Having read this page, I decided to give AFT a try, so I installed it by
sudo pacman -S android-file-transfer, connected the device (OnePlus 3T) to the computer through USB, set it to "Transfer files mode", and then opened AFT. So far so good, I see all folders inside my device, I can select files and dowload them. I haven't tried uploading, but I think everythig's ok.
Except that I'd prefer to browse the device in the terminal, so that I can make use of regexp to move stuff from/to the device.
I've found the following
$ ll /dev/disk/by-id ... usb-OnePlus_Device_Driver_5abf662b-0:0 -> ../../sr0 ...
but when I try
$ mkdir mount_here $ sudo mount /dev/sr0 mount_here
all I see is this
$ ll mount_here total 18466 dr-xr-xr-x 1 root root 2048 Sep 7 2016 ./ drwx------ 1 enrico enrico 912 Jun 17 15:34 ../ -r-xr-xr-x 1 root root 6538856 Mar 3 2015 'AndroidFileTransfer(OSX).dmg'* -r-xr-xr-x 1 root root 12320875 Sep 5 2016 OnePlus_USB_Drivers_Setup.exe* -r-xr-xr-x 1 root root 45056 Jun 3 2015 OnePlus_setup.exe* -r-xr-xr-x 1 root root 794 Jun 30 2015 adb_config_Linux_OSX.sh* -r-xr-xr-x 1 root root 97 Jun 3 2015 autorun.inf*