| Travis        | AppVeyor      | GitLab| Codecov| Repology| Chat |
|:-------------:|:-------------:|:-----:|:------:|:-------:|:----:|
| [![Build Status](https://travis-ci.org/Exiv2/exiv2.svg?branch=0.27-maintenance)](https://travis-ci.org/Exiv2/exiv2) | [![Build status](https://ci.appveyor.com/api/projects/status/d6vxf2n0cp3v88al/branch/0.27-maintenance?svg=true)](https://ci.appveyor.com/project/piponazo/exiv2-wutfp/branch/0.27-maintenance) | [![pipeline status](https://gitlab.com/D4N/exiv2/badges/0.27-maintenance/pipeline.svg)](https://gitlab.com/D4N/exiv2/commits/0.27-maintenance) | [![codecov](https://codecov.io/gh/Exiv2/exiv2/branch/0.27-maintenance/graph/badge.svg)](https://codecov.io/gh/Exiv2/exiv2) | [![Packaging status](https://repology.org/badge/tiny-repos/exiv2.svg)](https://repology.org/metapackage/exiv2/versions) | [![#exiv2-chat on matrix.org](matrix-standard-vector-logo-xs.png)](https://matrix.to/#/#exiv2-chat:matrix.org) |

![Exiv2](exiv2.png)

# Building Exiv2 and dependencies with conan

Conan is a portable package manager for C/C++ libraries. It can be used to create all  dependencies needed to build Exiv2, without needing to install system packages.

This document provides a step-by-step guide to show you the basic usage of conan. For more details about the tool,
please visit the [Conan documentation website](http://docs.conan.io/en/latest/).

Although we provide step-by-step instructions to enable you to build Exiv2 with conan, we recommend that you read conan's documentation to understand the main concepts: [Getting started with Conan](http://docs.conan.io/en/latest/getting_started.html)

To build Exiv2 with conan, you will also need to install CMake.  https://cmake.org/download/

_**We do not recommend using conan on MinGW, Cygwin, Unix or to cross compile from Linux to those platforms.**<br>
The build procedures for those platforms are discussed here: See [README.md](README.md)_

<name id="TOC"></a>
----
### TABLE OF CONTENTS

1. [Step by Step Guide](#1)
    1. [Install conan](#1-1)
    2. [Test conan installation](#1-2)
    3. [Create a build directory](#1-3)
    4. [Build dependencies, create build environment, build and test](#1-4)
2. [Platform Notes](#2)
    1. [Linux Notes](#2-1)
    2. [Visual Studio Notes](#2-2)
3. [Conan Architecture](#3)
    1. [conanfile.py](#3-1)
    2. [Conan Recipes](#3-2)
    3. [Conan server search path](#3-3)
    4. [Configuring conan on your machine](#3-4)
4. [Building Exiv2 with Adobe XMPsdk 2016](#4)
    1. [Add a remote directory to conan's recipe search path](#4-1)
    2. [Build dependencies and install conan artefacts in your build directory](#4-2)
    3. [Execute cmake to generate build files for your environment](#4-3)
    4. [Build Exiv2 and link Adobe XMPsdk library](#4-4)
5. [Webready Support](#5)

<name id="1"></a>
----

# 1 Step by Step Guide

<name id="1-1"></a>
##### 1.1) </a>Install conan:

```bash
$ pip install conan
```
For other installation methods (brew, installers, from sources), visit this [link]([install
conan](http://docs.conan.io/en/latest/installation.html)).

To upgrade the version of conan:

```bash
$ pip install conan --upgrade
```

<name id="1-2"></a>
##### 1.2) Test conan installation

```bash
$ conan --version
Conan version 1.23.0
```

<name id="1-3"></a>
##### 1.3) Create a build directory<name id="1-3"></a>

Create a build directory and run the conan commands:

```bash
$ mkdir build
$ cd build
$ conan profile list
```
_**Visual Studio Users**_

_The profile msvc2019Release96 in `%USERPROFILE%\.conan\profiles\msvc2019Release64` is:_

```ini
[build_requires]
[settings]
arch=x86_64
build_type=Release
compiler=Visual Studio
compiler.runtime=MD
compiler.version=16
os=Windows
arch_build=x86_64
os_build=Windows
[options]
[env]
```

_Profiles for Visual Studio are discussed in detail here: [Visual Studio Notes](#2-2)__

<name id="1-4"></a>
##### 1.4) Build dependencies, create build environment, build and test</a>


|         | Build Steps   | Linux and macOS                | Visual Studio |
|:--      |:--------------|--------------------------------|------------------------------|
| _**1**_ | Get conan to fetch dependencies<br><br>The output can be quite<br>long as conan downloads and/or builds<br>zlib, expat, curl and other dependencies.| $ conan install ..<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;--build missing       | c:\\..\\build> conan install .. --build missing<br>&nbsp;&nbsp;&nbsp;&nbsp;--profile msvc2019Release64 |
| _**2**_ | Get cmake to generate<br>makefiles or sln/vcxproj | $ cmake ..  | c:\\..\\build> cmake&nbsp;..&nbsp;-G&nbsp;"Visual Studio 16 2019"
| _**3**_ | Build                                             | $ cmake --build .       | c:\\..\\build>&nbsp;cmake&nbsp;--build&nbsp;.&nbsp;--config&nbsp;Release<br>You may prefer to open exiv2.sln and build using the IDE. |
| _**4**_ | Optionally Run Test Suite                         | $ make tests            | c:\\..\\build>&nbsp;cmake&nbsp;--build&nbsp;.&nbsp;--config&nbsp;Release --target tests<br/>[README.md](README.md) |



[TOC](#TOC)
<name id="2"></a>
## 2) Platform Notes

<name id="2-1"></a>
### 2.1) Linux Notes

##### Default Profile

When you run conan install for the first time, it will detect and write the default profile ~/.conan/profile/default.  On my Ubuntu system with GCC 4.9, this is:

```ini
[settings]
os=Linux
os_build=Linux
arch=x86_64
arch_build=x86_64
compiler=gcc
compiler.version=4.9
compiler.libcxx=libstdc++
build_type=Release
[options]
[build_requires]
[env]
```

##### Changing profile settings

One of the most important **profile** settings to be adjusted in your conan profile when working on Linux is the field:

```bash
compiler.libcxx=libstdc++11  # Possible values: libstdc++, libstdc++11, libc++
```
With the arrival of the c++11 standard, and the growing popularity of the *clang* compiler, it is increasingly important which version of the standard library to use (corresponds to the `-stdlib` compiler flag).

Recommended **libcxx**
settings works with conan and different compilers:

```bash
compiler.libcxx=libstdc++11  # will use -stdlib=libstdc++ and define _GLIBCXX_USE_CXX11_ABI=1
compiler.libcxx=libstdc++    # will use -stdlib=libstdc++ and define _GLIBCXX_USE_CXX11_ABI=0
compiler.libcxx=libc++       # will use -stdlib=libc++
```

As a rule of thumb, set `compiler.libcxx=libstdc++11` when using a version of gcc >= 5.1.

More information about the standard library and GCC [dual ABI in gcc](https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html) with GCC works.

Please, be aware that normally when using gcc >= 5.1, \_GLIBCXX\_USE\_CXX11\_ABI is set to 1 by default. However some linux
distributions might set that definition to 0 by default. In case you get linking errors about standard c++ containers or
algorithms when bringing the Exiv2 dependencies with conan, this might indicate a mismatch between the value set in
**compiler.libcxx** and the default values used in your distribution.

[TOC](#TOC)
<name id="2-2"></a>
### 2.2) Visual Studio Notes

We recommend that you install python as discussed here:  [https://github.com/Exiv2/exiv2/pull/1403#issuecomment-731836146](https://github.com/Exiv2/exiv2/pull/1403#issuecomment-731836146)

### Profiles for Visual Studio

Exiv2 v0.27 can be built with VS 2008, 2010, 2012, 2013, 2015 , 2017 and 2019.

Exiv2 v0.28 is being "modernised" to C++11 and will not support C++98.
We don't expect Exiv2 v0.28 to build with VS versions earlier than VS 2015.

You create profiles in %HOMEPATH%\.conan\profiles with a text editor.  For your convenience, you'll find profiles in `<exiv2dir>\cmake\msvc_conan_profiles`.

```
Profile :=    msvc{Edition}{Type}{Bits}
Edition :=  { 2019    | 2017  |  2015  }
Type    :=  { Release | Debug }
Bits    :=  { 64      | 32    }
Examples:     msvc2019Release64 msvc2017Release32  msvc2015Debug32
```

The profile msvc2019Release64 is as follows:

```ini
[build_requires]
[settings]
arch=x86_64
build_type=Release
compiler=Visual Studio
compiler.runtime=MD
compiler.version=16
os=Windows
arch_build=x86_64
os_build=Windows
[options]
[env]
```

### Tools for Visual Studio 2019

You will need cmake version 3.14 (and up) and conan 1.14 (and up).

Additionally, when I upgraded to conan 1.14.3, I had to manually update the file `settings.yml` as follows. For me: `%USERPROFILE% == C:\Users\rmills`:

```bat
copy/y %USERPROFILE%\.conan\settings.yml.new %USERPROFILE%\.conan\settings.yml
```

### CMake Generators for Visual Studio

In the step-by-step guide, the command `$ cmake ..` uses
the default CMake generator.  Always use the generator for your version of Visual Studio.  For example:

```bat
c:\..\build> conan install .. --build missing --profile msvc2019Release64
c:\..\build> cmake         .. -G "Visual Studio 16 2019" -A x64
c:\..\build> cmake --build .  --config Release
```

CMake provides Generators for different editions of Visual Studio.  The 64 and 32 bit Generators have different names:

| Architecture | Visual Studio 2019 | Visual Studio 2017 | Visual Studio 2015 |
|:---------    |--------------------|--------------------|--------------------|--------------------|
| 64 bit       | -G "Visual Studio 16 2019" -A x64          | -G "Visual Studio 15 2017 Win64" | -G "Visual Studio 14 2015 Win64"     |
| 32 bit       | -G "Visual Studio 16 2019" -A Win32        | -G "Visual Studio 15 2017"       | -G "Visual Studio 14 2015"           |

### Recommended settings for Visual Studio

##### 64 bit Release Build

| | Visual Studio 2019 | Visual Studio 2017 | Visual Studio 2015|
|:---------|--------------------|--------------------|--------------|
| _**conan install .. --profile**_ | msvc2019Release64 | msvc2017Release64 | msvc2015Release64 |
| _**cmake**_                   |  -G "Visual Studio 16 2019" -A x64   |  -G "Visual Studio 15 2017 Win64"    | -G "Visual Studio 14 2015 Win64" |
| _**profile**_<br><br><br><br><br><br><br>_ | arch=x86\_64<br>arch\_build=x86\_64<br>build\_type=Release<br>compiler.runtime=MD<br>compiler.version=16<br>compiler=Visual Studio<br>os=Windows<br>os\_build=Windows  | arch=x86\_64<br>arch\_build=x86\_64<br>build\_type=Release<br>compiler.runtime=MD<br>compiler.version=15<br>compiler=Visual Studio<br>os=Windows<br>os\_build=Windows  | arch=x86\_64<br>arch\_build=x86\_64<br>build\_type=Release<br>compiler.runtime=MD<br>compiler.version=14 <br>compiler=Visual Studio<br>os=Windows<br>os\_build=Windows |

##### Debug Builds

|| Visual Studio 2019 | Visual Studio 2017 | Visual Studio 2015 |
|:-------|-------|------|--------------|
| _**conan install .. --profile**_ | msvc2019Debug64 | msvc2017Debug64 | msvc2015Debug64 |
| _**profile**_<br>_ | build\_type=Debug<br>compiler.runtime=MDd | build\_type=Debug<br>compiler.runtime=MDd | build_type=Debug<br>compiler.runtime=MDd |

##### 32bit Builds

|| Visual Studio 2019 | Visual Studio 2017 | Visual Studio 2015 |
|:-----------|--------------------|--------------------|--------------------|
| _**conan install .. --profile**_ | msvc2019Release32 | msvc2017Release32 | msvc2015Release32 |
| _**cmake**_ | -G "Visual Studio 16 2019" -A Win32 | -G "Visual Studio 15 2017" | -G "Visual Studio 14 2015" |
| _**profile**_<br>_ | arch=x86<br>arch\_build=x86 | arch=x86<br>arch\_build=x86 | arch=x86<br>arch\_build=x86 |

##### Static Builds

The default builds of Exiv2 and sample applications build and use DLLs.

To build static libraries, use the cmake option `-DBUILD_SHARED_LIBS=Off`.  You will probably also want to use the static run-time.  The default is to use the dynamic run-time library.

```bash
$ cmake .. -DBUILD_SHARED_LIBS=Off -DEXIV2_ENABLE_DYNAMIC_RUNTIME=Off
```

If you wish to use the static C run-time library, use the following option in the conan profile.

|                      | Static Release      | Static Debug |
|:---                  |:---------           |:-------------------|
| **profile setting**  | compiler.runtime=MT | compiler.runtime=MTd |

If you receive a linker warning concerning `LIBCMT`, it is because you are attempting to link libraries which have been built with different run-time libraries.
You should link everything with the dynamic or static run-time. You can link a static library with the dynamic run-time if you wish.

### Changing profile settings with the conan command

It is recommended that you use profiles provided in `<exiv2dir>\cmake\msvc_conan_profiles`.

You can modify profile settings on the command line.
The following example demonstrates making substantial changes to profile settings by performing a 32 bit build using Visual Studio 2015 with a 2017 profile!  This example is not considered good practice, it is an illustration of some conan flexibility which may be useful when your build environment is automated.

```bash
$ conan install .. --profile msvc2017Release64 -s arch_build=x86 -s arch=x86 -s compiler.version=14
$ cmake         .. -G "Visual Studio 2015"
$ cmake --build .  --config Release
```

[TOC](#TOC)
<name id="3">
## 3 Conan Architecture

<name id="3-1">
##### 3.1) conanfile.py

In the root level of the **Exiv2** repository, the file `conanfile.py` defines C/C++ dependencies with the syntax: `Library/version@user/channel`

For example, **zlib**:

```python
self.requires('self.requires('zlib/1.2.11@conan/stable')')
```

[TOC](#TOC)
<name id="3-2">
##### 3.2) Conan _**Recipes**_

Conan searches remote servers for a _**recipe**_ to build a dependency.

A _**recipe**_ is a python file which indicates how to build a library from sources. The recipe
understands configurations: Platform/Compiler/Settings.  If the remote server has a pre-compiled package for
your configuration, it will be downloaded.  Otherwise, conan will compile the libraries on your machine using instructions in the recipe.

To illustrate, here is list of packages that returned by the command `$ conan search`

```bash
$ conan search --remote conan-center zlib/1.2.11@conan/stable
```

The output should be:

```bash
Existing packages for recipe zlib/1.2.11@conan/stable:

    Package_ID: 0000193ac313953e78a4f8e82528100030ca70ee
        [options]
            shared: False
        [settings]
            arch: x86_64
            build_type: Debug
            compiler: gcc
            compiler.version: 4.9
            os: Linux
        Outdated from recipe: False

    Package_ID: 014be746b283391f79d11e4e8af3154344b58223
        [options]
            shared: False
        [settings]
            arch: x86_64
            build_type: Debug
            compiler: gcc
            compiler.exception: seh
            compiler.threads: posix
            compiler.version: 5
            os: Windows
        Outdated from recipe: False

... deleted ....

```

[TOC](#TOC)
<name id="3-3">
##### 3.3) Conan server search path

Conan searches remote servers for a _**recipe**_ to build the dependency.  You can list them with the command:

```bash
$ conan remote list
```

You can add servers to the conan server search path:

```bash
$ conan remote add conan-piponazo https://api.bintray.com/conan/piponazo/piponazo
```

[TOC](#TOC)
<name id="3-4">
##### 3.4) Configuring conan on your machine

Conan stores its configuration and local builds in the directory ~/.conan (%HOMEPATH%\\.conan on Windows).

Conan installs several files and two directories:

```bash
$HOME/.conan/profiles   Configuration files for compilers/platforms
$HOME/.conan/data       Dependencies are built/stored in this directory
```

[TOC](#TOC)
<name id="3-5">
##### 3.5) Running `conan install` for the first time

The first time you run `$ conan install`, it will auto-detect your configuration and store a default profile in the file
$HOME/.conan/profiles/default

Normally you will want to define new profiles for choosing different compilers (msvc, gcc, clang), different
build_type (Release, Debug), runtimes (MD, MT, MDd, MTd)

The expected output should be something like this, in case it's the first time you run conan:

```bash
$ conan install ..  --build missing
Expat/2.2.5@pix4d/stable: Retrieving from predefined remote 'conan-center'
Expat/2.2.5@pix4d/stable: Trying with 'conan-center'...
Downloading conanmanifest.txt
[==================================================] 220B/220B
Downloading conanfile.py
[==================================================] 1.7KB/1.7KB
zlib/1.2.11@conan/stable: Retrieving from predefined remote 'conan-center'
zlib/1.2.11@conan/stable: Trying with 'conan-center'...
Downloading conanmanifest.txt
[==================================================] 121B/121B
Downloading conanfile.py
[==================================================] 5.7KB/5.7KB
libcurl/7.56.1@bincrafters/stable: Retrieving from predefined remote 'bincrafters'
libcurl/7.56.1@bincrafters/stable: Trying with 'bincrafters'...
Downloading conanmanifest.txt
...
PROJECT: Installing D:\Dev\Windows\projects\exiv2\conanfile.py
Requirements
    Expat/2.2.5@pix4d/stable from 'conan-center'
    OpenSSL/1.0.2n@conan/stable from 'conan-center'
    gtest/1.8.0@bincrafters/stable from 'conan-center'
    libcurl/7.56.1@bincrafters/stable from 'bincrafters'
    zlib/1.2.11@conan/stable from 'conan-center'
Packages
    Expat/2.2.5@pix4d/stable:6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7
    OpenSSL/1.0.2n@conan/stable:606fdb601e335c2001bdf31d478826b644747077
    gtest/1.8.0@bincrafters/stable:a35f8fa327837a5f1466eaf165e1b6347f6e1e51
    libcurl/7.56.1@bincrafters/stable:e37838f02fd790447943465f1c9317fd1c59b95c
    zlib/1.2.11@conan/stable:6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7

PROJECT: Retrieving package 6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7
Expat/2.2.5@pix4d/stable: Looking for package 6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7 in remote 'conan-center'
Downloading conanmanifest.txt
[==================================================] 323B/323B
Downloading conaninfo.txt
[==================================================] 438B/438B
Downloading conan_package.tgz
[==================================================] 133.6KB/133.6KB
Expat/2.2.5@pix4d/stable: Package installed 6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7
PROJECT: Retrieving package a35f8fa327837a5f1466eaf165e1b6347f6e1e51
gtest/1.8.0@bincrafters/stable: Looking for package a35f8fa327837a5f1466eaf165e1b6347f6e1e51 in remote 'conan-center'
Downloading conanmanifest.txt
[==================================================] 3.5KB/3.5KB
Downloading conaninfo.txt
[==================================================] 478B/478B
Downloading conan_package.tgz
[==================================================] 1001.1KB/1001.1KB
gtest/1.8.0@bincrafters/stable: Package installed a35f8fa327837a5f1466eaf165e1b6347f6e1e51
PROJECT: Retrieving package 6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7
...
PROJECT: Generator cmake created conanbuildinfo.cmake
PROJECT: Generator txt created conanbuildinfo.txt
PROJECT: Generated conaninfo.txt
PROJECT imports(): Copied 5 '.dll' files
(conan)
```

Note that it first downloads the recipes, and then the binary packages. When everything goes well, conan found
the recipes in the remotes, and it also found packages for our configuration (msvc2017, Release, MD).

However, if you use other configuration for which there are no packages in the remotes, you will get an error such as:

```bash
    PROJECT: WARN: Can't find a 'zlib/1.2.11@conan/stable' package for the specified options and settings:
    - Settings: arch=x86_64, build_type=Release, compiler=clang, compiler.version=3.9, os=Macos
    - Options: shared=False

    ERROR: Missing prebuilt package for 'zlib/1.2.11@conan/stable'
    Try to build it from sources with "--build zlib"
    Or read "http://docs.conan.io/en/latest/faq/troubleshooting.html#error-missing-prebuilt-package"
```

In that case, we can tell conan to build the library:

```bash
$ conan install .. --profile MyEsotericProfile --build missing
```

Once the command succeeds, we will have the libraries in our system (you can find the recipes and packages in
`$HOME/.conan/data`). When you execute the command `conan install` with the same profile, the following output is typical:

```bash
$ conan install ..
PROJECT: Installing D:\Dev\Windows\projects\exiv2\conanfile.py
Requirements
    Expat/2.2.5@pix4d/stable from 'conan-center'
    OpenSSL/1.0.2n@conan/stable from 'conan-center'
    gtest/1.8.0@bincrafters/stable from 'conan-center'
    libcurl/7.56.1@bincrafters/stable from 'bincrafters'
    zlib/1.2.11@conan/stable from 'conan-center'
Packages
    Expat/2.2.5@pix4d/stable:6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7
    OpenSSL/1.0.2n@conan/stable:606fdb601e335c2001bdf31d478826b644747077
    gtest/1.8.0@bincrafters/stable:a35f8fa327837a5f1466eaf165e1b6347f6e1e51
    libcurl/7.56.1@bincrafters/stable:e37838f02fd790447943465f1c9317fd1c59b95c
    zlib/1.2.11@conan/stable:6cc50b139b9c3d27b3e9042d5f5372d327b3a9f7

Expat/2.2.5@pix4d/stable: Already installed!
gtest/1.8.0@bincrafters/stable: Already installed!
zlib/1.2.11@conan/stable: Already installed!
OpenSSL/1.0.2n@conan/stable: Already installed!
libcurl/7.56.1@bincrafters/stable: Already installed!
PROJECT: Generator cmake created conanbuildinfo.cmake
PROJECT: Generator txt created conanbuildinfo.txt
PROJECT: Generated conaninfo.txt
PROJECT imports(): Copied 5 '.dll' files
```

Indicating that the packages were found in the local cache.

[TOC](#TOC)
<name id="4">
## 4 Building Exiv2 with Adobe XMPsdk 2016

With Exiv2 v0.27, you can build Exiv2 with Adobe XMPsdk 2016 on Linux/GCC, Mac/clang and Visual Studio 2017.
Other platforms such as Cygwin are not supported by Adobe.  Adobe/XMPsdk is built as a external library.
Applications which wish use the Adobe XMPsdk directly should build Exiv2 in this configuration and the
library can be used by the application and Exiv2.  The Adobe XMPsdk can be built as a static or shared library (.DLL)

To build Exiv2 with Adobe XMPsdk 2016, perform steps 1.1, 1.2 and 1.3 described above, then perform the following:

<name id="4-1">
##### 4.1) Add a remote directory to conan's recipe search path

By default, conan knows about several public conan repositories. Exiv2 requires
the **piponazo** repository to find the XmpSdk dependency which is not available from **conan-center** repository.

```bash
$ conan remote add conan-piponazo https://api.bintray.com/conan/piponazo/piponazo
```

<name id="4-2">
##### 4.2) Build dependencies and install conan artefacts in your build directory

```bash
$ conan install .. --options xmp=True --build missing
```

<name id="4-3">
##### 4.3) Execute cmake to generate build files for your environment:

You must tell CMake to link Adobe's library:

```bash
$ cmake .. -DEXIV2_ENABLE_EXTERNAL_XMP=On # -G "Visual Studio 15 2017 Win64" -DCMAKE_BUILD_TYPE=Release
```
**macOS** users should use the cmake _**Xcode**_ Generator

```bash
$ cmake .. -DEXIV2_ENABLE_EXTERNAL_XMP=On -G Xcode
```

<name id="4-4">
##### 4.4) Build Exiv2 and link Adobe XMPsdk library

```bash
$ cmake --build . --config Release
```

[TOC](#TOC)
<name id="5">
## 5 Webready Support

Exiv2 can perform I/O using internet protocols such as http, https and ftp.

The feature is disabled by default.  You will need to instruct conan to build/download necessary libraries (curl, openssl and libssh) and tell CMake to link to the libraries.

```bash
$ conan install .. --options webready=True
$ cmake -DEXIV2_ENABLE_WEBREADY=ON -DEXIV2_ENABLE_CURL=ON -DEXIV2_ENABLE_SSH=ON ..
```

[TOC](#TOC)

Written by Robin Mills<br>robin@clanmills.com<br>Updated: 2021-03-18

| Travis        | AppVeyor      | GitLab| Codecov| Repology| Chat |
|:-------------:|:-------------:|:-----:|:------:|:-------:|:----:|
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![Exiv2](exiv2.png)

# Exiv2 Sample Applications

Exiv2 is a C++ library and a command line utility to read, write, delete and modify Exif, IPTC, XMP and ICC image metadata.  Exiv2 also features a collection of sample and test command-line programs.  Please be aware that while the program _**exiv2**_ enjoys full support from Team Exiv2, the other programs have been written for test, documentation or development purposes.  You are expected to read the code to discover the specification of programs other than _**exiv2**_.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="TOC1">

### Sample Programs

The following programs are build and installed in /usr/local/bin.

| Name | Purpose | More information | Code |
|:---  |:---  |:---              |:-- |
| _**addmoddel**_   | Demonstrates Exiv2 library APIs to add, modify or delete metadata | [addmoddel](#addmoddel) | [addmoddel.cpp](samples/addmoddel.cpp) |
| _**exifcomment**_ | Set Exif.Photo.UserComment in an image  | [exifcomment](#exifcomment) | [exifcomment.cpp](samples/exifcomment.cpp) |
| _**exifdata**_    | Prints _**Exif**_ metadata in different formats in an image | [exifdata](#exifdata) | [exifdata.cpp](samples/exifdata.cpp) |
| _**exifprint**_   | Print _**Exif**_ metadata in images<br>Miscelleous other features | [exifprint](#exifprint)| [exifprint.cpp](samples/exifprint.cpp) |
| _**exifvalue**_   | Prints the value of a single _**Exif**_ tag in a file | [exifvalue](#exifvalue) | [exifvalue.cpp](samples/exifvalue.cpp) |
| _**exiv2**_       | Command line utility to read, write, delete and modify Exif, IPTC, XMP and ICC image metadata.<br>This is the primary test tool used by Team Exiv2 and can exercise almost all code in the library.  Due to the extensive capability of this utility, the APIs used are usually less obvious for casual code inspection. | [https://exiv2.org/manpage.html](https://exiv2.org/manpage.html)<br>[https://exiv2.org/sample.html](https://exiv2.org/sample.html) | |
| _**exiv2json**_   | Extracts data from image in JSON format.<br>This program also contains a parser to recursively parse Xmp metadata into vectors and objects. | [exiv2json](#exiv2json) | [exiv2json.cpp](samples/exiv2json.cpp) |
| _**geotag**_      | Reads GPX data and updates images with GPS Tags | [geotag](#geotag) | [geotag.cpp](samples/geotag.cpp) |
| _**iptceasy**_    | Demonstrates read, set or modify IPTC metadata | [iptceasy](#iptceasy) | [iptceasy.cpp](samples/iptceasy.cpp) |
| _**iptcprint**_   | Demonstrates Exiv2 library APIs to print Iptc data | [iptceasy](#iptceasy) | [iptcprint.cpp](samples/iptcprint.cpp) |
| _**metacopy**_    | Demonstrates copying metadata from one image to another | [metacopy](#metacopy) | [metacopy.cpp](samples/metacopy.cpp) |
| _**mrwthumb**_    | Sample program to extract a Minolta thumbnail from the makernote | [mrwthumb](#mrwthumb) | [mrwthumb.cpp](samples/mrwthumb.cpp) |
| _**taglist**_     | Print a simple comma separated list of tags defined in Exiv2 | [taglist](#taglist) |
| _**xmpdump**_     | Sample program to dump the XMP packet of an image | [xmpdump](#xmpdump) |
| _**xmpparse**_    | Read an XMP packet from a file, parse it and print all (known) properties. | [xmpparse](#xmpparse) | [xmpparse.cpp](samples/xmpparse.cpp) |
| _**xmpprint**_    | Read an XMP from a file, parse it and print all (known) properties.. | [xmpprint](#xmpprint) | [xmpprint.cpp](samples/xmpprint.cpp) |
| _**xmpsample**_   | Demonstrates Exiv2 library high level XMP classes | [xmpsample](#xmpsample) | [xmpsample.cpp](samples/exmpsample.cpp) |

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="TOC2">

### Test Programs

As Exiv2 is open source, we publish all our materials.  The following programs are actively used in our test harness.  Some were written during feature development of features and their on-going use may be limited, or even obsolete.  In general these programs are published as source and Team Exiv2 will not provide support to users.

| Name | Kind | More information |
|:---  |:---  |:---              |
| _**conntest**_ | Test http/https/ftp/ssh/sftp connection | [conntest](#conntest) |
| _**convert-test**_ | Conversion test driver | [convert-test](#convert-test) |
| _**easyaccess-test**_ | Sample program using high-level metadata access functions | [easyaccess-test](#easyaccess-test) |
| _**getopt-test**_ | Sample program to test getopt() | [getopt-test](#getopt-test) |
| _**ini-test**_ | Shows simple usage of the INIReader class | [ini-test](#ini-test) |
| _**iotest**_ | Test programs for BasicIo functions. | [iotest](#iotest) |
| _**iptctest**_ | Sample program test Iptc reading and writing. | [iptctest](#iptctest) |
| _**key-test**_ | Key unit tests | [key-test](#key-test) |
| _**largeiptc-test**_ | Test for large (>65535 bytes) IPTC buffer | [largeiptc-test](#largeiptc-test) |
| _**mmap-test**_ | Simple mmap tests | [mmap-test](#mmap-test) |
| _**path-test**_ | Test path IO | [path-test](#path-test) |
| _**prevtest**_ | Test access to preview images | [prevtest](#prevtest) |
| _**remotetest**_ | Tester application for testing remote i/o. | [remotetest](#remotetest) |
| _**stringto-test**_ | Test conversions from string to long, float and Rational types. | [stringto-test](#stringto-test) |
| _**tiff-test**_ | Simple TIFF write test | [tiff-test](#tiff-test) |
| _**werror-test**_ | Simple tests for the wide-string error class WError | [werror-test](#werror-test) |
| _**write-test**_ | ExifData write unit tests | [write-test](#write-test) |
| _**write2-test**_ | ExifData write unit tests for Exif data created from scratch | [write2-test](#write2-test) |
| _**xmpparser-test**_ | Read an XMP packet from a file, parse and re-serialize it. | [xmpparser-test](#xmpparser-test)|

[Sample](#TOC1) Programs [Test](#TOC2) Programs

## 2 Sample Program Descriptions

<div id="addmoddel">

#### addmoddel

```
Usage: addmoddel file
```

Demonstrates Exiv2 library APIs to add, modify or delete metadata.  _Code: [addmoddel.cpp](samples/addmoddel.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="exifcomment">

#### exifcomment

```
Usage: exifcomment file
```

This is a simple program that demonstrates how to set _**Exif.Photo.UserComment**_ in an image. _Code: [exifcomment.cpp](samples/exifcomment.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="exifdata">

### exifdata

```
Usage: exifdata file format
formats: csv | json | wolf | xml
```

This is a simple program to demonstrate dumping _**Exif**_ metadata in common formats.  _Code: [exifdata.cpp](samples/exifdata.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="exifprint">

#### exifprint

```
Usage: exifprint [ path | --version | --version-test ]
```

| Arguments | Description |
|:--        |:---  |
| path    | Path to image |
| --version     | Print version information from build |
| --version-test   | Tests Exiv2 VERSION API |

This program demonstrates how to print _**Exif**_ metadata in an image.  This program is also discussed in the platform ReadMe.txt file included in a build bundle.  The option **--version** was added to enable the user to build a test application which dumps the build information.  The option **--version-test** was added to test the macro EXIV2\_TEST\_VERSION() in **include/exiv2/version.hpp**.

There is one other unique feature of this program.  It is the only test/sample program which can use the EXV\_UNICODE\_PATH build feature of Exiv2 on Windows.

_Code: [exifprint.cpp](samples/exifprint.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="exifvalue">

#### exifvalue

```
Usage: exifvalue file tag
```
Prints the value of a single _**Exif**_ tag in a file. _Code: [exifvalue.cpp](samples/exifvalue.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="exiv2json">

#### exiv2json

```
Usage: exiv2json [-option] file
Option: all | exif | iptc | xmp | filesystem
```
| Arguments | Description |
|:--        |:---  |
| all      | All metadata |
| filesystem    | Filesystem metadata |
| exif     | Exif metadata |
| iptc     | Iptc metadata |
| xmp      | Xmp metadata |
| file   | path to image |

This program dumps metadata from an image in JSON format. _Code: [exiv2json.cpp](samples/exiv2json.cpp)_

exiv2json has a recursive parser to encode XMP into Vectors and Objects.  XMP data is XMP and can contain XMP `Bag` and `Seq` which are converted to JSON Objects and Arrays.  Exiv2 presents data in the format:  Family.Group.Tag.  For XMP, results in "flat" output such such as:

```
$ exiv2 -px ~/Stonehenge.jpg
Xmp.xmp.Rating                               XmpText     1  0
Xmp.xmp.ModifyDate                           XmpText    25  2015-07-16T20:25:28+01:00
Xmp.dc.description                           LangAlt     1  lang="x-default" Classic View
```

exiv2json parses the Exiv2 'Family.Group.Tag' data and restores the structure of the original data in JSON.  _Code: [exiv2json.cpp](samples/exiv2json.cpp)_

```
$ exiv2json -xmp http://clanmills.com/Stonehenge.jpg
{
  "Xmp": {
    "xmp": {
      "Rating": "0",
      "ModifyDate": "2015-07-16T20:25:28+01:00"
    },
    "dc": {
      "description": {
        "lang": {
          "x-default": "Classic View"
        }
      }
    },
    "xmlns": {
      "dc": "http:\/\/purl.org\/dc\/elements\/1.1\/",
      "xmp": "http:\/\/ns.adobe.com\/xap\/1.0\/"
    }
  }
}
$
```

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="geotag">

#### geotag

```
Usage: geotag {-help|-version|-dst|-dryrun|-ascii|-verbose|-adjust value|-tz value|-delta value}+ path+
```

Geotag reads one or more GPX files and adds GPS Tages to images.  _Code: [geotag.cpp](samples/geotag.cpp)_

If the path is a directory, geotag will read all the files in the directory.  It constructs a time dictionary of position data, then updates every image with GPS Tags.

| Arguments | Description |
|:--        |:---  |
| -help     | print usage statement |
| -version  | prints data and time of compiling geotag.cpp |
| -dst      | Apply 1 hour adjustment for daylight saving time. |
| -dryrun   | Read arguments and print report.  Does not modify images. |
| -ascii    | Output in ascii (not UTF8).  Prints `deg` instead of &deg;. |
| -verbose  | Report progress. |
| -adjust  value | Add/subtract time from image data. |
| -tz      value | Specify time zone. For example PST = -8:00 |
| -delta   value | Correction between Image DataTime and GPS time. |
| path+ | One or more directories, image paths or gpx paths.  Directories are searched for gpx and images |

I use this program frequently.  I have a little Canon camera which I take when I run.  My Samsung Galaxy Watch uploads my runs to Strava and I download the GPX.  If I'm in another time-zone and have forgotten to change the time setting in the camera, I use `-adjust` to alter the images.  The GPX time is always correct, however the camera is normally off by seconds or minutes.  This option enables you to correct for inaccuracy in the setting of the camera time.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="iptceasy">

#### iptceasy

```
Usage: iptceasy file
Reads and writes raw metadata. Use -h option for help.
```

Demonstrates read, set or modify IPTC metadata. _Code: [iptceasy.cpp](samples/iptceasy.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="iptcprint">

#### iptcprint

```
Usage: iptcprint file
Reads and writes raw metadata. Use -h option for help.
```

Demonstrates Exiv2 library APIs to print Iptc data. _Code: [iptcprint.cpp](samples/iptcprint.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="metacopy">

#### metacopy

```
Usage: metacopy [-iecxaph] readfile writefile
Reads and writes raw metadata. Use -h option for help.
```

Metacopy is used to copy a complete metadata block from one file to another.  _Code: [metacopy.cpp](samples/metacopy.cpp)_

Please note that some metadata such as Exif.Photo.PixelXDimension is considered to be part of the image and will not be copied.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="mrwthumb">

#### mrwthumb

```
Usage: mrwthumb file
```

Sample program to extract a Minolta thumbnail from the makernote. _Code: [mrwthumb.cpp](samples/mrwthumb.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="xmpparse">

#### xmpparse

```
Usage: xmpparse file
```

Read an XMP packet from a file, parse it and print all (known) properties.  _Code: [xmpparse.cpp](samples/xmpparse.cpp)_


[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="xmpprint">

#### xmpprint

```
Usage: xmpprint file
```

Read an XMP from a file, parse it and print all (known) properties. _Code: [xmpprint.cpp](samples/xmpprint.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="xmpsample">

#### xmpsample

```
Usage: xmpsample file
```

Demonstrates Exiv2 library high level XMP classes.  _Code: [xmpsample.cpp](samples/xmpsample.cpp)_

[Sample](#TOC1) Programs [Test](#TOC2) Programs

## 3 Test Program Descriptions

<div id="conntest">

#### conntest

```
Usage: conntest url {-http1_0}
```

Test http/https/ftp/ssh/sftp connection

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="convert-test">

#### convert-test

```
Usage: convert-test file
```

Conversion test driver

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="easyaccess-test">

#### easyaccess-test

```
Usage: easyaccess-test file
```

Sample program using high-level metadata access functions

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="getopt-test">

#### getopt-test

```
Usage: getopt-test
```
This program is used to test the function **getopt()**.  Prior to Exiv2 v0.27, the sample programs used the platform's C Runtime Library function **getopt()**.  Visual Studio builds used code in src/getopt.cpp.  Due to differences in the platform **getopt()**, the code in src/getopt.cpp was modified and adopted on every platforms.  This test program was added for test and debug purpose.  Please note that src/getopt.cpp is compiled and linked into the sample application and is not part of the Exiv2 library.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="ini-test">

#### ini-test

```
Usage: ini-test
```

This program is used to test reading the file ini-test.  This program was added in Exiv2 v0.26 when the ~/.exiv2 file was added to the Exiv2 architecture.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="iotest">

#### iotest

```
Usage: iotest filein fileout1 fileout2 [remote [blocksize]]
copy filein to fileout1 and copy filein to fileout2
fileout1 and fileout2 are overwritten and should match filein exactly

You may optionally provide the URL of a remote file to be copied to filein
If you use `remote`, you may optionally provide a blocksize for the copy buffer (default 10k)
```

Test programs for BasicIo functions.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="iptctest">

#### iptctest

```
Usage: iptctest image
Commands read from stdin.
```

Sample program test Iptc reading and writing.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="key-test">

#### key-test

```
Usage: key-test
```

Key unit tests

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="largeiptc-test">

#### largeiptc-test

```
Usage: largeiptc-test image datafile
```

Test for large (>65535 bytes) IPTC buffer

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="mmap-test">

#### mmap-test

```
Usage: mmap-test file
```

Simple mmap tests

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="path-test">

#### path-test

```
Usage: path-test file
```

Test path IO

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="prevtest">

#### prevtest

```
Usage: prevtest file
```

Test access to preview images

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="remotetest">

#### remotetest

```
Usage: remotetest remotetest file {--nocurl | --curl}
```

Tester application for testing remote i/o.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="stringto-test">

#### stringto-test

```
Usage: stringto-test
```

Test conversions from string to long, float and Rational types.

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="taglist">

#### taglist

```
$ taglist --help
Usage: taglist [--help]
           [--group name|
            Groups|Exif|Canon|CanonCs|CanonSi|CanonCf|Fujifilm|Minolta|Nikon1|Nikon2|Nikon3|Olympus|
            Panasonic|Pentax|Sigma|Sony|Iptc|
            dc|xmp|xmpRights|xmpMM|xmpBJ|xmpTPg|xmpDM|pdf|photoshop|crs|tiff|exif|aux|iptc|all|ALL
           ]
Print Exif tags, MakerNote tags, or Iptc datasets
```

Print a simple comma separated list of tags defined in Exiv2

This program encodes the library's tag definitions in ascii.
The data from this program is formatted as HTML on the web-site.  https://exiv2.org/metadata.html

For example, to show the binary definition of Group `Nikon3`:

```
$ taglist Nikon3
Version,    1,  0x0001, Nikon3, Exif.Nikon3.Version,    Undefined,  Nikon Makernote version
ISOSpeed,   2,  0x0002, Nikon3, Exif.Nikon3.ISOSpeed,   Short,  ISO speed setting
ColorMode,  3,  0x0003, Nikon3, Exif.Nikon3.ColorMode,  Ascii,  Color mode
Quality,    4,  0x0004, Nikon3, Exif.Nikon3.Quality,    Ascii,  Image quality setting
WhiteBalance,   5,  0x0005, Nikon3, Exif.Nikon3.WhiteBalance,   Ascii,  White balance
Sharpening, 6,  0x0006, Nikon3, Exif.Nikon3.Sharpening, Ascii,  Image sharpening setting
Focus,  7,  0x0007, Nikon3, Exif.Nikon3.Focus,  Ascii,  Focus mode
FlashSetting,   8,  0x0008, Nikon3, Exif.Nikon3.FlashSetting,   Ascii,  Flash setting
FlashDevice,    9,  0x0009, Nikon3, Exif.Nikon3.FlashDevice,    Ascii,  Flash device
...
```

We can see those tags being used:

```
$ exiv2 -pa --grep Nikon3 http://clanmills.com/Stonehenge.jpg
Exif.Nikon3.Version                          Undefined   4  2.11
Exif.Nikon3.ISOSpeed                         Short       2  200
...
```

This information is formatted (search Nikon (format 3) MakerNote Tags): [https://exiv2.org/tags-nikon.html](https://exiv2.org/tags-nikon.html)

#### taglist all

These options are provided to list every Exif tag known to Exiv2.  The option `all` prints Group.Name for every tag.  The option `ALL` print Group.Name followed by the TagInfo for that tag.  For example:

```bash
$ taglist all | grep ISOSpeed$
Photo.ISOSpeed
PanasonicRaw.ISOSpeed
CanonCs.ISOSpeed
CanonSi.ISOSpeed
Casio2.ISOSpeed
MinoltaCs5D.ISOSpeed
MinoltaCs7D.ISOSpeed
Nikon1.ISOSpeed
Nikon2.ISOSpeed
Nikon3.ISOSpeed
Olympus.ISOSpeed
Olympus2.ISOSpeed
```

```bash
$ taglist ALL | grep ISOSpeed,
Photo.ISOSpeed,	34867,	0x8833,	Photo,	Exif.Photo.ISOSpeed,	Long,	This tag indicates the ISO speed value of a camera or input device that is defined in ISO 12232. When recording this tag, the PhotographicSensitivity and SensitivityType tags shall also be recorded.
PanasonicRaw.ISOSpeed,	23,	0x0017,	PanasonicRaw,	Exif.PanasonicRaw.ISOSpeed,	Short,	ISO speed setting
CanonCs.ISOSpeed,	16,	0x0010,	CanonCs,	Exif.CanonCs.ISOSpeed,	SShort,	ISO speed setting
CanonSi.ISOSpeed,	2,	0x0002,	CanonSi,	Exif.CanonSi.ISOSpeed,	Short,	ISO speed used
Casio2.ISOSpeed,	20,	0x0014,	Casio2,	Exif.Casio2.ISOSpeed,	Short,	ISO Speed
MinoltaCs5D.ISOSpeed,	38,	0x0026,	MinoltaCs5D,	Exif.MinoltaCs5D.ISOSpeed,	Short,	ISO speed setting
MinoltaCs7D.ISOSpeed,	28,	0x001c,	MinoltaCs7D,	Exif.MinoltaCs7D.ISOSpeed,	Short,	ISO speed setting
Nikon1.ISOSpeed,	2,	0x0002,	Nikon1,	Exif.Nikon1.ISOSpeed,	Short,	ISO speed setting
Nikon2.ISOSpeed,	6,	0x0006,	Nikon2,	Exif.Nikon2.ISOSpeed,	Short,	ISO speed setting
Nikon3.ISOSpeed,	2,	0x0002,	Nikon3,	Exif.Nikon3.ISOSpeed,	Short,	ISO speed setting
Olympus.ISOSpeed,	4097,	0x1001,	Olympus,	Exif.Olympus.ISOSpeed,	SRational,	ISO speed value
Olympus2.ISOSpeed,	4097,	0x1001,	Olympus,	Exif.Olympus.ISOSpeed,	SRational,	ISO speed value
Sony1MltCs7D.ISOSpeed,	28,	0x001c,	MinoltaCs7D,	Exif.MinoltaCs7D.ISOSpeed,	Short,	ISO speed setting
```



[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="tiff-test">

#### tiff-test

```
Usage: tiff-test file
```

Simple TIFF write test

[Sample](#TOC1) Programs [Test](#TOC2) Programs


<div id="werror-test">

#### werror-test

```
Usage: werror-test
```

Simple tests for the wide-string error class WError

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="write-test">

#### write-test

```
Usage: write-test file case
where case is an integer between 1 and 11
```

ExifData write unit tests

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="write2-test">

#### write2-test

```
Usage: write2-test file
```

ExifData write unit tests for Exif data created from scratch

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="xmpdump">

#### xmpdump

```
Usage: xmpdump file
```

Sample program to dump the XMP packet of an image

[Sample](#TOC1) Programs [Test](#TOC2) Programs

<div id="xmpparser-test">

#### xmpparser-test

```
Usage: xmpparser-test file
```

Read an XMP packet from a file, parse and re-serialize it.

[Sample](#TOC1) Programs [Test](#TOC2) Programs



Robin Mills<br>
robin@clanmills.com<br>
Revised: 2020-11-20

| Travis        | AppVeyor      | GitLab| Codecov| Repology| Chat |
|:-------------:|:-------------:|:-----:|:------:|:-------:|:----:|
| [![Build Status](https://travis-ci.org/Exiv2/exiv2.svg?branch=0.27-maintenance)](https://travis-ci.org/Exiv2/exiv2) | [![Build status](https://ci.appveyor.com/api/projects/status/d6vxf2n0cp3v88al/branch/0.27-maintenance?svg=true)](https://ci.appveyor.com/project/piponazo/exiv2-wutfp/branch/0.27-maintenance) | [![pipeline status](https://gitlab.com/D4N/exiv2/badges/0.27-maintenance/pipeline.svg)](https://gitlab.com/D4N/exiv2/commits/0.27-maintenance) | [![codecov](https://codecov.io/gh/Exiv2/exiv2/branch/0.27-maintenance/graph/badge.svg)](https://codecov.io/gh/Exiv2/exiv2) | [![Packaging status](https://repology.org/badge/tiny-repos/exiv2.svg)](https://repology.org/metapackage/exiv2/versions) | [![#exiv2-chat on matrix.org](matrix-standard-vector-logo-xs.png)](https://matrix.to/#/#exiv2-chat:matrix.org) |

<div id="1">
# Welcome to Exiv2

Exiv2 is a C++ library and a command-line utility to read,
write, delete and modify Exif, IPTC, XMP and ICC image metadata.

| Exiv2 Resource | Location |
|:----------     |:------    |
| Releases and Documentation<br>Prereleases:<br>Project Resources<br>License (GPLv2)<br>CMake Downloads  | [https://exiv2.org](https://exiv2.org)<br>[https://pre-release.exiv2.org](https://pre-release.exiv2.org)<br>[https://github.com/Exiv2/exiv2](https://github.com/Exiv2/exiv2)<br>[COPYING](COPYING)<br>[https://cmake.org/download/](https://cmake.org/download/) |
| README.md<br>README-CONAN.md<br>README-SAMPLES.md | User Manual. _This document_<br>Conan User Manual _[click here](README-CONAN.md)_<br>Sample Code Manual. _[click here](README-SAMPLES.md)_ |

The file ReadMe.txt in a build bundle describes how to install the library on the platform.  ReadMe.txt also documents how to compile and link code on the platform.

<div id="TOC">
### TABLE  OF  CONTENTS
![Exiv2](exiv2.png)

1. [Welcome to Exiv2](#1)
2. [Building, Installing, Using and Uninstalling Exiv2](#2)
    1. [Build, Install, Use and Uninstall Exiv2 on a UNIX-like system](#2-1)
    2. [Build and Install Exiv2 with Visual Studio](#2-2)
    3. [Build Options](#2-3)
    4. [Dependencies](#2-4)
    5. [Building and linking your code with Exiv2](#2-5)
    6. [Consuming Exiv2 with CMake](#2-6)
    7. [Using pkg-config to compile and link your code with Exiv2](#2-7)
    8. [Localisation](#2-8)
    9. [Building Exiv2 Documentation](#2-9)
   10. [Building Exiv2 Packages](#2-10)
   11. [Debugging Exiv2](#2-11)
   12. [Building  Exiv2 with Clang and other build chains](#2-12)
   13. [Building  Exiv2 with ccache](#2-13)
   14. [Thread Safety](#2-14)
   15. [Library Initialisation and Cleanup](#2-15)
   16. [Cross Platform Build and Test on Linux for MinGW](#2-16)
   17. [Building with C++11 and other compilers](#2-17)
   18. [Static and Shared Libraries](#2-18)
   19. [Support for bmff files (CR3, HEIF, HEIC, and AVIF)](#2-19)
3. [License and Support](#3)
    1. [License](#3-1)
    2. [Support](#3-2)
4. [Test Suit](#4)
    1. [Running tests on a UNIX-like system](#4-1)
    2. [Running tests on Visual Studio builds](#4-2)
    3. [Unit tests](#4-3)
    4. [Python tests](#4-4)
    5. [Test Summary](#4-5)
5. [Platform Notes](#5)
    1. [Linux](#5-1)
    2. [macOS](#5-2)
    3. [MinGW/msys2](#5-3)
    4. [Cygwin](#5-4)
    5. [Visual Studio](#5-5)
    6. [Unix](#5-6)

[TOC](#TOC)
<div id="2">
## 2 Building, Installing, Using and Uninstalling Exiv2

You need [CMake](https://cmake.org/download/) to configure the Exiv2 project and the GCC or Clang compiler and associated tool chain.

<div id="2-1">
### 2.1 Build, Install, Use Exiv2 on a UNIX-like system

```bash
$ cd ~/gnu/github/exiv2  # location of the project code
$ mkdir build && cd build
$ cmake .. -DCMAKE_BUILD_TYPE=Release
$ cmake --build .
$ make tests
$ sudo make install
```

This will install the library into the "standard locations".  The library will be installed in `/usr/local/lib`, executables (including the exiv2 command-line program) in `/usr/local/bin/` and header files in `/usr/local/include/exiv2`

cmake generates files in the build directory.  cmake generates the project/solution/makefiles required to build the exiv2 library and sample applications.  cmake also creates the files exv\_conf.h and exiv2lib\_export which contain compiler directives about the build options you have chosen and the availability of libraries on your machine.

#### Using the exiv2 command-line program

To execute the exiv2 command line program, you should update your path to search /usr/local/bin/

```bash
$ export PATH="/usr/local/bin:$PATH"
```

You will also need to locate libexiv2 at run time:

```bash
$ export LD_LIBRARY_PATH="/usr/local/lib:$LD_LIBRARY_PATH"      # Linux, Cygwin, MinGW/msys2
$ export DYLD_LIBRARY_PATH="/usr/local/lib:$DYLD_LIBRARY_PATH"  # macOS
```

#### Uninstall

I don't know why anybody would uninstall Exiv2.

```bash
$ cd ~/gnu/github/exiv2  # location of the project code
$ cd build
$ sudo make uninstall
```

These commands will remove the exiv2 executables, library, header files and man page from the standard locations.

[TOC](#TOC)
<div id="2-2">
### 2.2 Build and Install Exiv2 with Visual Studio

We recommend that you use conan to download the Exiv2 external dependencies on Windows.  On other platforms (maxOS, Ubuntu and others), you should use the platform package manger.  These are discussed: [Platform Notes](#5) The options to configure and compile the project using Visual Studio are similar to UNIX like systems.
See [README-CONAN](README-CONAN.md) for more information about Conan.

When you build, you may install with the following command.

```cmd
> cmake --build . --target install
```
This will create and copy the exiv2 build artefacts to C:\Program Files (x86)\exiv2\.  You should modify your path to include C:\Program Files (x86)\exiv2\bin.

[TOC](#TOC)
<div id="2-3">
### 2.3 Build options

There are two groups of CMake options.  There are many options defined by CMake.  Here are some particularly useful options:

| Options       | Purpose (_default_)       |
|:------------- |:------------- |
| CMAKE\_INSTALL\_PREFIX<br/>CMAKE\_BUILD\_TYPE<br/>BUILD\_SHARED\_LIBS | Where to install on your computer _**(/usr/local)**_<br/>Type of build _**(Release)**_ See: [Debugging Exiv2](#2-11) <br/>Build exiv2lib as shared or static _**(On)**_ |

Options defined by <exiv2>/CMakeLists.txt include:

```bash
576 rmills@rmillsmm:~/gnu/github/exiv2/exiv2 $ grep ^option CMakeLists.txt
option( BUILD_SHARED_LIBS          "Build exiv2lib as a shared library"      ON )
option( EXIV2_ENABLE_XMP           "Build with XMP metadata support"         ON )
option( EXIV2_ENABLE_EXTERNAL_XMP  "Use external version of XMP"            OFF )
option( EXIV2_ENABLE_PNG           "Build with png support (requires libz)"  ON )
...
option( EXIV2_ENABLE_BMFF          "Build with BMFF support"                 OFF)
577 rmills@rmillsmm:~/gnu/github/exiv2/exiv2 $
```

Options are defined on the CMake command-line:

```bash
$ cmake -DBUILD_SHARED_LIBS=On -DEXIV2_ENABLE_NLS=Off
```

It is planned to set the default -DEXIV2\_ENABLE\_BMFF=On for Exiv2 v1.00.  BMFF support is disabled by default in v0.27.


[TOC](#TOC)
<div id="2-4">
### 2.4 Dependencies

The following Exiv2 features require external libraries:

| Feature                     | Package   |  Default | To change default              | Availability |
|:--------------------------  |:--------  |:--------:| :----------------------------  |:-----------  |
| PNG image support           | zlib      | ON       | -DEXIV2\_ENABLE\_PNG=Off       | [http://zlib.net/](http://zlib.net/) |
| XMP support                 | expat     | ON       | -DEXIV2\_ENABLE\_XMP=Off       | [http://expat.sourceforge.net](http://expat.sourceforge.net)/<br/>Use _**Expat 2.2.6**_ and later |
| Natural language system     | gettext   | OFF      | -DEXIV2\_ENABLE\_NLS=On        | [http://www.gnu.org/software/gettext/](http://www.gnu.org/software/gettext/) |
| Character set conversion    | libiconv  |          | Disabled for Visual Studio.<br>Linked when installed on UNIX like platforms.                              | [https://www.gnu.org/software/libiconv/](https://www.gnu.org/software/libiconv/) |
| Unit test framework         | gtest     | OFF      | -DEXIV2\_BUILD\_UNIT\_TESTS=On | [https://github.com/google/googletest/archive/](https://github.com/google/googletest/archive/release-1.8.0.tar.gz)<br/>Use _**release-1.8.0.tar.gz**_ |

On UNIX systems, you may install the dependencies using the distribution's package management system. Install the
development package of a dependency to install the header files and libraries required to build Exiv2. The script
`ci/install_dependencies.sh` is used to setup CI images on which we build and test Exiv2 on many platforms when we modify code.  You may find that helpful in setting up your platform dependencies.

Natural language system is discussed in more detail here: [Localisation](#2-8)

Notes about different platforms are included here: [Platform Notes](#5)

You may choose to install dependences with conan.  This is supported on all platforms and is especially useful for users of Visual Studio.
See [README-CONAN](README-CONAN.md) for more information.

### Libiconv

The library libiconv is used to perform character set encoding in the tags Exif.Photo.UserComment, Exif.GPSInfo.GPSProcessingMethod and Exif.GPSInfo.GPSAreaInformation.  This is documented in the exiv2 man page.

CMake will detect libiconv of all UNIX like systems including Linux, macOS, UNIX, Cygwin64 and MinGW/msys2.  If you have installed libiconv on your machine, Exiv2 will link and use it.

The library libiconv is a GNU library and we do not recommend using libiconv with Exiv2 when building with Visual Studio.

Exiv2 includes the file cmake/FindIconv.cmake which contains a guard to prevent CMake from finding libiconv when you build with Visual Studio.  This was added because of issues reported when Visual Studio attempted to link libconv libraries installed by Cygwin, or MinGW or gnuwin32. [https://github.com/Exiv2/exiv2/issues/1250](https://github.com/Exiv2/exiv2/issues/1250)

There are build instructions about Visual Studio in libiconv-1.16/INSTALL.window require you to install Cygwin.  There is an article here about building libiconv with Visual Studio. [https://www.codeproject.com/Articles/302012/How-to-Build-libiconv-with-Microsoft-Visual-Studio](https://www.codeproject.com/Articles/302012/How-to-Build-libiconv-with-Microsoft-Visual-Studio).

If you wish to use libiconv with Visual Studio you will have to build libiconv and remove the "guard" in cmake/FindIconv.cmake.  Team Exiv2 will not provide support concerning libiconv and Visual Studio.

[TOC](#TOC)
<div id="2-5">
### 2.5 Building and linking your code with Exiv2

There are detailed platform notes about compiling and linking in `releasenotes/{platform}/ReadMe.txt`

where `platform: { CYGWIN | Darwin | Linux | MinGW | msvc | Unix }`

In general you need to do the following:

1) Application code should be written in C++98 and include exiv2 headers:

```cpp
#include <exiv2/exiv2.hpp>
```

2) Compile your C++ code with the directive: **`-I/usr/local/include`**

3) Link your code with libexiv2 using the linker options: **`-lexiv2`** and **`-L/usr/local/lib`**

The following is a typical command to build and link with libexiv2:

```bash
$ g++ -std=c++98 myprog.cpp -o myprog -I/usr/local/include -L/usr/local/lib -lexiv2
```

[TOC](#TOC)
<div id="2-6">
### 2.6 Consuming Exiv2 with CMake

When exiv2 is installed, the files required to consume Exiv2 are installed in `${CMAKE_INSTALL_PREFIX}/lib/cmake/exiv2`

You can build samples/exifprint.cpp as follows:

```bash
$ cd <exiv2dir>
$ mkdir exifprint
$ cd    exifprint
$ cat - > CMakeLists.txt <<EOF
cmake_minimum_required(VERSION 3.8)
project(exifprint VERSION 0.0.1 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 98)
set(CMAKE_CXX_EXTENSIONS OFF)

find_package(exiv2 REQUIRED CONFIG NAMES exiv2)    # search ${CMAKE_INSTALL_PREFIX}/lib/cmake/exiv2/
add_executable(exifprint ../samples/exifprint.cpp) # compile this
target_link_libraries(exifprint exiv2lib)          # link exiv2lib
EOF
$ cmake .                                          # generate the makefile
$ make                                             # build the code
$ ./exifprint                                      # test your executable
Usage: bin/exifprint [ path | --version | --version-test ]
$
```

[TOC](#TOC)
<div id="2-7">
### 2.7 Using pkg-config to compile and link your code with Exiv2

When exiv2 is installed, the file exiv2.pc used by pkg-config is installed in `${CMAKE_INSTALL_PREFIX}/lib/pkgconfig`  You will need to set the following in your environment:

```bash
$ export PKG_CONFIG_PATH="/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH"
```

To compile and link using exiv2.pc, you usually add the following to your Makefile.

```bash
PKGCONFIG=pkg-config
CPPFLAGS := `pkg-config exiv2 --cflags`
LDFLAGS := `pkg-config exiv2 --libs`
```

If you are not using make, you can use pkg-config as follows:

```bash
g++ -std=c++98 myprogram.cpp -o myprogram $(pkg-config exiv2 --libs --cflags)
```

[TOC](#TOC)
<div id="2-8">
### 2.8 Localisation

Localisation is supported on a UNIX-like platform:  Linux, macOS, Cygwin and MinGW/msys2.  Localisation is not supported for Visual Studio builds.

Crowdin have provided Exiv2 with a free open-source license to use their services.  The Exiv2 localisation project is located at [https://crowdin.com/project/exiv2](https://crowdin.com/project/exiv2).  You will also need to register to have a free user account on Crowdin.  The Crowdin setup is discussed here: [https://github.com/Exiv2/exiv2/issues/1510](https://github.com/Exiv2/exiv2/issues/1510).  It is recommended that you coordinate with Leonardo before contributing localisation changes on Crowdin.  You can contact Leonardo by via GitHub.

To build localisation support, use the CMake option `-DEXIV2_ENABLE_NLS=On`.  You must install the `gettext` package with your package manager or from source.  The `gettext` package is available from [http://www.gnu.org/software/gettext/](http://www.gnu.org/software/gettext/) and includes the library `libintl` and utilities to build localisation files.  If CMake produces error messages which mention libintl or gettext, you should verify that the package `gettext` has been correctly built and installed.

You must install the build to test localisation.  This ensures that the localisation message files can be found at run-time.  You cannot test localisation in the directory `build\bin`.

1) Running exiv2 in another language

```bash
$ env LANG=fr_FR exiv2    # env LANGUAGE=fr_FR exiv2 on Linux!
exiv2: Une action doit être spécifié
exiv2: Au moins un fichier est nécessaire
Utilisation : exiv2  [ options ] [ action ] fichier ...

Manipulation des métadonnées EXIF issues des images.
$
```

2) Adding additional languages to exiv2

To support a new language which we'll designate 'xy' for this discussion:

2.1) Generate a po file from the po template:

```bash
$ cd <exiv2dir>
$ mkdir -p po/xy
$ msginit --input=po/exiv2.pot --locale=xy --output=po/xy.po
```
2.2) Edit/Translate the strings in po/xy.po

I edited the following:

```bash
#: src/exiv2.cpp:237
msgid "Manipulate the Exif metadata of images.\n"
msgstr ""
```
to:

```bash
#: src/exiv2.cpp:237
msgid "Manipulate the Exif metadata of images.\n"
msgstr "Manipulate image metadata.\n"
```

2.3) Generate the messages file:

```bash
$ mkdir -p             po/xy/LC_MESSAGES
$ msgfmt --output-file=po/xy/LC_MESSAGES/exiv2.mo po/xy.po
```

2.4) Install and test your messages:

You have to install your messages to test them.  It's not possible to test a messages file by executing build/bin/exiv2.

```bash
$ sudo mkdir -p                          /usr/local/share/locale/xy/LC_MESSAGES
$ sudo cp -R  po/xy/LC_MESSAGES/exiv2.mo /usr/local/share/locale/xy/LC_MESSAGES
$ env LANG=xy exiv2                      # env LANGUAGE=xy on Linux!
exiv2: An action must be specified
exiv2: At least one file is required
Usage: exiv2 [ options ] [ action ] file ...

Manipulate image metadata.   <--------- Edited message!
$
```

2.5) Submitting your new language file for inclusion in future versions of Exiv2:

You may submit a PR which contains po/xy.po AND a modification to po/CMakeLists.txt

Or, open a new issue on https://github.com/exiv2/exiv2 and attach the file xy.po.zip which can be created as follows:

```
$ zip xy.po.zip po/xy.po
  adding: po/xy.po (deflated 78%)
ls -l xy.po.zip
-rw-r--r--+ 1 rmills  staff  130417 25 Jun 10:15 xy.po.zip
$
```

[TOC](#TOC)
<div id="2-9">
### 2.9 Building Exiv2 Documentation

Building documentation requires installing special tools.  You will probably prefer to
read the documentation on-line from the project website: https://exiv2.org

To build documentation, use the CMake option **`-DEXIV2_BUILD_DOC=On`**.
Additionally, you will require an additional build step to actually build the documentation.

```bash
$ cmake ..options.. -DEXIV2_BUILD_DOC=On
$ make doc
```

To build the documentation, you must install the following products:

| Product      | Availability |
|:------------ |:------------ |
| doxygen<br/>graphviz<br/>python<br/>xsltproc<br/>md5sum  | [http://www.doxygen.org/](http://www.doxygen.org/)<br/>[http://www.graphviz.org/](http://www.graphviz.org/)<br/>[http://www.python.org/](http://www.python.org/)<br/>[http://xmlsoft.org/XSLT/](http://xmlsoft.org/XSLT/)<br/>[http://www.microbrew.org/tools/md5sha1sum/](http://www.microbrew.org/tools/md5sha1sum/) |

[TOC](#TOC)
<div id="2-10">
### 2.10 Building Exiv2 Packages

To enable the building of Exiv2 packages, use the CMake option `-DEXIV2_TEAM_PACKAGING=On`.

You should not build Exiv2 Packages.  This feature is intended for use by Team Exiv2 to create Platform and Source Packages on the buildserver.

There are two types of Exiv2 packages which are generated by cpack from the cmake command-line.

1) Platform Package (header files, binary library and samples.  Some documentation and release notes)

Create and build exiv2 for your platform.

```bash
$ git clone https://github.com/exiv2/exiv2
$ mkdir -p exiv2/build
$ cd       exiv2/build
$ cmake .. -G "Unix Makefiles" -DEXIV2_TEAM_PACKAGING=On
...
-- Build files have been written to: .../build
$ cmake --build . --config Release
...
[100%] Built target addmoddel
$ make package
...
CPack: - package: /path/to/exiv2/build/exiv2-0.27.1-Linux.tar.gz generated.
```

2) Source Package

```bash
$ make package_source
Run CPack packaging tool for source...
...
CPack: - package: /path/to/exiv2/build/exiv2-0.27.1-Source.tar.gz generated.
```

You may prefer to run `$ cmake --build . --config Release --target package_source`


[TOC](#TOC)
<div id="2-11">
### 2.11 Debugging Exiv2

1) Generating and installing a debug library

In general to generate a debug library, you should use the option *cmake* option `-DCMAKE_RELEASE_TYPE=Debug` and build in the usual way.

```bash
$ cd <exiv2dir>
$ mkdir build
$ cd build
$ cmake .. -G "Unix Makefiles" "-DCMAKE_BUILD_TYPE=Debug"
$ make

```

You must install the library to ensure that your code is linked to the debug library.

You can check that you have generated a debug build with the command:

```bash
$ exiv2 -vVg debug
exiv2 0.27.1
debug=1
$
```

[TOC](#TOC)

2) About preprocessor symbols `NDEBUG` and `EXIV2_DEBUG_MESSAGES`

Exiv2 respects the symbol `NDEBUG` which is set only for Release builds. There are sequences of code which are defined within:

```cpp
#ifdef EXIV2_DEBUG_MESSAGES
....
#endif
```

Those blocks of code are not compiled unless you define `EXIV2_DEBUG_MESSAGES`. They are provided for additional debugging information. For example, if you are interested in additional output from webpimage.cpp, you can update your build as follows:

```bash
$ cd <exiv2dir>
$ touch src/webpimage.cpp
$ make CXXFLAGS=-DEXIV2_DEBUG_MESSAGES
$ bin/exiv2 ...
-- or --
$ sudo make install
$ exiv2     ...
```

If you are debugging library code, it is recommended that you use the exiv2 command-line program as your test harness as Team Exiv2 is very familiar with this tool and able to give support.

[TOC](#TOC)

3) Starting the debugger

This is platform specific.  On Linux:

```bash
$ gdb exiv2
```

[TOC](#TOC)

4) Using Debugger IDEs such as Xcode, CLion, Visual Studio, Eclipse or QtCreator

I have used all those IDEs to debug the Exiv2 library and applications.  All of them work.  You may find it takes initial effort, however I assure you that they all work well.

I work on macOS and use Xcode to develop Exiv2.  For a couple of years, Team Exiv2 had free
open-source licences from JetBrains for CLion.  I really liked CLion as it is cross platform
and runs on Windows, Mac and Linux.  It has excellent integration with CMake and will automatically
add **`-DCMAKE_BUILD_TYPE=Debug`** to the cmake command.  It keeps build types in separate directories
such as **`<exiv2dir>/cmake-build-debug`**.

[TOC](#TOC)

5) cmake --build . options **`--config Release|Debug`** and **`--target install`**

Visual Studio and Xcode can build debug or release builds without using the option **`-DCMAKE_BUILD_TYPE`** because the generated project files can build multiple types.  The option **`--config Debug`** can be specified on the cmake command-line to specify the build type.  Alternatively, if you prefer to build in the IDE, the UI provides options to select the configuration and target.

With the Unix Makefile generator, the targets can be listed:

```bash
$ make help
The following are some of the valid targets for this Makefile:
... all (the default if no target is provided)
... clean
... depend
... install/local
.........
```

[TOC](#TOC)
<div id="2-12">
### 2.12 Building Exiv2 with **clang** and other build chains

1) On Linux

```bash
$ cd <exiv2dir>
$ rm -rf build ; mkdir build ; cd build
$ cmake .. -DCMAKE_C_COMPILER=$(which clang) -DCMAKE_CXX_COMPILER=$(which clang++)
$ cmake --build .
```

**_OR_**

```bash
$ export CC=$(which clang)
$ export CXX=$(which clang++)
$ cd <exiv2dir>
$ rm -rf build ; mkdir build ; cd build
$ cmake ..
$ cmake --build .
```

2) On macOS

Apple provide clang with Xcode.  GCC has not been supported by Apple since 2013.  The _"normal unix build"_ uses Clang.

3) On Cygwin, MinGW/msys2, Windows (using clang-cl) and Visual Studio.

I have been unable to get clang to work on any of those platforms.

[TOC](#TOC)
<div id="2-13">
### 2.13 Building Exiv2 with ccache

To speed up compilation, the utility ccache can be installed to cache the output of the compiler.  This greatly speeds up the build when you frequently built code that has not been modified.

Installing and using ccache (and other similar utilities), is platform dependent.  On Ubuntu:

```bash
$ sudo apt install --yes ccache
```

To build with ccache, use the cmake option **-DBUILD\_WITH\_CCACHE=On**

```bash
$ cd <exiv2dir>
$ mkdir build ; cd build ; cd build
$ cmake .. -G "Unix Makefiles" -DBUILD_WITH_CCACHE=On
$ make
# Build again to appreciate the performance gain
$ make clean
$ make
```

Due to the way in which ccache is installed in Fedora (and other Linux distros), ccache effectively replaces the compiler.  A default build or **-DBUILD\_WITH\_CCACHE=Off** is not effective and the environment variable CCACHE_DISABLE is required to disable ccache. [https://github.com/Exiv2/exiv2/issues/361](https://github.com/Exiv2/exiv2/issues/361)

[TOC](#TOC)
<div id="2-14">
### 2.14 Thread Safety

Exiv2 heavily relies on standard C++ containers. Static or global variables are used read-only, with the exception of the XMP namespace registration function (see below). Thus Exiv2 is thread safe in the same sense as C++ containers:
Different instances of the same class can safely be used concurrently in multiple threads.

In order to use the same instance of a class concurrently in multiple threads the application must serialize all write access to the object.

The level of thread safety within Exiv2 varies depending on the type of metadata: The Exif and IPTC code is reentrant. The XMP code uses the Adobe XMP toolkit (XMP SDK), which according to its documentation is thread-safe. It actually uses mutexes to serialize critical sections. However, the XMP SDK initialisation function is not mutex protected, thus Exiv2::XmpParser::initialize is not thread-safe. In addition, Exiv2::XmpProperties::registerNs writes to a static class variable, and is also not thread-safe.

Therefore, multi-threaded applications need to ensure that these two XMP functions are serialized, e.g., by calling them from an initialization section which is run before any threads are started.  All exiv2 sample applications begin with:

```cpp
#include <exiv2/exiv2.hpp>
int main(int argc, const char* argv[])
{
    Exiv2::XmpParser::initialize();
    ::atexit(Exiv2::XmpParser::terminate);
#ifdef EXV_ENABLE_BMFF
    Exiv2::enableBMFF(true);
#endif
    ...
}
```
The use of the _**thread unsafe function**_ Exiv2::enableBMFF(true) is discussed in [2.19 Support for bmff files](#2-19)

[TOC](#TOC)
<div id="2-15">
### 2.15 Library Initialisation and Cleanup

As discussed in the section on Thread Safety, Exiv2 classes for Exif and IPTC metadata are fully reentrant and require no initialisation or cleanup.

Adobe's XMPsdk is generally thread-safe, however it has to be initialized and terminated before and after starting any threads to access XMP metadata. The Exiv2 library will initialize this if necessary, however it does not terminate the XMPsdk.

The exiv2 command-line program and sample applications call the following at the outset:

```cpp
    Exiv2::XmpParser::initialize();
    ::atexit(Exiv2::XmpParser::terminate);
#ifdef EXV_ENABLE_BMFF
    Exiv2::enableBMFF(true);
#endif
```

[TOC](#TOC)
<div id="2-16">
### 2.16 Cross Platform Build and Test on Linux for MinGW

You can cross compile Exiv2 on Linux for MinGW.  We have used the following method on **Fedora** and believe this is also possible on Ubuntu and other distros.  Detailed instructions are provided here for **Fedora**.

### Cross Build and Test On Fedora

####1 Install the cross platform build tools

```bash
$ sudo dnf install mingw64-gcc-c++ mingw64-filesystem mingw64-expat mingw64-zlib cmake make
```

####2 Install Dependancies

You will need to install x86_64 libraries to support the options you wish to use.  By default, you will need libz and expat.  Your `dnf` command above has installed them for you.  If you wish to use features such as `webready` you should install openssl and libcurl as follows:

```bash
[rmills@rmillsmm-fedora 0.27-maintenance]$ sudo yum install libcurl.x86_64 openssl.x86_64
Last metadata expiration check: 0:00:18 ago on Fri 10 Apr 2020 10:50:30 AM BST.
Dependencies resolved.
=========================
Package                          Architecture                                        Version                                                      Repository                       Size
=========================
Installing:
...
```

####3 Get the code and build

```bash
$ git clone://github.com/exiv2/exiv2 --branch 0.27-maintenance exiv2
$ cd exiv2
$ mkdir build_mingw_fedora
$ mingw64-cmake ..
$ make
```

Note, you may wish to choose to build with optional features and/or build static libraries.  To do this, request appropriately on the mingw64-cmake command:

```bash
$ mingw64-cmake .. -DEXIV2_TEAM_EXTRA_WARNINGS=On \
                   -DEXIV2_ENABLE_VIDEO=On        \
                   -DEXIV2_ENABLE_WEBREADY=On     \
                   -DEXIV2_ENABLE_WIN_UNICODE=On  \
                   -DBUILD_SHARED_LIBS=Off
```
The options available for cross-compiling are the same as provided for all builds.  See: [Build Options](#2-3)


####4 Copy "system dlls" in the bin directory

These DLLs are required to execute the cross-platform build in the bin from Windows

```bash
for i in libexpat-1.dll libgcc_s_seh-1.dll libstdc++-6.dll libwinpthread-1.dll zlib1.dll ; do
    cp -v /usr/x86_64-w64-mingw32/sys-root/mingw/bin/$i bin
done
```

####5 Executing exiv2 in wine

You may wish to use wine to execute exiv2 from the command prompt.  To do this:

```bash
[rmills@rmillsmm-fedora build_mingw_fedora]$ wine cmd
Microsoft Windows 6.1.7601

Z:\Home\gnu\github\exiv2\0.27-maintenance\build_mingw_fedora>bin\exiv2
exiv2: An action must be specified
exiv2: At least one file is required
Usage: exiv2 [ options ] [ action ] file ...

Manipulate the Exif metadata of images.

Z:\Home\gnu\github\exiv2\0.27-maintenance\build_mingw_fedora>
```

If you have not installed wine, Fedora will offer to install it for you.

####6 Running the test suite

On a default wine installation, you are in the MSDOS/cmd.exe prompt.  You cannot execute the exiv2 test suite in this environment as you require python3 and MSYS/bash to run the suite.

You should mount the your Fedora exiv2/ directory on a Windows machine on which you have installed MinGW/msys2.  You will need python3 and make.

My build machines is a MacMini with VMs for Windows, Fedora and other platforms.  On Fedora, I build in a Mac directory which is shared to all VMs.

```bash
[rmills@rmillsmm-fedora 0.27-maintenance]$ pwd
/media/psf/Home/gnu/github/exiv2/0.27-maintenance
[rmills@rmillsmm-fedora 0.27-maintenance]$ ls -l build_mingw_fedora/bin/exiv2.exe
-rwxrwxr-x. 1 rmills rmills 754944 Apr 10 07:44 build_mingw_fedora/bin/exiv2.exe
[rmills@rmillsmm-fedora 0.27-maintenance]$
```

On MinGW/msys2, I can directly access the share:

```bash
$ cd //Mac/Home/gnu/github/exiv2/0.27/maintenance/build_mingw_fedora
$ export EXIV2_BINDIR=$pwd/bin
$ cd ../test
$ make tests
```

You will find that 3 tests fail at the end of the test suite.  It is safe to ignore those minor exceptions.

[TOC](#TOC)
<div id="2-17">
### 2.17 Building with C++11 and other compilers

Exiv2 uses the default compiler for your system.  Exiv2 v0.27 was written to the C++ 1998 standard and uses auto\_ptr.  The C++11 and C++14 compilers will issue deprecation warnings about auto\_ptr.  As _auto\_ptr support has been removed from C++17, you cannot build Exiv2 v0.27 with C++17 or later compilers._  Exiv2 v1.00 and later do not use auto\_ptr and will build with all modern C++ Standard Compilers.

To build with C++11:

```bash
$ cd <exiv2dir>
$ mkdir build ; cd build
$ cmake .. -DCMAKE_CXX_STANDARD=11 -DCMAKE_CXX_FLAGS=-Wno-deprecated
$ make
```

The option -DCMAKE\_CXX\_STANDARD=11 specifies the C++ Language Standard.  Possible values are 98, 11 or 14.

The option -DCMAKE\_CXX\_FLAGS=-Wno-deprecated suppresses warnings from C++11 concerning auto\_ptr.  The compiler will issue deprecation warnings about video, eps and ssh code in Exiv2 v0.27.  This is intentional.  These features of Exiv2 will not be available in Exiv2 v1.00.

**Caution:** Visual Studio users should not use -DCMAKE\_CXX\_FLAGS=-Wno-deprecated.

[TOC](#TOC)
<div id="2-18">
### 2.18 Static and Shared Libraries

You can build either static or shared libraries.  Both can be linked with either static or shared run-time libraries.  You specify the shared/static with the option `-BUILD_SHARED_LIBS=On|Off` You specify the run-time with the option `-DEXIV2_ENABLE_DYNAMIC_RUNTIME=On|Off`.  The default for both options default is On.  So you build shared and use the shared libraries which are `.dll` on Windows (msvc, Cygwin and MinGW/msys), `.dylib` on macOS and `.so` on Linux and UNIX.

CMake creates your build artefacts in the directories `bin` and `lib`.  The `bin` directory contains your executables and .dlls.  The `lib` directory contains your static libraries.  When you install exiv2, the build artefacts are copied to your system's prefix directory which by default is `/usr/local/`.  If you wish to test and use your build without installing, you will have to set you PATH appropriately.  Linux/Unix users should also set `LD_LIBRARY_PATH` and macOS users should set `DYLD_LIBRARY_PATH`.

The default build is SHARED/DYNAMIC and this arrangement treats all executables and shared libraries in a uniform manner.

**Caution:** _The following discussion only applies if you are linking to a static version of the exiv2 library._  You may get the following error from CMake:

```bash
CMake Error at src/CMakeLists.txt:30 (add_library):
Target "my-app-or-library" links to target "Iconv::Iconv" but the target was
not found. Perhaps a find_package() call is missing for an IMPORTED
target, or an ALIAS target is missing?
```

Be aware that the warning concerning `src/CMakeLists.txt:30 (add_library)` refers to your file src/CMakeLists.txt.  Although exiv2 has statically linked `Iconv()`, your code also needs to link.  You achieve that in your src/CMakeLists.txt with the code:

```cmake
find_package(Iconv)
if( ICONV_FOUND )
    target_link_libraries( my-app-or-library PRIVATE Iconv::Iconv )
endif()
```

This is discussed: [https://github.com/Exiv2/exiv2/issues/1230](https://github.com/Exiv2/exiv2/issues/1230)

[TOC](#TOC)
<div id="2-19">
### 2.19 Support for bmff files (CR3, HEIF, HEIC, and AVIF)

**Attention is drawn to the possibility that bmff support may be the subject of patent rights. _Exiv2 shall not be held responsible for identifying any or all such patent rights.  Exiv2 shall not be held responsible for the legal consequences of the use of this code_.**

Access to the bmff code is guarded in two ways.  Firstly, you have to build the library with the cmake option: `-DEXIV2_ENABLE_BMFF=On`.  Secondly, the application must enable bmff support at run-time by calling the following function.

```cpp
EXIV2API bool enableBMFF(bool enable);
```

The return value from `enableBMFF()` is true if the library has been build with bmff support (cmake option -DEXIV2_ANABLE_BMFF=On).

Applications may wish to provide a preference setting to enable bmff support and thereby place the responsibility for the use of this code with the user of the application.

[TOC](#TOC)
<div id="3">
## 3 License and Support

All project resources are accessible from the project website.
    https://github.com/Exiv2/exiv2

<div id="3-1">
### 3.1 License

Copyright (C) 2004-2021 Exiv2 authors.
You should have received a copy of the file [COPYING](COPYING) which details the GPLv2 license.

Exiv2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

Exiv2 program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


[TOC](#TOC)
<div id="3-2">
### 3.2 Support

For new bug reports, feature requests and support:  Please open an issue in Github.  [https://github.com/exiv2/exiv2](https://github.com/exiv2/exiv2)

[TOC](#TOC)
<div id="4">
## 4 Running the test suite

#### Different kinds of tests:

| Description        | Language  | Location       | Command<br>_(in build directory)_ | CMake Option to Build |
|:--                 |:--        |:--             |:--                     |:--   |
| Run all tests      |           |                                   | $ make tests                             |  |
| Run all tests      |           | **Visual Studio Users**           | > cmake --build . --target tests         |  |
| Bash tests         | python    | tests/bash\_tests       | $ make bash_tests    | -DEXIV2\_BUILD\_SAMPLES=On     |
| Python tests       | python    | tests                   | $ make python_tests  | -DEXIV2\_BUILD\_SAMPLES=On     |
| Unit tests         | C++       | unitTests               | $ make unit_test     | -DEXIV2\_BUILD\_UNIT\_TESTS=On |
| Version test       | C++       | src/version.cpp         | $ make version_test  | Always in library              |

The term _**bash scripts**_ is historical.  The implementation of the tests in this collection originally required bash.  These
scripts have been rewritten in python.  Visual Studio Users will appreciate the python implementation as it avoids the
installation of mingw/cygwin and special PATH settings.

#### Environment Variables used by the test suite:

If you build the code in the directory \<exiv2dir\>build, tests will run using the default values of Environment Variables.

| Variable           | Default                    | Platforms     | Purpose |
|:--                 |:--                         |:--            |:--      |
| EXIV2_BINDIR       | **\<exiv2dir\>/build/bin** | All Platforms | Path of built binaries (exiv2.exe) |
| EXIV2_PORT         | **12762**<br>**12671**<br>**12760**  | Cygwin<br>MinGW/msys2<br>Other Platforms | Test TCP/IP Port   |
| EXIV2_HTTP         | **http://localhost**       | All Platforms | Test http server   |
| EXIV2_ECHO         | _**not set**_              | All Platforms | For debugging bash scripts |
| VALGRIND           | _**not set**_              | All Platforms | For debugging bash scripts |
| VERBOSE            | _**not set**_              | All Platforms | Causes make to report its actions |
| PATH<br>DYLD\_LIBRARY\_PATH<br>LD\_LIBRARY\_PATH    | $EXIV2\_BINDIR/../lib | Windows<br>macOS<br>Other platforms | Path of dynamic libraries |

The Variable EXIV2\_PORT or EXIV2\_HTTP can be set to None to skip http tests.  The http server is started with the command `python3 -m http.server $port`.  On Windows, you will need to run this manually _**once**_ to authorise the firewall to permit python to use the port.

[TOC](#TOC)
<div id="4-1">
### 4.1 Running tests on a UNIX-like system

You can run tests directly from the build:

```bash
$ cmake .. -G "Unix Makefiles" -DEXIV2_BUILD_UNIT_TESTS=On
$ make
... lots of output ...
$ make tests
... lots of output ...
$
```

You can run individual tests in the `test` directory.  **Caution:** If you build in a directory other than \<exiv2dir\>/build, you must set EXIV2\_BINDIR to run tests from the `test` directory.

```bash
$ cd <exiv2dir>/build
$ make bash_tests
addmoddel_test (testcases.TestCases) ... ok
....
Ran 176 tests in 9.526s
OK (skipped=6)

$ make python_tests
... lots of output ...
test_run (tiff_test.test_tiff_test_program.TestTiffTestProg) ... ok
----------------------------------------------------------------------
Ran 176 tests in 9.526s
OK (skipped=6)
$
```

[TOC](#TOC)
<div id="4-2">
### 4.2 Running tests on Visual Studio builds from cmd.exe

**Caution:** _The python3 interpreter must be on the PATH, build for DOS, and called python3.exe.  I copied the python.exe program:

```cmd
> copy c:\Python37\python.exe c:\Python37\python3.exe
> set "PATH=c:\Python37;%PATH%
```

You can execute the test suite as described for UNIX-like systems.
The main difference is that you must use cmake to initiate the test
as make is not a system utility on Windows.

```bash
> cd <exiv2dir>/build
> cmake --build . --target tests
> cmake --build . --target python_tests
```

##### Running tests from cmd.exe

You can build with Visual Studio using Conan.  The is described in detail in [README-CONAN.md](README-CONAN.md)

As a summary, the procedure is:

```
c:\...\exiv2>mkdir build
c:\...\exiv2>cd build
c:\...\exiv2\build>conan install .. --build missing --profile msvc2019Release
c:\...\exiv2\build>cmake .. -DEXIV2_BUILD_UNIT_TESTS=On -G "Visual Studio 16 2019"
c:\...\exiv2\build>cmake --build . --config Release
... lots of output from compiler and linker ...
c:\...\exiv2\build>
```

If you wish to use an environment variables, use set:

```
set VERBOSE=1
cmake --build . --config Release --target tests
set VERBOSE=
```

[TOC](#TOC)
<div id="4-3">
### 4.3 Unit tests

The code for the unit tests is in `<exiv2dir>/unitTests`.  To include unit tests in the build, use the *cmake* option `-DEXIV2_BUILD_UNIT_TESTS=On`.

There is a discussion on the web about installing GTest: [https://github.com/Exiv2/exiv2/issues/575](https://github.com/Exiv2/exiv2/issues/575)

```bash
$ pushd /tmp
$ curl -LO https://github.com/google/googletest/archive/release-1.8.0.tar.gz
$ tar xzf   release-1.8.0.tar.gz
$ mkdir -p  googletest-release-1.8.0/build
$ pushd     googletest-release-1.8.0/build
$ cmake .. ; make ; make install
$ popd
$ popd
```

[TOC](#TOC)
<div id="4-4">
### 4.4 Python tests

You can run the python tests from the build directory:

```bash
$ cd <exiv2dir>/build
$ make python_tests
```

If you wish to run in verbose mode:

```bash
$ cd <exiv2dir>/build
$ make python_tests VERBOSE=1
```

The python tests are stored in the directory tests and you can run them all with the command:

```bash
$ cd <exiv2dir>/tests
$ export LD_LIBRARY_PATH="$PWD/../build/lib:$LD_LIBRARY_PATH"
$ python3 runner.py
```

You can run them individually with the commands such as:

```bash
$ cd <exiv2dir>/tests
$ python3 runner.py --verbose bugfixes/redmine/test_issue_841.py  # or $(find . -name "*841*.py")
```

You may wish to get a brief summary of failures with commands such as:

```bash
$ cd <exiv2dir>/build
$ make python_tests 2>&1 | grep FAIL
```

[TOC](#TOC)
<div id="4-5">
### 4.5 Test Summary

| *Tests*      | Unix Style Platforms _(bash)_      | Visual Studio _(cmd.exe)_             |
|:--           |:---                                |:--                                    |
|              | $ cd \<exiv2dir\>/build            |  \> cd \<exiv2dir\>/build             |
| tests        | $ make tests                       | \> cmake --build . --config Release --target tests |
| bash_tests   | $ make bash_tests                  | \> cmake --build . --config Release --target bash_tests |
| python_tests | $ make python_tests                | \> cmake --build . --config Release --target python_tests |
| unit_test    | $ make unit_test                   | \> cmake --build . --config Release --target unit_test |
| version_test | $ make version_test                | \> cmake --build . --config Release --target version_test |

The name **bash_tests** is historical.  They are implemented in python.

[TOC](#TOC)
<div id="5">
## 5 Platform Notes

There are many ways to set up and configure your platform.  The following notes are provided as a guide.

<div id="5-1">
### 5.1 Linux

Update your system and install the build tools and dependencies (zlib, expat, gtest and others)

```bash
$ sudo apt --yes update
$ sudo apt install --yes build-essential git clang ccache python3 libxml2-utils cmake python3 libexpat1-dev libz-dev zlib1g-dev libssh-dev libcurl4-openssl-dev libgtest-dev google-mock
```

For users of other platforms, the script <exiv2dir>/ci/install_dependencies.sh has code used to configure many platforms.  The code in that file is a useful guide to configuring your platform.

Get the code from GitHub and build

```bash
$ mkdir -p ~/gnu/github/exiv2
$ cd ~/gnu/github/exiv2
$ git clone https://github.com/exiv2/exiv2
$ cd exiv2
$ mkdir build ; cd build ;
$ cmake .. -G "Unix Makefiles"
$ make
```

[TOC](#TOC)
<div id="5-2">
### 5.2 macOS

You will need to install Xcode and the Xcode command-line tools to build on macOS.

You should build and install libexpat and zlib.  You may use brew, macports, build from source, or use conan.

I recommend that you build and install CMake from source.

[TOC](#TOC)
<div id="5-3">
### 5.3 MinGW/msys2

Please note that the platform MinGW/msys2 32 is obsolete and superceded by MinGW/msys2 64.

#### MinGW/msys2 64 bit
Install: [https://repo.msys2.org/distrib/x86\_64/msys2-x86\_64-20200903.exe](https://repo.msys2.org/distrib/x86_64/msys2-x86_64-20200903.exe)

The file `appveyor_mingw_cygwin.yml` has instructions to configure the AppVeyor CI to configures itself to build Exiv2 on MinGW/msys2 and Cygwin/64.

I use the following batch file to start the MinGW/msys2 64 bit bash shell from the Dos Command Prompt (cmd.exe)

```bat
@echo off
setlocal
set "PATH=c:\msys64\mingw64\bin;c:\msys64\usr\bin;c:\msys64\usr\local\bin;"
set "PS1=\! MSYS \u@\h:\w \$ "
set "HOME=c:\msys64\home\rmills"
if NOT EXIST %HOME% mkdir %HOME%
cd  %HOME%
color 1f
c:\msys64\usr\bin\bash.exe -norc
endlocal

```

#### Install MinGW Dependencies

Install tools and dependencies:

```bash
for i in base-devel git coreutils dos2unix tar diffutils make                     \
    mingw-w64-x86_64-toolchain mingw-w64-x86_64-gcc      mingw-w64-x86_64-gdb     \
    mingw-w64-x86_64-cmake     mingw-w64-x86_64-gettext  mingw-w64-x86_64-python3 \
    mingw-w64-x86_64-libexpat  mingw-w64-x86_64-libiconv mingw-w64-x86_64-zlib    \
    mingw-w64-x86_64-gtest
do (echo y | pacman -S $i) ; done
```

#### Download exiv2 from github and build

```bash
$ mkdir -p ~/gnu/github/exiv2
$ cd       ~/gnu/github/exiv2
$ git clone https://github.com/exiv2/exiv2
$ cd exiv2
$ mkdir build ; cd build ;
$ cmake .. -G "Unix Makefiles"   # or "MSYS Makefiles"
$ make
```

#### MinGW and Regex

The exiv2 command-line program provides an option **`--grep`** to filter output.  The implementation requires the header file **`<regex.h>`** and supporting library to be available during the build.  When not available, the option **`--grep`** degrades to a substring match.  Because there are several versions of **`<regex.h>`** available on the MinGW platform, detection of regex is always disabled on this platform and uses substring match.  The following command reveals if regex is included in your build:

```bash
$ exiv2 -vVg regex
exiv2 0.27.1
have_regex=1
$
```

[TOC](#TOC)
<div id="5-4">
### 5.4 Cygwin/64

Please note that the platform Cygwin/32 is obsolete and superceded by Cygwin/64.

Download: [https://cygwin.com/install.html](https://cygwin.com/install.html) and run setup-x86_64.exe.  I install into c:\\cygwin64

You need:
make, cmake, curl, gcc, gettext-devel pkg-config, dos2unix, tar, zlib-devel, libexpat1-devel, git, libxml2-devel python3-interpreter, libiconv, libxml2-utils, libncurses, libxml2-devel libxslt-devel python38 python38-pip python38-libxml2

The file `appveyor_mingw_cygwin.yml` has instructions to configure the AppVeyor CI to configures itself to build Exiv2 on MinGW/msys2 and Cygwin/64.

To build unit tests, you should install googletest-release-1.8.0 as discussed [4.3 Unit tests](#4-3)

I use the following batch file "cygwin64.bat" to start the Cygwin/64 bash shell from the Dos Command Prompt (cmd.exe).

```bat
@echo off
setlocal
set "PATH=c:\cygwin64\usr\local\bin;c:\cygwin64\bin;c:\cygwin64\usr\bin;c:\cygwin64\usr\sbin;"
if NOT EXIST %HOME% mkdir %HOME%
set "HOME=c:\cygwin64\home\rmills"
cd  %HOME%
set "PS1=\! CYGWIN64:\u@\h:\w \$ "
bash.exe -norc
endlocal
```

[TOC](#TOC)
<div id="5-5">
### 5.5 Visual Studio

We recommend that you use Conan to build Exiv2 using Visual Studio. Exiv2 v0.27 can be built with Visual Studio versions 2008 and later.  We actively support and build with Visual Studio 2015, 2017 and 2019.

As well as Visual Studio, you will need to install CMake, Python3, and Conan.

1) Binary installers for CMake on Windows are availably from [https://cmake.org/download/](https://cmake.org/download/).<br/>
2) Binary installers for Python3 are available from [python.org](https://python.org)<br/>
3) Conan can be installed using python/pip.  Details in [README-CONAN.md](README-CONAN.md)


```
..>copy c:\Python37\python.exe c:\Python37\python3.exe
```

The python3 interpreter must be on your PATH.

[TOC](#TOC)
<div id="5-6">
### 5.6 Unix

Exiv2 can be built on many Unix and Linux distros.  With v0.27.2, we are starting to actively support the Unix Distributions NetBSD and FreeBSD.  For v0.27.3, I have added support for Solaris 11.4

We do not have CI support for these platforms on GitHub.  However, I regularly build and test them on my MacMini Buildserver.  The device is private and not on the internet.

I have provided notes here based on my experience with these platforms.   Feedback is welcome.  I am willing to support Exiv2 on other commercial Unix distributions such as AIX, HP-UX and OSF/1 if you provide with an ssh account for your platform.  I will require super-user privileges to install software.

For all platforms you will need the following components to build:

1. gcc or clang
2. cmake
3. bash
4. sudo
5. gettext

To run the test suite, you need:

1. python3
2. chksum
3. dos2unix
4. xmllint

#### NetBSD

You can build exiv2 from source using the methods described for linux.  I built and installed exiv2 using "Pure CMake" and didn't require conan.

You will want to use the package manager `pkgsrc` to build/install the build and test components listed above.

I entered links into the file system

```
# ln -s /usr/pkg/bin/python37 /usr/local/bin/python3
# ln -s /usr/pkg/bin/bash /bin/bash`
```

It's important to ensure that `LD_LIBRARY_PATH` includes `/usr/local/lib` and `/usr/pkg/lib`.

It's important to ensure that `PATH` includes `/usr/local/bin`, `/usr/pkg/bin` and `/usr/pkg/sbin`.

#### FreeBSD

Clang is pre-installed as ``/usr/bin/{cc|c++}` as well as libz and expat.  FreeBSD uses pkg as the package manager which I used to install cmake and git.

```bash
$ su root
Password:
# pkg install cmake
# pkg install git
# pkg install bash
# pkg install python
```

**Caution**: _The package manager *pkg* is no longer working on FreeBSD 12.0.  I will move to 12.1 for future work.  Others have reported this issue on 12.1.  Broken package manager is very bad news.  There are other package managers (such as ports), however installing and getting it to work is formidable._

```
634 rmills@rmillsmm-freebsd:~/gnu/github/exiv2/0.27-maintenance/build $ sudo pkg install libxml2
Updating FreeBSD repository catalogue...
pkg: repository meta /var/db/pkg/FreeBSD.meta has wrong version 2
pkg: Repository FreeBSD load error: meta cannot be loaded No error: 0
Fetching meta.txz: 100%    916 B   0.9kB/s    00:01
pkg: repository meta /var/db/pkg/FreeBSD.meta has wrong version 2
repository FreeBSD has no meta file, using default settings
Fetching packagesite.txz: 100%    6 MiB 340.2kB/s    00:19
pkg: repository meta /var/db/pkg/FreeBSD.meta has wrong version 2
pkg: Repository FreeBSD load error: meta cannot be loaded No error: 0
Unable to open created repository FreeBSD
Unable to update repository FreeBSD
Error updating repositories!
635 rmills@rmillsmm-freebsd:~/gnu/github/exiv2/0.27-maintenance/build $
```

#### Solaris

Solaris uses the package manager pkg.  To get a list of packages:

```bash
$ pkg list
```

To install a package:

```bash
$ sudo pkg install developer/gcc-7
```


[TOC](#TOC)

Written by Robin Mills<br>robin@clanmills.com<br>Updated: 2021-08-10