execfuse: A C repository from vi

execfuse is a implement FUSE filesystems using a bunch of scripts.

Consider it as a "shell FUSE binding".

For each FUSE call (except of ones that deals with file descriptors) execfuse calls your script. For opening files it provides a bit higher level abstraction: "read_file" script is called when file should be read and "write_file" is called when file should be saved.

Example:

$ mkdir -p m
$ ./execfuse examples/xmp m
$ ls -l m/bin/sh
lrwxrwxrwx 1 root root 4 Mar 26 00:26 m/bin/sh -> bash
(executes "examples/xmp/readlink /bin/bash" for this)
$ ls m/etc/iproute2/
ematch_map  group  rt_dsfield  rt_protos  rt_realms  rt_scopes	rt_tables
(executes "exampels/xmp/readdir /etc/iproute" for this)
$ m/bin/echo qqq
qqq
$ mkdir -p m/tmp/1/2/3
$ echo 12345 > m/tmp/12345
(executes "exampels/xmp/write_file /tmp/12345" with content piped to stdin)
$ rm -Rf m/tmp/1*
$ fusermount -u m

Limitations:

Each file must fit in memory, can't write/read part of file
Slow by design
Limited error handling, especially for writing files
Modifications to files are visible only after file closing

Filesystem examples:

examples/xmp - try to be fusexmp_fh
examples/hello - very simple demo filesystem
examples/video_frames - extract frames from video as *.ppm files and enumerate keyframes (using ffmpeg)

vi/execfuse