Nyd*_*enn 5 command-line text-processing
我想删除最后一行中包含空字段的行 $7
文件：
1 1479870 5022248660 1 40001 189445122 740020
1 1911574 3015889020 1 33001 162049034 633004
1 1569783 5029193930 1 22001 133687297 522216
1 2069616 1025856960 2 25001 185608704
1 1741598 5021128160 1 44001 164870942 644027
1 1052941 5020319300 1 10001 156161802 610007
1 1686734 5020347480 1 13001 131405824 513304
1 1872263 5029089700 1 23001 185092353 723017
所需的输出：
1 1479870 5022248660 1 40001 189445122 740020
1 1911574 3015889020 1 33001 162049034 633004
1 1569783 5029193930 1 22001 133687297 522216
1 1741598 5021128160 1 44001 164870942 644027
1 1052941 5020319300 1 10001 156161802 610007
1 1686734 5020347480 1 13001 131405824 513304
1 1872263 5029089700 1 23001 185092353 723017