Configuration files

Configuration files are expected to be in ini-file format. They are read using configparser.ConfigParser with extended Interpolation.

Each subcommand of sayod-backup needs to be given an option --config <FILE>.

For an option value mytask.x, the following paths will be tried in sequence, reading each existing file:

• $HOME/.config/sayod/mytask.x
• $HOME/.config/sayod/mytask
• $HOME/.config/sayod/mytask.rc
• $HOME/.config/sayod/mytask.ini

N.B. from configparse Documentation for Python 3.13.2:

Any conflicting keys are taken from the more recent configuration while the previously existing keys are retained.

After reading all files, a new ini-file section env is created which contains all environment variables, only with $ replaced by its fullwidth form ＄ (because the regular dollar sign $ would lead to interpolation attempts).

Then, all values listed in section [defaults] are taken to be file names whose contents are read into the configuration; relative filenames are relative to the main configuration file's path. Interpolation rules still apply, but there is no recursion into the default's [defaults] section. The key names in [defaults] are ignored and should be used for information purposes only.

Finally, the four initial files are read again to ensure that the values read through [defaults] are actually only defaults and can be overwritten by the current configuration.

Interpolation happens at retrieval, but new environment variables aren't read.

Example

For the two configuration files

# mytask.rc
[defaults]
change_source = other.ini

[source]
path = /home
asdf = newvalue

and

# other.ini
[source]
asdf = xyz
jklö = qwer_${source:asdf}

the following values are provided:

$ sayod-backup --config mytask.rc config --section source --key path
/home
$ sayod-backup --config mytask.rc config --section source --key asdf
newvalue
$ sayod-backup --config mytask.rc config --section source --key jklö
qwer_newvalue
$ [[ "$(sayod-backup --config mytask.rc config --section env --key HOME)" == "$HOME" ]] && echo "env read correctly" || echo "wtf?"
env read correctly