brock@uncacsci-pi3-d:~$ ls /sys/class/gpio/
export  gpio27  gpiochip0  gpiochip100  gpiochip128  unexport
brock@uncacsci-pi3-d:~$ ls -l
total 4016
drwxr-xr-x 10 brock brock    4096 Nov  8  2016 Adafruit_Python_BNO055
-rw-r--r--  1 brock brock 4194304 Apr 29  2017 disk.img
-rw-r--r--  1 brock brock      65 Feb  3 07:48 GPIO.docs
-rw-r--r--  1 brock brock    3418 Feb  2 19:36 house.scan
-rw-r--r--  1 brock brock    1126 Feb  2 20:09 RPi-run-0.txt
-rw-r--r--  1 brock brock     967 Feb  2 20:09 RPi-run-0.txt~
-rw-r--r--  1 brock brock    3138 Feb  2 20:23 RPi-run-1.txt
-rw-r--r--  1 brock brock   13166 Feb  3 08:10 RPi-run-2.txt
-rw-r--r--  1 brock brock   12213 Feb  2 21:01 RPi-run-2.txt~
-rw-r--r--  1 brock brock     220 Feb  2 20:57 RPiTest
-rw-r--r--  1 brock brock      69 Feb  2 19:47 RPiTest~
-rw-r--r--  1 brock brock    9111 Nov  8  2016 RUNOUT-00.TXT
brock@uncacsci-pi3-d:~$ ls -l
total 4016
drwxr-xr-x 10 brock brock    4096 Nov  8  2016 Adafruit_Python_BNO055
-rw-r--r--  1 brock brock 4194304 Apr 29  2017 disk.img
-rw-r--r--  1 brock brock      65 Feb  3 07:48 GPIO.docs
-rw-r--r--  1 brock brock    3418 Feb  2 19:36 house.scan
-rw-r--r--  1 brock brock    1126 Feb  2 20:09 RPi-run-0.txt
-rw-r--r--  1 brock brock     967 Feb  2 20:09 RPi-run-0.txt~
-rw-r--r--  1 brock brock    3138 Feb  2 20:23 RPi-run-1.txt
-rw-r--r--  1 brock brock   13166 Feb  3 08:10 RPi-run-2.txt
-rw-r--r--  1 brock brock   12213 Feb  2 21:01 RPi-run-2.txt~
-rw-r--r--  1 brock brock     220 Feb  2 20:57 RPiTest
-rw-r--r--  1 brock brock      69 Feb  2 19:47 RPiTest~
-rw-r--r--  1 brock brock    9111 Nov  8  2016 RUNOUT-00.TXT
brock@uncacsci-pi3-d:~$ cd /sys/class/gpio
brock@uncacsci-pi3-d:/sys/class/gpio$ ls
export  gpio27  gpiochip0  gpiochip100  gpiochip128  unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ ls -l
total 0
-rwxrwx--- 1 root gpio 4096 Feb  2 20:19 export
lrwxrwxrwx 1 root gpio    0 Feb  2 20:19 gpio27 -> ../../devices/platform/soc/3f200000.gpio/gpiochip0/gpio/gpio27
lrwxrwxrwx 1 root gpio    0 Feb  2 19:32 gpiochip0 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpiochip0
lrwxrwxrwx 1 root gpio    0 Feb  2 19:32 gpiochip100 -> ../../devices/gpiochip2/gpio/gpiochip100
lrwxrwxrwx 1 root gpio    0 Feb  2 19:32 gpiochip128 -> ../../devices/gpiochip1/gpio/gpiochip128
-rwxrwx--- 1 root gpio 4096 Feb  2 20:19 unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ echo 27 > unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ ls -l
total 0
-rwxrwx--- 1 root gpio 4096 Feb  2 20:19 export
lrwxrwxrwx 1 root gpio    0 Feb  2 19:32 gpiochip0 -> ../../devices/platform/soc/3f200000.gpio/gpio/gpiochip0
lrwxrwxrwx 1 root gpio    0 Feb  2 19:32 gpiochip100 -> ../../devices/gpiochip2/gpio/gpiochip100
lrwxrwxrwx 1 root gpio    0 Feb  2 19:32 gpiochip128 -> ../../devices/gpiochip1/gpio/gpiochip128
-rwxrwx--- 1 root gpio 4096 Feb  3 08:14 unexport
brock@uncacsci-pi3-d:/sys/class/gpio$