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continuously print string as if being entered from the keyboard

Terminal - continuously print string as if being entered from the keyboard
cycle(){ while :;do((i++));echo -n "${3:$(($i%${#3})):1}";sleep .$(($RANDOM%$2+$1));done;}
2010-10-08 23:45:40
User: putnamhill
Functions: echo sleep
continuously print string as if being entered from the keyboard

Cycles continuously through a string printing each character with a random delay less than 1 second. First parameter is min, 2nd is max. Example: 1 3 means sleep random .1 to .3. Experiment with different values. The 3rd parameter is the string. The sleep will help with battery life/power consumption.

cycle 1 3 $(openssl rand 100 | xxd -p)

Fans of "The Shining" might get a kick out of this:

cycle 1 4 ' All work and no play makes Jack a dull boy.'


There is 1 alternative - vote for the best!

Terminal - Alternatives
cat /dev/urandom | hexdump -C | grep "ca fe"
2010-09-27 08:20:44
Functions: cat grep hexdump

just make some data scrolling off the terminal. wow.

j=0;while true; do let j=$j+1; for i in $(seq 0 20 100); do echo $i;sleep 1; done | dialog --gauge "Install part $j : `sed $(perl -e "print int rand(99999)")"q;d" /usr/share/dict/words`" 6 40;done
2010-10-08 12:12:00
User: houghi
Functions: echo seq sleep

This will turn it in an infinite loop and also shows random words from a file, so it won't be the same each time and also not just a number.

for i in `seq 0 100`;do timeout 6 dialog --gauge "Install..." 6 40 "$i";done
2010-09-28 06:38:20
User: javisol

The first parameter after timeout is the key parameter; number of seconds to wait. With a 6 you have 600 seconds for your coffee break (10min).

for i in {0..600}; do echo $i; sleep 1; done | dialog --gauge "Install..." 6 40
2010-10-05 02:29:23
User: dennisw
Functions: echo sleep

Dialog's gauge widget accepts progress updates on stdin. This version runs dialog once and updates it every second.

There's no need to use timeout which causes screen flicker since it restarts dialog for each update.

while [ true ]; do head -n 100 /dev/urandom; sleep .1; done | hexdump -C | grep "ca fe"

Know a better way?

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What others think

Hello !

Please, can somebody explain to me how does this expression "${3:$(($i%${#3})):1}" work ?

Comment by JisSey 226 weeks and 5 days ago

ok I got it now ;)

{array:position:number of element to get}

array=3 is a substitution for $3 (the 3rd parameter) when using the function call

i%array_length is a loop cylcling between the vallues 0,1,2,3...,(array_length - 1)

I have improved a bit the function by initializing the iterative variable so the printing can start from the first letter of the sentence =>

cycle(){i=$((${#3}-1));while :;do((i++));echo -n "${3:$(($i%${#3})):1}";sleep .$(($RANDOM%$2+$1));done;}

Comment by JisSey 226 weeks and 5 days ago

Your point of view

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