pwgen

#!/bin/bash
#via: http://thdonline.wordpress.com/2009/03/14/shell-script-to-generate-random-password/
#with a slight modification for my preferences

CHAR_ARRAY=( {a..z} {A..Z} {0..9}  \! \@ \# \% \^ \& \* \( \) \[ \] \{ \} \: \; \, \. \< \>)

get_words() {
    a=`cat /usr/share/dict/words | perl -MList::Util=shuffle -wne "chomp(@a=shuffle(<>));print join('-',splice @a,0,$1)"`
	echo $a
}

while getopts "wndhc?" opt; do
	case $opt in
        w)
		    words=true
			;;
		n)
			CHAR_ARRAY=( {a..z} {A..Z} {0..9} )
			;;
		d)
			CHAR_ARRAY=( {0..9} )
			;;
		h)
			CHAR_ARRAY=( {0..9} {a..f} )
			;;
		c)
			CHAR_ARRAY=( {a..z} {A..Z} )
			;;
		?)
			echo "Usage: $0 [options] [length]
	-w <length> number of words as a phrase
	-n 'nice' output, Alphanumberic only
	-d digits 0-9
	-h hex 0-9 and a-f
	-c characters only, A-Z and a-z"
			exit
			;;
	esac
done
shift $(($OPTIND - 1))

MAXSIZE=$1

if [ "$MAXSIZE" != "" -a "$MAXSIZE" == "${MAXSIZE//[^0-9]/}" ]
then
#I don't like the extra output
	MAXSIZE=$MAXSIZE
else
	MAXSIZE=16
fi

if [ $words ]
then
    pw=$(get_words $MAXSIZE)
	echo -n "$pw"
else
	MODNUM=${#CHAR_ARRAY[*]}
	for ((i=0; i < $MAXSIZE; i++ ))
	do
		NUM=$(( RANDOM % $MODNUM ))
		echo -n "${CHAR_ARRAY[$NUM]}"
	done
fi
echo ""