Basic Unix commands
User identification
-------------------
(Command) (Result)
hostname Displays name of current machine.
who Lists users who are logged on to current
machine.
whoami Returns current username (you).
finger [option] [username] Returns information about [username].
finger -l joe Shows long listing of user "joe".
Directory manipulation
----------------------
(Command) (Result)
pwd Prints the present working directory, i.e.,
prints the absolute pathname of current
directory
ls [option] [directory] Lists files in [directory] (or current
directory, if no [directory] given).
ls Lists all normal, (i.e., non-hidden)
files in current directory.
ls -a Lists all files in current directory,
including "hidden" files.
ls -l Displays long listing of normal files in
current directory, including file sizes
and permissions.
ls -al Combination of previous options.
ls -l letters Displays long listing of normal files in
the directory called "letters"
cd [directory] Changes directory -- i.e., makes
[directory] current.
cd letters Makes the directory "letters" current.
cd .. Makes the parent of the current
directory current.
cd Makes your home directory current.
mkdir [directory] Creates a directory called [directory].
rmdir [directory] Removes directory called [directory].
who Lists users who are logged on currently.
File manipulation
-----------------
(Command) (Result)
more [file] Lists contents of [file] with pause
between pages.
more office todo Lists contents of files "office" and
"todo", pausing between pages.
head [file] Lists the first few lines of [file].
tail [file] Lists the last few lines of [file].
rm [file] Deletes (removes) [file].
rm -r [directory] Recursively removes [directory] and all
of its subdirectories and files. Use
extreme caution when using this command!
cp [source] [target] Copies the contents of [source] file to
[target] file.
If [target] file exists, its data will
be replaced by that in [source] file.
If [target] file does not exist, then it
will be created containing the data in
[source] file.
[target] may be a directory, in which
case a copy of [source] file will be
placed in the directory [target].
cp myletter letterdir Creates "myletter" in the directory
called "letterdir"
mv [source] [target] Moves contents of [source] file to
[target] file, then removes [source] file.
If [target] exists then its data will be
replaced by that in [source].
If [target] does not exist then [source]
will be renamed [target file].
[target] may be a directory, in which
case [source] file will be moved into
that directory.
mv myletter theletter Renames "myletter" as "theletter"
mv myletter letters Where "letters" is a directory, will
move "myletter" into "letters".
cat [file] Displays contents of [file]
continuously.
cat joe Displays contents of "joe" to standard
output device.
tail [file] Lists the last few lines of [file].
cat [file] [file] ... Creates an output file that is the
[file] > [file] combination of all of the input files.
rm -r [directory] If output file exists, it will bend all
replaced.
cat part1 part2 > whole Creates a file "whole" that is a
combination of the files "part1" and to
"part2".
cat > [file] Creates a file consisting of input from
the keyboard. (Hold down the Control
key and type a "d" to terminate input.)
cat > temp Creates a file "temp" containing the
hello there data "hello there".
^D
cat >> [file] Appends input from the keyboard to file.
(Hold down the Control key and type a
"d" to terminate input.)
If file does not exist it will be
created.
cat >> temp Appends a line consisting of the words
last line "last line" to the file "temp".
^D
grep [option] '[string]' Returns every line of [file] which
[file] contains the character string [string].
grep 'Lee' folks Where the file "folks" contains
Jane Doe 103
Lee Kramer 33
Mike Randolph 11
Jane Krulee 94
Tom Selles 34
would return
Lee Kramer 33
grep -i 'lee' folks The "-i" option makes grep case-
insensitive, so this command would
return:
Jane Krulee 94
Lee Kramer 33
sort [options] [file] Sorts lines of [file].
sort folks > list Puts sorted version of the file "folks"
into the file "list":
rm -r [directory] Mike Randolph 11xists, it will bend all
Tom Selles 34
sort +1 folkst2 > whole Sorts the file "folks" according to the
SECOND word ("+1") in each line: and to
"part2".
sort +2rn folks Sorts the file "folks" in reverse order.
("r") according totrol THIRD word ("+2")
in each line, which is to be interpreted
as a numeric value ("n"):
Jane Doe 103
Jane Krulee 94
Tom Selles 34
Lee Kramer 33
Mike Randolph 11
Miscellaneous
-------------
(Command) (Result)
date Display today's date and the current
time.
mail [user] < [file] Mail [file] to [user].
passwd Change your password.
logout Exit the system.
Fps Display a list of all your processes
(i.e., running programs).
[command] & Start [command] as a "background"
process, returning to system prompt
immediately.
[command] > [file] Save output of [command] in [file].
[command] >> [file] Append output of [command] to [file].
[command1] | [command2] Feed output of [command1] as input into
[command2] ("pipeline").
man [command] Read on-line reference manual page for
[command].
rm -r [directory] Remove the [directory] and all of its
subdirectories.
For more information
--------------------
The following Unix documents are available for 2-hour checkout
from the EECS Computing Facilities Office, Tech rm. B626:
Getting Started with SunOS (Sun Microsystems)
Introducing the Unix System (McGilton and Morgan)
______________________________________________________________________________
Based on "A Summary of Basic Unix Commands," by Travis
Seymour, 1991.