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Like when you do brew install wget or mysqld restart I want some lines of information constantly run through my terminal window. Is there maybe something I can monitor or any stream of information I can jump in? Is it maybe possible to watch the activity monitor processes in the terminal?

Why would I want to have that? Because it looks super cool when you have that Matrix-like code running over your monitor. And I could need that for some home movie scenes.

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Matrix-like (aka top down) or similar to brew (horizontally) are two different things, what exactly are you looking for? And did you already ask the mighty Google for an answer? – patrix Aug 6 '13 at 15:33
Quite different, you are right! Now that I looked at it again, Matrix-like does much more look like a toy or a screensaver than a productive tool running. Homebrew-like would be much better. I found some kid's tutorials on youtube about how to let random numbers run thorugh the terminal but that doesn't look very professional. – leymannx Aug 6 '13 at 15:56
Download source code of a major program and compile it in your terminal, that would "look" professional, anything else is pretty much just noise unless it's useful output like watching some logs (as @Matteo suggests). Of course, compiling also takes major resources. – nerdwaller Aug 6 '13 at 16:52
up vote 5 down vote accepted

Pulling ideas from this Q&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:


while IFS= read -r line; do
    for (( offset = 0 ; offset < length ; offset++ )); do
        printf '%s' "$char"
        if (( bol )) && [[ "$char" == " " ]]; then
        sleep 0.05

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

    printf '\n'

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.

tr -c "[:digit:]" " " < /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
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If you have some files that are growing you can use tail -f. For example

 $ tail -f /var/log/system.log

There are several terminal tools similar to activity monitor, for example top (delivered with OS X) and htop (you will have to install it with MacPorts or Homebrew).

You could also download the sources of a large software package (e.g., gcc, OpenOffice) and then compile it. This will usually generate a lot of output on the console.

You could also generate huge directory listings

$ ls -lRt

or find (the second one will delay each line by one second)

$ find .
$ find . -print -exec sleep 1 \;
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top is quite nice, some characters are constantly changing. But has no lines runnning over the screen. Downloading sources, I find it's too much data for only fun. – leymannx Aug 6 '13 at 16:00
Combine a cat /var/log/system.log with a pipe to the slow type script below and you'd have a nice, continuous flow of Terminal output. – Ian C. Aug 6 '13 at 23:36

The matrix command:

od -c /dev/random

Read carefully, at a given time you will see the secret key.

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Something like

while sleep 1; do
    t=$(( RANDOM % 80 ))
    for ((i=0; i < $t; i++)); do
        echo -n '*'
        sleep 1

might do the trick. Change the length of the sleeps for different speeds and replace the * with whatever you want (even $(( RANDOM % 10 )) for varying numbers).

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You can try tcpdump in Terminal. It lists the connections your computer makes through the active network interfaces. When you're having any network activity it will show running data on the screen.

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