ZDIR(3)

NAME
zdir - work with file-system directories

SYNOPSIS

//  This is a stable class, and may not change except for emergencies. It
//  is provided in stable builds.
//  Create a new directory item that loads in the full tree of the specified
//  path, optionally located under some parent path. If parent is "-", then
//  loads only the top-level directory, and does not use parent as a path.
CZMQ_EXPORT zdir_t *
    zdir_new (const char *path, const char *parent);
//  Destroy a directory tree and all children it contains.
CZMQ_EXPORT void
    zdir_destroy (zdir_t **self_p);
//  Return directory path
CZMQ_EXPORT const char *
    zdir_path (zdir_t *self);
//  Return last modification time for directory.
CZMQ_EXPORT time_t
    zdir_modified (zdir_t *self);
//  Return total hierarchy size, in bytes of data contained in all files
//  in the directory tree.
CZMQ_EXPORT off_t
    zdir_cursize (zdir_t *self);
//  Return directory count
CZMQ_EXPORT size_t
    zdir_count (zdir_t *self);
//  Returns a sorted list of zfile objects; Each entry in the list is a pointer
//  to a zfile_t item already allocated in the zdir tree. Do not destroy the
//  original zdir tree until you are done with this list.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT zlist_t *
    zdir_list (zdir_t *self);
//  Remove directory, optionally including all files that it contains, at
//  all levels. If force is false, will only remove the directory if empty.
//  If force is true, will remove all files and all subdirectories.
CZMQ_EXPORT void
    zdir_remove (zdir_t *self, bool force);
//  Calculate differences between two versions of a directory tree.
//  Returns a list of zdir_patch_t patches. Either older or newer may
//  be null, indicating the directory is empty/absent. If alias is set,
//  generates virtual filename (minus path, plus alias).
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT zlist_t *
    zdir_diff (zdir_t *older, zdir_t *newer, const char *alias);
//  Return full contents of directory as a zdir_patch list.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT zlist_t *
    zdir_resync (zdir_t *self, const char *alias);
//  Load directory cache; returns a hash table containing the SHA-1 digests
//  of every file in the tree. The cache is saved between runs in .cache.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT zhash_t *
    zdir_cache (zdir_t *self);
//  Print contents of directory to open stream
CZMQ_EXPORT void
    zdir_fprint (zdir_t *self, FILE *file, int indent);
//  Print contents of directory to stdout
CZMQ_EXPORT void
    zdir_print (zdir_t *self, int indent);
//  Create a new zdir_watch actor instance:
//
//      zactor_t *watch = zactor_new (zdir_watch, NULL);
//
//  Destroy zdir_watch instance:
//
//      zactor_destroy (&watch);
//
//  Enable verbose logging of commands and activity:
//
//      zstr_send (watch, "VERBOSE");
//
//  Subscribe to changes to a directory path:
//
//      zsock_send (watch, "ss", "SUBSCRIBE", "directory_path");
//
//  Unsubscribe from changes to a directory path:
//
//      zsock_send (watch, "ss", "UNSUBSCRIBE", "directory_path");
//
//  Receive directory changes:
//      zsock_recv (watch, "sp", &path, &patches);
//
//      // Delete the received data.
//      free (path);
//      zlist_destroy (&patches);
CZMQ_EXPORT void
    zdir_watch (zsock_t *pipe, void *unused);
//  Self test of this class.
CZMQ_EXPORT void
    zdir_test (bool verbose);
Please add '@interface' section in './../src/zdir.c'.

DESCRIPTION

The zdir class gives access to the file system index. It will load a directory tree (a directory plus all child directories) into a zdir structure and then let you navigate that structure. It exists mainly to wrap non-portable OS functions to do this.

Please add @discuss section in ./../src/zdir.c.

EXAMPLE

From zdir_test method.

    // need to create a file in the test directory we're watching
    // in order to ensure the directory exists
    zfile_t *initfile = zfile_new ("./zdir-test-dir", "initial_file");
    assert (initfile);
    zfile_output (initfile);
    fprintf (zfile_handle (initfile), "initial file\n");
    zfile_close (initfile);
    zfile_destroy (&initfile);
    zdir_t *older = zdir_new ("zdir-test-dir", NULL);
    assert (older);
    if (verbose) {
        printf ("\n");
        zdir_dump (older, 0);
    }
    zdir_t *newer = zdir_new (".", NULL);
    assert (newer);
    zlist_t *patches = zdir_diff (older, newer, "/");
    assert (patches);
    while (zlist_size (patches)) {
        zdir_patch_t *patch = (zdir_patch_t *) zlist_pop (patches);
        zdir_patch_destroy (&patch);
    }
    zlist_destroy (&patches);
    zdir_destroy (&older);
    zdir_destroy (&newer);
    zdir_t *nosuch = zdir_new ("does-not-exist", NULL);
    assert (nosuch == NULL);
    // zdir_watch test:
    zactor_t *watch = zactor_new (zdir_watch, NULL);
    assert (watch);
    if (verbose) {
        zsock_send (watch, "s", "VERBOSE");
        assert (zsock_wait (watch) == 0);
    }
    zclock_sleep (1001); // wait for initial file to become 'stable'
    zsock_send (watch, "si", "TIMEOUT", 100);
    assert (zsock_wait (watch) == 0);
    zsock_send (watch, "ss", "SUBSCRIBE", "zdir-test-dir");
    assert (zsock_wait (watch) == 0);
    zsock_send (watch, "ss", "UNSUBSCRIBE", "zdir-test-dir");
    assert (zsock_wait (watch) == 0);
    zsock_send (watch, "ss", "SUBSCRIBE", "zdir-test-dir");
    assert (zsock_wait (watch) == 0);
    zfile_t *newfile = zfile_new ("zdir-test-dir", "test_abc");
    zfile_output (newfile);
    fprintf (zfile_handle (newfile), "test file\n");
    zfile_close (newfile);
    zpoller_t *watch_poll = zpoller_new (watch, NULL);
    // poll for a certain timeout before giving up and failing the test.
    assert (zpoller_wait (watch_poll, 1001) == watch);
    // wait for notification of the file being added
    char *path;
    int rc = zsock_recv (watch, "sp", &path, &patches);
    assert (rc == 0);
    assert (streq (path, "zdir-test-dir"));
    free (path);
    assert (zlist_size (patches) == 1);
    zdir_patch_t *patch = (zdir_patch_t *) zlist_pop (patches);
    assert (streq (zdir_patch_path (patch), "zdir-test-dir"));
    zfile_t *patch_file = zdir_patch_file (patch);
    assert (streq (zfile_filename (patch_file, ""), "zdir-test-dir/test_abc"));
    zdir_patch_destroy (&patch);
    zlist_destroy (&patches);
    // remove the file
    zfile_remove (newfile);
    zfile_destroy (&newfile);
    // poll for a certain timeout before giving up and failing the test.
    assert (zpoller_wait (watch_poll, 1001) == watch);
    // wait for notification of the file being removed
    rc = zsock_recv (watch, "sp", &path, &patches);
    assert (rc == 0);
    assert (streq (path, "zdir-test-dir"));
    free (path);
    assert (zlist_size (patches) == 1);
    patch = (zdir_patch_t *) zlist_pop (patches);
    assert (streq (zdir_patch_path (patch), "zdir-test-dir"));
    patch_file = zdir_patch_file (patch);
    assert (streq (zfile_filename (patch_file, ""), "zdir-test-dir/test_abc"));
    zdir_patch_destroy (&patch);
    zlist_destroy (&patches);
    zpoller_destroy (&watch_poll);
    zactor_destroy (&watch);
    // clean up by removing the test directory.
    zdir_t *testdir = zdir_new ("zdir-test-dir", NULL);
    zdir_remove (testdir, true);
    zdir_destroy (&testdir);

AUTHORS

The czmq manual was written by the authors in the AUTHORS file.

RESOURCES

Main web site:

Report bugs to the email <zeromq-dev@lists.zeromq.org[1]>

COPYRIGHT

Copyright (c) the Contributors as noted in the AUTHORS file. This file is part of CZMQ, the high-level C binding for 0MQ: http://czmq.zeromq.org. This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. LICENSE included with the czmq distribution.

NOTES

1.  zeromq-dev@lists.zeromq.org
    mailto:zeromq-dev@lists.zeromq.org