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  1. Agustin's Linux Manual
  2. System Administration
  3. About the Author
  4. Contents
  5. Administration
  6. Terminals
  7. Command Basics
  8. Root Directory
  9. Executing Commands
  10. File specs
  11. File Permission
  12. How permissions are assigned
  13. Change ownership chown
  14. Running multiple commands
  15. Killing Processes
  16. Bash configuration files
  17. VI Editor
  18. Creating path environment
  19. Midnight Commander
  20. Linuxconf Utility
  21. Networking
  22. Domain Name Service DNS
  23. Router and Gateway
  24. Adding Users
  25. User Accounts
  26. Managing Groups
  27. Mounting File System
  28. NFS Mounts
  29. Disk Quotas
  30. Run levels
  31. Linuxconf Control
  32. Mandrake Control Center
  33. Creating a Boot Disk
  34. Switching Boot Mode
  35. Hardware Configurations
  36. Printer Configuration
  37. Installing Printers
  38. Samba Printer
  39. Managing services
  40. Managing Users
  41. Program Scheduler
  42. Software Management
  43. Installing CUPS


UNIX has been an operating system running on a wide variety of machines interconnected with other machines called terminals (dumb terminals) consisting of keyboards, and monitors interconnected to the central computer. Users at these terminals were basically teletyping, using string 'tty' for terminal device files.

There were no standards that comply with the requirements and every brand had its own “specs” such as its own keyboard, its own display, its own ideas in the signal transmission and reception, characters control codes and so on.

Linux terminals mostly use either 'vt100' or 'Linux' as their terminal type. In order to clean up the mess, a central file was created, the termcap '/etc/termcap'.


In the early 90s the XFree86 was fine tuned and soon ported to Intel-based UNIX clones like FreeBSD, NetBSD or Linux. X has the capability of running multiple 'virtual' terminals. X even came with such an application, 'xterm'. Therefore you'll find that 'xterm' and 'virtual terminal' are often used.

Fig. 3.1
Fig. 3.1


The shell is part of the operating system (kernel), which translates the input/output (IO), allowing the user to communicate with the system by using commands. The first UNIX shell (sh) was written by Steve Bourne, and is called the 'Bourne shell. Many others shells were developed based on the original Bourne Shell. Linux's standard shell is 'bash', the GNU Bourne.

Command aliases

This table describes some aliases that you can use when executing commands. I though to present it here before you actually start working in the console

cd ..executes 'cd ..'go to parent directory
dexecutes 'ls'list directory
lexecutes 'ls'list directory
laexecutes 'ls -a'list complete directory, i.e. including files starting with a dot
llexecutes 'ls -l -k'list directory in long format, i.e. with file attributes, print file size in KB and not in bytes
lsexecutes 'ls -F --color=auto'list directories, append file type indicators and use colors
lsdexecutes 'ls -d */'list subdirectories only, no files
mdexecutes 'mkdir'create directory
pexecutes 'cd -'go back to previous directory
rdexecutes 'rmdirdelete (empty) directory
sexecutes 'cd ..'go to parent directory
usedexecutes 'du -sm * | sort -n'display disk usage of subdirectories in MB, list by size
Table 3.2

Note. The tab key is also used as shortcut, when typing a command and some of the first characters of a file name – hit the tab key and the file name will be auto completed.