Basic unix commands

 



Command
Action
Example
alias
Creates a temporary name for a Unix command.
alias   name command

To remove an alias:
unalias   name
ansiprint
Prints a file to a printer connected to your computer.
ansiprint   file
assets
Displays your account resources, use, and threshold.
     
bg
Places a suspended job in the background.
     
cat
Displays a specified file.
cat   file
cd
Changes current directory to a different directory.
cd   directory

To change back to your home directory:
cd    

Directory abbreviations:
~     Home directory
..     Parent directory
.       Current working directory

chmod
Changes permission status for a file or directory.
chmod   code file
chmod   code directory

To keep a file private:
chmod   600 file

To give everyone read permission:
chmod   664 file
compress
Reduces the size of a file and adds .Z to the file's name.
compress   file

To restore a compressed file:
uncompress   file.Z
cp
Makes a copy of a file.
cp   file1 file2

To copy a file into a different directory:
cp   file directory

To inquire before overwriting an existing file:
cp -i   file1 file2
diff
Compares two files and displays the differences.
     
fg
Restarts a suspended job in the foreground.
     
finger
Displays user information at the specified computer.
finger   userid@computer

To change your finger entry information:
chfn
ftp
Starts the file transfer program with a remote computer.
ftp   address
grep
Finds lines in a file matching a character pattern.
grep -icvn   pattern file

-i     Ignores case
-c     Lists count of lines that contain pattern
-v     Lists all lines except those with pattern
-n     Lists line number for each found pattern

head
Displays the first ten lines of a file.
head   file

To display the first n number of lines:
head -n   file
help
Displays an online help note.
help   note

To display a list of help notes:
help -l
history
Displays a list of your most recent commands.
history

To repeat the nth command from the list:
!   n

To repeat your most recent command:
!!
jobs
Displays active jobs and their corresponding job numbers.
jobs

To start a job in the background:
job   &

To return a job to the foreground by the job number:
fg   %number

To send a running job to the background:
z bg
kill
Terminates a process by its process identification number.
kill   pid

To use the strongest form of the kill command:
kill -9   pid
logout
Ends your computer session.

ls
Lists the files and subdirectories in your current directory.
ls -Fltra

-l     Lists long format
-t     Lists by modification time
-r     Lists in reverse order
-F     Lists file type with special character
-a     Lists all files including dot (.) files

lynx
Starts a text-only Web browser session
lynx

Starts a Web browser session at a specific Web address.
lynx   url
man
Displays Unix Manual entry for a command.
man   command

To search Manual Index for a keyword or topic:
man -k   keyword
mesg
Displays your talk and write message access status.
mesg

To set your message status to yes or no:
mesg y (or n)
mkdir
Creates a new directory within your current directory.
mkdir   directory
more
Displays a file one screen at a time.
more   file

Use to scroll forward and q to quit.

mv
Moves a file to a different directory.
mv   file directory

Moves a directory to a second directory.
mv   directory1 directory2

To rename file1 as file2:
mv   file1 file2

To rename directory1 as directory2:
mv   directory1 directory2

To inquire before overwriting an existing file:
mv -i   file1 file2
passwd
Starts program to change account password.

pico
Starts the Pico text editor with a file.
pico   file
pine
Starts the Pine® electronic mail program.

ps
Displays processes and their corresponding process identification numbers.

pwd
Displays absolute pathname of current directory.

rm
Permanently deletes a file.
rm   file

To verify prior to removal:
rm -i   file
rmdir
Deletes an empty directory.
rmdir   directory

To verify prior to removal:
rmdir -i   directory
spell
Checks the spelling in a file.
spell   file
telnet
Starts a telnet session with a remote computer.
telnet   address
vi
Starts the vi text editor with a file.
vi   file
w
Displays a list of who is on system.

wc
Counts lines, words, and characters in a file.
wc   file



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