randpass

#!/bin/sh
#
# About
# -----
# Generate simple passwords, via /dev/urandom.
#
#
# License
# -------
#
# Copyright (c) 2013 by Steve Kemp.  All rights reserved.
#
# This script is free software; you can redistribute it and/or modify it under
# the same terms as Perl itself.
#
# The LICENSE file contains the full text of the license.
#
#


if [ ! -e /dev/urandom ]; then
    echo "/dev/urandom isn't available"
    exit 2
fi


#
#  The character set to use.
#
cset="[:alnum:]"

#
#  Default length
#
len=8

while getopts "h?fn:" opt; do
  case $opt in
    h)
      echo "Usage: $0 [-n N] [-f]"
      exit 0
      ;;
    \?)
      echo "Usage: $0 [-n N] [-f]"
      exit 0
      ;;
    f)
      cset="[:graph:]"
      ;;
    n)
      len=$OPTARG
      ;;
  esac
done

#
#  Output the password
#
printf "%s\n" $(cat /dev/urandom | tr -cd "$cset" | head -c $len )