UNIX Quick Reference Sheet


UNIX Quick Reference Sheet

This a summary of some common Unix commands. Some of these commands may not be on your Unix Systems and some commands may not work exactly as show.

1 Log In Session

1.1 Log In

Enter username at login: prompt. Be carefull - Unix is case sensitive.
Enter password at
password: prompt.

1.2 Change Password

passwd

1.3 Log Out

logout or exit

2 File System

2.1 Create a File

cat > file Enter text and end with ctrl-D

vi file Edit file using the vi editor

2.2 Make a Directory

mkdir directory-name

2.3 Display File Contents

cat file display contents of file

more file display contents of file one screenfull at a time.

view file a read only version of vi.

less file similar to, but more powerfull than more.

See the man page for more infomation on less.

2.4 Comparing Files

diff file1 file2 line by comparison

cmp file1 file2 byte by byte comparison

2.5 Changing Access Modes

chmod mode file1 file2 ...

chmod -R mode dir (changes all files in dir )

Mode Settings

u user (owner)

g group

o other

+ add permission

- remove permission

r read

w write

x execute

Example: chmod go+rwx public.html adds read, write, and execute permissions for group and other on public.html.

2.6 List Files and Directories

ls list contents of directory

ls -a include files with "." (dot files)

ls -l list contents in long format (show modes)

2.7 Move (or Rename) Files and Directories

mv src-file dest-file rename src-file to dest-file

mv src-file dest-dir move a file into a directory

mv src-dir dest-dir rename src-dir, or move to dest-dir

mv -i src dest copy & prompt before overwriting

2.8 Copy Files

cp src-file dest-file copy src-file to dest-file

cp src-file dest-dir copy a file into a directory

cp -R src-dir dest-dir copy one directory into another

cp -i src dest copy & prompt before overwriting

2.9 Remove File

rm file remove (delete) a file

rmdir dir remove an empty directory

rm -r dir remove a directory and its contents

rm -i file remove file, but prompt before deleting

2.10 Compressing files

compress file encode file, replacing it with file.Z

zcat file.Z display compressed file

uncompress file.Z decode file.Z, replacing it with file

2.11 Find Name of Current Directory

pwd display absolute path of working directory

2.12 Pathnames

simple:

One filename or directory name for accessing local file or directory.
Example:
foo.c

absolute:

List of directory names from root directory to desired file or directory name, each separated by /.
Example:
/src/shared

relative:

List of directory names from working directory to desired file or directory name, each separated by /.
Example:
Mail/inbox/23

2.13 Directory Abbreviations

~ Your home (login) directory

~username Another user's home directory

. Working (current) directory

.. Parent of working directory

../.. Parent of parent directory

2.14 Change Working Directory

cd / go to the root directory

cd go to your login (home) directory

cd ~username go to username's login (home) directory

not allowed in the Bourne shell

cd ~username/directory go to username's indicated directory

cd .. go up one directory level from here

cd ../.. go up two directory levels from here

cd /full/path/name/from/root change directory to absolute path named

note the leading slash

cd path/from/current/directory change directory to path relative to here.

note there is no leading slash

3.0 Commands

3.1 Date

date display date and time

3.2 Wild Cards

? single character wild card

* Arbitrary number of characters

3.3 Printing

lpr file print file on default printer

lpr -Pprinter file print file on printer

lpr -c# file print # copies of file

lpr -d file interpret file as a dvi file

lpq show print queue (-Pprinter also valid)

lprm -# remove print request # (listed with lpq)

3.4 Redirection

command > file direct output of command to file instead of

to standard output (screen), replacing current

contents of file

command > > file as above, except output is appended to the current

contents of file

command <> command receives input from file instead of

from standard input (keyboard)

cmd1 | cmd2 "pipe" output of cmd1 to input of cmd2

script file log everything displayed on the terminal to file;

end with exit

4 Search Files

grep string filelist show lines containing string in any file

in filelist

grep -v string filelist show lines not containing string

grep -i string filelist show lines containing string, ignore case

5 Information on Users

finger user or

finger user@machine get information on a user

finger @machine list users on machine

who list current users

6 Timesavers

6.1 Aliases

alias string command abbreviate command to string

6.2 History: Command Repetition

Commands may be recalled

history show command history

!num repeat command with history number num

!str repeat last command beginning with string str

!! repeat entire last command line

!$ repeat last word of last command line

7.0 Process and Job Control

7.1 Important Terms

pid Process IDentification number. See section 7.2.

job-id Job identification number. See section 7.2.

7.2 Display Process and/or Job IDs

ps report processes and pid numbers

ps gx as above, but include "hidden" processes

jobs report current jobs and job id numbers

7.3 Stop (Suspend) a Job

ctrl-Z NOTE:process still exists!

7.4 Run a Job in the Background

To start a job in background add & to the end of the command.

Example: xv foo.gif &


To force a running job into the background:

ctrl-Z stop the job

bg "push" the job into the background

7.5 Bring a Job to the Foreground

fg bring a job to foreground

fg %job-id foreground by job-id (see 7.2)

7.6 Kill a Process or Job

ctrl-C kill foreground process

kill -KILL pid# see 7.2 for

kill -KILL %job-id# displaying pids & job-ids

8.0 Mail Handler (MH)

MH commands are issued directly to the terminal.

inc incorporate new mail

scan show list of mail messages

show show current message

next show next message

prev show previous message

repl reply to current message

forw forward current message

comp compose a mail message

rmm remove current mail message

cmd -help print help on mh commmand cmd

The file .mh_profile is used to enable/disable MH features. man mh-profile for more information.

9.0 On-line Assistance

On-line Documentation

man command-name display on-line manual pages

man -k string list one-line summaries of manual pages containing string