mirro 0.3.0

A safe editing wrapper: edits a temp copy, compares, and saves original backup if changed.

mirro

mirro is a tiny safety-first editing wrapper for text files. You edit a temporary file, mirro detects whether anything changed, and if it did, it saves a backup of the original before writing your changes.

Why mirro?

Well... have you ever been in the “ugh, I forgot to back this up first” situation?

No?

Stop lying... 🥸

mirro gives you a built-in safety net:

• never edits the real file directly

• detects whether the edit actually changed content

• creates a timestamped backup only when changes occurred

• clearly labels backups so you know exactly what they came from

• respects the user’s $EDITOR when possible

• requires sudo only when actually needed

• accepts most of your favourite editor's flags

It’s simple, predictable, and hard to misuse.

I mean... the only thing you need to remember is to use it.

How it works

mirro reads the original file (or pre-populates new files with a friendly message).

It writes that content into a temporary file.

It launches your $EDITOR to edit the temp file.

When the editor closes, mirro compares old vs new.

If nothing changed:

file hasn't changed

If changed:

file changed; original backed up at: ~/.local/share/mirro/ (or /root/.local/share/mirro/ under sudo)

Backed up files include a header:

# ---------------------------------------------
# mirro backup
# Original file: /path/to/whatever.conf
# Timestamp: 2025-11-10 17:44:00 UTC
# ---------------------------------------------

So you never lose track of the original location.

Backup directory

By default all the backups will be stored at:

~/.local/share/mirro/

so under sudo:

/root/.local/share/mirro/

Backups are named like:

filename.ext.orig.20251110T174400

Functionalities

List all backup files stored in your backup directory.

mirro --list

Output includes permissions, owner/group, timestamps, and backup filenames.

Restore the most recent backup for a given file.

mirro --restore-last ~/.config/myapp/config.ini

This:

1. finds the newest backup matching the filename,

2. strips the mirro header from it,

3. and overwrites the target file with its original contents.

Remove old backup files.

mirro --prune-backups

This removes backups older than the number of days set in MIRRO_BACKUPS_LIFE.

Remove backups older than N days

mirro --prune-backups=14

This keeps the last 14 days of backups and removes everything older.

Remove all backups

mirro --prune-backups=all

This deletes every backup in the backup directory.

Environment Variable

MIRRO_BACKUPS_LIFE controls the default number of days to keep when using mirro --prune-backups. Its default value is 30 if not set otherwise.

export MIRRO_BACKUPS_LIFE=7

Backups older than 7 days will be removed.

Invalid or non-numeric values fall back to 30 days.

Note: a value of 0 is invalid.

Installation

NOTE: To use mirro with sudo, the path to mirro must be in the $PATH seen by root.
Either:

• install mirro as root (preferred), or
• add the path to mirro to the secure_path parameter in /etc/sudoers. For example, where /home/user/.local/bin is where mirro is:

Defaults secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/home/user/.local/bin"

Install via PyPI (preferred):

pip install mirro

Or clone the repo and install locally:

git clone https://github.com/mdaleo404/mirro.git
cd mirro/
poetry install

How to run the tests

• Clone this repository

• Ensure you have Poetry installed

• Run poetry run pytest -vvvv --cov=mirro --cov-report=term-missing --disable-warnings

pre-commit

This project uses pre-commit to run automatic formatting and security checks before each commit (Black, Bandit, and various safety checks).

To enable it:

poetry install
poetry run pre-commit install

This ensures consistent formatting, catches common issues early, and keeps the codebase clean.