老男孩出的Shell编程企业面试题4：

批量创建10个系统帐号oldboy01-oldboy10并设置密码（密码为随机8位字符串）。

我的Shell脚本如下:

#!/bin/bash

for num in 01 02 03 04 05 06 07 08 09 10
do
        username=oldboy$num
        password=`head -c 500 /dev/urandom | md5sum | head -c 8`
        egrep "^$username" /etc/passwd >& /dev/null
        if [ $? -ne 0 ]
        then
                useradd $username
                echo $password | passwd $username --stdin &>/dev/null
                if [ $? -eq 0 ]
                then
                        echo "$username:$password"
                fi
        fi
done

运行结果如下:

[root@CentOS66 shellstudy]# ./creatuser.sh 
oldboy01:d7e86b4e3b
oldboy02:7fbc6033fc
oldboy03:aabd217934
oldboy04:bbe4b5a094
oldboy05:38041b6159
oldboy06:e51d10d669
oldboy07:c292390561
oldboy08:61badd5747
oldboy09:60eed14fda
oldboy10:a5d5a6c1f6