imx6使用电容屏时需要获取对应的usb的event。其中用到了shell的一些命令。分析如下。

#   inputCheckLine=`cat /proc/bus/input/devices | grep -n "Vendor=0eef" | grep "Product=0020 Version=0001"| awk -F: '{print $1}'`

#   touchEvent=`sed -n "$((${inputCheckLine}+5))p" /proc/bus/input/devices | grep -o "event."`

    inputCheckLine=`cat /proc/bus/input/devices | grep -n "AR1020 Touchscreen" | awk -F: '{print $1}'`

    touchEvent=`sed -n "$((${inputCheckLine}+4))p" /proc/bus/input/devices | grep -o "event."`

root@freescale ~$ cat /proc/bus/input/devices

I: Bus= Vendor= Product= Version=

N: Name="gpio-keys"

P: Phys=gpio-keys/input0

S: Sysfs=/devices/platform/gpio-keys/input/input0

U: Uniq=

H: Handlers=kbd event0

B: PROP=

B: EV=

B: KEY=   

I: Bus= Vendor= Product= Version=

N: Name="AR1020 Touchscreen"

P: Phys=

S: Sysfs=/devices/virtual/input/input1

U: Uniq=

H: Handlers=cpufreq_interactive mouse0 event1

B: PROP=

B: EV=b

B: KEY=

B: ABS=

......

grep -n匹配并打印行号

root@freescale ~$ cat /proc/bus/input/devices | grep -n "AR1020 Touchscreen"

:N: Name="AR1020 Touchscreen"

这样获得了AR1020 Touchscreen所在的行。所需要的event1在16行

root@freescale ~$ sed -n "16p" /proc/bus/input/devices

H: Handlers=cpufreq_interactive mouse0 event1 

root@freescale ~$ sed -n "16p" /proc/bus/input/devices | grep -o "event."

event1

sed -n    : 不输出到终端

sed '16p' : 打印第16行

grep -o   : only match