Lire des fichiers avec PHP

PHP et le système de fichiers

file_get_contents()

<?php
$content = file_get_contents('/var/www/html/data.txt');

if ($content === false) {
    echo 'Could not read file';
} else {
    echo $content;
    echo strlen($content) . ' bytes';
}

Vérifier l'existence d'un fichier

<?php
$path = '/var/data/config.json';

if (!file_exists($path)) {
    die('Config file not found');
}

if (!is_readable($path)) {
    die('No permission to read file');
}

$json = file_get_contents($path);
$config = json_decode($json, true);

file() — lire dans un tableau

<?php
$lines = file('data.csv', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

foreach ($lines as $lineNum => $line) {
    echo ($lineNum + 1) . ': ' . $line . PHP_EOL;
}

fopen, fread, fclose

<?php
$handle = fopen('large_file.txt', 'r');

if ($handle === false) die('Cannot open file');

// Read 1KB at a time
while (!feof($handle)) {
    $chunk = fread($handle, 1024);
    echo $chunk;
}

fclose($handle);

fgets pour lire ligne par ligne

<?php
$handle = fopen('server.log', 'r');

while (($line = fgets($handle)) !== false) {
    if (str_contains($line, 'ERROR')) {
        echo 'Found error: ' . $line;
    }
}

fclose($handle);

Lire des fichiers distants

<?php
$json = file_get_contents('https://api.example.com/data.json');

// Prefer cURL for more control and error handling
$ch = curl_init('https://api.example.com/data.json');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
$status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

SplFileObject

<?php
$file = new SplFileObject('data.txt', 'r');

foreach ($file as $lineNum => $line) {
    echo $lineNum . ': ' . $line;
}

// Read specific line:
$file->seek(5);
echo $file->current(); // line 6 (0-indexed)

Lire des fichiers JSON

<?php
function loadJsonConfig(string $path): array {
    if (!file_exists($path)) {
        throw new RuntimeException("Config not found: $path");
    }
    $json = file_get_contents($path);
    $data = json_decode($json, true);
    if (json_last_error() !== JSON_ERROR_NONE) {
        throw new RuntimeException('Invalid JSON: ' . json_last_error_msg());
    }
    return $data;
}

$cfg = loadJsonConfig('/app/config.json');

Informations sur les fichiers

<?php
$path = '/var/www/html/image.jpg';

echo filesize($path);           // bytes
echo filetype($path);           // 'file'
echo filemtime($path);          // last modified timestamp
echo date('Y-m-d', filemtime($path));

$info = pathinfo($path);
echo $info['dirname'];    // /var/www/html
echo $info['basename'];   // image.jpg
echo $info['extension'];  // jpg

Verrouiller les fichiers

<?php
$handle = fopen('counter.txt', 'r+');

if (flock($handle, LOCK_EX)) {  // exclusive lock
    $count = (int) fread($handle, 20);
    $count++;
    fseek($handle, 0);
    fwrite($handle, $count);
    fflush($handle);
    flock($handle, LOCK_UN);    // release
}

fclose($handle);

Vérification rapide

Récapitulatif : lecture des fichiers