linux脚本：shell, 判断输入参数的个数（命令行）
if [ $# != 3 ] ; thenecho "USAGE: $0 from to"echo " e.g.: $0 ~/oucaijun/from ~/oucaijun/to"exit 1 ...
花费 14 ms
if [ $# != 3 ] ; thenecho "USAGE: $0 from to"echo " e.g.: $0 ~/oucaijun/from ~/oucaijun/to"exit 1 ...
命令如下： touch access_`date +%Y%m%d%H`.log ...