Editing Sed (section)

==History==
First appearing in [[Version 7 Unix]],{{r|reader}} sed is one of the early Unix commands built for command line processing of data files. It evolved as the natural successor to the popular [[grep]] command.<ref name=early_history>
{{cite web
| title = On the Early History and Impact of Unix
| url = http://www.columbia.edu/~rh120/ch001j.c11
| quote = "A while later a demand arose for another special-purpose program, gres, for substitution: g/re/s. Lee McMahon undertook to write it, and soon foresaw that there would be no end to the family: g/re/d, g/re/a, etc. As his concept developed it became sed…"
}}
</ref> The original motivation was an analogue of grep (g/re/p) for substitution, hence "g/re/s".<ref name="reader">{{cite tech report |first1=M. D. |last1=McIlroy |author-link1=Doug McIlroy |year=1987 |url=http://www.cs.dartmouth.edu/~doug/reader.pdf |title=A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 |series=CSTR |number=139 |institution=Bell Labs}}</ref> Foreseeing that further special-purpose programs for each command would also arise, such as g/re/d, McMahon wrote a general-purpose line-oriented stream editor, which became sed.<ref name=early_history /> The syntax for sed, notably the use of <code>/</code> for [[pattern matching]], and <code>s///</code> for substitution, originated with [[ed (text editor)|ed]], the precursor to sed, which was in common use at the time,<ref name=early_history /> and the regular expression syntax has influenced other languages, notably [[ECMAScript]] and [[Perl]]. Later, the more powerful language [[AWK]] developed, and these functioned as cousins, allowing powerful text processing to be done by [[shell script]]s. sed and AWK are often cited as progenitors and inspiration for Perl, and influenced Perl's syntax and semantics, notably in the matching and substitution operators.

[[GNU]] sed added several new features, including [[#In-place editing|in-place editing]] of files. ''Super-sed'' is an extended version of sed that includes regular expressions compatible with [[Perl]]. Another variant of sed is ''minised'', originally reverse-engineered from 4.1BSD sed by [[Eric S. Raymond]] and currently maintained by [[René Rebe]]. minised was used by the [[GNU Project]] until the GNU Project wrote a new version of sed based on the new GNU regular expression library. The current minised contains some extensions to BSD sed but is not as [[feature-rich]] as GNU sed. Its advantage is that it is very fast and uses little memory. It is used on embedded systems and is the version of sed provided with [[Minix]].<ref>{{Cite web |last1=Raymond |first1=Eric Steven |author-link1=Eric S. Raymond |last2=Rebe |first2=René |author-link2=René Rebe |date=2017-03-03 |title=tar-mirror/minised: A smaller, cheaper, faster SED implementation |url=https://github.com/tar-mirror/minised |url-status=live |archive-url=https://web.archive.org/web/20180613031040/https://github.com/tar-mirror/minised |archive-date=2018-06-13 |access-date=2024-05-20 |website=[[GitHub]]}}</ref>