For every command yadm supports, a program can be provided to run before or after that command. These are referred to as “hooks”. yadm looks for hooks in the directory $HOME/.config/yadm/hooks. Each hook is named using a prefix of pre_ or post_, followed by the command which should trigger the hook. For example, to create a hook which is run after every yadm pull command, create a hook named post_pull. Hooks must have the executable file permission set.

If a pre_ hook is defined, and the hook terminates with a non-zero exit status, yadm will refuse to run the yadm command. For example, if a pre_commit hook is defined, but that command ends with a non-zero exit status, the yadm commit will never be run. This allows one to “short-circuit” any operation using a pre_ hook.

Hooks have the following environment variables available to them at runtime:

The command which triggered the hook
The exit status of the yadm command
The yadm command with all command line arguments
The path to the yadm repository
The path to the work-tree