Brief Note on Linux

Control Keys

• Ctrl+D: end of input
• Ctrl+C: break
• Ctrl+Z: suspend

Device Naming

• /dev/hda: first IDE hard disk
• /dev/hda1: first partition in first IDE HD
• /dev/fd0: floppy drive
• /dev/ttyS0: serial port
• /dev/lpt0: printer port

Directory Structure

• /bin: general commands
• /boot: kernel
• /dev: device files
• /etc: configuration files
• /home: user home directory
• /lib: library an modules
• /mnt: mount point
• /proc: system status
• /root: root's home directory
• /sbin: system commands
• /tmp: working directory
• /usr:
• /var:

Online Help

• man

File Management

• pwd, cd, ls, mv, cp, rm, mkdir, rmdir, ln
• which, locate, find
• chmod, chgrp, chown
• vi, cat, more
• tar, gzip, gunzip
• mount, umount, mkfs, fsck
  /etc/fstab
• df, du

Network Diagnosis Tools

• ping, netstat, traceroute, nslookup

Internet Client Commands

• telnet, ftp, mail, lynx

Login, Logout, Shell

• login, su, logout, ash, bash, bsh, sh, tcsh, zsh, exit
• redirection, pipelining
• Alt+F1~F6: switch to virtual console 1~6
• Alt+F7: switch to X-Windows console

Account Management

• useradd, passwd, usermod, userdel, chfn, chsh, finger
• /etc/passwd, /etc/shadow

Group Management

• groupadd, gpasswd, groupmod, groupdel
• /etc/group

Process Control

• ps, top, kill, xxx&, fg, bg

Shutdown

• shutdown, halt

System Configuration

• linuxconf, setup

Misc. Commands

• date, whoami, who, w, talk, write

Linux Loader

• /etc/lilo.conf
• lilo

Boot-up Sequence

1. /sbin/init
   /etc/inittab
2. /etc/rc.d/rc.sysinit
3. run-level script
   /etc/rc.d/rc3.d/Sxx -> /etc/rc.d/init.d/--
4. /etc/rc.d/rc.local

Drivers and Loadable Modules

• built-in modules in kernel and in /dev/
• loadable modules
  • /sbin/kerneld
  • /etc/conf.modules
  • /lib/modules/-

Networking Device Setting

• Loadable network device driver: /etc/conf.modules
• Network interface management: ifconfig
• Network routing management: route

Boot-up Networking Setting

• S10network -> /etc/rc.d/init.d/network
  /etc/sysconfig/network, /etc/sysconfig/network-scripts/-
• S55routed -> /etc/rc.d/init.d/routed

Network Configuration File

• /etc/hosts
• /etc/services
• /etc/protocols
• /etc/HOSTNAME
• /etc/inetd.conf
• /etc/host.conf

FTP Server

• /etc/ftpaccess
• /etc/ftpconversation
• /etc/ftphosts
• /etc/ftpuser
• /etc/ftpgroup
• /home/ftp

HTTP Server - Apache

• /etc/httpd/conf/-
• /home/httpd