find /sys -name port_number|xargs grep .
/sys/devices/pci0000:00/0000:00:1a.1/usb3/3-1/3-1:1.0/ttyUSB0/port_number:0 /sys/devices/pci0000:00/0000:00:1a.1/usb3/3-1/3-1:1.0/ttyUSB1/port_number:1 /sys/devices/pci0000:00/0000:00:1a.1/usb3/3-1/3-1:1.0/ttyUSB2/port_number:2
find /sys -name port_number|xargs grep .
/sys/devices/ pci0000: 00/0000: 00:1a.1/ usb3/3- 1/3-1:1. 0/ttyUSB0/ port_number: 0 pci0000: 00/0000: 00:1a.1/ usb3/3- 1/3-1:1. 0/ttyUSB1/ port_number: 1 pci0000: 00/0000: 00:1a.1/ usb3/3- 1/3-1:1. 0/ttyUSB2/ port_number: 2
/sys/devices/
/sys/devices/