The Whirlwind computer at MIT was the first "real-time" computer, and arguably the FirstGraphicalUserInterface. But there was apparently no keyboard connected to it. So what was the first CommandLineInterface?
The VannevarBush -> DougEngelbart (XeroxParc) -> Mac/Windows/KDE/GNOME+ history of GraphicalUserInterfaces is so well known, it seemed odd that the first instance of a CLI interface goes unremarked in so many websites on computer history.
GeneralElectric's Multics was the first shell [http://www.multicians.org/shell.html]
Interactions with mainframe systems via a console typewriter would fall under the CLI classification. How far before the CDC 1604 does the console typewriter go back?
When did people first edit and move files by command line as a matter of course?
There was interactive control of computer systems long before there were random access files, which this definition implies a need for. Do commands to rewind, mount, and unload tape files count?
Sure, for the "move" part of "edited and moved." But obviously the "files" bit is a red herring. We're not talking about interactive control, we're talking about a command line. Text in front of user's eyes, user types a command, hits return/enter/whatever, new text appears perhaps showing results of command.
1960s
People were using PDP-8s at home long before the Altair. In fact, Xerox PARC had personal computers with mice and windows on ethernets with file servers and laser printers before the Altair. Unix predates CP/M, and Unix was preceded by a lot of time-sharing operating systems, each of which had a command line interface.