while批量创建用户
vim while_create_user.sh
#!/usr/bin/bash
#while create user
#v1.0 by xfeng
while read line
do
if [ ${#line} -eq 0 ];then #变量的字符串长度
echo "the line is null..."
continue #continue跳过本次循环，break跳过所有循环，exit直接终止程序
fi
user=`echo $line|awk '{print $1}'`
pass=`echo $line|awk '{print $2}'`
id $user &>/dev/null
if [ $? -eq 0 ];then
echo "user $user already exists"
else
useradd $user
echo "$pass"|pass --stdin $user &>/dev/null
if [ $? -eq 0 ];then
echo "$user is created...."
fi
fi
done< $1 #while读取文件是按行读取，for读取文件默认是以空格或者tab键作为分隔符
echo "All is ok....."
continue跳过空行循环，继续执行后面的内容；break跳过本次循环及后面所有内容循环，执行循环以外的内容；exit跳过本次程序，退出shell。
cat a.txt
feng 123456
xiao 445566
sh -vx while_create_user.sh a.txt