bash - 如果一列的值或两个连续行不匹配，如何打印分隔符

我有如下输入，如果两行之间的第三列的值不同，则需要在行之间放置分隔符。

one two three four
five six three seven
eight nine ten elevel
alpha beta ten gama
tango charlie oscar bla

预期结果:

one two three four
five six three seven
=
eight nine ten elevel
alpha beta ten gama
=
tango charlie oscar bla

我认为这是行得通的，但行不通。

awk '{col3=$3;next} $3!=col3{$0="\n="$0;print $0}' input

最佳答案

$ awk '$3!=p && NR>1 { print "=" } { print; p=$3 }' file
one two three four
five six three seven
=
eight nine ten elevel
alpha beta ten gama
=
tango charlie oscar bla