simple script to clean a csv file that has an expected structure

clean-csv.php

#!/usr/bin/env php
<?php

// Note: this script assumes a CSV structure of:
// email,firstName,lastName
// 
// The script dudupes by email and trims all fields.  Rows
// missing an email are discarded.  Validity of email is otherwise
// not checked.
// 
// Output is dumped to stdout, so use like so:
//  
//    ./clean-csv.php /path/to/input.csv > /path/to/output.csv

$raw = file($argv[1]);

$map = [];

foreach ($raw as $row) {
    list($email, $firstName, $lastName) = explode(',', $row);
    
    if (!$email) continue;
    if (!$firstName && !$lastName) continue;
    
    $map[$email] = [$firstName, $lastName];
}

echo PHP_EOL;
foreach ($map as $email => $names) {
    echo implode(',', [
        trim($email),
        trim($names[0]),
        trim($names[1])
    ]).PHP_EOL;
}
echo PHP_EOL;