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Interactive Ways to Check a Script

In order to test a script with different values, we need a way to make them accessible to the script. This can be done in two basic ways: from the Command Line or interactively. The scripts below utilize the interactive technique.

We will use the area-of-a-triangle problem for this demonstration.

A PHP Script to Handle Information Interactively using fgets()

The following code should be saved in a file called triInteractiveCL1.php.

<?php
// triInteractiveCL1.php
// This script illustrates how to process information
// interactively provided by the user to a script for testing purposes
// using the fgets() function

// Interactively obtain the dimensions $b (base) and $h (height)
// of the triangle
// Get b
echo ("Enter the value for the base: ");
$b = trim(fgets(STDIN));
// Get h
echo ("Enter the value for the height: ");
$h = trim(fgets(STDIN));

echo "Calculating the Area of a Triangle\n";
// Print the base
echo "b is $b.\n";

// Print the height
echo "h is $h.\n";

// Calculate and print result
$A = $b * $h / 2;
echo "The area of a triangle with a base of $b and a height of $h is $A.\n";
?>

Notes

Run this script by typing the following on the Command Line.
```
php -f triIntreractiveCL1.php
```
STDIN, STanDard INput, is the keyboard in Unix/Linux. fgets(STDIN) obtains a full line of input from the keyboard, including the terminating newline character, Hex 0A. The trim() function removes the newline character.
Since PHP uses loosely typed data, the text version of the data is automatically manipulated so that it can be used in calculations.

A PHP Script to Handle Information Interactively using fscanf()

The following code should be saved in a file called triInteractiveCL2.php.

<?php
// triInteractiveCL2.php
// This script illustrates how to process information
// interactively provided by the user to a script for testing purposes
// using the fscanf() function

// Interactively obtain the dimensions $b (base) and $h (height)
// of the triangle
// Get b
echo ("Enter the value for the base: ");
fscanf (STDIN, "%d\n", $b);
// Get h
echo ("Enter the value for the height: ");
fscanf (STDIN, "%d\n", $h);

echo "Calculating the Area of a Triangle\n";
// Print the base
echo "b is $b.\n";

// Print the height
echo "h is $h.\n";

// Calculate and print result
$A = $b * $h / 2;
echo "The area of a triangle with a base of $b and a height of $h is $A.\n";
?>

Notes

Run this script by typing the following on the Command Line.
```
php -f triIntreractiveCL2.php
```
The fscanf() function scans data from a file stream (which STDIN is considered to be) and parses it using the formatting information specified. This function is adapted from the C language. %d indicates that the character data should be treated as a decimal integer. The inclusion of the terminating newline character, Hex 0A, in the formatting specification causes it to be removed.