Questions in: Core PHP

You can insert the content of a file into a PHP file before
the server executes it, with the include() or require()
function.
The two functions are identical in every way, except how
they handle errors.
The include() function generates a warning but the script
will continue execution while the require() function
generates a fatal error and the script execution will stop
after the error.

include() produces a Warning message where as require()
gives Fatal Error.

$_SERVER['REMOTE_ADDR']

echo $_SERVER['REMOT_ADDR'];
it returns client IP Address

Yes, we can
<?php
//Connect access database
$con=odbc_connect("DRIVER={Microsoft Access Driver
(*.mdb)}; DBQ=" . str_replace("/", "\", $_SERVER
["DOCUMENT_ROOT"]) . "foldernamedbname.mdb", "db_username"
, "db_password")or die("could'nt connect database");
if (!$con) {
die('Could not connect: ' . odbc_error());
}
?>

ya its working niceley in my local system
still i have to check in server...
any way code is connecting database.

we can use count() function for it like
count($_POST) ;

think count($_POST) will work.check it out.

This type of error will be displayed when mysql extension is
not enabled in your configuration file. This means,
mysql_connect is not supported.

"Call to unsupported or undefined
function mysql_connect();"
these message is displayed when mysql dll file is not
specified in php.ini file or .dll which support mysql is
comment on php.ini file.

No. it is not possible

Why it is not possible??

hyper text preprocessor

PHP (recursive acronym for "PHP: Hypertext Preprocessor")

Yes, it is possible to get screen resolution. But much more
easy with javascript:
Use => screen.width && screen.heigth

we need to change htpd.conf file for this ........have to
specify the extension which apache will parse as PHP file.

use rand() or mt_rand()
example:rand() or rand(20,30);

using rand() function we generate the random numbers.
example : $num="12345678";
$result=rand($num);
the $result gives the random numbers.

<?
print ".PHP";
?>

<?
echo 'PHP';
?>
this file save as .php extention.

We would recomend using GnUPG not PGP, GnUPG can be used for
comercial sites without a license.
You will need shell access, i.e. telnet or SSH. SSH is more
secure. Also a linux machine and a copy of PGP installed on
your machine. You will also need to generate a key pair,
this consists of a public and private key. The public key is
uploaded to the server the private key is kept on your
machine. See the PGP help file for more information.
GnUPG must be installed, (Check with your server admin)
Access the shell as your user then do the following command :-
mkdir .gnupg
chmod 777 .gnupg
gpg --gen-key
use a dummy name and when it gets to the bit where it
generates the keys make sure the machine is doing I/O to get
the entropy.. ie. telnet in again and do a du / or something
its best to have this ready and just hit enter as you finish
the key creation
This creates a dummy key pair, this is not used but is needed.
This takes anything from a few seconds to a few minutes
depending on the speed of the server.
as the user, just ftp the ascii public key to the server.
This will be called something.asc. Upload it making sure its
ASCII not binary (See your FTP software help file)
then type ..
gpg --import file.asc
Then ..
gpg --list-keys
get the name of the new key that was uploaded, this will be
something like :-
pub 1024D/FA46F142 2000-11-03 Darren Casey
The next part is to set the permissions for the .gnupg
directory so the webserver can access the files. Type the
following commands :-
cd .gnupg
chmod 666 trustdb.gpg
chmod 604 secring.gpg
chmod 604 random_seed
chmod 644 pubring.gpg

$d=450;
$d = str_pad($d,6,0,0);
echo $d;
OUT PUT
000450

Using sprinf("%04d",$num);
The above function will return a number of length 4.

Basicaly, any output to screen before an header function,
gives rise to this error.

When page has html doctype on the starting of page.or some
echo statement on page when page is return or there is
header function on same page.

By utilizing the com_load and the dotnet_load respectively
you can incorporate COM objects and .NET libraries into your
PHP code, thus anytime you see "library code" in a question,
make sure you remember these two functions.

Unset can be used for empty the value of variable or contents of file but unlink destroy file.

unlink: is used to delete a file unset is used to destroy an eralier declared variable

here are three basic types of runtime errors in PHP:
1. Notices: These are trivial, non-critical errors that PHP
encounters while executing a script - for example,
accessing a variable that has not yet been defined. By
default, such errors are not displayed to the user at all -
although you can change this default behaviour.
2. Warnings: These are more serious errors - for example,
attempting to include() a file which does not exist. By
default, these errors are displayed to the user, but they
do not result in script termination.
3. Fatal errors: These are critical errors - for example,
instantiating an object of a non-existent class, or calling
a non-existent function. These errors cause the immediate
termination of the script, and PHP?s default behaviour is
to display them to the user when they take place.

As per above answer, PHP gives one more error message that
is :
Parse Error: When we make mistake in PHP code like, missing
semicolon or any unexpected symbol in code

imagetypes ? Return the image types supported by this PHP
build
This function returns a bit-field corresponding to the
image formats supported by the version of GD linked into
PHP. The following bits are returned, IMG_GIF | IMG_JPG |
IMG_PNG | IMG_WBMP | IMG_XPM
Example 1. imagetypes()

errors are classified into 3 types
1.fatal errors
2.parser errors
3.startup errors

Its three types
1. Fatal error : this will stop the script.
2. Warning
3. Notice