linux_shell_类似sql的orderby 取最大值

{"time":"2015.08.14 21:45:13","total":}
{"time":"2015.08.14 21:45:24","total":}
{"time":"2015.08.14 21:45:34","total":}
{"time":"2015.08.14 21:45:47","total":}
{"time":"2015.08.14 21:45:57","total":}
{"time":"2015.08.14 21:50:08","total":}
{"time":"2015.08.14 21:50:34","total":}
{"time":"2015.08.14 21:50:58","total":}
{"time":"2015.08.14 21:55:14","total":}
{"time":"2015.08.14 21:55:26","total":}

需求场景 ，通过shell 筛选 每分钟的最大一条输出（最后一条） ：

awk -F'","' 'BEGIN{line=""}{pre=substr(line,10,16);a=substr($1,10,16);if(line != "" && pre!=a){print line}line=$0}' .info | head