# Regular expression > 정규표현식 정규표현식 ## History > The seeds of regular expressions were planted in the early [1940s](https://wiki.g15e.com/pages/1940s.txt) by two neuro-physiologists, and , who developed models of how they believed the worked at the level. Regular expressions became a reality several years later when mathematician formally described these models in an algebra he called . He devised a simple notation to express these regular sets, and called them regular expressions. > > Through the [1950s](https://wiki.g15e.com/pages/1950s.txt) and [1960s](https://wiki.g15e.com/pages/1960s.txt), regular expressions enjoyed a rich study in theoretical mathematics circles. has written a good summary for the mathematically inclined. > > Although there is evidence of earlier work, the first published computational use of regular expressions I have actually been able to find is 's <1968> article "Regular Expression Search Algorithm" in which he describes a regular-expression compiler that produced object code. This led to his work on , an editor that formed the basis for the editor . > > 's regular expressions were not as advanced as those in , but they were the first to gain widespread use in non-technical fields. had a command to display lines of the edited file that matched a given regular expression. The command, `g/Regular Expression/p`, was read "Global Regular Expression Print." This particular function was so useful that it was made into its own utility, (after which - extended grep - was later modeled). --Chapter 3, ## Tools - https://www.debuggex.com/ - 정규식을 유사한 형태로 시각화.