I have found a nice method of searching randomly generated data for certain words. This takes a while but can bear fruit in the end.
Here is an example, this is searching through the /dev/urandom file and then finding an instance of the word “linux”.
jason@jason-Lenovo-H50-55:~$ time tr -cd [:lower:] < /dev/urandom | fold -w 6 | nl | grep -m1 "linux" 14875225 llinux real 0m5.554s user 0m6.689s sys 0m4.276s |
This is like having a million monkeys on typewriters. But the longer the word you are looking for, the longer it would take to find it. A word like “moderation” would take far longer to find. I am not sure of the use this could be put to, but it is interesting nonetheless.
Finding 4 letter words is very fast, but longer words take an exponentially longer time to find.
jason@jason-Lenovo-H50-55:~$ time tr -cd [:lower:] < /dev/urandom | fold -w 15 | nl | grep -m1 "unix" 77595 kpunixxylldvaxk real 0m0.084s user 0m0.047s sys 0m0.089s jason@jason-Lenovo-H50-55:~$ time tr -cd [:lower:] < /dev/urandom | fold -w 15 | nl | grep -m1 "unix" 10175 xounixvzdapwafx real 0m0.022s user 0m0.030s sys 0m0.008s jason@jason-Lenovo-H50-55:~$ time tr -cd [:lower:] < /dev/urandom | fold -w 6 | nl | grep -m1 "unix" 4783 ununix real 0m0.011s user 0m0.012s sys 0m0.011s jason@jason-Lenovo-H50-55:~$ time tr -cd [:lower:] < /dev/urandom | fold -w 6 | nl | grep -m1 "unix" 27357 zdunix real 0m0.023s user 0m0.023s sys 0m0.022s |
This example took quite a while, but it did work in the end.
jason@jason-Lenovo-H50-55:~$ WORD="multix"; time tr -cd [:lower:] < /dev/urandom | fold -w 6 | nl | grep -m1 "$WORD" | sed 's/\b$WORD\b//g' 183394705 multix real 1m8.419s user 1m22.998s sys 0m52.960s |
This is another version, this is improved over the others.
jason@jason-Lenovo-H50-55:~$ WORD="apple"; time tr -cd [:lower:] < /dev/urandom | fold -w ${#WORD} | nl | grep -m1 "$WORD" | sed 's/\b$WORD\b//g' 36504080 apple real 0m11.320s user 0m14.958s sys 0m8.519s |
This section of the one-liner: fold -w ${#WORD} gets the length of the $WORD variable in chars and then this sets the final length of the output. That is a very useful trick when using bash scripting.