Bash Shell使用技巧

1. Makefile与Shell取环境变量的不同方法

Makefile: cc=$(CROSS_COMPILE)

Shell: cc=$CROSS_COMPILE

2.从命令中得到值

removable=$(cat /sys/block/$1/removable)

3. while

export TSLIB_TSDEVICE=/dev/ts

counter=1

while [ 1 ] --> 无限循环

while [ $counter -lt 10 ]

do

aplay music.wav &

ts_test &

counter_inner=1

while [ $counter_inner -lt 60 ]

do

sleep 4

counter_inner=$(( $counter_inner + 1 ))

done

pkill ts_test

counter=$(( $counter + 1 ))

echo "the counter is $counter"

done

4. For

for file in $( find . -type f -name "*.bz2" | sort )

do

tar xvfj $file -C /scratch/paul/lite/linux/src/

done

5. 如何过滤bash的错误输出?

arm-none-linux-gnueabi-gcc -v 2>/dev/null

stdin 0<

stdout 1>

stderr 2>