① linux中用shell时奇怪的字符串拼接和时间计算问题
testt=$(date +%Y-%m-%d)
date2="14/08/12"
test=20
testtt="${test}${date2}"
time1=$(date +%s -d "$testt" )
time2=$(date +%s -d "$testtt" )
time=$(($time1-$time2))
echo $time
改成引号，去掉括号！！
② Linux shell: 变量与字符串拼接出新变量到if语句
不能这样写 "${TN3RD_$(echo ${library} | tr '[a-z]' '[A-Z]')_SUPPORT}"
直接写：
if [ "$library" == "zlib" ];then
echo "${library} is included"
fi