get_cmake

Canonical project URL: https://github.com/Crascit/get_cmake

The scripts in this repository are intended primarily for copying directly into your own project and used as part of automated CI jobs. They retrieve official release packages from an official location, verify the downloaded files and unpack the release to a configurable directory. They should not require any administrative privileges, as the official packages are fully relocatable and can be run directly from the local output directory created by the script.

The script can be used to retrieve all official CMake releases since 3.18.6. Release candidates can also be retrieved starting with the 3.21 feature release.

Incorporating Into Your Project

You should be able to embed or copy this whole repository to your own project's source tree. Only embed it as a git submodule if you can guarantee that the remote repo isn't compromised (e.g. a mirror or fork on your local network, not the canonical repo on GitHub). Otherwise, make an actual copy and embed it directly in your repository. Whichever approach is taken, you should preserve the directory structure, but you are free to place it all under whatever directory you find convenient.

The scripts will automatically create a local keyring file and use that if it finds any public keys in the trusted_pubkeys subdirectory relative to the script's location. You can tell the script to look in a different location for public key files instead if needed. Public key files may need to be updated occasionally when new public keys are used. If you want to rely on your default keychain instead, don't copy the trusted_pubkeys subdirectory to your project or tell the script to look in a non-existent directory.

Using The Scripts

The scripts accept a command line argument specifying the CMake version you want to download. This should be the full version number, like 3.20.0. Release candidates can also be retrieved (e.g. 3.21.0-rc1). If no version is specified, the latest CMake release will be downloaded. CI scripts should always ask for a specific CMake version for repeatability and traceability reasons.

Note that a release candidate is considered to be a release. If you do not want a release candidate, do not ask for the latest and ask for a specific version instead.

The script offers a few options for controlling things like the output directory and verbosity. See the output from running the script with the --help option for details.

After running the script, you will typically want to add the relevant directory to your PATH to use the downloaded CMake version. The directory is different for different platforms due to the different package structure. The following examples show how to run the script, setup the PATH and run cmake to print the version:

# Linux with default output directory
./get_cmake.bash 3.20.0
export PATH=`pwd`/cmake-3.20.0/bin:${PATH}
cmake --version

# macOS with custom output directory and accounting for app bundle structure
./get_cmake.bash --output cmake 3.20.0
export PATH=`pwd`/cmake/CMake.app/Contents/bin:${PATH}
cmake --version

Requirements

The scripts assume a few common tools are available. The requirements vary a little between platforms, as specified below.

Linux

• bash
• jq
• sha256sum
• gpg
• curl
• tar
• sort
• sed
• tail

macOS

• bash
• jq
• shasum
• gpg
• curl
• tar
• sort
• sed
• tail

Windows

TBA

Other Resources

NOTE: For problems with the scripts in this repository, open a GitHub issue against this project.

General questions about using CMake are best asked in the CMake forums.

The book Professional CMake: A Practical Guide is also a popular resource for learning how to use CMake.