UNIX Quick Reference Sheet

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 < file         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