# Tar FUSE

This program mounts a tar file system to a directory through FUSE.

Have you ever wanted to have a nice, convenient view into a tar file without
having to unpack it, and without having to learn a ton of obscure tar commands?
Have you ever wanted to be able to do `find -type f -name "*.ml"`, or any other
search command, only inside a tar file?

If you've experienced any of the above, this is your lucky day! Just mount the
tar file to a directory:

```sh
$ fusetar my-archive.tar mnt/
```

And just like that, everything inside the tarball is available to you as a
read-only file system, to search, read or do whatever else.

An example with the debian rootfs:

```sh
$ wget https://github.com/kbaraniak/debian-rootfs/releases/download/bookworm-270224/debian-amd64-bookworm-rootfs-270224.tar.xz
...
$ xz -d debian-amd64-bookworm-rootfs-270224.tar.xz
$ mkdir -p mnt
$ fusetar debian-amd64-bookworm-rootfs-270224.tar mnt/
$ ls debian-amd64-bookworm-rootfs-270224.tar.xz
bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
```

As you can see, the root file system inside the tar archive is transparently presented to you now under your mounted directory!

Note that it is read-only. Tar is a streaming format, and it is quite awkward to try to make changes/additions to it.

With that being said, if you absolutely need to write files to the directory (but not to the archive), it is quite easy to make this directory writable - you can simply use overlayfs to overlay an empty directory over this mount. This way, your changes would be preserved inside a separate directory, while unchanged content from the archive remains available:

```sh
$ mkdir -p mnt/ upper/ workdir/ merged/ 
$ ./main.exe debian-amd64-bookworm-rootfs-270224.tar -f mnt & 
[1] 46526
$ sudo mount -t overlay overlay -olowerdir=./mnt,upperdir=./upper,workdir=./workdir ./merged
$ echo "hi" > merged/hello-world.txt
$ ls -la merged
total 5
drwxr-xr-x 1 haxala1r users  30 Nov 27 17:37 .
drwxr-xr-x 1 haxala1r users 362 Nov 27 17:36 ..
lrwxrwxrwx 1 root     root    0 Jul  2  2023 bin -> usr/bin
drwxr-xr-x 1 root     root    0 Jul  2  2023 boot
drwxr-xr-x 1 root     root    0 Feb 27  2024 dev
drwxr-xr-x 1 root     root    0 Feb 27  2024 etc
-rw-r--r-- 1 haxala1r users   3 Nov 27 17:37 hello-world.txt
drwxr-xr-x 1 root     root    0 Jul  2  2023 home
lrwxrwxrwx 1 root     root    0 Jul  2  2023 lib -> usr/lib
lrwxrwxrwx 1 root     root    0 Jul  2  2023 lib64 -> usr/lib64
drwxr-xr-x 1 root     root    0 Jul  2  2023 media
drwxr-xr-x 1 root     root    0 Jul  2  2023 mnt
drwxr-xr-x 1 root     root    0 Jul  2  2023 opt
drwxr-xr-x 1 root     root    0 Jul  2  2023 proc
drwxr-xr-x 1 root     root    0 Feb 27  2024 root
drwxr-xr-x 1 root     root    0 Jul  2  2023 run
lrwxrwxrwx 1 root     root    0 Jul  2  2023 sbin -> usr/sbin
drwxr-xr-x 1 root     root    0 Jul  2  2023 srv
dr-xr-xr-x 1 root     root    0 Feb 27  2024 sys
drwxr-xr-x 1 root     root    0 Jul  2  2023 tmp
drwxr-xr-x 1 root     root    0 Jul  2  2023 usr
drwxr-xr-x 1 root     root    0 Feb 27  2024 var
```