to grep 100 letters out of 500 letters on certain criteria

I am having file containing 500 letters sorted on the basis of serial numbers. Now I want to grep 100 letters for which serial numbers are saved in other file. Is it possible to get the letters of these 100 numbers only using any option .

Write a script that reads the list of numbers to look for one at at time. Feed each one at a time to grep to search in other list.

May even help if you provided examples, but grep has the option to read from a file for its patterns

Originally Posted by l_ravi69 I am having file containing 500 letters sorted on the basis of serial numbers. Now I want to grep 100 letters for which serial numbers are saved in other file. Is it possible to get the letters of these 100 numbers only using any option .

The letters are all in one file. What distinguishes the beginning and end of each letter? Is the relevant serial number prefixed to every line in each letter?

Daniel B. Martin