How to produce constant output in a Terminal window?
Pulling ideas from this unix.stackexchange.com Q&amp;A about generating "hollywood" style terminal output.

The Slow Type

This script produces that delayed typing like effect you see in movies. Where the computer prints things in the terminal at some really awful and slow rate.

Save the following to a file named hollywood:

#!/bin/bash

while IFS= read -r line; do
    length="${#line}"
    bol=1
    for (( offset = 0 ; offset &lt; length ; offset++ )); do
        char="${line:offset:1}"
        printf '%s' "$char"
        if (( bol )) &amp;&amp; [[ "$char" == " " ]]; then
            continue
        fi
        bol=0
        sleep 0.05
    done

    if (( length == 0 )); then
        sleep 0.$(( RANDOM % 3 + 2 ))
    else
        sleep 0.$(( RANDOM % 7 + 3 ))
    fi

    printf '\n'
done


Set execute permissions on the file hollywood:

chmod +x hollywood


And then pipe it the output from dmesg to give it a large chunk of snazzy looking text to slowly print on the screen:

dmesg | hollywood


The Hex Dump

This dumps hex data to the screen. Looks impressive but is largely unintelligible to the masses.

hexdump -C /dev/urandom | GREP_COLOR='1;32' grep --color=auto 'ca fe'


The Matrix

Numbers. Numbers everywhere.

LC_CTYPE=C tr -c "[:digit:]" " " &lt; /dev/urandom | dd cbs=$COLUMNS conv=unblock | GREP_COLOR="1;32" grep --color "[^ ]"


Unfortunately, with that one there isn't a good way to control the speed.

There's a better version of this available view Homebrew called cmatrix. You can install and run it with:

brew install cmatrix
cmatrix