#Jmtpfs
##Description
A mtp over FUSE virtual filesystem ported to macOS.
Allows you to use MTP (media transfer protocol) through libmtp to transfer files to android devices that do not support UMS (anything > 4.4).
As mounting is accomplished through FUSE, the device should be accessible both from the finder and any command line utility.
##Build & Installation
These are build directions for OSX
First install osxfuse
Then get Homebrew if you don't already have it.
brew install the following:
libmtp
libusb
libmagic
Then after cding to the cloned directory run
./configure
Hopefully there are no errors.
Then run make
And finally
make install
This will build the jmtpfs binary and place it in /usr/local/bin.
##Usage:
The way Fuse works is that it builds a virtual file system given a mountpoint (we will use a folder for this purpose)
Let's mount our device to the desktop.
To do this, create a folder called nexus (or whatever you like) inside your desktop (or someother place if you prefer). You only have to do this once.
Next run
jmtpfs -o local [path to created folder]
Where [path to created folder] is replaced by the posix path.
For example: jmtpfs -o local ~/Desktop/nexus
The -o local flag creates a local mount so that it appears in the finder sidebar.
You can then access the files on the device as if it were a normal disk.
Passing the -l option will list the attached MTP devices.
You can then choose which device to mount with the -device option.
You can pass -h for help.
Unmounting can be done via the finder (eject) or via the osx standard umount
If you want to get really fancy you can add a name and icon:
jmtpfs -o volname="Nexus 5" -o volicon=/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/com.apple.iphone-4-black.icns ~/Desktop/nexus
Alternatively, in the releases tab is a helper application that is essentially a wrapper application (created with Platypus) around the above shell script. Upon launch, it takes care of automatically creating a folder in the OSX-convetion /Volumes directory and mounts into that created directory. Upon unmount, it deletes that created folder and leaves /Volumes as it was before. It also includes the name and drive icon so the fuse mountpoint can easily be interacted with via Finder.
that will automatically run the above using a shell script upon launching the app.
##Uninstalling
The only thing created is the binary in /usr/local/bin/jmtpfs
You can either delete this manually or run make uninstall which does the same thing for you.
##Performance and implementation notes:
Libmtp (and I assume the MTP protocol itself) doesn't support seeking within a file or partial file reads or writes. You have to fetch or send the entire file. To simluate normal random access files, when a file is opened the entire file contents are copied from the device to a temporary file. Reads and writes then operate on the temporary file. When the file is closed (or if a flush or fsync occurs) then if a write has occurred since the file was last opened the entire contents of the temporary file are sent back to the device. This means repeatedly opening a file, making a small change, and closing it again will be very slow.
Renaming or moving a file is implemented by copying the file from the device, writing it back to the device under the new name, and then deleting the original file. This makes renames, especially for large files, slow. This has special significance when using rsync to copy files to the device. Rsync copies to a temporary file, and then when the copy is complete it renames the temporary file to the real filename. So when rsyncing to a jmtpfs filessystem, for each file, the data gets copied to the device, read back, and then copied to the device again. There is a true rename (but not move) supported by libmtp, but this appears to confuse some Android apps, so I don't use it. Image files, for example, will disappear from the Gallery if they're renamed.
##Credits
Credits to @kiorky and @JasonFerrara for their initial work.
If you're using this for the purpose of transferring files to android using a fuse file system, also look into adbfs which is slightly more stable