Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.1k views
in Technique[技术] by (71.8m points)

bash - grep -vf too slow with large files

I am trying filter data from data.txt using patterns stored in a file filter.txt. Like below,

grep -v -f filter.txt data.txt > op.txt

This grep takes more than 10-15 minutes for 30-40K lines in filter.txt and ~300K lines in data.txt.

Is there any way to speed up this?

data.txt

data1
data2
data3

filter.txt

data1

op.txt

data2
data3

This works with solution provided by codeforester but fails when filter.txt is empty.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Based on Inian's solution in the related post, this awk command should solve your issue:

awk 'FNR==NR {hash[$0]; next} !($0 in hash)' filter.txt data.txt > op.txt

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...