思路：

涉及到的文件：

1、/etc/passwd

echo“ $ACCOUNT:x:$[$MAXUID+1]:$[$MAXGID+1]::/home/$ACCOUNT:/bin/bash” >>/etc/passwd

2、/etc/shadow

chmod u+w /etc/shadow

echo “$ACCOUNT::::::::”>>/etc/shasow

chmod u-w /etc/shadow

3、/etc/group

echo “$ACCOUNT:x:$[$MAXGID+1]:” >> /etc/group

4、家目录

mkdir /home/$ACCOUNT

cp -a /etc/skel/.  /home/$ACCONT

chown -R $ACCOUNT:$ACCOUNT /home/$ACCOUNT

chmod 700 /home/$ACCOUNT

5、MAIL

touch /var/spool/mail/$ACCOUNT

chmod 660 /var/spool/mail/$ACCOUNT

chown $ACCOUNT:mail /var/spool/mail/$ACCOUNT

6、口令

echo “123” | passwd --stdin $ACCOUNT

执行脚本时，遇到错误的时候最好打开调试开关：bash -x 脚本文件，或者在脚本中可能出现错误的地方添加一条 set -x 指令。

[root@localhost ~]# vim useradd.sh
#!bin/bash
read -p "please input one user : " ACCOUNT
grep -q $ACCOUNT /etc/passwd && echo "the user $ACCOUNT is exist" && exit
#test current max uid and gid
MAXUID=`cut -f3 -d: /etc/passwd |sort -n |tail -n 2 |head -n 1`
if [ $MAXUID -lt 500 ];then
MAXUID=500
fi

#!bin/bash
read -p "please input one user : " ACCOUNT
grep -q $ACCOUNT /etc/passwd && echo "the user $ACCOUNT is exist" && exit
#test current max uid and gid
MAXUID=`cut -f3 -d: /etc/passwd |sort -n |tail -n 2 |head -n 1`
if [ $MAXUID -lt 500 ];then
MAXUID=500
fi

MAXGID=`cut -f4 -d: /etc/passwd |sort -n |tail -n 2 |head -n 1`
if [ $MAXGID -lt 500 ];then
MAXGID=500
fi
#change /etc/passwd
echo "$ACCOUNT:x:$[$MAXUID+1]:$[$MAXGID+1]::/home/$ACCOUNT:/bin/bash" >>/etc/passwd
#change /etc/shawdow
chmod u+w /etc/shadow
echo "$ACCOUNT::::::::" >>/etc/shadow
chmod u-w /etc/shadow
#change /etc/group
echo "$ACCOUNT:x:$[$MAXGID+1]:" >>/etc/group
#create home dir
mkdir /home/$ACCOUNT
cp -a /etc/skel/. /home/$ACCOUNT
chown -R $ACCOUNT:$ACCOUNT /home/$ACCOUNT
chmod 700 /home/$ACCOUNT
#create user mailbox
touch /var/spool/mail/$ACCOUNT
chmod 660 /var/spool/mail/$ACCOUNT
chown -R $ACCOUNT:mail /var/spool/mail/$ACCOUNT
#change user passwd
echo "123" |passwd --stdin $ACCOUNT &>/dev/null

SHELL之手工创建账号