By: Tony Andrews
Linux directory ordering system
Navigating and creating directories
Listing directories and files
Creating directories
Changing directories
Removing directories
Displaying content of a file
Copying files
Moving files
Removing files
Searching the content of a file
Managing files
Wildcards and general searches
◦ Wildcard “*” and “?”
◦ Find
Access rights to files
◦ Listing processes
◦ Killing processes
Finding more help with commands in command
◦ Manual
◦ Whatis
◦ Apropos
The linux operating system is built like a tree.
◦ Top directory is the root directory “/”
◦ Followed by other ones like home etc.
◦ Music is located at: /Home/Tony/Music
Command “ls” lists all of the files and
directories in the current directory.
◦ Ie.)
The command “ls –a” lists all of the files and
some hidden files that start with “.” or “..”
Command “ls –l” is a long list which shows all
of the files and directories as well as how
large they are and when they were created.
◦ Ie.)
The command “mkdir name” creates a directory
within the current directory.
◦ Ex.) “mkdir oldmusic” creates the directory called
“oldmusic” within the current directory.
The command “cd .” stays in the current
The command “cd dirname” changes to a new
directory within the current one.
◦ Ex.)
◦ To move back up from the “oldmusic” directory to the
directory before it enter the command “cd ..”
To list the current pathway in the directory
tree use the command “pwd”.
◦ Ex.)
◦ To navigate to any directory in the tree enter the
command: “cd ~/name(1)/name(2)/…/name(n)”
 Ex.)
Once a directory is created, it can be removed
by using “rmdir”, however the directory has to
be empty first.
◦ Multiple directories can be removed by using
spaces between each directory.
 Ex.) “rmdir directory1 directory2” removes both
directory 1 and 2.
Displaying content of a file in the command
window can be done a few different ways.
◦ To display the entire file type: “cat filename”
 For example, “cat science.txt” would display the whole
science.txt document.
 Kind of hard to read.
◦ To have the file display better on the command
window type: “less filename”
 “less science.txt” would display science.txt in a way
that is easier to see in the window.
 Instead of using the arrow keys or a scroll on a mouse
you press the space bar and get out of the document
view by pressing the Q key.
◦ The “head file” command shows the first ten lines of a
file and the “tail file” command shows the last ten lines
of a file.
 The number of lines shown for both commands can be
specified by using “head –n file” or “tail –n file” where n is
any number less than or equal to the number of lines in the
 Multiple files can be seen at the same time.
 Ex.) Want to display the first 16 lines of 2 separate
documents “science.txt” and “zebras.txt”. Type in:
 “head -16 science.txt zebras.txt”. Both documents with 16
lines in the beginning of each will be the output.
◦ All of these displaying commands only work if the files
are in the same directory.
Copying files
◦ To copy a file use the “cp” command
◦ When a file is copied within the same directory, it is
saved under a different file name but has the same
content, and the original is still in the directory with it.
 Ex.) “cp file1 file2” copies the content of file1 into a new
◦ To copy a file to a new directory type:
 “cp file1 directory/”
Moving files
◦ To move a file use: “mv” command.
◦ Moving a file within the same directory is another way of
renaming a file.
◦ To move a file to another directory type:
 “mv file1 directory/”
Removing files
◦ Use the command “rm”.
 Ex.) “rm file1” removes file1 from the system.
Searching files
◦ To search a given file for any keyword type: “grep
‘keyword’ file”
 Ex.) Typing “grep science science.txt” outputs all of the lines
of the document which contain the word science with s in a
 “grep” can be combined with –i, -v, -n, or –c to narrow the
 Typing “grep –i ‘keyword’ file” ignores whether keyword is
uppercase or not and outputs all the lines which contain the
 Typing “grep –v ‘keyword’ file” ignores the keyword
and outputs all lines without it.
 “grep –n ‘keyword’ file” gives the line number and the
line with the keyword.
 Finally “grep –c ‘keyword’ file” gives the total number
of lines with the keyword.
◦ “grep” can be combined with some or all of the
letters to narrow the search more.
 Ex.) “grep –ivc science science.txt” ignores all instances
of the word science with any case and produces the
total number of lines in the document without the
word science.
Wildcards are used with list commands to search
for specific files in a directory.
◦ Wildcard “*” is used before or after a filename.
 Ex.) “ls *ide” lists all of the instances of files ending with ide,
and “ls ide*” lists all files beginning with ide.
◦ Wildcard “?” is used in a keyword to represent one letter
out of that word.
 Ex.) “ls ?one” lists all files that have 4 letters ending in “one”
like bone but not drone or stone.
The command “find” is a general search of the
◦ Ex.) find . -name "*.txt" –print
 starts with the current directory ( . ) and then moves through
the lower directories to find any file than ends in .txt and
lists them in the command window.
A file is made with certain access rights, which
means that one can either read, write, or execute
it. However, some files are programed in such a
way that they can’t be tampered with.
The access rights are shown by using the
command: “ls –l”
◦ The output code describing the access rights is given on
the far left of the output
 Ex.) The output for a file called “biglist.txt” is
 -rw-rw-rw-. 1 tony tony 68 Jan 31 21:57 biglist.txt
 -rw-rw-rw- is the access rights for the file, the left most space
indicates whether or not it is a file, directory, or something else.
The 9 spaces after that indicate access rights for the user,
group, or any others that have access to the file.
The “chmod” command allows you to
customize access rights for a file.
◦ Ex.) “chmod go-rwx biglist.txt” means that groups
or others can’t read or write the file biglist.txt.
◦ The negative sign before rwx removed the read,
write, and execute access rights for groups and
others. But left the user rights unchanged.
◦ Putting a positive sign before rwx would add those
rights for groups and others.
The command “ps” lists all the processes that
are running either in the foreground or
◦ It lists things like the process identification number
(PID) on the far left side and the commands on the
far right hand side for each process
 Ex.)
To kill a process determine the PID by
entering the command “ps”, then “kill PID”
◦ Ex.)
The command “man ‘commandname’” gives a
manual for any command. It gives a couple
paragraphs on what the command is and
common uses.
◦ Ex.) “man cp” gives the manual for the copy
The command “whatis ‘command’” gives a
couple uses for the command and short
descriptions for each command.
◦ Ex.)
The command “apropos ‘keyword’” can be
used if you forget a command.
◦ Ex.) “apropos move” gives all commands involving
the word move in a description.
Stonebank, Michael. "UNIX Tutorial for Beginners"
UNIX Tutorial for Beginners, 19 Oct 2001. Web. 2
Feb 2011.
riehemann, susanne. "Basic UNIX commands." Basic
UNIX commands. Computing Information for Stanford
Linguists , 07 Nov 2001. Web. 3 Feb 2011.

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