Execute this command (lowercase LS):
ls
This command shows files and directories in the
current working directory,
as shown below.
"ls" by itself isn't very useful, because it doesn't tell you much about the items. The next command is far more helpful.
Execute this command (lowercase LS -L):
ls -l
This "long list" tells you a lot more information,
as shown below.
The first character in each line is "d" for directories, or "-" for files. Towards the right, it shows the size of the file or directory in bytes and the date it was last modified, with the name at the far right.
My working directory contains only directories, no files.
If you want a brief summary of command options, execute the command followed by "--help". Execute this command:
ls --help
A "brief" help page appear, as shown below.
Even that "brief" page contains far more information than I usually want to see. Most of those arguments are obscure and I never use them. My main source of help is actually Google.
Ooen a Web browser and go to google.com. Then search for
linux ls examples
You get a lot of really useful information, as shown below.
Go to this page and skim through the options to see some more ways to use "ls".
http://linoxide.com/linux-command/linux-ls-command/
Execute this command:
man ls
This shows you a long, technical, and
very confusing manual page about "ls"
as shown below. This type of help is
almost completely useless for beginners--it
provides far too much information.
Press q to exit man.
nano file1
Nano opens, as shown below.
Nano is a very simple text editor,
like Notepad without the mouse.
Type in some text.
Notice the bottom of the nano screen--the available commands are shown here in a shorthand form.
Notice the lower left entry "^X Exit". This means that you can exit nano by pressing Ctrl+X. Press it now.
The next screen asks if you want to save the file. The bottom shows your options: Y, N, or Ctrl+C. Type Y.
At this screen, you can press Enter to save the file, or edit the name before saving it. Unfortunately, the list of commands at the bottom don't tell you either of those facts.
Press Enter.
To see what you've done, execute this command:
ls -l
There's now an entry for "file1",
as shown below.
pwd
The result is "/root",
as shown below. That's the directory
we've been using.
Execute these commands. The first one makes a new directory, and the second one lists out the contents of the current working directory.
mkdir proj0
ls -l
Now there's a directory named "proj0"
in the working directory,
as shown below.
Execute these commands. The first one moves file1 into the "proj0" directory, and the second one lists out the contents of the current working directory.
mv file1 proj0
ls -l
"file1" no longer appears in the list,
as shown below.
Execute these commands. The first one moves into the "proj0" directory, the second one shows the new working directory, and and the third one lists out the contents of the new current working directory.
cd proj0
pwd
ls -l
This directory contains only one file,
as shown below.
date
date > file2
ls -l
There's now a file named "file2",
as shown below.
Execute this command to open "file2" in nano.
nano file2
The file contains the date,
as shown below.
Press Ctrl+X to exit nano.
nano count
Enter this text,
as shown below.
#!/bin/bash
for i in 1 2 3
do
echo $i
done
Press Ctrl+X, Y, Enter to save the file.
This script should count from one to three. Execute this command to run the script:
./count
An error message appears, saying
"Permission denied",
as shown below.
To see why this happened, execute this command:
ls -l
Notice the beginning of the line
containing "count"
as shown below.
This line starts with "-", indicating that this is a file, not a directory. The next 9 letters are the permission string, using these letters:
The current permission string doesn't contain any "x" characters, so no one has permission to execute it.
Execute these commands to give execute permission to the "count" file for all users, and to see the new permissions:
chmod a+x count
ls -l
As shown below,
the file now has three "x" permissions,
and the name turns green, to indicate
that this is an executable file.
Execute this command to run the "count" script:
./count
As shown below,
the script runs, counting from 1 to 3.
ifconfig
As shown below,
there are two adapters:
eth0 has an IP address (labelled "inet") and goes to the Internet.
lo is the loopback address and doesn't go anywhere. Your computer uses that address to talk to itself, which is useless for normal Web browsing.
Execute this command test your Internet connection:
ping google.com
As shown below,
you should see "reply" messages,
indicating that your Internet connection is
working.
Press Ctrl+C to stop the pings.
If you move your computer to a new network, it might lose connectivity because it's still using an old IP address.
To fix that problem, execute this command:
dhclient -v eth0
As shown below,
your computer sends out DHCPDISCOVER messages,
and gets an IP address from the router.
Hello from YOURNAME!
Run your script and capture a whole-desktop image resembling the image below.
Email the images to cnit.123@gmail.com with a Subject line of Proj X0 from Your Name.