diff --git a/README.md b/README.md
index 1b6942e..eaa8bc6 100644
--- a/README.md
+++ b/README.md
@@ -39,8 +39,11 @@ pci "maj projet"
 
 prel -C
 
-commit="$(git log --grep="Init changelog . version ${version}p82" --format=%H)"
+commit="$(git log --grep="Init changelog . version ${version}p82" --format=%H)" &&
+echo "commit=$commit"
+
 git checkout dev74
+
 git cherry-pick "$commit"
 pp -a
 ~~~
diff --git a/bin/nucache.php b/bin/nucache.php
new file mode 100755
index 0000000..290263c
--- /dev/null
+++ b/bin/nucache.php
@@ -0,0 +1,7 @@
+#!/usr/bin/php
+<?php
+require $_composer_autoload_path?? __DIR__.'/../vendor/autoload.php';
+
+use nulib\tools\NucacheApp;
+
+NucacheApp::run();
\ No newline at end of file
diff --git a/composer.json b/composer.json
index b86627d..4c36f26 100644
--- a/composer.json
+++ b/composer.json
@@ -90,8 +90,8 @@
 		"nur_bin/ldap-delete.php",
 		"nur_bin/ldap-get-infos.php",
 		"nur_bin/ldap-search.php",
-		"nur_bin/sqlite-storage.php",
-		"nur_bin/mysql-storage.php"
+		"nur_bin/storage.sqlite.php",
+		"nur_bin/storage.mysql.php"
 	],
 	"scripts": {
 		"uc": "@php sbin/update_classes.php"
diff --git a/nur_bin/mysql-storage.php b/nur_bin/storage.mysql.php
similarity index 100%
rename from nur_bin/mysql-storage.php
rename to nur_bin/storage.mysql.php
diff --git a/nur_bin/sqlite-storage.php b/nur_bin/storage.sqlite.php
similarity index 100%
rename from nur_bin/sqlite-storage.php
rename to nur_bin/storage.sqlite.php
diff --git a/src/cache/CacheChannel.php b/src/cache/CacheChannel.php
new file mode 100644
index 0000000..f222b09
--- /dev/null
+++ b/src/cache/CacheChannel.php
@@ -0,0 +1,116 @@
+<?php
+namespace nulib\cache;
+
+use nulib\cl;
+use nulib\db\CapacitorChannel;
+use nulib\php\time\DateTime;
+use nulib\php\time\Delay;
+
+class CacheChannel extends CapacitorChannel {
+  /** @var int durée de vie par défaut du cache */
+  const DURATION = "1D"; // jusqu'au lendemain
+
+  const INCLUDES = null;
+
+  const EXCLUDES = null;
+
+  const COLUMN_DEFINITIONS = [
+    "group_id" => "varchar(64) not null",
+    "id" => "varchar(64) not null",
+    "date_start" => "datetime",
+    "duration_" => "text",
+    "primary key (group_id, id)",
+  ];
+
+  static function get_cache_ids($id): array {
+    if (is_array($id)) {
+      $keys = array_keys($id);
+      if (array_key_exists("group_id", $id)) $groupIdKey = "group_id";
+      else $groupIdKey = $keys[1] ?? null;
+      $groupId = $id[$groupIdKey] ?? "";
+      if (array_key_exists("id", $id)) $idKey = "id";
+      else $idKey = $keys[0] ?? null;
+      $id = $id[$idKey] ?? "";
+    } else {
+      $groupId = "";
+    }
+    if (preg_match('/^(.*\\\\)?([^\\\\]+)$/', $groupId, $ms)) {
+      # si le groupe est une classe, faire un hash du package pour limiter la
+      # longueur du groupe
+      [$package, $groupId] = [$ms[1], $ms[2]];
+      $package = substr(md5($package), 0, 4);
+      $groupId = "${groupId}_$package";
+    }
+    return ["group_id" => $groupId, "id" => $id];
+  }
+
+  function __construct(?string $duration=null, ?string $name=null) {
+    parent::__construct($name);
+    $this->duration = $duration ?? static::DURATION;
+    $this->includes = static::INCLUDES;
+    $this->excludes = static::EXCLUDES;
+  }
+
+  protected string $duration;
+
+  protected ?array $includes;
+
+  protected ?array $excludes;
+
+  function getItemValues($item): ?array {
+    return cl::merge(self::get_cache_ids($item), [
+      "item" => null,
+    ]);
+  }
+
+  function onCreate($item, array $values, ?array $alwaysNull, ?string $duration=null): ?array {
+    $now = new DateTime();
+    $duration ??= $this->duration;
+    return [
+      "date_start" => $now,
+      "duration" => new Delay($duration, $now),
+    ];
+  }
+
+  function onUpdate($item, array $values, array $pvalues, ?string $duration=null): ?array {
+    $now = new DateTime();
+    $duration ??= $this->duration;
+    return [
+      "date_start" => $now,
+      "duration" => new Delay($duration, $now),
+    ];
+  }
+
+  function shouldUpdate($id, bool $noCache=false): bool {
+    if ($noCache) return true;
+
+    $cacheIds = self::get_cache_ids($id);
+    $groupId = $cacheIds["group_id"];
+    if ($groupId) {
+      $includes = $this->includes;
+      $shouldInclude = $includes !== null && in_array($groupId, $includes);
+      $excludes = $this->excludes;
+      $shouldExclude = $excludes !== null && in_array($groupId, $excludes);
+      if (!$shouldInclude || $shouldExclude) return true;
+    }
+
+    $found = false;
+    $expired = false;
+    $this->each($cacheIds,
+      function($item, $values) use (&$found, &$expired) {
+        $found = true;
+        $expired = $values["duration"]->isElapsed();
+      });
+    return !$found || $expired;
+  }
+
+  function setCached($id, ?string $duration=null): void {
+    $cacheIds = self::get_cache_ids($id);
+    $this->charge($cacheIds, null, [$duration]);
+  }
+
+  function resetCached($id) {
+    $cacheIds = self::get_cache_ids($id);
+    $this->delete($cacheIds);
+  }
+}
diff --git a/src/cache/CacheData.php b/src/cache/CacheData.php
new file mode 100644
index 0000000..ae0ea6e
--- /dev/null
+++ b/src/cache/CacheData.php
@@ -0,0 +1,50 @@
+<?php
+namespace nulib\cache;
+
+use nulib\cl;
+use nulib\php\func;
+use Traversable;
+
+class CacheData {
+  /** @var string identifiant de cette donnée */
+  const NAME = null;
+
+  /** @var callable une fonction permettant de calculer la donnée */
+  const COMPUTE = null;
+
+  function __construct($compute=null, ?string $name=null) {
+    $this->name = $name ?? static::NAME ?? "";
+    $this->compute = func::withn($compute ?? static::COMPUTE);
+  }
+
+  protected string $name;
+
+  protected ?func $compute;
+
+  protected function compute() {
+    $compute = $this->compute;
+    return $compute !== null? $compute->invoke(): null;
+  }
+
+  function getName() : string {
+    return $this->name;
+  }
+
+  /** obtenir la donnée, en l'itérant au préalable si elle est traversable */
+  function get($compute=null) {
+    $this->compute ??= func::withn($compute);
+    $data = $this->compute();
+    if ($data instanceof Traversable) {
+      $data = cl::all($data);
+    }
+    return $data;
+  }
+
+  /** obtenir un itérateur sur la donnée ou null s'il n'y a pas de données */
+  function all($compute=null): ?iterable {
+    $this->compute ??= func::withn($compute);
+    $data = $this->compute();
+    if ($data !== null && !is_iterable($data)) $data = [$data];
+    return $data;
+  }
+}
diff --git a/src/cache/CacheDataChannel.php b/src/cache/CacheDataChannel.php
new file mode 100644
index 0000000..768b6d0
--- /dev/null
+++ b/src/cache/CacheDataChannel.php
@@ -0,0 +1,53 @@
+<?php
+namespace nulib\cache;
+
+use Closure;
+use IteratorAggregate;
+use nulib\cache\CacheChannel;
+use nulib\cache\storage_cache;
+use nulib\cl;
+use nulib\db\CapacitorChannel;
+use Traversable;
+
+class CacheDataChannel extends CapacitorChannel implements IteratorAggregate {
+  const COLUMN_DEFINITIONS = [
+    "key" => "varchar(128) primary key not null",
+    "all_values" => "mediumtext",
+  ];
+
+  function __construct($id, callable $builder, ?string $duration=null) {
+    $this->cacheIds = $cacheIds = CacheChannel::get_cache_ids($id);
+    $this->builder = Closure::fromCallable($builder);
+    $this->duration = $duration;
+    $name = "{$cacheIds["group_id"]}-{$cacheIds["id"]}";
+    parent::__construct($name);
+  }
+
+  protected array $cacheIds;
+
+  protected Closure $builder;
+
+  protected ?string $duration = null;
+
+  function getItemValues($item): ?array {
+    $key = array_keys($item)[0];
+    $row = $item[$key];
+    return [
+      "key" => $key,
+      "item" => $row,
+      "all_values" => implode(" ", cl::filter_n(cl::with($row))),
+    ];
+  }
+
+  function getIterator(): Traversable {
+    $cm = storage_cache::get();
+    if ($cm->shouldUpdate($this->cacheIds)) {
+      $this->capacitor->reset();
+      foreach (($this->builder)() as $key => $row) {
+        $this->charge([$key => $row]);
+      }
+      $cm->setCached($this->cacheIds, $this->duration);
+    }
+    return $this->discharge(false);
+  }
+}
diff --git a/src/cache/CacheFile.php b/src/cache/CacheFile.php
new file mode 100644
index 0000000..3feb150
--- /dev/null
+++ b/src/cache/CacheFile.php
@@ -0,0 +1,368 @@
+<?php
+namespace nulib\cache;
+
+use Exception;
+use nulib\cv;
+use nulib\file;
+use nulib\file\SharedFile;
+use nulib\os\path;
+use nulib\php\func;
+use nulib\php\time\DateTime;
+use nulib\php\time\Delay;
+use nulib\str;
+use nulib\ValueException;
+
+class CacheFile extends SharedFile {
+  /** @var string|int durée de vie par défaut des données mises en cache  */
+  const DURATION = "1D"; // jusqu'au lendemain
+
+  const EXT = ".cache";
+
+  protected function ensure_source($source): CacheData {
+    if ($source instanceof CacheData) return $source;
+    if (cv::subclass_of($source, CacheData::class)) return new $source();
+    if (func::is_callable($source)) return new CacheData($source);
+    throw ValueException::invalid_type($source, CacheData::class);
+  }
+
+  function __construct($file, ?array $params=null) {
+    if ($file === null) {
+      $rand = bin2hex(random_bytes(8));
+      $file = path::join(sys_get_temp_dir(), $rand);
+    }
+    $file = path::ensure_ext($file, self::EXT);
+    $this->basedir = path::dirname($file);
+    $basename = path::filename($file);
+    $this->basename = str::without_suffix(self::EXT, $basename);
+    $this->initialDuration = Delay::with($params["duration"] ?? static::DURATION);
+    $this->overrideDuration = $params["override_duration"] ?? false;
+    $this->readonly = $params["readonly"] ?? false;
+    $this->cacheNull = $params["cache_null"] ?? false;
+    $data = $params["data"] ?? null;
+    $this->sources = null;
+    if ($data === null) {
+      $this->source = null;
+    } elseif ($data instanceof CacheData) {
+      $this->source = $data;
+    } elseif (func::is_callable($data)) {
+      $this->source = new CacheData($data);
+    } elseif (!is_array($data)) {
+      $this->source = self::ensure_source($data);
+    } else {
+      $sources = [];
+      $index = 0;
+      foreach ($data as $key => $source) {
+        $source = self::ensure_source($source);
+        if ($key === $index) {
+          $index++;
+          $key = $source->getName();
+        }
+        $sources[$key] = $source;
+      }
+      $this->sources = $sources;
+      $this->source = null;
+    }
+    parent::__construct($file);
+  }
+
+  /** @var string répertoire de base des fichiers de cache */
+  protected string $basedir;
+
+  /** @var string nom de base des fichiers de cache */
+  protected string $basename;
+
+  protected Delay $initialDuration;
+
+  protected bool $overrideDuration;
+
+  protected bool $readonly;
+
+  protected bool $cacheNull;
+
+  protected ?array $sources;
+
+  protected ?CacheData $source;
+
+  protected function getSource($data): CacheData {
+    if ($data === null) {
+      return $this->source ??= new CacheData(function() {
+        return $this->compute();
+      });
+    }
+    $source = $data;
+    if (is_string($source) || is_int($source)) {
+      $source = $this->sources[$source] ?? null;
+      if ($source === null) throw ValueException::invalid_key($data);
+    }
+    if ($source instanceof CacheData) return $source;
+    throw ValueException::invalid_type($data, CacheData::class);
+  }
+
+  /**
+   * vérifier si le fichier est valide. s'il est invalide, il faut le recréer.
+   *
+   * on assume que le fichier existe, vu qu'il a été ouvert en c+b
+   */
+  function isValid(): bool {
+    # considèrer que le fichier est invalide s'il est de taille nulle
+    return $this->getSize() > 0;
+  }
+
+  protected ?DateTime $start;
+
+  protected ?Delay $duration;
+
+  protected ?array $datafilenames;
+
+  /** charger les données. le fichier a déjà été verrouillé en lecture */
+  protected function loadMetadata(): void {
+    if ($this->isValid()) {
+      $this->rewind();
+      [
+        "start" => $start,
+        "duration" => $duration,
+        "datafiles" => $datafilenames,
+      ] = $this->unserialize(null, false, true);
+      if ($this->overrideDuration) {
+        $duration = Delay::with($this->initialDuration, $start);
+      }
+      $datafilenames = array_fill_keys($datafilenames, true);
+    } else {
+      $start = null;
+      $duration = null;
+      $datafilenames = [];
+    }
+    $this->start = $start;
+    $this->duration = $duration;
+    $this->datafilenames = $datafilenames;
+  }
+
+  /**
+   * tester s'il faut mettre les données à jour. le fichier a déjà été
+   * verrouillé en lecture
+   */
+  protected function shouldUpdate(bool $noCache=false): bool {
+    if ($this->isValid()) {
+      $expired = $this->duration->isElapsed();
+    } else {
+      $expired = false;
+      $noCache = true;
+    }
+    return $noCache || $expired;
+  }
+
+  /** sauvegarder les données. le fichier a déjà été verrouillé en écriture */
+  protected function saveMetadata(): void {
+    $this->duration ??= $this->initialDuration;
+    if ($this->start === null) {
+      $this->start = new DateTime();
+      $this->duration = Delay::with($this->duration, $this->start);
+    }
+    $datafilenames = array_keys($this->datafilenames);
+    $this->ftruncate();
+    $this->serialize([
+      "start" => $this->start,
+      "duration" => $this->duration,
+      "datafiles" => $datafilenames,
+    ], false, true);
+  }
+
+  protected function loadData(string $datafile) {
+    return file::reader($datafile)->unserialize();
+  }
+
+  protected function saveData(string $datafile, $data): void {
+    file::writer($datafile)->serialize($data);
+  }
+
+  protected function unlinkDatafile(string $datafilename): void {
+    $datafile = path::join($this->basedir, $datafilename);
+    @unlink($datafile);
+    unset($this->datafilenames[$datafilename]);
+  }
+
+  protected function unlinkFiles(bool $datafilesOnly=false): void {
+    if (!$datafilesOnly) @unlink($this->file);
+    foreach ($this->datafilenames as $datafilename) {
+      $this->unlinkDatafile($datafilename);
+    }
+  }
+
+  /** tester si $value peut être mis en cache */
+  protected function shouldCache($value): bool {
+    return $this->cacheNull || $value !== null;
+  }
+
+  protected ?DateTime $ostart;
+
+  protected ?Delay $oduration;
+
+  protected ?array $odatafilenames;
+
+  protected function beforeAction() {
+    $this->loadMetadata();
+    $this->ostart = cv::clone($this->start);
+    $this->oduration = cv::clone($this->duration);
+    $this->odatafilenames = cv::clone($this->datafilenames);
+  }
+
+  protected function afterAction() {
+    $start = $this->start;
+    $duration = $this->duration;
+    $oduration = $this->oduration;
+    $datafilenames = $this->datafilenames;
+    $modified = false;
+    if ($start != $this->ostart) $modified = true;
+    if ($duration === null || $oduration === null) $modified = true;
+    elseif ($duration->getDest() != $oduration->getDest()) $modified = true;
+    # égalité stricte uniquement pour $datafiles qui est un array
+    if ($datafilenames !== $this->odatafilenames) $modified = true;
+    if ($modified && !$this->readonly) {
+      $this->lockWrite();
+      $this->saveMetadata();
+    }
+  }
+
+  protected function action(callable $callback, bool $willWrite=false) {
+    if ($willWrite && !$this->readonly) $this->lockWrite();
+    else $this->lockRead();
+    try {
+      $this->beforeAction();
+      $result = $callback();
+      $this->afterAction();
+      return $result;
+    } finally {
+      $this->start = null;
+      $this->duration = null;
+      $this->datafilenames = null;
+      $this->unlock(true);
+    }
+  }
+
+  protected function compute() {
+    return null;
+  }
+
+  function get($data=null, bool $noCache=false) {
+    return $this->action(function () use ($data, $noCache) {
+      $source = $this->getSource($data);
+      $dataname = $source->getName();
+      $datafilename = ".{$this->basename}.{$dataname}".self::EXT;
+      $datafile = path::join($this->basedir, $datafilename);
+
+      $updateMetadata = $this->shouldUpdate($noCache);
+      $updateData = !array_key_exists($datafilename, $this->datafilenames);
+      if (!$this->readonly && ($updateMetadata || $updateData)) {
+        $this->lockWrite();
+        if ($updateMetadata) {
+          # il faut refaire tout le cache
+          $this->unlinkFiles(true);
+          $this->start = null;
+          $this->duration = null;
+          $updateData = true;
+        }
+        if ($updateData) {
+          # calculer un fichier
+          try {
+            $data = $source->get();
+          } catch (Exception $e) {
+            # ne pas garder le fichier en cas d'exception
+            $this->unlinkDatafile($datafile);
+            throw $e;
+          }
+        } elseif (file_exists($datafile)) {
+          $data = $this->loadData($datafile);
+        } else {
+          $data = null;
+        }
+        if ($this->shouldCache($data)) {
+          $this->saveData($datafile, $data);
+          $this->datafilenames[$datafilename] = true;
+        } else {
+          # ne pas garder le fichier s'il ne faut pas mettre en cache
+          $this->unlinkDatafile($datafile);
+        }
+      } elseif (file_exists($datafile)) {
+        $data = $this->loadData($datafile);
+      } else {
+        $data = null;
+      }
+      return $data;
+    });
+  }
+
+  function all($data=null, bool $noCache=false): ?iterable {
+    $data = $this->get($data, $noCache);
+    if ($data !== null && !is_iterable($data)) $data = [$data];
+    return $data;
+  }
+
+  function delete($data=null): void {
+    $source = $this->getSource($data);
+    $dataname = $source->getName();
+    $datafilename = ".{$this->basename}.{$dataname}".self::EXT;
+    $this->unlinkDatafile($datafilename);
+  }
+
+  /** obtenir les informations sur le fichier */
+  function getInfos(): array {
+    return $this->action(function () {
+      if (!$this->isValid()) {
+        return ["valid" => false];
+      }
+      $start = $this->start;
+      $duration = $this->duration;
+      $datafilenames = $this->datafilenames;
+      $datafiles = [];
+      foreach (array_keys($datafilenames) as $datafilename) {
+        $datafile = path::join($this->basedir, $datafilename);
+        $name = $datafilename;
+        str::del_prefix($name, ".{$this->basename}.");
+        str::del_suffix($name, self::EXT);
+        if (file_exists($datafile)) {
+          $size = filesize($datafile);
+        } else {
+          $size = null;
+        }
+        $datafiles[$name] = $size;
+      }
+      return [
+        "valid" => true,
+        "start" => $start,
+        "duration" => strval($duration),
+        "date_start" => $start->format(),
+        "date_end" => $duration->getDest()->format(),
+        "datafiles" => $datafiles,
+      ];
+    });
+  }
+
+  const UPDATE_SUB = -1, UPDATE_SET = 0, UPDATE_ADD = 1;
+
+  /**
+   * mettre à jour la durée de validité du fichier
+   *
+   * XXX UPDATE_SET n'est pas implémenté
+   */
+  function updateDuration($nduration, int $action=self::UPDATE_ADD): void {
+    if ($this->readonly) return;
+    $this->action(function () use ($nduration, $action) {
+      if (!$this->isValid()) return;
+      $duration = $this->duration;
+      if ($action < 0) $duration->subDuration($nduration);
+      elseif ($action > 0) $duration->addDuration($nduration);
+    }, true);
+  }
+
+  /** supprimer les fichiers s'ils ont expiré */
+  function deleteExpired(bool $force=false): bool {
+    if ($this->readonly) return false;
+    return $this->action(function () use ($force) {
+      if ($force || $this->shouldUpdate()) {
+        $this->unlinkFiles();
+        return true;
+      }
+      return false;
+    }, true);
+  }
+}
diff --git a/src/cache/storage_cache.php b/src/cache/storage_cache.php
new file mode 100644
index 0000000..1fc6814
--- /dev/null
+++ b/src/cache/storage_cache.php
@@ -0,0 +1,39 @@
+<?php
+namespace nulib\cache;
+
+use nulib\cache\CacheChannel;
+use nulib\cache\CacheDataChannel;
+use nulib\db\Capacitor;
+use nulib\db\CapacitorStorage;
+use nulib\db\sqlite\SqliteStorage;
+
+class storage_cache {
+  protected static ?CapacitorStorage $storage = null;
+
+  static function set_storage(CapacitorStorage $storage): CapacitorStorage {
+    return self::$storage = $storage;
+  }
+
+  protected static function get_storage(): CapacitorStorage {
+    return self::$storage ??= new SqliteStorage("");
+  }
+
+  protected static ?CacheChannel $channel = null;
+
+  static function set(?CacheChannel $channel): CacheChannel {
+    $channel ??= new CacheChannel();
+    new Capacitor(self::get_storage(), $channel);
+    return self::$channel = $channel;
+  }
+
+  static function get(): CacheChannel {
+    if (self::$channel !== null) return self::$channel;
+    else return self::set(null);
+  }
+
+  static function new(?CacheDataChannel $channel, $id=null, ?callable $builder=null): CacheDataChannel {
+    $channel ??= new CacheDataChannel($id, $builder);
+    new Capacitor(self::get_storage(), $channel);
+    return $channel;
+  }
+}
diff --git a/src/tools/NucacheApp.php b/src/tools/NucacheApp.php
new file mode 100644
index 0000000..583e44e
--- /dev/null
+++ b/src/tools/NucacheApp.php
@@ -0,0 +1,129 @@
+<?php
+namespace nulib\tools;
+
+use Exception;
+use nulib\app\cli\Application;
+use nulib\ext\yaml;
+use nulib\cache\CacheFile;
+use nulib\os\path;
+use nulib\output\msg;
+
+class NucacheApp extends Application {
+  const ACTION_READ = 10, ACTION_INFOS = 20, ACTION_CLEAN = 30;
+  const ACTION_UPDATE = 40, ACTION_UPDATE_ADD = 41, ACTION_UPDATE_SUB = 42, ACTION_UPDATE_SET = 43;
+
+  const ARGS = [
+    "merge" => parent::ARGS,
+    "purpose" => "gestion de fichiers cache",
+    ["-r", "--read", "name" => "action", "value" => self::ACTION_READ,
+      "help" => "Afficher le contenu d'un fichier cache",
+    ],
+    ["-i", "--infos", "name" => "action", "value" => self::ACTION_INFOS,
+      "help" => "Afficher des informations sur le fichier cache",
+    ],
+    ["-k", "--clean", "name" => "action", "value" => self::ACTION_CLEAN,
+      "help" => "Supprimer le fichier cache s'il a expiré",
+    ],
+    ["-a", "--add-duration", "args" => 1,
+      "action" => [null, "->setActionUpdate", self::ACTION_UPDATE_ADD],
+      "help" => "Ajouter le nombre de secondes spécifié à la durée du cache",
+    ],
+    ["-b", "--sub-duration", "args" => 1,
+      "action" => [null, "->setActionUpdate", self::ACTION_UPDATE_SUB],
+      "help" => "Enlever le nombre de secondes spécifié à la durée du cache",
+    ],
+    #XXX pas encore implémenté
+    //["-s", "--set-duration", "args" => 1,
+    //  "action" => [null, "->setActionUpdate", self::ACTION_UPDATE_SET],
+    //  "help" => "Mettre à jour la durée du cache à la valeur spécifiée",
+    //],
+  ];
+
+  protected $action = self::ACTION_READ;
+
+  protected $updateAction, $updateDuration;
+
+  protected $args;
+
+  function setActionUpdate(int $action, $updateDuration): void {
+    $this->action = self::ACTION_UPDATE;
+    switch ($action) {
+    case self::ACTION_UPDATE_SUB:
+      $this->updateAction = CacheFile::UPDATE_SUB;
+      break;
+    case self::ACTION_UPDATE_SET:
+      $this->updateAction = CacheFile::UPDATE_SET;
+      break;
+    case self::ACTION_UPDATE_ADD:
+      $this->updateAction = CacheFile::UPDATE_ADD;
+      break;
+    }
+    $this->updateDuration = $updateDuration;
+  }
+
+  protected function findCaches(string $dir, ?array &$files): void {
+    foreach (glob("$dir/*") as $file) {
+      if (is_dir($file)) {
+        $this->findCaches($file, $files);
+      } elseif (is_file($file) && fnmatch("*.cache", $file)) {
+        $files[] = $file;
+      }
+    }
+  }
+
+  function main() {
+    $files = [];
+    foreach ($this->args as $arg) {
+      if (is_dir($arg)) {
+        $this->findCaches($arg, $files);
+      } elseif (is_file($arg)) {
+        $files[] = $arg;
+      } else {
+        msg::warning("$arg: fichier introuvable");
+      }
+    }
+    $showSection = count($files) > 1;
+    foreach ($files as $file) {
+      switch ($this->action) {
+      case self::ACTION_READ:
+        if ($showSection) msg::section($file);
+        $cache = new CacheFile($file, [
+          "readonly" => true,
+          "duration" => "INF",
+          "override_duration" => true,
+        ]);
+        yaml::dump($cache->get());
+        break;
+      case self::ACTION_INFOS:
+        if ($showSection) msg::section($file);
+        $cache = new CacheFile($file, [
+          "readonly" => true,
+        ]);
+        yaml::dump($cache->getInfos());
+        break;
+      case self::ACTION_CLEAN:
+        msg::action(path::ppath($file));
+        $cache = new CacheFile($file);
+        try {
+          if ($cache->deleteExpired()) msg::asuccess("fichier supprimé");
+          else msg::adone("fichier non expiré");
+        } catch (Exception $e) {
+          msg::afailure($e);
+        }
+        break;
+      case self::ACTION_UPDATE:
+        msg::action(path::ppath($file));
+        $cache = new CacheFile($file);
+        try {
+          $cache->updateDuration($this->updateDuration, $this->updateAction);
+          msg::asuccess("fichier mis à jour");
+        } catch (Exception $e) {
+          msg::afailure($e);
+        }
+        break;
+      default:
+        self::die("$this->action: action non implémentée");
+      }
+    }
+  }
+}
diff --git a/tbin/.gitignore b/tbin/.gitignore
index 74dd8df..f9f3cae 100644
--- a/tbin/.gitignore
+++ b/tbin/.gitignore
@@ -1,2 +1,3 @@
 /output-forever.log
 /devel/
+/*.cache
diff --git a/tbin/test-nucache.php b/tbin/test-nucache.php
new file mode 100755
index 0000000..802926f
--- /dev/null
+++ b/tbin/test-nucache.php
@@ -0,0 +1,76 @@
+#!/usr/bin/php
+<?php
+require __DIR__.'/../vendor/autoload.php';
+
+use nulib\cache\CacheData;
+use nulib\cache\CacheFile;
+use nulib\ext\yaml;
+use nulib\os\sh;
+
+function show(string $prefix, CacheFile $cache, bool $dumpInfos=true): void {
+  Txx("$prefix=", $cache->get());
+  if ($dumpInfos) {
+    yaml::dump($cache->getInfos());
+  }
+}
+
+//system("rm -f *.cache .*.cache");
+
+$what = [
+  //"null",
+  "one",
+  //"two",
+  //"three",
+];
+$duration = 10;
+
+if (in_array("null", $what)) {
+  $null = new CacheFile("null", [
+    "duration" => $duration,
+  ]);
+  show("null", $null);
+}
+
+if (in_array("one", $what)) {
+  $one = new class("one", [
+    "duration" => $duration,
+  ]) extends CacheFile {
+    protected function compute() {
+      return 1;
+    }
+  };
+  show("one", $one);
+}
+
+if (in_array("two", $what)) {
+  $two = new CacheFile("two", [
+    "duration" => $duration,
+    "data" => new CacheData(function () {
+      return 2;
+    }),
+  ]);
+  show("two", $two);
+}
+
+if (in_array("three", $what)) {
+  $data31 = new CacheData(function () {
+    return 31;
+  }, "data31name");
+
+  $data32 = new CacheData(function () {
+    return 32;
+  });
+
+  $three = new CacheFile("three", [
+    "data" => [
+      "data31" => $data31,
+      $data31, # name=data31name
+      "data32" => $data32,
+      $data32, # name=""
+    ],
+  ]);
+  Txx("three.0=", $three->get("data31"));
+  Txx("three.1=", $three->get("data31name"));
+  Txx("three.2=", $three->get("data32"));
+  Txx("three.3=", $three->get(""));
+}