Technical Terms and Definitions

SED - Programming

SED stands for Stream EDitor. Sed is a non-interactive editor, written by the late Lee E. McMahon in 1973 or 1974. A brief history of sed's origins may be found in an early history of the Unix tools, at .

Instead of the user altering a file interactively by moving the cursor on the screen (like with Word Perfect), the user sends a script of editing instructions to sed, plus the name of the file to edit (or the text to be edited may come as output from a pipe). In this sense, sed works like a filter -- deleting, inserting and changing characters, words, and lines of text. Its range of activity goes from small, simple changes to very complex ones.

Sed reads its input from stdin (Unix shorthand for "standard input," i.e., the console) or from files (or both), and sends the results to stdout ("standard output," normally the console or screen). Most people use sed first for its substitution features. Sed is often used as a find-and-replace tool.