Script:shell脚本生成随机字符串

#!/bin/bash
# bash generate random alphanumeric string
#

# bash generate random  character alphanumeric string (upper and lowercase) and
NEW_UUID=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w  | head -n )

# bash generate random  character alphanumeric string (lowercase only)
cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w  | head -n 

# Random numbers in a range, more randomly distributed than $RANDOM which is not
# very random in terms of distribution of numbers.

# bash generate random number between  and
cat /dev/urandom | tr -dc '0-9' | fold -w  | head -n  | head --bytes 

# bash generate random number between  and
NUMBER=$(cat /dev/urandom | tr -dc '0-9' | fold -w  | head -n  | sed -e 's/^0*//' | head --bytes )
if [ "$NUMBER" == "" ]; then
  NUMBER=
fi

# bash generate random number between  and
NUMBER=$(cat /dev/urandom | tr -dc '0-9' | fold -w  | head -n  | sed -e 's/^0*//' | head --bytes )
if [ "$NUMBER" == "" ]; then
  NUMBER=
fi