Debian's which hunt

The original motivation for ‘which’ was the original C shell not having any equivalent built-in functionality, so somebody hacked together a C shell script that not only found a relevant program in the search path, but also checked if a command was aliased to anything, since C shell had an unfortunate misfeature of executing its initialization files even when you ran such script non-interactively. Seriously, look at this:

https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/whi...

When people switched to other, better shells, they kept using ‘which’ and even worse – passed this “knowledge” to other, younger users who promptly started using ‘which’ themselves, and at this point a major feature of it was lost, since the script didn’t care about any aliases defined in any shell other than the C shell. And since people mostly learn *n?x based on a hearsay, not reading the documentation*, usage of ‘which’ persists to this day and people don’t learn about better alternatives.

* Cannot blame them, honestly. When MS-DOS 6.0, released in 1993 had nice, interactive and hyperlinked help system that allowed me to learn DOS to an advanced degree in a year back when I was only a small child, Linux and BSDs have still mostly only inconvenient, horrible to use man pages which were designed originally to be printed physically as a book, but are terribly inadequate for an interactive on-screen usage. Sure, there is also GNU Texinfo, but most people don’t know about it – because “all documentation is in the man pages” is another incorrect knowledge passed down by generations – and its default command line viewer has an outdated, unergonomical, contrary to people’s expectations user interface.

‘Which’ is not the only C-shellism that managed to unfortunately persist to this day. Every time you see people recommending other people to learn some magic incantation like ‘sudo !@#$%^&’, you see another case of it. Back when C shell was in the widespread use, no shell actually implemented interactive command line editing or interactive history recall and search, so this was the only option to reexecute a previous command with some modification, and in fact a major selling point of the C shell. Today, it’s basically pointless, requiring bigger cognitive load, more prone to mistakes (especially those of the catastrophic kind), and in most typical cases, doesn’t even save any keystroke – for example, S U D O SPACE ! ! ENTER has the same amount of them as ↑ HOME S U D O SPACE ENTER. But the second one is much more intuitive.