How should Implementation of Pipeline and Tail command be done in C language?

Question

How do I write a C program that implements the following commands:

tail -5 /etc/passwd | grep e | sort  > result.txt

What should the C program contain? How should r_read and r_write be implemented in the C program?

Answer 1

coreutils are opensource so you can read their sources. Here's a link where you can find sources to coreutils http://git.savannah.gnu.org/cgit/coreutils.git/tree/src