IT 244: Introduction to Linux/Unix

IT 244: Introduction to Linux/Unix
Class 7 Exercise

Create the text file foo.txt with a text editor
```
nano foo.txt
```
Add some text

Save and quit.
Run cat on the file
```
cat foo.txt
```
cat prints the file to the terminal.
Change the extension of foo.txt
```
mv foo.txt foo.xyz
```
Open the renamed file with nano
```
nano foo.xyz
```
nano opens the file without difficulty.

nano does not care about the extension.
Change some text in the renamed file

Save and quit.
Run cat on the renamed file
```
cat foo.xyz
```
cat does not care about the extension.

Find your current location
```
pwd
```
You should be in the ex7 directory inside your ex directory of your it244 directory.
Go up one level to your parent directory
```
cd ..
```
.. means the directory one level up.
Look at your current location
```
pwd
```
You have moved up one level.
Go to the root directory
```
cd /
```
Look at your current location
```
pwd
```
You are at the top of the filesystem.
Look at the directories inside the root directory
```
ls
```
Notice that the home and courses directories are subdirectories of the root directory.
Return to your home directory
```
cd
```
Look at your current location
```
pwd
```
Your home directory is inside the directory named home, which is, itself, under the root directory, /.
Return to the ex7 directory inside your it244/ex direcotry
```
cd it244/ex/ex7
```
Check you current location
```
pwd
```

Run stat to get some information about the Linux host
```
stat -f /home
```
Run stat with grep to learn the largest filename possible
```
stat -f /home | grep Namelen
```
Create a file with spaces in the name
```
touch 'hello there'
```
If you did not put "hello there" in quotes, you would create 2 new files, hello and there.
List the contents of your current directory
```
ls
```
It looks like you have created two new files.
Perform a long listing on your current directory
```
ls -l
```
Now you can see that there is only one new file.
Remove the file you just created
```
rm 'hello there'
```
Make sure the file is gone
```
ls
```

Create the file bar.txt
```
touch bar.txt
```
Look at the contents of the directory
```
ls
```
Create another bar.txt file
```
touch bar.txt
```
Look at the contents of the directory
```
ls
```
You only have one bar.txt file since you can only have one file with a given name in any one directory.
Create the file Bar.txt
```
touch Bar.txt
```
List the files in your current directory
```
ls
```
You have two files since, as far as Unix is concerned, bar.txt and Bar.txt are totally different file names.
Create some new files
```
touch fOO.txt FOO.txt FOO.TXT
```
List the contents of your current directory
```
ls
```
You should see the files you just created since they have different capitalizations.
Remove all .txt files from your ex7 directory
```
rm  *.txt
```

Go to your ex7 directory
```
cd ~/it244/ex/ex7
```
Make sure you are in your ex7 directory
```
pwd
```
If not, see me.
Create the script ex7.sh
```
nano  ex7.sh
```
Write into this file commands from most of the sections above

Copy all the commands from the sections from The Hierarchical Filesystem to Case sensitivity
Skip the section Extensions.
Save this file

Save and quit.
Run this script looking for error messages
```
bash  ex7.sh > /dev/null
```
Running ex7.sh this way will only print error messages.

If you see nothing your script has no Unix errors.

If you find any errors, fix them.
Test your script
```
~ghoffman/it244_test/ex07.sh
```
When the script asks if you are ready for more, hit Return or Enter.