如何从管道中两次使用STDIN [英] How to use STDIN twice from pipe

问题描述

我有一个类似

awk 'FNR==NR {col1[$1]++; col2[$2]++; next} {print $0, col2[$2] "/" length(col1)}' input input

但是如果我有很多文件，并且需要将此脚本用于串联的文件，例如:

But in case I have lot of files and need to use this script for concatenated files together like:

cat *all_input | awk 'FNR==NR {col1[$1]++; col2[$2]++; next} {print $0, col2[$2] "/" length(col1)}' STDIN STDIN

不起作用.如何从管道中两次使用STDIN?

Does not work. How to use STDIN twice from pipe?

推荐答案

您不需要使用管道.如果您使用的是bash，请使用将进程替换为<(cmd) ，即实现重定向，使过程的输入或输出(某些命令序列)显示为临时文件.

You don't need to use a pipe. If you are using bash use process-substitution as <(cmd) i.e. to achieve a redirection where the input or output of a process (some sequence of commands) appear as a temporary file.

awk 'FNR==NR {col1[$1]++; col2[$2]++; next} {print $0, col2[$2] "/" length(col1)}' <(cut -f3 5- input) <(cut -f3 5- input)

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