# The startup watch (`parts/startup-watch.sh`)

## SYNOPSIS

```
wrenctl part startup-watch         set it up again (part of the base; the first time it takes a
                                   record of your startup files as they are)
bash ~/wren/parts/startup-watch.sh --remove    take it out
bash ~/wren/parts/startup-watch.sh --manual    print the manual steps below

wren-watch                         what changed since you last accepted
wren-watch diff                    the changes themselves (sudo asks your password)
wren-watch accept [FILE...]        take them as yours, all or those files (sudo asks)
(a click on "startup changed" in the bar: the same, as 1 see, 2 take as yours, 3 or Esc leave)
```

A program running as you that wants to start again at every login has to change one of a few files:
your shell's startup files (`~/.profile`, `~/.bashrc`, ...), tmux's, vim's, curl's and wget's
settings, sway's config, `~/.config/autostart`, systemd user units, `~/.local/bin`, mako's config,
`.desktop` files and default apps, Wren Linux's on-lock programs, your list of what opens at login,
`~/.ssh/config`, `rc` and `authorized_keys`, and git's and gpg-agent's settings (`wren-watch --help`
lists them).

This keeps their fingerprints, and a copy of each text file, where nothing running as you can change
them: root's, in `/var/lib/wren-watch`.

A root timer compares them at boot and every 15 minutes, following no link and reading regular files
only, and writes what changed where you can read it but not change it. A file stays on that list
until you accept it, even if it is back as it was by the next look: a program could change it, wait
for it to be used, and put it back. `diff` says so for such a file, as it has nothing to show.

The bar then shows "startup changed", with a notification; a click shows the list and the changes.
`sudo wren-watch accept` takes them as yours, with your password, so a program running as you can't
accept its own change without it.

`sudo wren-watch diff` reads your files as they are now with your rights, not root's, and follows no
link, so a link planted there can't show it a root-only file.

`wrenctl install`, `part`, `remove` and `update` take what their own run changed as Wren Linux's,
except a file that had changed before the run, which is left for you.

## LIMITS

- It notices, it doesn't prevent: the change is made, and works, until you see it and undo it.
- It sees only the files it watches. A program can also start from a file it doesn't watch, or run
  on in memory until you log out.
- Up to 15 minutes pass before a change shows (and until the next login, if you log out first).
- What a change made while `wrenctl` runs, to a file that run also changes, is taken with it.

## MANUAL INSTALL

```
sudo apt install --no-install-recommends python3 diffutils
sudo install -o root -g root -m 0755 @WREN_DIR@/bin/wren-watch /usr/local/bin/wren-watch
# root's check, at boot and every 15 minutes: it may write only its record and list
printf '%s\n' '[Unit]' 'Description=Wren Linux: compare the startup files with their record' '' \
    '[Service]' 'Type=oneshot' 'ExecStart=/usr/local/bin/wren-watch check-all' \
    'ProtectSystem=strict' 'ReadWritePaths=/var/lib/wren-watch /run/wren-watch' 'ProtectHome=read-only' \
    'PrivateTmp=yes' 'PrivateNetwork=yes' 'NoNewPrivileges=yes' 'RuntimeDirectory=wren-watch' \
    'RuntimeDirectoryPreserve=yes' 'StateDirectory=wren-watch' | sudo tee /etc/systemd/system/wren-watch.service
printf '%s\n' '[Unit]' 'Description=Wren Linux: compare the startup files every 15 minutes' '' \
    '[Timer]' 'OnBootSec=1min' 'OnUnitActiveSec=15min' '' '[Install]' 'WantedBy=timers.target' |
    sudo tee /etc/systemd/system/wren-watch.timer
sudo systemctl daemon-reload
sudo systemctl enable --now wren-watch.timer
# The record, as your files are now
sudo wren-watch accept
```

To undo:

```
sudo systemctl disable --now wren-watch.timer
sudo rm /etc/systemd/system/wren-watch.service /etc/systemd/system/wren-watch.timer /usr/local/bin/wren-watch
sudo rm -rf /var/lib/wren-watch /run/wren-watch
sudo systemctl daemon-reload
```