[em500]

> What command-line programming language interpreters are left when those are removed?

zsh/bash/ksh93, tcsh, awk, sqlite3, elisp (assuming emacs survives for now) and javascript console. I don't know why you'd want to limit things to pre-installed command line interpreters though.

> You have the shell itself, but that’s hardly enough to write anything cool.

What kind of cool things do you envision the curious beginner to write, using only the current preinstalled Python/Ruby/perl, that they can't do with the remaining interpreters that I mentioned?

[TimTheTinker]

> What kind of cool things do you envision the curious beginner to write, using only the current preinstalled Python/Ruby/perl, that they can't do with the remaining interpreters that I mentioned?

What about the iconic 4th grader "greetings and cool things" script? Here's something like what it looked like for me (on the IBM PC in my classroom):

    5 CLS
    7 RANDOMIZE TIMER
    10 PRINT "Hello there. I'm a computer. What is your name?"
    20 INPUT G$
    30 PRINT "Hello "+G$+". You are welcome to computer land."
    40 PRINT "What would you like to do today?"
    50 PRINT "1) Make noises"
    60 PRINT "2) Make a maze"
    70 PRINT "3) Exit"
    80 PRINT "Enter your selection:"
    100 INPUT S$
    110 IF S$="1" GOTO 200
    120 IF S$="2" GOTO 300
    130 IF S$="3" GOTO 400
    140 PRINT "Try again."
    150 GOTO 40
    200 SOUND 20+(RND*20000), RND*3
    210 GOTO 200
    300 SCREEN 1
    310 IF RND>.5 THEN PRINT "/"; ELSE PRINT "\";
    320 GOTO 310
    400 PRINT "Bye."

That kind of stuff is perfect for Ruby and Python. I don't envision kids getting that far with shell scripts, awk, sqlite3, or elisp. They might with HTML and JavaScript, but that requires learning HTML as well as JS and is sandboxed in the web browser; it's also not as "Cool! Look what I can make the computer do!" as messing around in the terminal. (Note, I’m glad BASIC isn't as available anymore -- we're not getting kids into certain bad programming habits early-on, like use of GOTO. But BASIC would still be more approachable than shell scripting, awk, etc.)

[em500]

    clear
    echo "Hello there. I'm a computer. What's your name?"
    read G
    echo "Hello $G. You are welcome to computer land."

    while true
    do
    echo ""
    echo "What would you like to do today?"
    echo "1) Say something random"
    echo "2) Make a maze"
    echo "3) Exit"
    echo "Enter your selection"
    read S
      if [ "$S" = "1" ]; then
        say $( head -n $((7*RANDOM)) /usr/share/dict/words | tail -n 1 )
      elif [ "$S" = "2" ]; then
        for i in {1..3000}; do
          if (($RANDOM>16384)); then printf '/'; else printf '\'; fi
        done
      elif [ "$S" = "3" ]; then
        echo "Bye."
        exit 
      else 
        echo "Try again." 
      fi
    done

This doesn't seem much different than the BASIC example to me. I think only the lack of GOTO in shell scripts makes this look slightly more complicated (requiring either putting all the statements in the if ... elif parts or defining functions).

I honestly don't see how a Python or Ruby version would be much better than a shell version for this. Perhaps you can show by example?

[TimTheTinker]

You do have a point - that's not too bad, but to my eyes it's still more arcane than Python and Ruby (spoken as someone who has written less than 30 shell scripts in my life).

I still contend that Ruby and Python are far more accessible than shell scripting, because they are very popular, especially Python, cross-platform, and less arcane.

[em500]

For my own curiosity I did the simplest Python version I could think of to see how it would compare:

    import os
    import random
    import sys
    
    os.system("clear")
    print "Hello there. I'm a computer. What's your name?"
    G = raw_input()
    print "Hello " + G + ". You are welcome to computer land."
  
    while True:
        print ""
        print "What would you like to do today?"
        print "1) Say something random"
        print "2) Make a maze"
        print "3) Exit"
        print "Enter your selection"
        S = raw_input()
        if S == "1":
            F = open("/usr/share/dict/words").readlines()
            W = random.choice(F)
            os.system("say {}".format(W))
        elif S == "2":
            for i in range(1, 3000):
                if random.random()>0.5:
                    sys.stdout.write("/")
                else: 
                    sys.stdout.write("\\")
        elif S == "3":
            print "Bye."
            exit()
        else:
            print "Try again."

It looks like a tossup to me, all 3 versions have their own share of magic that will confuse the beginner. I say this as someone who reads and writes a lot more python than bash daily.

[TimTheTinker]

Another of my favorites -- this was fun in middle school (years 6-8) when I had a spare minute or two to sit down at a random computer (maybe in a computer lab).

    10 SCREEN 9
    20 CLS
    30 COLOR 1, INT(RND*10)
    40 SOUND 20+(RND*5000),.2
    50 GOTO 30

The effect is rather striking, like someone must have really messed up the computer.

My main gripe with Windows NT was that it would go back to the NT screen saver -- I couldn't get it to stay displaying my program, because there wasn't any true DOS mode.

[em500]

How would you do this on macOS with just the built-in Python or Ruby?

[TimTheTinker]

I have no idea... I just wanted to share something fun I did around 25 years ago.