How do I delete lines of 1st file if it matches the string present in the 2nd file in linux?

Question

Consider I have two text files.

First File name - "Emails.txt" with the following data:

[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]

Second text file - "Banned.txt" with the following strings:

@gotmail.com
@cmail.com
@uor.edu

How to delete all the lines in the 1st text file "Emails.txt" if it matches the stings of any line present in the second text file "Banned.txt"?

The desired output of the new file should be:

[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]

Can this be done using SED or awk in Linux? Can you please suggest how to do this?

Answer 1

grep -v is enough. The flag -f allows you to do exactly what you want:

grep -vf Banned.txt Emails.txt

If you want to do something more complicated out of the list of banned addresses, e.g. impose that they match the whole of the domain, you'll need to generate a regex from your Banned file:

cat Banned.txt | tr "\n" "|" | sed -e 's,|,$\\|,g' | sed -e 's,\\|$,,'

gives the desired

@gotmail.com$\|@cmail.com$\|@uor.edu$

Then:

cat Banned.txt | tr "\n" "|" | sed -e 's,|,$\\\\|,g' | sed -e 's,\\|$,,' | xargs -i grep -v '{}' Emails.txt

(doubling the number of escapes \ as they're being evaluated when going through xargs). This will match and remove [email protected] but not e.g. [email protected].