file_exists(“test.txt”);

is_file(“test.txt”);

is_dir(“/temp”);

Checking States

is_readable(“test.txt”);

is_writable(“test.txt”);

is_executable(“test.txt”);

Determining File Size

filesize(“test.txt”);

Getting Date information

fileatime(“test.txt”) //last accessed time

filemtime(“test.txt”) // last modified time

filectime(“test.txt”) // last changed time

Creating file and Delete

touch(“myfile.txt”)

unlink(“myfile.txt”)

Open file for writing, reading, appending

$fp = fopen(“test.txt”, “r”);

$fp = fopen(“test.txt”,”w”);

$fp = fopen(“test.txt”, “a”);

mkdir(“testdir”);

Remove Directory

rmdir(“testdir”);

Open a Directory for Reading

$dh = opendir(“testdir”);

Reading the contents of Directory

$dirname=”.”;

$dh = opendir($dirname) or die (“Couldn’t open dir”);

while(!(($file = readdir($dh)) === false)){

if (is_dir(“$dirname/$file”)){

echo “(D)”;

}

echo $file.”<br/>”;

}

closedir($dh);

fopen() returns false when the file can not be openned.

if ($fp=fopen(“test.txt”, “w”)){

//do something

}

Close File

fclose($fp);

Reading from file

fgets($fp, 1024);  // get 1024 bytes

feof($fp);  // end of the file

fread($fp, 16);  // get 16 bytes

fseek($fp, 64);  // move point to particular byte

fgetc($fp);  // get the first letter

fwrite($fp, “Hello World”);  //write into file

fputs($fp, “Hell world again”); // add into file

Looking Files

flock($fp, LOCK_SH); //share

flock($fp, LOCK_EX); //exclusive

flock($fp, LOCK_UN); //unlock

Now you know which is my suggestion.Introduction: The Basics
Chapter 1: The FAQs of Life
Chapter 2: Reconfiguring PHP to Do Your Bidding
Chapter 3: PHP Security
Chapter 4: Security Measures
Chapter 5: Working with Words and HTML
Chapter 6: Working with Dates
Chapter 7: Working with Files
Chapter 8: Tracking and Controlling Users
Chapter 9: Working with Email
Chapter 10: Working with Pictures
Chapter 11: Working with Web Pages
Chapter 12: Intermediate Tricks

It covers a lot of area of PHP programing. The tips it provides are so important and many people may omit.

phpBB’s official site is hacked because of this issue for weeks.

To upgrade phplist is simple.

1. BACKUP your database!
2. BACKUP your old config.php file, or optionally backup your whole PHPlist so you can rollback if something would go wrong.
3. Replace your old PHPlist with the new version.
4. Copy your configuration files to lists/config or re-edit the new config file.
5. Go to http://yourdomain/lists/admin/∞ and choose the Upgrade link in the System Functions section.
6. Click the link in this page.

The most updated one is v2.10.9.

OK. Now my list is safe and other content of this site is safe even.

The strpos() function is used to search for a string or character within a string.

If a match is found in the string, this function will return the position of the first match. If no match is found, it will return FALSE.

Let’s see if we can find the string “world” in our string:

<?php
echo strpos(“Hello world!”,”world”);
?>

The output of the code above will be:

6

As you see the position of the string “world” in our string is position 6. The reason that it is 6, and not 7, is that the first position in the string is 0, and not 1.

The strlen() function is used to find the length of a string.

Let’s find the length of our string “Hello world!”:

The output of the code above will be:

The length of a string is often used in loops or other functions, when it is important to know when the string ends. (i.e. in a loop, we would want to stop the loop after the last character in the string)

In this tutorial we are going to look at some of the most common functions and operators used to manipulate strings in PHP.

After we create a string we can manipulate it. A string can be used directly in a function or it can be stored in a variable.

Below, the PHP script assigns the string “Hello World” to a string variable called $txt:

The output of the code above will be:

Now, lets try to use some different functions and operators to manipulate our string.

The Concatenation Operator

There is only one string operator in PHP.

The concatenation operator (.) is used to put two string values together.

To concatenate two variables together, use the dot (.) operator:

The output of the code above will be:

If we look at the code above you see that we used the concatenation operator two times. This is because we had to insert a third string.

Between the two string variables we added a string with a single character, an empty space, to separate the two variables.

When a variable is set it can be used over and over again in your script

All variables in PHP start with a $ sign symbol.

The correct way of setting a variable in PHP:

$var_name = myvalue;

New PHP programmers often forget the $ sign at the beginning of the variable. In that case it will not work.

Let’s try creating a variable with a string, and a variable with a number:

<?php
$txt = "Hello World!";
$number = 18;
?>

Variable Naming Rules

* A variable name must start with a letter or an underscore “_”
* A variable name can only contain alpha-numeric characters and underscores (a-Z, 0-9, and _ )
* A variable name should not contain spaces. If a variable name is more than one word, it should be separated with underscore ($my_string), or with capitalization ($myString)

I prefer to use following format

via