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In page Unix shell:

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The first Unix shell was the Thompson shell, sh, written by Ken Thompson at Bell Labs and distributed with Versions 1 through 6 of Unix, from 1971 to 1975.[1] Though rudimentary by modern standards, it introduced many of the basic features common to all later Unix shells, including piping, simple control structures using if and goto, and filename GLOBbing. Though not in current use, it is still available as part of some Ancient UNIX systems and is the default shell on current FreeBSD systems.[citation needed]