sed is a Unix text processing utility. The name is short for "stream editor." Like other filters in the Unix paradigm, the input to sed is a stream of text, and the output is an edited version of that text.

sed has been branded a "power tool" and "Swiss Army Knife." While most developers don't need a stream editor on a daily basis, sed is a great tool for your automated text manipulation toolbox.

Memorizing all the capabilities and syntax details of sed can be a daunting task. But after reading this article, you will know enough to recognize when using sed is appropriate, and you'll be familiar with the features of sed that are used most often in practice. When necessary, you can return to this article for a refresher on the more advanced features of the tool.

See my Object Computing (OCI) article That's What I SED.