Question

我有一个大文本文件，我想从中删除另一个文本文件中的某些行。似乎Unix shell中的sed命令是一种很好的方法。但是，我无法弄清楚要使用哪些标志。

database.txt：

this is line 1
this is line 2
this is line 3
this is line 4
this is line 5

lines_to_remove.txt

this is line 1
this is line 3

what_i_want.txt

this is line 2
this is line 4
this is line 5

Answer 1

grep比sed更适合：

grep -Fxv -f lines_to_remove.txt database.txt > what_i_really_really_want.txt

Answer 2

在awk：

$ awk 'NR==FNR{a[$0];next}!($0 in a)' remove.txt database.txt
this is line 2
this is line 4
this is line 5

$ awk 'NR==FNR{a[$0];next}!($0 in a)' remove.txt database.txt > output.txt

Answer 3

我会使用comm：

comm -1 <(sort database.txt) <(sort lines_to_remove.txt) > what_i_want.txt

该命令更适合您的需求。

注意：<(commmand)语法是一种基础，因此在SO上受到很多诽谤。这是以下方面的简写：

sort database.txt > sorted_database.txt
sort lines_to_remove.txt > sorted_lines_to_remove.txt
comm -1 sorted_database.txt sorted_lines_to_remove.txt > what_i_want.txt

使用sed从txt文件中删除行

3 个答案: