Unix utility SED provides an effective and versatile way of deleting one or more lines from a designated file to match the needs of the user. This Unix command is used for command line processing.

A key point to these tools (from a practical point ) is that they are very memory efficient and allow work on just a "line".

Wow. It’s amazing we ever made it out of the 20th century. It’s like reading about farmers who would plow by hand. I remember the epiphany (long time ago) of discovering how awk solved my problem of ...