Compare Fields in 2 Different Files

[John.Mar]

Hi all,
I'm trying to compare between 2 files in the following manner: if a string in file 1 column 1 is found in file 2 columns 2 OR 3, then print the line from file 2 where a match was found. The catch is that I'm not looking for an exact match- I've found many solutions which solve that.
Example:

file1.txt
23
1444
223
89

file2.txt
1,23,34545
1,3223,343433
344,4345,989
12,15,632

expectedoutput.txt
1,23,34545
1,3223,343433
344,4345,899

The solutions I've found (no good) would yield the following output:

1,23,34545

A few clarifications:
1. The fields will always be numbers.
2. The values in file1 can be of any length.
3. The values in file2 can be of any length.
4. The value from file 1 which I'm searching file 2 for can be in any part of column 2 or 3- beginning, middle, or end.
5. File 1 contains roughly 50,000 values, file 2 can contain 4 million +

Thanks a lot in advance!

[rflrob]

In python, I think I'd do something like the following:

f1_name = 'file1.txt'
f2_name = 'file2.txt'
f1s = [line.strip() for line in open(f1_name)]

for line in open(f2_name):
    col2, col3 = line.strip().split(',')[1:3]
    for entry in f1s:
        if entry in col2 or entry in col3:
            print line
            break # breaks out of the inner for loop

It's not super efficient, but if you're only doing it a handful of times, probably not that bad.

[vmrosario]

bash is also an option

while read line
do
grep "$line" file2.txt
done < file1.txt

[John.Mar]

Hi all,

Thanks for the replies, I haven't tested them out yet.
I ended up using fgrep -f file1 file2
Works perfectly, I'll try the offered solutions in a bit