PHP fwrite without duplicate - php

Question

I want to write the code in such a way that, it will write and save any input in a .TXT file. Then there should be functions that will search the whole file (txt) if a text or word has been written or saved before, it should bring error.
If someone has written Love and another person wants to input Love again, it should bring an error message.
here is my code
<?php
$name=$_POST['name'];
$myfile=
fopen("man.txt" , "a+") or
die("Unable to open file!");
fwrite($myfile, "Name:".$name. "\r\n")
?>

Answer 1

Here I have used the in_array function to check an array we have populated ($users) for the submitted name.
If the name is found, is echos "Name Exists". If it is not found it echos "No" and adds the name.
<?php
$name = $_POST['name'];
if (empty($name)) { echo "Please enter your name"; } else $name=$name;
$myfile= fopen("mam.txt" , "a+") or die("Unable to open file!");
$path="mam.txt";
if (file_exists($path)) {
$contents = file_get_contents($path);
$contents = explode("\r\n", $contents);
$users = array();
foreach ($contents as $value) {
$users[] = $value;
}
// Search the file for the submitted name
if (in_array($name, $users)) {
// The name already exists
echo "Name exist";
} else {
// The name doesnt exist
echo "NO";
// Add the new name
fwrite($myfile, $name. "\r\n");
}
}
?>