VIEW-OS(1viewos)

💖 NAME 💖

umfuse — a User Mode FUSE implementation, made for umview 🦋

---

✨ SYNOPSIS ✨

um_add_service umfuse.so
umview ... --preload umfuse.so

---

🌸 DESCRIPTION 🌸

okay bestie, so umfuse is the user-mode version of virtual FUSE filesystems for umfuse — no kernel module, no drama, we're doing this entirely in userspace 💅 The way it works is: once you load this service module, you can literally mount umfuse file systems. That's the whole gig.

And here's the slay part: FUSE and umfuse are source level compatible. Which means you can take a FUSE file system implementation and compile it as a dynamic library. fr fr. Just one rule though — the name of umfuse file system implementation libraries must begin with umfuse. Non-negotiable, it's the vibe check. 👑

File systems implemented with umfuse get mounted and umounted by the standard utilities mount(8) and umount(8). Yes, the boring classics. They ate.

Example, for the visual learners 🎀:

$ mount -t umfuseext2 /path/to/file.img /mount/point
...
$ umount /mount/point

🛠️ mount options 🛠️

The mount command for umfuse file systems lets you pass some specific options, and they are:

• debug — gives you verbose feedback on every single operation happening on the virtual file system. It's giving "narrator voice" for your syscalls ✨
• fuseuid=uid — sets the effective uid for operations on the virtual file system.
• fusegid=gid — sets the effective gid for operations on the virtual file system.
• human — lowkey important: umfuse's default mode is omnipotent, meaning the user acts as root inside the mounted file system 😳 When a file system gets mounted with the human option, access control is enforced. So you become a regular little mortal. Grounded. 🫶

🧚 umfuse modules main program invocation options 🧚

umfuse calls the main program of the module using the standard syntax:

umfusexxxx -o options source mountpoint

But sometimes FUSE modules were designed to accept a different syntax (they're quirky like that 🙈), and you can match the calling syntax by using the following options:

• nosource — no image file should be specified.
• pre=string — the string contains parameters that must be put before -o options.
• post=string — the string contains parameters that must be added at the end.
• format=string — okay this one is the most powerful rewriting rule 👑 If the main needs a completely different structure, format can be used. The format string is similar to that used in printf. The %O %S %M descriptors get substituted in the call like this: %O=-o options, %S=source, %M=mountpoint. Iconic, honestly.
• showcall — shows the call syntax before the actual call. Use it for debugging, bestie 🔍

---

👀 SEE ALSO 👀

umview(1) um_add_service(1) um_del_service(1) um_ls_service(1) um_mov_service(1)

---

💜 AUTHORS 💜

View-OS is a project of the Computer Science Department, University of Bologna. Project Leader: Renzo Davoli. 🌈

<http://www.sourceforge.net/projects/view-os>

Howto's and further information can be found on the project wiki <wiki.virtualsquare.org>. go read it, iykyk 📚

---

and that's the whole page, periodt 💅 this was the VIEW-OS(1viewos) manual — "VIEW-OS: a process with a view", dated June 10, 2006. mwah, go mount something 🦋✨