What does grep stand for, and the 75 year history of the regular expression
The article discusses the origins and history of the command 'grep', which stands for g/re/p, a command used in Unix for searching text. It traces back to Stephen Kleene's 1951 work on regular expressions and highlights Ken Thompson's implementation of this notation in the 1960s. The name 'grep' has persisted over the decades, reflecting its foundational role in text processing.
- ▪Grep is short for g/re/p, which means globally search for a regular expression and print every matching line.
- ▪The concept of regular expressions originated from Stephen Kleene's 1951 RAND memo.
- ▪Ken Thompson implemented regex notation in the 1960s, leading to the creation of the grep command in 1973.
Opening excerpt (first ~120 words) tap to expand
← Blog·22 May 2026·Updated 23 May 2026·6 min readWhat does grep stand for, and the seventy-five-year history of the regular expressiongrep is short for g/re/p — the ed command syntax for global regular expression print. Regular expressions themselves go back to a 1951 RAND memo by Stephen Kleene. The thirty-year flavour war is a footnote to the original math.✦AI-assisted postDrafted with help from Claude, edited and fact-checked by Mart. See transparency policy →#regex#history#unixJoe Condon and Ken Thompson working on Belle, 1977 — picture courtesy of Bell Laboratories.
…
Excerpt limited to ~120 words for fair-use compliance. The full article is at Hacker News (Newest).
Discussion
0 commentsMore from Hacker News (Newest)
