compare two files and get the positions in third file in linux

Question

I need help with comparison of two files and get the positions in third file, both files will have the same fields but the order will be unsorted in 2nd file, third file will give the line number where the data is found.

eg. file1.txt
A
B
C
D

file2.txt
B
D
A
C

outputfileposition.txt
3
1
4
2

Any help appreciated, thanks in advance

123 · Answer 1 · 2015-06-17T08:39:46.110

1

In awk

awk 'FNR==NR{a[$0]=FNR;next}{print a[$0] > "outputfileposition.txt"}' file{2,1}.txt

edited Jun 17 '15 at 08:39

answered Jun 17 '15 at 07:24

123

10,778
2
22
45

1

nice, and if pattern is present in second file but not in first it return 0. – NeronLeVelu Jun 17 '15 at 08:24
2

It should be `file{2,1}` instead – slayedbylucifer Jun 17 '15 at 08:38
@slayedbylucifer Yes it should, sorry I didn't test it. – 123 Jun 17 '15 at 08:39

score 0 · Answer 2 · answered Jun 17 '15 at 07:22

0

This will do the trick :

while read line
do
   grep -n $line file2.txt | grep -o ^[0-9]* >> outputfileposition.txt
done < file1.txt

answered Jun 17 '15 at 07:22

blackSmith

3,054
1
20
37

compare two files and get the positions in third file in linux

2 Answers2