1, Configure SMTP mail service according to the following requiremnets:
— Your mail server should accept mail from remote hosts and localhost
— harry must be able to receive mail from remote hosts
— Mail delivered to mary should spool into the default mail spool for mary /var/spool/mail/mary
install the postfix,
yum install -y postfix
start the postfix and make it auto on when booting,
service postfix start chkconfig postfix on
modify the main.cf
vim /etc/postfix/main.cf
the original inet_interfaces is localhost, if needs to receive the internal and external mails, needs to switch on inet_interfaces = all, and comments off localhost, as following,
inet_interfaces = all #inet_interfaces = $myhostname #inet_interfaces = $myhostname, localhost #inet_interfaces = localhost
harry is local user, so he can receive the external mail, mary should spool into the default mail spool for mary /var/spool/mail/mary, this one also no need to do anything.
Restart the service,
service postfix restart chkconfig postfix on
check ports is on now,
netstat -ntulp | grep :25
check the hostname,
postconf myhostname
if the hostname is incorrect, needs to modify the /etc/postfix/main.cf, in the line of mydestination add “server3.example.com”
mydestination=…..,server3.example.com
send an email to test the SMTP,
echo "hello mary" | mail -s "subject" mary@server3.example.com
mail -u mary
2, Configure an email alias your MTA such that mail sent to harry is received by the local user mary
modify the /etc/aliase
vim /etc/aliase
add one line as following, and add harry at the end, mail transferred to mary and harry also can receive mail.
harry mary,harry
update the database,
newaliases
test the result,
echo "hello harry" | mail -s "subject" harry@server3.example.com
mail -u mary mail -u harry
chkconfig postfix on
3, Create a shell script /root/program:
–when you input “kernel” parameter to the shell script that will return “user”
–when you input “user” parameter to the shell script that will return “kernel”
–while script no parameter or parameter is wrong,standard error “usage:/root/program kernel|user”
vim /root/program
add the source code,
#!/bin/bash if [ "$1" == "user" ]; then echo "kernel"; elif [ "$1" == "kernel" ]; then echo "user"; else echo "usage:/root/program kernel|user." fi
here needs to pay attention to one thing, [ “$1” == “user” ], there are some spaces in the middle, if you missed out the space, the shell program will not work. test the result, ./program user will output kernel, ./program kernel, will output user, if ./program, it will output “usage:/root/program kernel|user.”
another way to achieve this is by using the case program,
#!/bin/bash
case $1 in
user)
echo "kernel" ;;
kernel)
echo "user" ;;
*) echo 'usage:/root/program kernel|user.'
esac
4, ftp service, allow anonymous to upload file, upload folder path as /var/ftp/upload
lock the local user to home directory, limit certain user to home directory
limit certain user to login to ftp service.
install the vsftp,
yum install vsftp
start the service and make it auto on,
service vsftpd restart chkconfig vsftpd on
modify the vsftpd.conf,
vim /etc/vsftpd/vsftpd.conf
uncomment following two lines, save and restart the vsftpd service,
anon_upload_enable=YES anon_mkdir_write_enable=YES
restart the service
service vsftpd restart
create the uploading folder,
mkdir -p /var/ftp/upload
change the access right,
chown ftp.ftp /var/ftp/upload chmod 775 /var/ftp/upload
change the selinux bool value,
getsebool -a | grep ftp
setsebool -P allow_ftpd-anon_write on Setsebool -P allow_ftpd_anon_full_access on
test the result,
lftp 192.168.0.103
ls and !ls to display the folder,
put post.log
lock the user to home directory,
vim /etc/vsftpd/vsftpd.conf
switch on chroot_local_user
chroot_local_user=YES
restart the vsftp
service vsftpd restart
test the result,
ftp 192.168.0.103
login as student, and try to go to other folder,
cd /var/ftp
it will return error, “550 failed to change directory”
limit certain user to home directory,
vim /etc/vsftpd/vsftpd.conf
uncomment following two lines,
chroot_list_enable=YES chroot_list_file=/etc/vsftpd/chroot_list
create file chroot_list,
vim /etc/vsftpd/chroot_list
add sutdent and visitor
limit certain user to login ftp service, modify /etc/vsftpd/ftpusers, to add the users needs to be limited.
vim /etc/vsftpd/ftpusers