Steps:
In GRUB selection screen, press ‘e’ to edit the first line
Debian GNU/Linux, kernel 2.4.27-2-386
press ‘e’ to edit the second line
BEFORE: kernel /boot/vmlinuz-2.4.27-2-386 root=/dev/hda1 ro
AFTER : kernel /boot/vmlinuz-2.4.27-2-386 root=/dev/hda1 ro init=/bin/bash
press ‘b’ to boot
mount -no remount,rw /
passwd root
reboot
Introduction
use linux account to login
access user’s home directory (e.g. /home/alan)
Install Proftpd
aptitude install proftpd
Stop Proftpd
/etc/init.d/proftpd stop (start / reload / restart)
Configure deny list
vim /etc/ftpusers
/etc/init.d/proftpd reload
Install FTP client
aptitude intsall ftp
Display number of users
ftpcount
Display user list
ftpwho
Download files without prompt
ftp -i 192.168.1.1
mget *
Edit crontab
crontab -e
mm hh dd MM WK COMMAND (eg. * * 7 1 * uptime >> /var/log/uptime.log)
List all cron jobs
crontab -l
Remove crontab
crontab -r
Install crontab from file
crontab ~/mycron.txt (install)
Manage crontab of other user
crontab -u alan -e
crontab -u alan -l
crontab -u alan -r
crontab -u alan ~/mycron.txt
Control who can access crontab
vim /etc/cron.deny
vim /etc/cron.allow
(Enter username)
Compression Method
gzip (1K corrupted will cause whole file crashed)
bzip2 (better; 1K corruped only cause 900K crashed)
bzip2 (.bz2)
Install
aptitude intsall bzip2
Compress
bzip2 /xxx
bzip2 -k /xxx (k: keep the old file)
Decompress
bzip2 -d /xxx.bz2
bzip2 -dk /xxx.bz2 (k: keep the old file)
gzip (.gz)
Install
aptitude intsall gzip
Compress
gzip /xxx
Decompress
gzip -d /xxx
tar (.tar .tar.bz2)
Compress
tar -cf /xxx.tar /xxx
tar -cjf /xxx.tar.bz2 /xxx
tar -czf /xxx.tar.gz /xxx
Decompress
tar -xf /xxx.tar
tar -xjf /xxx.tar.bz2
tar -xzf /xxx.tar.gz
Install
aptitude install apache2
(home folder: /var/www/apache2-default/)
Edit port
vim /etc/apache2/ports.conf
/etc/init.d/apache2 reload
Change home directory
vim /etc/apache2/sites-enabled/000-default
# RedirectMatch ^/$ /apache2-default/
(redirect = edit the url)
/etc/init.d/apache2 reload
Add virtual directory
vim /etc/apache2/sites-enabled/000-default
Alias /virtual/ /var/www/real
<Directory “/var/www/real”>
</Directory>
/etc/init.d/apache2 reload
Add virtual host
vim /etc/apache2/sites-available/cse
NameVirtualHost *
<VirtualHost *>
ServerName cse.ust.com
DocumentRoot /cse/
</VirutalHost>
vim /etc/apache2/sites-available/cpeg
<VirtualHost *>
ServerName cpeg.ust.com
DocumentRoot /cpeg/
</VirutalHost>
a2ensite cse
a2ensite cpeg
/etc/init.d/apache2 reload
Enable userdir
a2enmod userdir
mkdir /home/alan/public_html
chmod 755 /home/alan/public_html
http://127.0.0.1/~alan
Introduction
allows normal users to run command as root
Install sudo
apt-get install sudo
Configuration
Edit /etc/sudoers and enter these 2 lines:
uname host=(runas) cmd
alan pc1,pc2=(root,daemon) /bin/ls,/bin/cp,/usr/bin/whoami
Using sudo
sudo whoami
sudo -u david whoami
Get full sessions as root
sudo su –
Logging
/var/log/auth.log
Create User Account
adduser USERNAME
Delete User Account
deluser USERNAME
Additional Options:
apt-get install perl-modules
deluser –remove-all-files USERNAME
deluser –backup USERNAME
deluser –remove-all-files –backup USERNAME
Create Group
addgroup GROUPNAME
Delete Group
delgroup GROUPNAME
delgroup –only-if-empty GROUPNAME
Add user to a group
adduser USERNAME GROUPNAME
Remove user from a group
deluser USERNAME GROUPNAME
Lock User Account
passwd -l USERNAME
Unlock User Account
passwd -u USERNAME
List Age
chage -l USERNAME
Change Age
chage -E 2007/09/01 USERNAME
Print UID, GID
id USERNAME