---
name: "zdir_patch"
section: "3"
platform: "linux"
package: "libczmq-dev"
version: "4.2.1-3+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/zdir_patch"
---

# zdir\_patch(3)

Class for work with directory patches

## NAME

zdir\_patch - Class for work with directory patches

## SYNOPSIS

```
//  This is a stable class, and may not change except for emergencies. It
//  is provided in stable builds.
#define ZDIR_PATCH_CREATE 1                  // Creates a new file
#define ZDIR_PATCH_DELETE 2                  // Delete a file
//  Create new patch
CZMQ_EXPORT zdir_patch_t *
    zdir_patch_new (const char *path, zfile_t *file, int op, const char *alias);
//  Destroy a patch
CZMQ_EXPORT void
    zdir_patch_destroy (zdir_patch_t **self_p);
//  Create copy of a patch. If the patch is null, or memory was exhausted,
//  returns null.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT zdir_patch_t *
    zdir_patch_dup (zdir_patch_t *self);
//  Return patch file directory path
CZMQ_EXPORT const char *
    zdir_patch_path (zdir_patch_t *self);
//  Return patch file item
CZMQ_EXPORT zfile_t *
    zdir_patch_file (zdir_patch_t *self);
//  Return operation
CZMQ_EXPORT int
    zdir_patch_op (zdir_patch_t *self);
//  Return patch virtual file path
CZMQ_EXPORT const char *
    zdir_patch_vpath (zdir_patch_t *self);
//  Calculate hash digest for file (create only)
CZMQ_EXPORT void
    zdir_patch_digest_set (zdir_patch_t *self);
//  Return hash digest for patch file
CZMQ_EXPORT const char *
    zdir_patch_digest (zdir_patch_t *self);
//  Self test of this class.
CZMQ_EXPORT void
    zdir_patch_test (bool verbose);
Please add '@interface' section in './../src/zdir_patch.c'.
```

## DESCRIPTION

The zdir\_patch class works with one patch, which says "create this file" or "delete this file" (referring to a zfile item each time).

Please add *@discuss* section in *./../src/zdir\_patch.c*.

## EXAMPLE

**From zdir\_patch\_test method**.

```
const char *SELFTEST_DIR_RW = "src/selftest-rw";
const char *testfile = "bilbo";
const char *prefix   = "/";
char *prefixed_testfile = zsys_sprintf ("%s%s", prefix, testfile);
assert (prefixed_testfile);
// Make sure old aborted tests do not hinder us
zsys_file_delete (prefixed_testfile);
zfile_t *file = zfile_new (SELFTEST_DIR_RW, testfile);
assert (file);
zdir_patch_t *patch = zdir_patch_new (SELFTEST_DIR_RW, file, patch_create, prefix);
assert (patch);
zfile_destroy (&file);
file = zdir_patch_file (patch);
assert (file);
assert (streq (zfile_filename (file, SELFTEST_DIR_RW), testfile));
assert (streq (zdir_patch_vpath (patch), prefixed_testfile));
zdir_patch_destroy (&patch);
zstr_free (&prefixed_testfile);
#if defined (__WINDOWS__)
zsys_shutdown();
#endif
```

## 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\.

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