How can I search for keywords using logical AND conditions in files on Ubuntu?

Question

I've been trying to search for multiple keyword in my Ubuntu files. I know how to do it for one file :

find /[myRep] -type f | xargs grep -rl "myFunction"

I wanted to do it for two keywords, such as myFunction and myClass , to get all the files that can instantiate myFunction in myClass .

I tryed to use :

find /[myRep] -type f | xargs grep -rl "myFunction" | xargs grep -rl "myClass"

I get results, but I'm not sure if this is accurate. Plus, I wonder if there is a simple way to add more logical conditions in the search, such as "OR", or "NOT" commands ...

Answer 1

Use Regex Alternation for Logical OR Conditions

If you're trying to find files that contain either "myFunction" or "myClass", you could use an extended regular expression with alternation For example:

# Using GNU Find and GNU Grep
find . exec grep --extended-regexp --files-with-matches 'myFunction|myClass' {} +

When passed a list of files to grep, this will show you matching files that contain either word.

Logical AND is Trickier

A logical AND is trickier because you have to account for ordering. You can either:

1. Filter files on one set of requirements, then the other.
2. Use a more full-feature program where you can store state.

As a trivial example of the first case:

# Use nulls to separate filenames for safety.
find /etc/passwd -print0 |
    xargs -0 egrep -Zl root |
    xargs -0 egrep -Zl www

As a contrived example of the second case, you could use GNU awk:

# Print name of current file if it matches both alternates
# on different lines.
find /etc/passwd -print0 |
    xargs -0 awk 'BEGIN {matches=0};
                  /root|www/ {matches+=1};
                  matches >= 2 {print FILENAME; matches=0; nextfile}'

Answer 2

Your command looks fine to me. You first grep all files to find those which contain "myFunction" and then pass them through another grep for "myClass". As a result, you will end up with files containing both "myFunction" and "myClass".