Replicating Bell Labs 1982 demo of a spell checker and talking calculator - https://youtu.be/XvDZLjaCJuw

spell_check_and_talking_calc.sh

#!/bin/bash
#
#  Replicating Kernighan's spell checker demo (https://youtu.be/XvDZLjaCJuw?t=315)
#  and Lorinda Cherry's talking calculator (https://youtu.be/XvDZLjaCJuw?t=800)
#  from the 1982 Bell Labs UNIX video
#
#  Tested with Python 2.7 on Mac and Linux; your mileage may vary with Python 3.
#    - You will need to 'pip install --user inflect' for the calculator part.
#    - On Linux, you will need to install the 'flite' package for your distro.
#

ln -s /usr/share/dict/words dict
alias p='cat'

makewords() {
    [ -t 0 ] && local infile=$1
    eval "${infile:+cat '$infile' |} tr -cd  'A-Za-z\\n ' | tr ' ' '\\n'"
}

lowercase() {
    [ -t 0 ] && local infile=$1
    eval "${infile:+cat '$infile' |} tr A-Z a-z"
}

unique() { uniq "$@"; }

mismatch() {
    diff "${1:--}" "${2:-dict}" | sed -n 's/^< \(.*\)/\1/p'
}

# [sic]
echo "At Bell Labortories
UNIX systems privide
more timesharing ports
than all other systems
combined" > sentence

p sentence

makewords sentence >words
p words

lowercase words >lcwords
p lcwords

sort lcwords >sortedwords
p sortedwords

unique sortedwords >uniquewords
p uniquewords

mismatch uniquewords dict

# Lorinda Cherry's demo of pipes / stream processing
makewords sentence | lowercase | sort | unique | mismatch

# make a script 'check' incorporating the functions above
set +o histexpand
echo "#!/bin/bash
$(declare -f makewords)
$(declare -f lowercase)
$(declare -f unique)
$(declare -f mismatch)
makewords \"\$1\" | lowercase | sort | unique | mismatch" >check
chmod a+x check

./check sentence

# desk calculator; turn numbers into English, then speak
speak() {
    if [ $(uname -s) = "Darwin" ]; then
        # for different voices on macOS try 'say -v ?'
        if test -t 0; then say "$*"; else say; fi
    else
        # 'flite' wants input on stdin
        if test -t 0; then flite <<<"$*"; else flite; fi
    fi
}

# source: https://stackoverflow.com/a/25026089/785213
# hat tip: https://stackoverflow.com/q/965210
# hat tip: https://stackoverflow.com/a/30091579/785213
number() {
    python -c '
import sys, inflect
i=inflect.engine()
try:
    print(
        i.number_to_words(
            sys.argv[1] if sys.stdin.isatty()
            else sys.stdin.readline()
        )
    )
# catch BrokenPipeError exceptions
except Exception as e:
    pass
' "$@"
}

# Bell Labs' Lorinda Cherry - talking calculator demo from 1982
# see: https://youtu.be/XvDZLjaCJuw?t=800
dc | number | speak
8 3-p
q

# make a script 'talkcalc'
set +o histexpand
echo "#!/bin/bash
$(declare -f speak)
$(declare -f number)
dc \"\$@\" | number | speak" >talkcalc
chmod a+x talkcalck

./talkcalc
2 100^p
q

# rm sentence words lcwords sortedwords uniquewords dict check talkcalc

Since dc reads from standard input, you can send input from a pipe as well:

echo "2 100^p" | dc | number | speak

(dc is an RPN calculator, and p is for "print," in case that wasn't obvious)