【printf】

1、小于10的数实现自动补零

num_=$(printf "%02d" num)

2、十进制转十六进制

printf "%X\n" 255
FF

3、十六进制转十进制

echo $((0XFF))
255

VERSION=4.01.39
YEAR=23
MONTH=11
DAY=9

VERSION_NUM=`echo ${VERSION} |  awk -F"." '{print $1$2$3}'`
#echo ${VERSION_NUM}
VERSION_NUM_HEX=`printf "%X" ${VERSION_NUM}`
#echo ${VERSION_NUM_HEX}
#echo ${VERSION_NUM_HEX:0:2}
#echo ${VERSION_NUM_HEX:0-2:2}

F181_Ver_1=`echo ${VERSION_NUM_HEX:0:2}`
F181_Ver_2=`echo ${VERSION_NUM_HEX:0-2:2}`
F181_Ver_3=`printf "%02X" ${YEAR}`
F181_Ver_4=`printf "%02X" ${MONTH}`
F181_Ver_5=`printf "%02X" ${DAY}`


F181_Ver={0x${F181_Ver_1},0x${F181_Ver_2},0x${F181_Ver_3},0x${F181_Ver_4},0x${F181_Ver_5},0x01}
echo ${F181_Ver}