shell-生成随机数

echo "+-0123456789@ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz<>" | cut -c $(( $RANDOM % 67 ))

printf "%d" \'a #输出ASCII数字
printf \\x`printf %x 67` #输出字符
echo "67" | awk '{printf("%c\n",$1)}' #输出字符

_NUM=10
_count=1
>./tmp
echo "ABCDEFGHIJKLMNOPQRSTUVWXYZ" | cut -c $(( $(( $RANDOM % 25 )) + 1 )) >> ./tmp
echo "ABCDEFGHIJKLMNOPQRSTUVWXYZ" | cut -c $(( $(( $RANDOM % 25 )) + 1 )) >> ./tmp
echo "+-#%@<>" | cut -c $(( $(( $RANDOM % 6 )) + 1 )) >> ./tmp
while [ "${_count}" -le "${_NUM}" ];do
_count=$(( ${_count} + 1 ))
echo "+-0123456789@ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz<>" | cut -c $(( $(( $RANDOM % 56 )) + 1 )) >> ./tmp
done
cat ./tmp | tr '\n' ' ' | sed 's# ##g' && rm -f ./tmp
echo