PHP Programming/PHP CLI
Contrary to popular belief, PHP is not just a web server language. PHP can also be used to create regular programs. PHP can be used to create GUI applications, shell scripts, and even daemons, among other things.
The boon is that all (or most) of the usual PHP libraries are available to your PHP CLI program too. MySQL, XML, etc. It's all (or mostly) still available.
Example PHP-CLI Program
[edit | edit source]Below is an example PHP-CLI program:
<?php print('Hello World'); ?>
If we saved this as "helloworld.php", then we'd run this PHP CLI program via the command:
php helloworld.php
This would produce the output:
Hello World
Difference Between PHP and PHP CLI
[edit | edit source]There are some important differences between server-side PHP and PHP CLI. Here's a list of them:
- There is no
$_GET
super global array. - There is no
$_POST
super global array. - There is no
$_COOKIE
super global array. - When you do a print, the output goes to the standard output and not a web browser.
- You can get command line arguments via the
$argv
variable. - You can get the number of command line arguments via the
$argc
variable.
Using argv
and argc
[edit | edit source]Like many programs, it is necessary to access the command line variable used to invoke the program. To do this in PHP we have two variables:
With register_globals = on;
in the php.ini file one can use:
$argv
$argc
With register_globals = off;
in the php.ini file one can use:
$_SERVER['argv']
$_SERVER['argc']
(For those know Bash, C or C++ program languages. they'll find these pair of variables to be very familiar)
Below is an program that makes use of the $argc
and $argv
variables:
<?php
print('ARGC = ' . $argc ."\n\n");
foreach ($argv as $k=>$v) {
print("ARGV[$k] = $v\n");
}
?>
<?php
print('ARGC = ' . $_SERVER['argc'] ."\n\n");
foreach ($_SERVER['argv'] as $k => $v) {
print("ARGV[$k] = $v\n");
}
?>
If we save this PHP program as "test1.php", and ran it with:
php test1.php apple orange banana pineapple
Then we'd get:
ARGC = 5 ARGV[0] = test1.php ARGV[1] = apple ARGV[2] = orange ARGV[3] = banana ARGV[4] = pineapple
(Note that like in Bash, C and C++ programs, the first element of $argv
is the name of the program.)