Random number generator commandfu

random.txt

# Method 1
cat /dev/random | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 5

tr => translate/delete input stream
  -d => delete from stream
  -c => complement of SET1, SET1 being 'a-zA-Z0-9' i.e. delete all chars except the ones in SET1 from input stream

fold => wrap output into 16 column fixed width i.e. generate passwords of length 8
head => top 5 results only

This command generates 5 random numbers, each being 8 character long and containing uppercase/lowercase letters and numbers.

# Method 2
cat /dev/urandom | tr -dc [:alnum:] | head -c8; echo

*urandom is non-blocking for entropy unavailability, while random blocks. So, prefer randon.

Credit: https://blog.colovirt.com/2009/01/07/linux-generating-strong-passwords-using-randomurandom/