Basic Commands ls cp ls –l (in detail format) echo ls –a (all files including hidden files) whoami pwd who cd more touch init [1..6] grep ssh cat vi (Text Editor)

Network Administration Module 0 : Linux – Basic Commands

Basic Commands (Cont…) | (pipeline) env > (redirect) set >> (redirect append) info history hostname !n (execute history) uptime mkdir rm rmdir mv shutdown – h now shutdown –r now

Basic Commands (Cont…) fdisk jobs su find su - ifconfig mount ifdown umount ifup uname –r man ln (hard link) man –k ln –s (soft Link)

Device files IDE hard drive – /dev/hda, /dev/hdb, … Partition (IDE) – /dev/hda1, /dev/hda2 … SATA hard drive – /dev/sda, /dev/sdb, … Partition (SATA) – /dev/sda1, /dev/sda2, … CDROM - /dev/cdrom DVDROM - /dev/dvd Floppy Drive - /dev/fd0

Disk Management df mkswap du For file and directory mkfs fsck option –k in 1-k block-size –m in 1-M block-size –h human readable mkswap du For file and directory mkfs fsck

User Management useradd usermod userdel Option –r (remove all files in home directory) groupadd groupmod groupdel

User Management (Configuration files) /etc/passwd student:x:501:501:Full Time:/home/student:/bin/bash /etc/shadow student1:!!:13571:0:99999:7::: student:$1$SaChG8Zj$vQuk0TSIgd:13560:0:99999:7::: /etc/group student:x:501:johnchan,jameswong username UID Group ID Home directory Default shell Password (not used) Description / GECOS username password Group Name Group ID Group members Group password (Not used)

Environment Variables PS1 – PS4 PATH HOME SHELL USER Commands set env echo $XXXX Note: When you use shell variable, you need to $ before the name of the variable (e.g. $PATH) Environment variable e.g. PATH

File System File System supported by Linux ext2 / ext3 (ext3 with journaling) FAT16 NTFS HPFS …. ISO9660 (CDROM)

Directory Layout / Structure /dev /etc /etc/sysconfig /lib /bin and /sbin /mnt (or /media) /opt /proc /usr /usr/local /var /var/log /home /root You should understand/know which type of file is stored in these directories? any specific functions.

Important Files (configuration files) /etc/fstab /etc/inittab /etc/crontab /etc/grub.conf /etc/hosts /etc/passwd /etc/group /etc/shadow ~/.bash_profile ~/.bash_logout /etc/bashrc ~/.bashrc You should understand/know What kind of information is stored in these configuration files? Functions of these configuration files (i.e. Which program/component is controlled by these configuration files).

Kernel Version Linux Kernel Version Meaning of kernel version Different portion of kernel version Kernel Version.Major.Minor.Patch (e.g. 2.6.18.45) Distribution Example: Redhat, Mandrake, Debian, SuSe, Ubuntu, Knoppix, Fedora Core, CentOS … … What is distribution meant? What is System Administration / Duty of Administrator Administrator account - root You should know which command(s) can be used to complete a specific task e.g create a new user account – useradd command and passwd command

Home Directory & Run Level Relative path and absolute path . Current directory .. Parent directory Home Directory : ~ Configuration Files Meaning of the content of some configuration files (e.g. passwd, group, shadow) Directory Layout Run Level 0, 1, 3, 5 and 6