Using SPLFileInfo, DirectoryIterator, and php://temp

gistfile1.php

<?php
$dir = new DirectoryIterator('/Users/matt/Projects/Domain-Calendar');
$files = new RegexIterator($dir, '/^composer/');
foreach($files as $file) {
    echo $file->getPathName().PHP_EOL;
}

gistfile2.php

<?php
// Fake dataset - imagine this was bigger
$data = [
    ['id','Name',   'Type'],
    ['1', 'Orange', 'Fruit'],
    ['2', 'Cheese', 'Dairy comestible'],
];

// Build CSV
$file = new SPLTempFileObject();
foreach ($data as $row) {
    $file->fputcsv($row);
}

// Display it
header('Content-type: text/csv; charset=utf-8');
$file->rewind();
$file->fpassthru();

gistfile3.php

<?php
$info = new SPLFileInfo('/Users/matt/Projects/Domain-Calendar/README.md');

// Prints 'README.md'
echo $info->getFilename().PHP_EOL;

// Prints /Users/matt/Projects/DomainCalendar
echo $info->getPath().PHP_EOL;

// Prints '/Users/matt/Projects/DomainCalendar/README.md'
echo $info->getPathName().PHP_EOL;

// Prints bool(false)
var_dump($info->isDir());

// Returns an SPLFileObject 
$file = $info->openFile('r');

// Prints each line with its line number
foreach ($file as $line_num => $line) {
    // Note that $line includes the line-ending
    echo "$line_num: $line";
}