This is a shell script that will pull 5 random characters from /dev/random and print them out to standard output. It was created as the input component for a random password generator that I am currently writing.
Note on using /dev/random: as usual, using this source for entropy will give you pure randomness, though due to the nature of the random source (see Wikipedia entry on /dev/random) the script may sometimes lock up and fail to generate a complete output, as it has run out of randomness. If you are intending to use this alot, then it is advised to use /dev/urandom that doesn’t block, although that comes at the cost of a small bit of entropy.
#!/bin/bash # Script for pulling x characters from a random source # and prints them out to stdout # Version 1.0.0 # By Simon Cook (https://simoncook.org) # Fill in the two variables below # "entropy" is the source of randomness # "chars" is the number of chars we want entropy=/dev/random chars=5 # Pull x characters from source i=0 while read -r -n1 char do echo -n "$char" (( i++ )) if [ "$i" -eq "$chars" ]; then echo "" exit 0 fi done < "$entropy"
Licensing: This small script is released under the CC-GNU GPL licence.
.