Ed (text editor)
line-oriented text editor
ed (pronounced as distinct letters, ) is a line editor. It was one of the first features of the Unix operating system. Although not commonly used today, it remains part of the POSIX and Open Group standards, alongside the full-screen editor vi.
History
The ed text editor was one of the first three key elements of the Unix operating system—assembler, editor, and shell—developed by Ken Thompson in August 1969 on a PDP-7 at AT&T Bell Labs. Many of its features came from the qed text editor developed at Thompson's alma mater University of California, Berkeley.Thompson was very familiar with qed, and had reimplemented it on the CTSS and Multics systems. Thompson's versions of qed were notable as the first to implement regular expressions. Regular expressions are also implemented in ed, though their implementation is considerably less general than that in qed.
Dennis M. Ritchie produced what Doug McIlroy later described as the "definitive" ed, and aspects of ed went on to influence ex, and later vi. The non-interactive Unix command grep was inspired by a common special use of qed and later ed, where the command g/re/p performs a global regular expression search and prints the lines containing matches. The Unix stream editor, sed, implemented many of the scripting features of qed that were not supported by ed on Unix.
This brief starts where responsible research should: with the source description of “Ed (text editor)” as line-oriented text editor. Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the general reference register because the source frames it as line-oriented text editor. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Aug 9, 2026. The linked authority identifier is Q283992. 1 of 2 selected statements include explicit references; 1 carry qualifiers and 1 use preferred rank. The first chronological checks are 1969.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Ed (text editor)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.