如果字段重复，则删除行 [英] Remove line if field is duplicate

问题描述

如果第一个字段重复，则查找awk(或sed)单行代码以从输出中删除行.

Looking for an awk (or sed) one-liner to remove lines from the output if the first field is a duplicate.

删除重复行的示例如下:

An example for removing duplicate lines I've seen is:

awk 'a !~ $0; {a=$0}'

尝试将其用作没有运气的基础(我认为将$ 0更改为$ 1可以解决问题，但似乎没有效果).

Tried using it for a basis with no luck (I thought changing the $0's to $1's would do the trick, but didn't seem to work).

推荐答案

awk '{ if (a[$1]++ == 0) print $0; }' "$@"

这是关联数组的一种标准用法(非常简单).

This is a standard (very simple) use for associative arrays.

这篇关于如果字段重复，则删除行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！