If you know the answer to any of the unanswered questions below please
jump in and help.  You just need to click the "Edit this Entry" link on
the appropriate page.

    http://php.faqts.com

Cheers,

Nathan


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


-------------------------------------------------------------
when uploading binary files, some bytes are become corrupted, but file size isnt changing, why ?
http://www.faqts.com/knowledge-base/view.phtml/aid/724
-------------------------------------------------------------
Dmitry Jo



-------------------------------------------------------------
Is there a way of forcing PHP to require explicit variable declaration, as in PERL with "use strict" ?
http://www.faqts.com/knowledge-base/view.phtml/aid/725
-------------------------------------------------------------
b linc



-------------------------------------------------------------
Dear All, I try to configure PHP3 but it keeps complaining about a missing file /usr/local/apache/bin/apxs. Where can I get this file??? Please Help!
http://www.faqts.com/knowledge-base/view.phtml/aid/726
-------------------------------------------------------------
Ronald Tolboom



-------------------------------------------------------------
Can I create symbolic links using PHP?
http://www.faqts.com/knowledge-base/view.phtml/aid/727
-------------------------------------------------------------
Elrond Sheppard



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


-------------------------------------------------------------
How do I setup so mail() will work under windows?
http://www.faqts.com/knowledge-base/view.phtml/aid/715
-------------------------------------------------------------
Nathan Wallace
Phil Driscoll

No problem. Just set:

    SMTP   = the.mail.server.name   ;for win32 only
    sendmail_from = you@wherever.com ;for win32 only

in your php.ini file and then call the mail function as described in the
manual.


-------------------------------------------------------------
How can I remove profanity from a string?
How can I censor selected words from a string?
http://www.faqts.com/knowledge-base/view.phtml/aid/716
-------------------------------------------------------------
Nathan Wallace
Richard Lynch

Try using this function:

<?php
  function sanitize($text){
    //Any George Carlin or FCC fans remember the whole "deadly 7"list?
    static $naughty = array('shit', 'fuck');
    while (list(,$bad) = each($naughty)){
      $text = str_replace($bad, make_string('*', strlen($bad)), $text);
    }
    return $text;
  }
?>

Note:  Sure wish there was a stri_replace...
And make_string is a PHP4 thing, so you may need to roll your own.


-------------------------------------------------------------
Can I change NT registry settings from PHP / Apache?
http://www.faqts.com/knowledge-base/view.phtml/aid/728
-------------------------------------------------------------
Nathan Wallace
Richard Lynch

Scary!

Okay, presumably you know what you're doing to edit the settings...

Assuming the user that Apache is logged in as is capable of executing
and editing whatever needs to be executed and edited, you could use
exec() to run command-line registry-editing programs...


-------------------------------------------------------------
Why do I get this error '403.1 Forbidden: Execute Access Forbidden' with PWS?
http://www.faqts.com/knowledge-base/view.phtml/aid/729
-------------------------------------------------------------
Nathan Wallace
yorke, The Eyrie

This error can be caused if you try to execute a CGI, ISAPI, or other
executable program from a directory that does not allow programs to be
executed.

You need to set the execute flag on the directory under PWS.


-------------------------------------------------------------
How can I get the class name of an object?
http://www.faqts.com/knowledge-base/view.phtml/aid/730
-------------------------------------------------------------
Nathan Wallace
Richard Lynch, Gregor Welters

PHP4/Zend is supposed to have such a function, I think...

Otherwise, give the class a property named "classname" and fill it with
the classname.


-------------------------------------------------------------
How do I setup PHP on Solaris 7?
http://www.faqts.com/knowledge-base/view.phtml/aid/731
-------------------------------------------------------------
Nathan Wallace
Chad Cunningham

I have it on several Solaris7 machines. I've used gcc and Sun's
workshop C compiler. I'd stick with gcc, it's a bit friendlier. Also
make sure you don't use any of the GNU linking stuff. Basically I use
gcc to compile, but have /usr/ccs/bin/ before any of the GNU stuff on
the path. If you use gnu's ld, you're most likely going to have
problems. We were getting a lot of frequent core dumps with php/apache
until we realized gnu's ld had some issues with building php as a
loadable module.


-------------------------------------------------------------
How can I get the name of the user logged in using HTTP authentication?
What is the REMOTE_USER apache variable for?
http://www.faqts.com/knowledge-base/view.phtml/aid/733
-------------------------------------------------------------
Nathan Wallace
Brent Bearden, Richard Lynch

REMOTE_USER is the name of the user currently logged in using HTTP
authentication.

It is available in PHP as the variable:

    $REMOTE_USER

$REMOTE_USER is set by Apache, or not, depending on the whim of the
configuration in httpd.conf


-------------------------------------------------------------
Why does PHP_SELF contain php.exe?
Why do my URL's contain php.exe?
http://www.faqts.com/knowledge-base/view.phtml/aid/734
-------------------------------------------------------------
Nathan Wallace
Richard Lynch, Robin Gibson

On Windows, when you give any php3 url in the browser, say:

    http://localhost/hello.php3

and the php3 script calls itself in the script from a form submit, i.e:

    <form action=<?php echo $PHP_SELF ?>

then when the script runs the second time, the url changes to:

    http://localhost/php3/php.exe/hello.php3

It seems goofy, but that's how Apache actually does the Action stuff: 
It maps it into a big long URL that has php.exe in it and the script you
want.  So your action definition in the httpd.conf probably looks like
this:

    Action application/x-httpd-php3 "/php3/php.exe"

You can just use ACTION=hello.php3 instead of $PHP_SELF if you prefer.

There is a simple fix.  Just add this line to the beginning of any page
using the $PHP_SELF global:

    $PHP_SELF = str_replace($SCRIPT_NAME, "", $PHP_SELF);

$SCRIPT_NAME contains (e.g..)  "/php3/php.exe" - the path to the PHP
executable. The fix yanks that out of $PHP_SELF.


-------------------------------------------------------------
What is the difference between standard function arguments and passing by reference?
When should I pass function arguments by reference?
http://www.faqts.com/knowledge-base/view.phtml/aid/736
-------------------------------------------------------------
Nathan Wallace
Richard Lynch

Passing by reference is good for two things:

1. Avoid passing a *HUGE* amount of data into a function which must copy
it all and then throw away that copy when it is done.  PHP3 does this
(and only this) using function (&$x)

2. Allow you to *alter* the actual value of a variable:

<?php
  function show($x){
    $x = 3;
    echo "In-Show: $x<BR>\n";
  }
  
  function munge(&$x){
    $x = 4;
    echo "In-Munge: $x<BR>\n";
  }
  
  $y = 2;
  echo "Pre-Show: $y<BR>\n";
  show($y);
  echo "Post-Show: $y<BR>\n";
  echo "Pre-Munge: $y<BR>\n";
  munge($y);
  echo "Post-Munge: $y<BR>\n";
?>

Assuming PHP4 behaves like C, this will output:

Pre-Show: 2
In-Show: 3
Post-Show: 2
Pre-Munge: 2
In-Munge: 4
Post-Munge: 4

NOTE THAT LAST LINE!!! munge actually *changed* the value of $y

Disclaimer:  I probably got the syntax wrong.  But the point should
still be valid...


-------------------------------------------------------------
Do I have to close database connections at the end of my scripts?
http://www.faqts.com/knowledge-base/view.phtml/aid/723
-------------------------------------------------------------
Nathan Wallace, Mike S. Krischker


No.

If you are using persistent connections they won't be closed, even if
you do call the close function for your database.  They remain connected
until the Apache process is killed.

If you are not using persistent connections then the connection will be
closed automatically by PHP at the end of script execution.

Having said all that, it's probably good programming technique / style
to close your connections.


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


-------------------------------------------------------------
What does an ampersand (&) before a function parameter do?
How can I pass a variable by reference to a function?
http://www.faqts.com/knowledge-base/view.phtml/aid/134
-------------------------------------------------------------
Nathan Wallace
Chad Cunningham

It passes the variable by reference, which is to say that rather than
passing the function the contents of the variable, it passes the memory
address of the variable instead.

See function -> Passing by Reference -> Arguments in:

    http://www.php.net/manual/control-structures.php3


-------------------------------------------------------------
Can I close a persistent connection?
Are persistent connections ever closed?
What causes the error 'MySQL Connection Failed:  Too many connections' ?
http://www.faqts.com/knowledge-base/view.phtml/aid/230
-------------------------------------------------------------
Nathan Wallace
Paul DuBois, Chad Cunningham, Nathan Wallace

You cannot close a persistent connection in PHP.  Closing a persistent
link in a script defeats the purpose of having a persistent link. If you
want to close it, just open the connection with mysql_connect() so that
you can close it.

One persistent connection is established for each Apache child process
the first time that the database connect is called in the lifetime of
that process.  For more info about persistent connections see:

    http://www.php.net/manual/features.persistent-connections.php3

In Apache the child process only serves a certain number of requests
before it is killed and a new child started.  When the process is killed
the connection to the database that it held will be closed.  Hence, your
database connections do have a finite lifetime.

Here is an excerpt from:

    http://www.apache.org/docs/mod/core.html#maxrequestsperchild

    The MaxRequestsPerChild directive sets the limit on the number of
    requests that an individual child server process will handle. After
    MaxRequestsPerChild requests, the child process will die. If 
    MaxRequestsPerChild is 0, then the process will never expire.

    Setting MaxRequestsPerChild to a non-zero limit has two beneficial
    effects: 

      * it limits the amount of memory that process can consume by
        (accidental) memory leakage; 

      * by giving processes a finite lifetime, it helps reduce the
        number of processes when the server load reduces.

If you run an extremely high traffic site which does a lot of database
requests then you may need to be careful.  Although Apache/PHP has lost
the connection to the database and no longer uses it, MySQL does not
necessary close the connection.  Your timeout settings for httpd
processes and MySQL persistent connections need to be configured
properly.

The time the connection stays open relies on mysql settings. If you do:

    mysqladmin variables

you will see something like this:

+----------------------------+---------------------------------------+
| Variable_name              | Value                                 |
+----------------------------+---------------------------------------+
| back_log                   | 5                                     |
| connect_timeout            | 5                                     |