# ddir
[](https://github.com/yannickkirschen/ddir/actions/workflows/commit-lint.yml)
[](https://github.com/yannickkirschen/ddir/actions/workflows/push.yml)
[](https://github.com/yannickkirschen/ddir/actions/workflows/release.yml)
[](https://github.com/yannickkirschen/ddir/releases/)
`ddir` is a command line tool to calculate diffs between two directories and
resolve them.
Check out the [diff file format](#the-diff-file-format) as well.
## Installation
`pip install ddir`
This will install a binary called `ddir` on your `PATH` that you can execute.
Depending on your system, you may need sudo/admin permissions.
## Usage
```txt
Usage: ddir <commands>
Available commands:
help - show this help
version - show version
init - initialize a source directory
diff create <name> - create a diff for a target
diff resolve <name> --modes <modes> - resolve a diff for a target
diff list <name> - list all diffs for a target
target create - create a target in interactive mode
target list - list all targets
target delete <name> - delete target
legacy migrate - migrate from legacy ddir
```
## Fast mode
If you just want to compare change dates of files and not their content
(md5 hash), you can use the fast mode. Set that option when creating a target.
## Modes to resolve
The modes work like this: for each type (the order is `+`, `-`, `>`, `<`, `?`)
a number in the tuple indicates how to handle diffs of that type. There are
the following modes:
- 0: skip
- 1: apply (type dependent, see below)
- 2: choose manually
When choosing to apply diffs, the following will happen:
- `+`, `>`, `?`: override destination element with source element
- `<`: override source element with destination element
- `-`: delete destination element
## The diff file format
A diff file stores the differences between a file or a directory at a source
compared to a destination.
### Specification
We call a file or a directory an **element**. The type of one element is either
`d` for *directory* or `f` for *file*.
We differentiate between five diff types:
- `+` (**positive diff**): an element exists in the source but not the
destination
- `-` (**negative diff**): an element exists in the destination but not
the source
- `>` (**newer diff**): the source element is newer than the destination element
- `<` (**older diff**): the source element is older than the destination element
- `?` (**unknown diff**): the elements are somehow different, but we can't
categorize them; used if files differ but change dates are equal; requires
manual resolution
The diff file is a newline-separated text file with each line containing an
individual diff. Each line has the format:
`{diff type}:{element type}:{first element}:{second element}`
