Search futher if the amount of digits a number has is > 1 - php

Question

I'm learning PHP and started a small project with some file handling involved, a database checker on numbers (to keep it simple). What I mean by that is when you type in a number and hit the submit button php is going to search through a text file to get a name by the number.
The text file looks like:
1 Sandra
2 Piet
3 Francis
etc...
The code:
<?php
// Type your code here
$val = $row = NULL;
if (isset($_POST["submit"])) {
$myFile = fopen("testData.txt","r");
$number = $_POST["input"];
$cntNumber = strlen($number);
while (!feof($myFile)){
$val = fgetc($myFile);
if (is_numeric($val)) {
if ($cntNumber > 1) {
// Point where I Don't know what to do
} elseif ($val == $number) {
$row = fgets($myFile);
}
}
}
}
?>
<div style="width: 232px; height: 100px; border: 1px solid gray; margin-bottom: 5px;">
<?php
echo $row . "<br>";
?>
</div>
<form action="index.php" method="post">
<input name="input" placeholder="Number" type="text">
<input name="submit" value="Search" type="submit">
</form>
So if the number has more than one digit it has to search for the next matching digit, but I don't know how I can achieve that. I hope my explanation was clear enough, if not don't mind asking some question's.
Thanks in advance

Answer 1

I don't know whether you want to use f-file functions, but simplier solution is:
if (isset($_POST["submit"])) {
$myFile = file("testData.txt");
// print_r $myFile and see that this is array of lines
$number = $_POST["input"];
// iterate over your lines:
foreach ($myFile as $line) {
// as each line contains two values divided by a space,
// you can explode the line into two parts
$parts = explode(' ', $line);
// print_r($parts) to see result
// next check first part which is number:
if ($parts[0] == $number) {
echo 'Found!';
break; // exit loop as your value is found
}
}
}
If you want to use f-file functions then code can be:
$fh = fopen("testData.txt", "r");
while(!feof($fh)) {
$str = fgets($fh, 1024);
$parts = explode(' ', $str);
// print_r($parts) to see result
if ($parts[0] == $number) {
echo 'Found!' . $str;
break; // exit loop as your value is found
}
}
But I strongly recommend you to use databases as storages.