Reputation: 109
I have two files, each with two columns separated by a space.
I'd like to find the lines in which column 2 is not the same in both files and output them to a third file.
file A:
1 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
2 BBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
3 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
4 DDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
5 EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
6 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
7 GGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
8 HHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
file B:
1 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
2 BBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
3 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
4 DDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
5 WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
7 YYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
8 ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
9 EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
10 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
11 GGGGGGGGGGGGGGGGGGGGGGGGGGGGGG
12 HHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
desired output:
5 WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
7 YYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
8 ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
I assumed the easiest way to do this was grep
each line from file A in file B, but I'm new to bash and can't figure out the next step. Any help is greatly appreciated!
Upvotes: 0
Views: 1141
Reputation: 289505
You can use awk
for this:
$ awk 'FNR==NR {a[$1]=$2; next} $1 in a && a[$1] != $2' fileA fileB
5 WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
7 YYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
8 ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
It loops through the first file storing the values in an array a[1st col] = 2nd col
. Then, it loops through the second file and prints those lines matching these conditions:
To store it into a new file, just redirect the command to a file:
awk 'FNR==NR {a[$1]=$2; next} $1 in a && a[$1] != $2' fileA fileB > fileC
^^^^^^^
Upvotes: 5