-base/view.phtml/aid/2988
-------------------------------------------------------------
Dave Mitchell



-------------------------------------------------------------
Scalability of PHP. Is it possible to scale a PHP system to several computer through loadbalancing or similar??? HOW??
http://www.faqts.com/knowledge-base/view.phtml/aid/3013
-------------------------------------------------------------
Christian Bjørnbak



-------------------------------------------------------------
How do you get Xitami & php4 to work together with xitami aliases?
http://www.faqts.com/knowledge-base/view.phtml/aid/2986
-------------------------------------------------------------
Mike Lavengood



-------------------------------------------------------------
Help, how to I get php4 to build on HPUX 10.20 with gcc 2.7.2 - the *time_r functions bomb it out
http://www.faqts.com/knowledge-base/view.phtml/aid/2991
-------------------------------------------------------------
Jim Sauber



-------------------------------------------------------------
Why can't I run php from command line?
http://www.faqts.com/knowledge-base/view.phtml/aid/1746
-------------------------------------------------------------
Charles Chan, Henrik Hansen



-------------------------------------------------------------
can php update a textfile that i can use for a flash movie?
http://www.faqts.com/knowledge-base/view.phtml/aid/3025
-------------------------------------------------------------
philipp schiedl



-------------------------------------------------------------
Windows 98, PHP4RC2 - mail function does not work. Anyway what happened to the php3_*.dll's? Will there be a PHP4 version?
http://www.faqts.com/knowledge-base/view.phtml/aid/2992
-------------------------------------------------------------
Atanas Kebedjiev



## New Entries #################################################


-------------------------------------------------------------
I'm looking for doc's on php_admin_value and php_admin_flag. Any idea where I could find them? I have looked at zend.com and php.net with no luck.
http://www.faqts.com/knowledge-base/view.phtml/aid/2990
-------------------------------------------------------------
Thomas J. Mackie III, Nick Vasilogianis
taken from "Professional PHP Programming"

php_admin_value: name value - This sets of admin related variable 
specified by name to value.  Administrative configuration settings can 
only be set from within th emain Apache configuration file(httpd.conf), 
and not from the .htaccess files.

php_admin_flag: name on|off - This is used to set to either on or off 
any admin-related boolean configuration option specified by the name.


-------------------------------------------------------------
Can I use PHP with Oracle on Windows?
How do I enable the Oracle functions with PHP on Windows?
http://www.faqts.com/knowledge-base/view.phtml/aid/3010
-------------------------------------------------------------
Nathan Wallace
Gregor Zurowski, Zack Beatty

Yes, it does have Oracle 8 support. Include the php3_oci80.dll in your
php.ini file (via extentsion=php3_oci80.dll). Then you can use all OCI
function described in the manual. Don't forget to install Net8 on your
machine.

Here are the "php3_oci73.dll" functions that you are using (i.e.
ora_logon):

    http://www.php.net/manual/ref.oracle.php3

Here are the "php3_oci80.dll" functions you should be using (i.e.
OCIlogon):

    http://www.php.net/manual/ref.oci8.php3

You need to change all of the old Oracle functions to the new ones in
order to use the new oci80.dll.


-------------------------------------------------------------
Why do I keep getting a "permission denied" error for Postgres queries?
How can I give a user permissions in Postgres?
http://www.faqts.com/knowledge-base/view.phtml/aid/3026
-------------------------------------------------------------
Nathan Wallace
Doug Semig

This answer assumes that you want the Postgres user "nobody" to have
permissions.

What you have to do now is GRANT permissions for the user "nobody" to do
things with your tables.  Log in to psql as the owner of the database
and type in:

GRANT SELECT, INSERT, DELETE, UPDATE ON tablename TO nobody;

Type that line in for each table your web application will need to run
select, insert, delete, and update queries on.  Note that if you don't
want to grant the "nobody" user the ability to delete or update, then
you'd leave those out of the GRANT statement.


-------------------------------------------------------------
What are the advantages of storing session data in a database and not a file?
Should I use database session handling or file session handling?
http://www.faqts.com/knowledge-base/view.phtml/aid/3027
-------------------------------------------------------------
Nathan Wallace
Sascha Schumann, Richard Lynch

You need a database in the central-database, multiple-front-web-servers
scenario. If you have only one web server, files are good enough.

I'm thinking that once you have a database connection open, an extra
query to get their session info is probably less than opening / read /
closing a file...

If you're not already using a database, a straight file-system will be
faster, probably.

Caveats:
You really should spend time building samples and "fake" data and
pounding on a server to see where the bottle-neck is going to be, and
fixing that bottle-neck to get the most bang for the buck, but it
shouldn't be too hard to do a side-by-side comparison of file versus
database session-handling with sample date for your system.

The file-system solution won't scale to multi-tier architecture too
well.  The database system will, assuming you can scale your database in
the first place.


-------------------------------------------------------------
How can I create a color a shade darker than a given hex value?
http://www.faqts.com/knowledge-base/view.phtml/aid/3028
-------------------------------------------------------------
Nathan Wallace
Phil Driscoll

Extract the individual colour components using & and shifts, multiply by
a suitable factor (eg 0.9) then recombine

  $Red=intval((($Color & 0xFF0000)>>16)*0.9);
  $Green=intval((($Color & 0xFF00)>>8)*0.9);
  $Blue=intval(($Color & 0xFF)*0.9);

  $Color=($Red<<16)+($Green<<8)+$Blue;

Someone who understands operator precidence better than I do could
probably lose a few brackets. There's also probably some cute trick
which does the entire job in one shot.


-------------------------------------------------------------
How can I access a secure database server from a PHP web server?
How should I setup my web server network so the database server is not accessible to people?
http://www.faqts.com/knowledge-base/view.phtml/aid/3029
-------------------------------------------------------------
Nathan Wallace
Rick Widmer

You establish a second, separate network between the web servers and the
database server.  As long as the web servers don't forward packets the
two networks can never communicate, yet the web servers can access both
the Internet and the database server.

The key to security is not so much locking down the ports on the
database server as making sure the web servers do not forward packets
to/from the Internet. I'm not saying don't lock down unneeded ports,
that is common sense, just pointing out the key is not forwarding
packets thru the web servers.

How to set it up...


Database Server:

This machine is fairly normal and has only one network card. Shut off
everything but the database server.  No sendmail, httpd, etc. Disable
anything you don't _need_ in inetd.conf. If you don't need any inetd
services don't start the daemon.  

Pick an IP address from RFC1918 address space. (10.x.x.x, 192.168.x.x
and one other block I don't remember.) Add this address to your
/etc/hosts files or DNS so web server(s) can find the database server.


The Database Network:

Connect the database machine to a new hub or switch that is NOT
connected to the Internet.  If there is only one web server you can use
a crossover cable.  Connect the second network card in each web server
to the database network hub.  Make SURE it connects to nothing but web
servers that need access to the hidden database server.  One possible
exception would be a backup server. (As in a box with a tape drive.) It
would be able to see the web servers and the database, but not the
Internet, or your news and mail servers.


Web server(s):

Add a second network card.  Pick an RFC1918 address in the same subnet
as the database server.
Connect it to the database network.

Make sure IP forwarding is OFF, so the machine will not route packets
from one interface to the other.  THIS IS VERY IMPORTANT!!!  I compile
static kernels with IP Forwarding disabled for my servers.

Make sure the database server is referenced in /etc/hosts or DNS so you
can list it by name in the hostname parameter of all your scripts.

Start pointing your scripts at the hidden database server.


-------------------------------------------------------------
Why are there 2 functions : OCIParse and OCIExecute?
http://www.faqts.com/knowledge-base/view.phtml/aid/3030
-------------------------------------------------------------
Nathan Wallace
Arnaud Megret

It enables to bind in and out PHP variables with the query.  It is
possible to call OCIEXecute() multiple times after one call to OCIParse.
So you could bind variables to the SQL query, and executes it several
times changing the values of the binded variables before each call to
OCIExecute. Thus improving speed...


## Edited Entries ##############################################


-------------------------------------------------------------
How do you install OpenLDAP with PHP and Apache?
http://www.faqts.com/knowledge-base/view.phtml/aid/808
-------------------------------------------------------------
Joshua Starr, Henrik Hansen
PHP manual

You should compile PHP with the following configure flag:

--with-ldap=DIR

Where DIR is where LDAP is installed.


-------------------------------------------------------------
Does PHP work on an AIX platform?
http://www.faqts.com/knowledge-base/view.phtml/aid/1346
-------------------------------------------------------------
Jimmy A Blanco, Henrik Hansen


Yes the PHP source code should work on most unix platforms, including 
AIX


-------------------------------------------------------------
how can i compile php with mcrypt correctly? i tried, but failed.
http://www.faqts.com/knowledge-base/view.phtml/aid/1336
-------------------------------------------------------------
lily xie, Henrik Hansen, Nathan Wallace
PHP Manual

Compile PHP with the following configure flag:

--with-mcrypt

Which includes support for the mcrypt library. See the mcrypt 
documentation for more information[1]. If you use the optional DIR
argument, PHP will look for mcrypt.h in DIR/include. 

1. The documentations is here:
http://www.php.net/distributions/bigmanual.html#REF.MCRYPT


-------------------------------------------------------------
On which Operating systems is PHP (successfully) running?
http://www.faqts.com/knowledge-base/view.phtml/aid/2030
-------------------------------------------------------------
Wolfgang Schaefer, Henrik Hansen
PHP 3.0 maillinglist

php will run at least on the following platforms:

Linux, Unix, Windows NT, Macintosh, VMS and OS/2.


-------------------------------------------------------------
Is it possible to use dl("sharedlib.so") under linux, similar to the way it used under Windows?
http://www.faqts.com/knowledge-base/view.phtml/aid/2096
-------------------------------------------------------------
Scott Brause, Henrik Hansen


Yes it is, for example if you want to load the mysql functions do:

dl(mysql.so);


-------------------------------------------------------------
For maximum performance, should I use global vars when calling my own function, or should I pass the required vars as args?
http://www.faqts.com/knowledge-base/view.phtml/aid/2165
-------------------------------------------------------------
Steven Campbell, Marek Narkiewicz
www.php.net/manual

As I see it the most efficient and thus faster way would be to declare 
the variables global within the function. The tidiest code would result 
from passing the variables to the function. Therefore a good compromise 
would be to pass the variables to the function by reference rather than 
by value.
function foo($arg){
    echo $arg;
}
$word = "sheep";
foo(&$word);

this will echo "sheep"
This is more efficient as the variable in the function is only a 
pointer to the variable outside the function and can help you to 
maintain good code.
hth.


-------------------------------------------------------------
How do I install php3, mysql and apache on windows95?
http://www.faqts.com/knowledge-base/view.phtml/aid/2354
-------------------------------------------------------------
Preeti Sikri, Henrik Hansen


Look at this page which has docomentation on how to install 
php/mysql/etc on windows platforms

http://www.umesd.k12.or.us/php/win32install.html


-------------------------------------------------------------
What should I do to make my php to work with MySQL ?
http://www.faqts.com/knowledge-base/view.phtml/aid/2520
-------------------------------------------------------------
Antony Lee, Henrik Hansen
PHP manual

Compile PHP with:

--with-mysql=DIR

Which enables MySQL support. The parameter to this option is the MySQL 
install directory and defaults to /usr/local. This is the default 
installation directory of the MySQL distribution.

Bofore doing this you should have a working mysql server installed on 
your system.


-------------------------------------------------------------
Is there a port of PHP for OpenVMS?
http://www.faqts.com/knowledge-base/view.phtml/aid/2863
-------------------------------------------------------------
Istvan Banfi, Henrik Hansen


Yes the php source should compile under vms platforms.


-------------------------------------------------------------
What is PHP?
http://www.faqts.com/knowledge-base/view.phtml/aid/2881
-------------------------------------------------------------
Nathan Wallace, Tyler Bannister
Andrei Zmievski

PHP is a general-purpose scripting language that is especially suited
for Web development and can be embedded into HTML. Its syntax is
similar to C, Java, and Perl. PHP runs on many different platforms and
can be used as a standalone executable as well as under many web
servers.  It has excellent support for databases, various Internet
protocols, and general data manipulation. PHP can be extended through
its powerful API to include additional functionality.


-------------------------------------------------------------
How can I add/write to an existing file?
http://www.faqts.com/knowledge-base/view.phtml/aid/2650
-------------------------------------------------------------
Henrik Jönsson, Peter Morrissette, Colin Viebrock, Nathan Wallace
http://www.php.net/manual/function.fopen.php3

I generally do this (perhaps not the best way of doing it, but it 
works!):

Read the file you want to change into an array (or string).

Then add the changes to it accordingly (ofcourse this means you have to 
know where to add it) then write the file again.

Ex. (to add at the end of the file);


// set where the file is located
$file_path = "filepath & filename";


// start reading in the file into the array
$fileopen = @fopen($file_path, "r");

if (!$fileopen) { echo "Can't open file"; }

for ($i=0; $buffer = fgets($fileopen, 16192); $i++) {
  $arr_file[$i] = $buffer;
}

fclose($fileopen);


// this is what you want to add
$str_toadd = "This i want to add";


// write the file
$fileopen = @fopen($file_path, "w");
  for ($i=0; $i < sizeof($arr_file); $i++) {
    fwrite($fileopen, $arr_file[$i], 16192);
  }
  fwrite($fileopen, $str_toadd, 16192);
fclose($fileopen);

As said earlier, probably a bit messy, but I've had no worries using it.


--------------

If you are simply appending to the end of an existing file, then you 
should just use the append switch to fopen():

<?
    $fp = fopen($filename, "a");
    fwrite($fp, $newdata);
    fclose($fp);
?>

Just a *bit* cleaner. :)