Dates in PHP (Tomorrow, Yesterday, Today of a Given Date)
<?php
echo “<h4>Date Yesterday</h4>”;
$yesterday = date(“Y-m-d”, time()-86400);
echo $yesterday;
echo “<h4>Date Today</h4>”;
echo date(“Y-m-d”);
echo “<h4>Date Tomorrow</h4>”;
$tomorrow = date(“Y-m-d”, time()+86400);
echo $tomorrow;
echo “<hr>”;
echo “<h4>Previous Date from User-defined Date</h4>”;
$gdate = “2008-07-11”;
echo “(” . $gdate . ” supplied.) <br>”;
$dt = strtotime($gdate);
echo date(“Y-m-d”, $dt-86400);
echo “<h4>Next Date from User-defined Date</h4>”;
echo “(” . $gdate . ” supplied.) <br>”;
$dt = strtotime($gdate);
echo date(“Y-m-d”, $dt+86400);
// DAYS IN BETWEEN TWO DATES
function days_in_between($s, $e){
$d = array();
$s = strtotime($s);
$e = strtotime($e);
for($n=$s; $n<=$e; $n=$n+86400){
array_push($d, strftime(“%Y-%m-%d”, $n));
}
return $d;
}
?>
Useful PHP Functions
These are three of my favorite PHP functions. đ
string file_get_contents ( string $filename [, int $flags [, resource $context [, int $offset [, int $maxlen ]]]] ) – Get the contents of a url.
Example:
// following code will display the contents of the web page http://www.example.com $url = “http://www.example.com”; $contents = file_get_contents($url); echo $contents; |
bool mail ( string $to , string $subject , string $message [, string $additional_headers [, string $additional_parameters ]] ) – Requires an email server. This functions programatically sends an email based on the given parameters.
Example:
// send an email to someone@somedomain.com $to=”someone@somedomain.com $subj = “example”; $message=”this is an email”; if(mail($to, $subj, $message)) echo “Email was sent”; else echo “Email sending failed.”; |
int fwrite ( resource $handle , string $string [, int $length ] ) – Write something to a file. Note that the file and it’s parent directory should have permissions granted to a user such as “apache” or “www-data”.
Example:
// open a file called test.txt and if it does not exist, attempt to create it; place the pointer at the begining of the file $handle = fopen(“test.txt”, “a+”); $data = “I am programatically written.\n”; fwrite($handle, $data); fclose($handle); |
I’ll stick with these 3 functions for the meantime. With this though, you can make programs such as:
- A simple email interface. đ
- A logging system using just the last function
- A proxy browser or something.
PHP SESSION
This post was originally titled "PHP Developer Essentials" which was what I really wanted to post instead of "PHP Essentials". But as I was at it, I got really bored and I realize, I really just wanted to list all my favorite or let me just say "mostly used" php functions.
But to preserve the efforts, let me just leave what I have already typed here—Creating a session with PHP.
Creating a Session
login.php
<?php $login_name = $_POST[‘username’]; $login_password = $_POST[‘password’]; if($login_name==’admin’ && $login_password==’@dm!n’){ session_start(); session_cache_expire(15); $_SESSION[‘user’] = $_POST[‘username’]; header("Location: ‘home.html’"); } else{ die("Authentication Failed"); } ?> |
What this simple program does, is get post data from a form that uses the POST method and defined the URL of this code as the form target. The form will look like:
<form action=’login.php’ method=’post’> Username: <input type=’text’ name=’username’> Password: <input type=’password’ name=’password’> <input type=’submit’ value=’Login’> |
After retrieving post data, it will validate the user inputs then start a session and store the login data (username) in a session variable called (user). It will then set the window location to the home page using the header() function.