For example, there is the tilde, ~, which represents your starting folder. Type cd ~ / documents changes to the Documents folder in the current user 's home directory, which prevents me from typing / Users / justinpot / Documents each time. This is a practical shortcut, of course, but why is this particular character used?
Believe it or not, this is because of a 1970s keyboard. Here is a Lear Siegler ADM-3A terminal, first shipped in 1975.
It was a "silent terminal", which meant that it was not a computer per se, but that it allowed you to enter commands and display data from a computer. The ADM-3A was only $ 995, which is considered a good price at the time, which means that institutions could purchase multiple terminals of this type to connect to a central computer. To date, modern terminal emulators, such as those used in Linux and MacOS, mimic the functionality of these systems.
This is a piece of extremely influential material; a lot of early software development came on, which means that the layout of the keyboard influenced some design choices. Discover it:
Do you notice something? Here is a clearer picture.
See the key at the top right? This is the HOME key, which acts similarly to the Home key on the modern keyboards, placing the cursor at the top left when editing the text. This is also the key used for the tilde symbol: ~. This association was sufficient to represent the personal files.
This is true: a specific keyboard of over forty years ago is the reason why Linux and UNIX systems use ~ to represent the house, even though the ~ and Home keys could not not be separated on most modern keyboards. Bizarre, is not it?
And there are other hidden details in this keyboard. See the arrows on the H, J, K and L keys? By holding down the Control key and pressing these keys, you move the cursor to Terminal, which is why these keys are used to move the cursor in . These keyboard shortcuts vi have in turn inspired keyboard shortcuts of Twitter and even Facebook . This is true: even the Facebook keyboard shortcuts were inspired by a "silent terminal" sold for the first time in 1975.
Look more and you will notice some keys that you do not recognize at all. There is the key "Here Is", which the blogger Dave Cheney explains here . Basically, it confirmed who you are on the network. You will also see that the Escape key is places where Caps Lock is on modern keyboards, which sets the key MacBook Key Escape Key Controversy in a new light. I am sure that there are many other details I miss.
A device that you have never heard of influences the design decisions used by software users, who use it even more than forty years later. The story is not strange?