V2012.13
Agenda
• Old Business
– Delete Files
• New Business
– Week 9 Topics:
• Coming up:
– Yearbook Picture: Feb 7th @ 12:20PM in Main Gym
– JVS Open House: Feb 10th 1:30-3:30PM, 15181 OH RT58.
» Tours, teachers, and some students will be available
– Guest Speaker: Feb 12th
– Hyland Field Trip: Feb 21st (no details yet)
• Linux Intro (continued)
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New Business
• Intro to Linux
– Basic Commands
– Install Additional Software
– Practice Exercises
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Basic Commands
• Commands take the following form:
<Command> <Switches> <Parameters> <Target>
• Switches: single letters, preceded by a hyphen,
that adjust what the command does
• Parameters: things that the command needs to
know in order to work
• Target: the thing (such as a file) that the
command will be applied
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Basic Commands
• Let’s look at an example:
$ ls -l /home/seighman
Target
Switch
Command
This command tells the command line to list, in long format, the contents of the
directory “/home/seighman”. The command is “ls”; the switch “-l” tells Linux that
you want the list in long format; and the target of this command is the directory
“/home/seighman”. In this example, there are no parameters, so that part of the
command is just skipped
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Basic Commands - man
• So, how do I know what switch to use?
– manpages are your friend
$ man ls
LS(1)
User Commands
LS(1)
NAME
ls - list directory contents
SYNOPSIS
ls [OPTION]... [FILE]...
DESCRIPTION
List information about the FILEs (the current directory by default). Sort entries
alphabetically if none of -cftuvSUX nor --sort is specified
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Basic Commands
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pwd
ls
cd
mkdir
rmdir
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Basic Commands 2
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file
touch
cp
rm
mv
rename
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Basic Commands 2 - file
• ‘file’
$ file linuxcommands.pdf
linuxcommands.pdf: PDF document, version 1.5
• The file utility determines the file type. Linux does not
use extensions to determine the file type.
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Basic Commands 2 - file
• ‘touch’
$ touch test.txt
• One easy way to create a file is with touch
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Basic Commands 2 - cp
• ‘cp’
$ cp test.txt /home/seighman/Documents
• To copy a file, use cp with a source and a target
argument
• If the target is a directory, then the source files are
copied to that target directory.
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Basic Commands 2 - cp
• Some ‘cp’ examples:
$ cp -r
The -r option forces recursive copying of all files in all
subdirectories
• $ cp -i
Prevents cp from overwriting existing files, use -i (interactive)
• $ cp -p
Preserve permissions and time stamps from source files
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Basic Commands 2 - rm
• ‘rm’
$ rm test.txt
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Use rm to remove a file
There’s no notion of a ‘waste basket’
When you use rm to remove a file, the file is gone
Be careful when removing files!
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Basic Commands 2 - rm
• Some ‘rm’ examples:
$ rm –i text.txt
To prevent yourself from accidentally removing a file, you can
use -i.
$ rm –rf test
When you are logged on as root, be very careful with rm -rf
(the f means force and the r means recursive)
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Basic Commands 2 - mv
• ‘mv’
$ mv test.txt text1.txt
• Use mv to rename a file or to move the file to another
directory
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Basic Commands 2 - mv
• Some ‘mv’ examples:
$ mv
To prevent yourself from accidentally removing a file, you can
use -i.
$ mv
When you are logged on as root, be very careful with rm -rf
(the f means force and the r means recursive)
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Basic Commands 2 - rename
• ‘rename’
• The rename command can also be used but it has a
more complex syntax to enable renaming of many files
at once
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Basic Commands 2 - rename
• Some ‘rename’ examples:
$ rename 's/txt/doc/' *.txt
Switches all occurrences of txt to doc for all file names
ending in .txt.
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Super User
• The “sudo” command introduces the “superuser” or “root
user”
• The term “root” is the name for the main administrator in
a “Unix-like” system, such as Linux
• There are many commands that only the root user can
run
• Depending on the version of Linux you are using, you
will either have to log on as the root user or prefix your
command with “sudo”. The default Debian distribution of
Linux, for instance, has no root password set. So you will
have to use the “sudo” command
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Super User
• By using “sudo”, you’re saying, “Do the following
command as the root user”
• When you do this, you will be asked for your password
and, if you have the system permissions of a root user
(commonly called “being in the admin group”), then the
command will be run
• If you don’t have root permissions, you will get an error
message
WARNING: be very careful executing commands as
root (sudo), you can easily render your system
unuseable!
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Installing Software
• Installing software on Linux is a broad subject because
each version of Linux has its own way of doing things
• Most are variations on apt-get (Advanced Packaging
Tool), used by Debian, Ubuntu, and related distributions)
• yum (Yellowdog Update Manager), used by Fedora and
related distributions
• The basic syntax is:
$ sudo apt-get install <packagename>
$ sudo yum install <packagename>
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Using apt-get to Manage Software
• To install a software package:
$ sudo apt-get install <packagename>
• To update the local package database:
$ sudo apt-get update
• To install all available newer versions of packages:
$ sudo apt-get upgrade
• To remove a package:
$ sudo apt-get remove <packagename>
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Ubuntu Setup
• Install Ubuntu Tweak
– Open a ‘terminal’
– Enter the following commands:
$ sudo add-apt-repository ppa:tualatrix/ppa
$ sudo apt-get update
$ sudo apt-get install ubuntu-tweak
– You may need to logout and login again
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Practice Exercises
• Work through the exercises here:
http://ahstechcrew.org/docs/BasicCommandsPractice2.pdf
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Basic Commands 3
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tail
head
Cat
more
less
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