brock@uncacsci-pi3-d:/sys/class/gpio$ ls -l
total 0
-rwxrwx--- 1 root gpio 4096 Feb  2 19:32 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  2 19:32 unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ echo 17 > export
brock@uncacsci-pi3-d:/sys/class/gpio$ ls -l
total 0
-rwxrwx--- 1 root gpio 4096 Feb  2 20:15 export
lrwxrwxrwx 1 root gpio    0 Feb  2 20:15 gpio17 -> ../../devices/platform/soc/3f200000.gpio/gpiochip0/gpio/gpio17
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 19:32 unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ ls gpio17
active_low  device  direction  edge  power  subsystem  uevent  value
brock@uncacsci-pi3-d:/sys/class/gpio$ cd gpio17
brock@uncacsci-pi3-d:/sys/class/gpio/gpio17$ echo out > direction
brock@uncacsci-pi3-d:/sys/class/gpio/gpio17$ echo 0  > value
brock@uncacsci-pi3-d:/sys/class/gpio/gpio17$ echo 1 > value
brock@uncacsci-pi3-d:/sys/class/gpio/gpio17$ echo 0  > value
brock@uncacsci-pi3-d:/sys/class/gpio/gpio17$ echo 1 > value
brock@uncacsci-pi3-d:/sys/class/gpio/gpio17$ cd ..
brock@uncacsci-pi3-d:/sys/class/gpio$ echo 17 > unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ ls
export  gpiochip0  gpiochip100  gpiochip128  unexport
brock@uncacsci-pi3-d:/sys/class/gpio$ echo 27 > export
brock@uncacsci-pi3-d:/sys/class/gpio$ cd gpio27
brock@uncacsci-pi3-d:/sys/class/gpio/gpio27$ ls
active_low  device  direction  edge  power  subsystem  uevent  value
brock@uncacsci-pi3-d:/sys/class/gpio/gpio27$ export in > direction
brock@uncacsci-pi3-d:/sys/class/gpio/gpio27$ cat value
1
brock@uncacsci-pi3-d:/sys/class/gpio/gpio27$ cat value
0