GNU/Linux中两个文件(作为行集)的笛卡尔积 [英] Cartesian product of two files (as sets of lines) in GNU/Linux

问题描述

与笛卡尔积一样，如何使用外壳一线和通用GNU工具将两个文件中的行连接起来?最简洁，美观和"linuxy"的方式是什么?

How can I use shell one-liners and common GNU tools to concatenate lines in two files as in Cartesian product? What is the most succinct, beautiful and "linuxy" way?

例如，如果我有两个文件:

For example, if I have two files:

$ cat file1
a
b
$ cat file2
c
d
e

结果应该是

a, c
a, d
a, e
b, c
b, d
b, e

推荐答案

在此处执行此操作的shell脚本

Here's shell script to do it

while read a; do while read b; do echo "$a, $b"; done < file2; done < file1

尽管那会很慢. 我想不出任何预编译的逻辑来完成此任务. 速度的下一步将是在awk/perl中执行上述操作.

Though that will be quite slow. I can't think of any precompiled logic to accomplish this. The next step for speed would be to do the above in awk/perl.

awk 'NR==FNR { a[$0]; next } { for (i in a) print i",", $0 }' file1 file2

嗯，这个骇人的解决方案使用预编译的逻辑怎么样?

Hmm, how about this hacky solution to use precompiled logic?

paste -d, <(sed -n "$(yes 'p;' | head -n $(wc -l < file2))" file1) \
          <(cat $(yes 'file2' | head -n $(wc -l < file1)))

这篇关于GNU/Linux中两个文件(作为行集)的笛卡尔积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！