Pipe output to use as the search specification for grep on Linux

Question

How do I pipe the output of grep as the search pattern for another grep?

As an example:

grep   | xargs grep          


        

Answer 1

This is what I use to search for a file from a listing:

ls -la | grep 'file-in-which-to-search'

Answer 2

I tried this way , and it works great.

[opuser@vjmachine abc]$ cat a
not problem
all
problem
first
not to get
read problem
read not problem

[opuser@vjmachine abc]$ cat b
not problem xxy
problem abcd
read problem werwer
read not problem  98989
123 not problem 345
345 problem tyu

[opuser@vjmachine abc]$ grep -e "`grep problem a`" b --col
not problem xxy
problem abcd
read problem werwer
read not problem  98989
123 not problem 345
345 problem tyu

[opuser@vjmachine abc]$ 

Answer 3

I have found the following command to work using $() with my first command inside the parenthesis to have the shell execute it first.

grep $(dig +short) file

I use this to look through files for an IP address when I am given a host name.