1. Linux Commands Workout 1
Fall 2017

2. Linux Filesystem Linux filename scheme
Hidden filenames start with a “.” (dot)
most hidden files/directories are configuration-related (e.g., /home/john/.bashrc and /home/john/.ssh)
Directory and filenames are case sensitive
ls and LS are not the same
foo.mp3 ≠ foo.MP3
filenames can include only alphanumerics plus dots, dashes, and underscores.
however, most Linux filesystems allow the use of many non-alphanumeric characters, such as spaces, ~, ?, *, etc.
the forward slash (/) is never allowed in filenames, as there could then be ambiguity in interpreting pathnames
The tilde (~) sign is a shorthand notation for your home directory
cd and cd ~ are equivalent
~ can be used as in relative pathnames when specifying a file/directory
cd ~/test2

3. Linux Filesystem Example filenames: test1.text
Test1.text (completely different file from test1.text)
test1.text.save3
ls (command/executable)
.bashrc (hidden file)
.ssh (hidden directory)
a_long_name
alternative-long-name
file with space.text name (a name with spaces . even in extension)

4. Useful Linux Filesystem Commands
Explanation
pwd
Show/display current directory
mkdir dir
Make directory dir in CWD
mkdir dir/subdir
Make directory dir/subdir in CWD
mkdir –p dir2/subdir
Make directory dir2 and subdirectory ./dir2/subdir within dir2
cd dir
Change from CWD to subdirectory dir
cd ..
Go up a directory
cd ../dir2
Go up one level from CWD and then down to directory called dir2 ls
List files in CWD
touch file1.txt
Create file1.txt in CWD
touch ../dir2/file1.txt
Create file1.txt in subdirectory dir2 of parent directory
cp file1.txt ../dir2/file2
Copy file1.txt to file2 in location ../dir2
mv ./dir1/file1.txt ../dir2/file1.txt
Move file1.txt in subdirectory ./dir1 to file2 in location ../dir2 (file1.txt will no longer be in ./dir1)
mv file1.txt file2.txt
Move file1.txt to file2.txt in the same directory. NOTE: This has the effect of renaming a file
rm file1.txt
Delete file1.txt from CWD
rm –r dir2
Delete all files in subdirectory dir2 as well as dir2
ls argument options -a
Show all (including hidden) -R
Recursive list -r
Reverse order -t
Sort by last modified -S
Sort by file size -l
Long listing format -1
One file per line -m
Comma-­sep­arated output -Q
Quoted output

5. Basic Linux Commands to Teach

8. Linux commands workout
Create a file and change permissions on it using chown
Change permissions on a directory
Change permissions on a directory and all its contents recursively
chown -R
Get information on the processes currently running ps
ps –e
ps –ex
Find out your IP address: ifconfig
Test if your Internet is working: ping
Introduce vi as the command line editor
Show how to write data (in ‘i’ mode)
Save as a file (:w)
Exit vi (:q)
Save and exit (:wq)
Exit without saving (:w!)

9. Linux commands workout
Sort contents of a text file using the sort command
more big-text_file.txt
Display the file called big-text_file.txt one page at a time, proceed to next page using the spacebar
head big-text_file.txt
Display the first 10 lines of the file called big-text_file.txt
head -20 big-text_file.txt
Display the first 20 lines of the file called big-text_file.txt
tail big-text_file.txt
Display the last 10 lines of the file called big-text_file.txt
tail -20 big-text_file.txt
Display the last 20 lines of the file called big-text_file.txt