1. commands
Basic syntax of shell commands UNIX or shell commands have a basic structure
command -options target
command comes first (such as cd or ls)
any options (always proceeded by a – and also called flags)
target (such as the file to move or the directory to list)
These commands are written on the prompt (terminal command line).
Where am I?: pwd
Change directory: cd
what files and directories
are in my current directory: ls
If I need to know more about a command:
man command

2. ls ls ls –a ls –l ls –l –t ls -lS
lists all files and directories in current working directory ls
ls –a
ls –l
ls –l –t
ls -lS
lists all files and directories, including hidden files
long format
time sorted
size sorted

3. permissions links permissions owner group size date filename group
change permissions:
chmod [u,g,o][+-][r,w,x] filename
d - directory
- - regular file
r … read
w … write
x … execute
drwxrw-rw-
user
other
group

4. create, copy, delete directories
mkdir dir_name
rmdir dir_name
rm –r dir_name
cp –r dir_name dir_copy
creates an empty directory named dir_name
deletes an empty directory named dir_name
deletes a directory named dir_name and its contents
copies a directory named dir_name and its contents
to a directory named dir_copy

5. create, copy, remove files
touch file_name
cp file_name file_copy
mv file_name file_copy
rm file_name
creates an empty file named file_name
copies file_name to file_copy
renames file_name to file_copy
deletes file file_name

6. change directories cd dir_name cd .. cd cd / cd -
changes directory to dir_name
goes to parent directory
goes to home directory
goes to root directory
home is the parent
directory of students
goes to previous directory

7. absolute/relative paths
Pathnames consist of file/directory names, separated by slashes /
Any character except / is allowed. Use ''s around weird file names.
Extensions are not meaningful to UNIX, only to applications
Special file names
.file_name . ..
Absolute and relative file names
- Absolute to the root (start with slash) (e.g. /home/wuchtys/Desktop)
- Relative to the current working directory of the process (incl. . and ..) or
home directory (e.g. ~/Desktop is equivalent to
/home/wuchtys/Desktop)

8. less typing History history lists recent commands.
!<number> redoes that command
!<partial> redoes the most recent command that started with <partial> letters
Globbing
Describe to the shell (not OS) sets of file names with patterns
~ means the home directory
? means any character
* means any string (including empty)
[<letters>] means any one of the <letters> (except ...), which can also be a range
^ negates some glob expressions
File name completion
Many shells provide file name completion: Use tab key to expand partial file names