SHELL系列3-批量创建100个用户并设置密码

[root@mail ~]# echo 1234568 |passwd --stdin zhangsan
Changing password for user zhangsan
passwd: all authentication tokens updated successfully.

[root@mail ~]# echo $RANDOM
31427
[root@mail ~]# echo $RANDOM
10943
[root@mail ~]# echo $RANDOM
4070
[root@mail ~]# echo $RANDOM
20273

[root@mail ~]# echo $RANDOM |md5sum
d908b56aea8ba230846e9a6a21093f86  -
[root@mail ~]# echo $RANDOM |md5sum
d6a8e0adb2607506fc0e07a53c0e1448  -
[root@mail ~]# echo $RANDOM |md5sum
c2be3c5e60858b9416a4b72cd6968a03  -

[root@mail ~]# echo $RANDOM |md5sum |cut -c 1-8
0c61bdc7
[root@mail ~]# echo $RANDOM |md5sum |cut -c 1-8
0bc8559f
[root@mail ~]# echo $RANDOM |md5sum |cut -c 1-8
b531b827

[root@mail sh]# echo {1..10}
1 2 3 4 5 6 7 8 9 10

[root@mail sh]#  id zhangsan
uid=1000(zhangsan) gid=1000(zhangsan) groups=1000(zhangsan)
[root@mail sh]# id lisi
id: lisi: no such user

[root@mail sh]# id lisi
id: lisi: no such user
[root@mail sh]# echo $?
1
[root@mail sh]# ls
1.sh
[root@mail sh]# echo $?
0

例如：执行成功就执行else里面的，执行失败就执行then下面的

#!/bin/bash
USER_LIST=./user.list  #存放用户名，为以后删除用户提供名单
USER_FILE=./user.info  #在当恰目录下的user.info文件里记录user对应的密码
for USER in user{1..20};do  #创建20个用户
if ! id $USER &>/dev/null; then   #判断是否存在该用户，存在执行else下面，不存在就执行then下
PASS=$(echo $RANDOM | md5sum |cut -c 1-8) &>/dev/null   #截取8个随机密码
useradd $USER  #创建用户 
echo $PASS | passwd --stdin $USER &>/dev/null  #免交互给用户赋值密码
echo " $USER $PASS " >> $USER_FILE #把用户对应的密码写在一个文件里面
echo " $USER  " >> $USER_LIST
echo " $USER create sucessful! "                #执行成功返回该值
else
echo "$USER already exists!!!"                   #已存在该用户则返回该值
fi
done

[root@mail sh]# ./1.sh 
user1 create sucessful! 
user2 create sucessful! 
user3 create sucessful! 
user4 create sucessful! 
user5 create sucessful! 
[root@mail sh]# ./2.sh 
The user1 delete success !
The user2 delete success !
The user3 delete success !
The user4 delete success !
The user5 delete success !

#!/bin/bash
USER_LIST=$@
USER_FILE=./user.info
for USER in $USER_LIST; do
if ! id $USER &>/dev/null; then
PASS=$(echo $RANDOM | md5sum |cut -c 1-8) &>/dev/null
useradd $USER
echo $PASS | passwd --stdin $USER &>/dev/null
echo " $USER $PASS " >> $USER_FILE
echo " $USER create sucessful! "
else
echo "$USER already exists!!!"
fi
done

[root@mail sh]# ./1.sh  lisi wangwu zhao
lisi create sucessful! 
wangwu create sucessful! 
zhao create sucessful! 

#!/bin/bash
for user in `cat user.list`
do
userdel -r $user
echo "The $user delete success !"
done

#!/bin/bash
USER_FILE=./user.info
for USER in `cat user2.list`; do
  if ! id $USER &>/dev/null; then
    PASS=$(echo $RANDOM | md5sum |cut -c 1-8) &>/dev/null
    useradd $USER
    echo $PASS | passwd --stdin $USER &>/dev/null
    echo " $USER $PASS " >> $USER_FILE
    echo " $USER create sucessful! "
  else
    echo "$USER already exists!!!"
  fi
done