Concepts of filters, pipes, and redirection

During the initial setup and implementation of the Web site, you have been reviewing some of the documentation, scripts, and sample files that were installed on the Linux and Apache environment. In more than one place, you have noticed several familiar commands, but they have all been on one line. The ability of one command to send the output it generates to the input of a second command is a very important concept for the UNIX environment.


Describe the concepts of filters, pipes, and redirection and explain how and what the following commands are trying to accomplish (if some commands are not yet familiar, you can describe the overall process of each step):


ls /etc | grep conf | grep -v “/.” | sort > ~/conf

cat /etc/passwd | awk -F”:” ‘{print $1}’ | sort >> ~/users 2>&1


The deliverable for the assignment should include the following:


Description of filters (including the 3 standard files every filter uses)Description of pipesDescription of redirectionExplanation of the 2 commands above