How to compare files and pull out required data?

ldapguy · 11-10-2010, 04:28 AM

I have 2 files to compare and then print out information that match a certain pattern. I know basic scripting and was heading down the path of merging the 2 files together but this is the wrong approach. Would really appreciate a script that can do what is required:

file 1 contains dates, times and ID's:
2010-10-28 10:42 5939697357
2010-10-28 11:56 5919543491
2010-10-28 11:58 5919543491
2010-10-28 12:07 5919543491
2010-10-28 12:31 5976848509
2010-10-28 13:01 5995808867
2010-10-28 14:14 5938245291
2010-10-28 14:24 5938245291

File 2 contains just ID's:
5939697357
5919543491
5938245291

I need to compare the 2 files and print out the lines from file1 that contain any ID found in file2. I'm playing with awk and sed but cannot come up with a script.

angel115 · 11-10-2010, 04:45 AM

Try this:

Code:

#!/bin/bash

for i in `cat file2`; do
  awk "/$i/" file1
done

druuna · 11-10-2010, 04:51 AM

Hi,

Code:

#!/bin/bash

while read ids
do
  awk '$3=='$ids'' file1
done < file2

BTW: If both files are very big, this (and the previous answer #2) is not the most resource friendly way to do it.

Hope this helps.

estabroo · 11-10-2010, 04:51 AM

grep should work as well, grep -f file2 file1

ldapguy · 11-10-2010, 06:14 AM

Thanks guys for the quick reply. I've tried all 3 ways and they all work great. My files will never be too large in size, maybe 60 to 70 lines at most. Now I'll just do some testing with larger file sizes and see which one works best.

Much appreciated!!