fsmon

FileSystem Monitor utility that runs on Linux, Android, iOS and OSX.

Brought to you by Sergi Àlvarez at Nowsecure and distributed under the MIT license.

Contact: pancake@nowsecure.com

Usage

The tool retrieves file system events from a specific directory and shows them in colorful format or in JSON.

It is possible to filter the events happening from a specific program name or process id (PID).

$ ./fsmon -h
Usage: ./fsmon-macos [-Jjc] [-a sec] [-b dir] [-B name] [-p pid] [-P proc] [path]
 -a [sec]  stop monitoring after N seconds (alarm)
 -b [dir]  backup files to DIR folder (EXPERIMENTAL)
 -B [name] specify an alternative backend
 -c        follow children of -p PID
 -f        show only filename (no path)
 -h        show this help
 -j        output in JSON format
 -J        output in JSON stream format
 -n        do not use colors
 -L        list all filemonitor backends
 -p [pid]  only show events from this pid
 -P [proc] events only from process name
 -v        show version
 [path]    only get events from this path
Examples:
 fsmon /data
 fsmon -J / | jq -r .filename
 fsmon -B fanotify /home
$

Backends

fsmon filesystem information is taken from different backends depending on the operating system and apis available.

This is the list of backends that can be listed with fsmon -L:

• inotify (linux / android)
• fanotify (linux > 2.6.36 / android with custom kernel)
• devfsev (osx /dev/fsevents - requires root)
• kqueue (xnu - requires root)
• kdebug (bsd?, xnu - requires root)
• fsevapi (osx filesystem monitor api)

Compilation

fsmon is a portable tool. It works on iOS, OSX, Linux and Android (x86, arm, arm64, mips)

Linux

$ make

OSX + iOS fatbin

$ make

iOS

$ make ios

Android

$ make android NDK_ARCH=<ARCH> ANDROID_API=<API>

To get fsmon installed system wide just type:

$ make install

Changing installation path...

$ make install PREFIX=/usr DESTDIR=/