PHP Advanced and Object-Oriented Programming (2013)

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After that line, all PHP code goes within the normal PHP tags. Anything outside of the PHP tags is sent to the standard output just like Web-based PHP scripts :

#!/usr/bin/php
<?php
// Do whatever.
?>
This text is also displayed.
<?php
// Do whatever.
?>

Text outside of the PHP tags is revealed in the console.

For the first implementation of this concept, I’ll create a script that reads in a text file and reprints it, numbering the lines along the way.

To create a command-line script

1. Create a new PHP script in your text editor or IDE, to be named number.php, beginning with the shebang line (Script 12.1):

#!/usr/bin/php
<?php # Script 12.1 - number.php

Remember that the first line is the most important and that you might need to change it if PHP CLI was installed in a place other than /usr/bin. And although Windows users can skip this line, it’s best to leave it in there (allowing you to use it on another computer down the road).

Finally, you still need to use the PHP tags.

2. Identify what file will be numbered:

$file = 'states.txt';

Later in the chapter, you’ll see how to write this script so that the file information can be assigned when the script is run. For this first example, I’m just going to use a simple plain text file that lists the US states. You can use any plain text file, including even another PHP script from the book.

3. Print an introductory message:

echo "\nNumbering the file named '$file'...
-------------------\n\n";

4. Read in the file:

$data = file($file);

The file() function reads an entire file into an array. Each line becomes one array element. You could use fopen() and the other file functions instead, if you prefer.

5. Print each line with its number:

$n = 1;
foreach ($data as $line) {
echo "$n $line";
$n++;
}

To start, a counter is initialized so that the first line is numbered at 1. Then a foreach loop goes through the array. Within the loop, each line is printed, prefixed by the line number and a couple of spaces. You do not need to print a newline here, because the line read in from the original file retained that newline. Finally, the counter is incremented.

6. Print a closing message:

echo "\n-------------------
End of file '$file'.\n";

7. Complete the PHP script:

?>

8. Save the file as number.php.

Running a Command-Line Script

Now that you’ve written a script especially meant for a command-line execution (and wasn’t it nice not to mess with all that pesky HTML?), it’s time to learn how to run it. There are two ways of doing so.

The first option is to directly invoke PHP CLI, as you did when executing a bit of code, this time providing it with the name of a script to execute:

php scriptname.php

You’ll also see the -f flag used. It stands for file, and whether you use it or not makes no difference on the end result:

php -f scriptname.php

This method should work just fine, as long as php is in your PATH and you are in the same directory as scriptname.php. Variations to circumvent these limitations might be

/usr/bin/php scriptname.php
php /path/to/scriptname.php
C:\php\php.exe scriptname.php

The second method for executing PHP scripts is to treat the script as if it were an application in its own right:

scriptname.php (Windows)
./scriptname.php (Unix and Mac OS X)

This method, which is preferred, can have some tricks to it, so I’ll run through the details in the following steps.

To run a command-line script in Windows

1. Use the instructions outlined earlier in the chapter to access a DOS prompt.

2. Move into the directory where number.php was saved :

cd C:\path\to\directory

Start by moving into the same directory where the PHP script you want to execute is located.

3. Run the file using the php scriptname.php syntax :

php number.php

The execution of the number.php script.

Hopefully, this should work for you. If you get an error message, it’s most likely because php is not in your PATH. If you don’t know how to change your PATH, either search the Web for tutorials or turn to my support forums (www.LarryUllman.com/forums/).

4. Run the file using the alternative syntax:

number.php

If this doesn’t immediately work, it’s because you’ll need to tell Windows what program to use for running .php scripts. To do so (these instructions are for Windows 7, but should be similar on other versions of Windows):

a. Select number.php in the Windows Explorer.

b. Control+click or right-click and choose Open with > Choose default program.

c. Click Browse in the Open with dialog .

You may need to tell Windows what application to use for your scripts. The php executable will not likely come up as an option.

d. Find and select the php executable , and then click Open.

Find the installed php executable to finish the association.

e. Click OK in the Open with dialog.

From here on out, all .php scripts will run just fine from the command-line interface (assuming that you kept the Always use the selected program to open this kind of file box checked ).

To run a command-line script in Unix and Mac OS X

1. Use the instructions outlined earlier in the chapter to access a command-line prompt.

2. Move into the directory where number.php was saved:

cd /path/to/directory

3. Run the file using the php scriptname.php syntax :

php number.php

The first method for running the PHP script, showing the end of the output.

Hopefully, this should work for you. If you get an error message, it’s most likely because php is not in your PATH. If you don’t know how to change your PATH, either search the Web for tutorials or turn to my support forums (www.LarryUllman.com/forums/).

4. Make the file executable:

chmod +x number.php

If you’re not familiar with chmod, it’s a utility for changing the properties of files and directories. The +x code says to add executable status to number.php.

5. Run the file using the ./scriptname.php syntax :

./number.php

Executables can be run using the ./ executable syntax, assuming you are in the same directory as the program to be run.