Shell Programming and Scripting

Hi,
Need one more help

We have 2 file which we need to compare
First file data.txt has data like

223300
440066


and second file ref.txt has
223300|abcd
223456|rtye
5423890|uytr
440066|uiyu

I need to compare these 2 file and the output should be
223300|abcd
440066|uiyu


basically all the data in data.txt file which has matching records in ref.txt should be listed

Please help

Code:

$ cat comp1.txt
223300
440066
 
$ cat comp2.txt
223300|abcd
223456|rtye
5423890|uytr
440066|uiyu
 
$ grep -f comp1.txt comp2.txt
223300|abcd
440066|uiyu

THe problem here is that the files to be compared are huge.
One has data in range of 2 million and another has 30 million records
Please let me know a fast way of comparing these two files

In that case you could try the join command. But make sure the input files are sorted on the "index" key first.

Code:

sort flie1 > file1.srt
sort file2 > file2.srt
join -t '|' -j 1 file1.srt file2.srt

I agree with Whiteboard, but I would use fgrep instead of grep. It's faster.

Use fgrep -f to do it -- it's very fast.