Unix Commands

1. Files

1.1. Filename Substitution

Wild Cards ? *

Character Class (c is any single character) [c…]

Range [c-c]

Home Directory ~

Home Directory of Another User ~user

List Files in Current Directory ls [-l]

List Hidden Files ls -[l]a

1.2. File Manipulation

Display File Contents cat filename

Copy cp source destination

Move (Rename) mv oldname newname

Remove (Delete) rm filename

Create or Modify file pico filename

1.3. File Properties

Seeing Permissions ls -l filename

Changing Permissions chmod nnn filename

chmod c=p…[,c=p…] filename

n, a digit from 0 to 7, sets the access level for the user

(owner), group, and others (public), respectively. c is one of:

u–user; g–group, o–others, or a–all. p is one of: r–read

access, w–write access, or x–execute access.

Setting Default Permissions umask ugo

ugo is a (3-digit) number. Each digit restricts the default

permissions for the user, group, and others, respectively.

Changing Modification Time touch filename

Making Links ln [-s] oldname newname

Seeing File Types ls -F

1.4. Displaying a File with less

Run less less filename

Next line RETURN

Next Page SPACE

Previous line k

Previous Page b

1.5. Directories

Change Directory cd directory

Make New Directory mkdir directory

Remove Directory rmdir directory

Print Working (Show Current) Directory pwd

2. Commands

2.1. Command-line Special Characters

Quotes and Escape

Join Words "…"

Suppress Filename, Variable Substitution '…'

Escape Character \

Separation, Continuation

Command Separation ;

Command-Line Continuation (at end of line) \

2.2. I/O Redirection and Pipes

Standard Output >

(overwrite if exists) >!

Appending to Standard Output >>

Standard Input <

Standard Error and Output >&

Standard Error Separately

( command > output ) >& errorfile

Pipes/ Pipelines command | filter [ | filter]

Filters

Word/Line Count wc [-l]

Last n Lines tail [-n]

Sort lines sort [-n]

Multicolumn Output pr -t

List Spelling Errors ispell

2.3. Searching with grep

grep Command grep "pattern" filename

command | grep "pattern"

Search Patterns

beginning of line ^

end of line $

any single character .

single character in list or range […]

character not in list or range [^…]

zero or more of preceding char. or pattern *

zero or more of any character .*

escapes special meaning \

3. C-Shell Features.

3.1 History Substitution

Repeat Previous Command !!

Commands Beginning with str !str

Commands Containing str !?str[?]

All Arguments to Prev. Command !*

Word Designators

All Arguments :*

Last Argument :$

First Argument :^

n'th Argument :n

Arguments x Through y :x-y

Modifiers

Print Command Line :p

Substitute Command Line :[g]s/l/r/

3.2 Aliases

alias Command alias name 'definition'

definition can contain escaped history substitution event

and

word designators as placeholders for command-line arguments.

3.3. Variable Substitution

Creating a Variable set var

Assigning a Value set var = value

Expressing a Value $var

Displaying a Value echo $var

value is a single word, an expression in quotes, or an

expression that results in a single word after variable,

filename and command substitution takes place.

Assigning a List set var = (list)

list is a space-separated list of words, or an expression that

results in a space-separated list.

Selecting the n'th Item $var[n]

Selecting all Items $var

Selecting a Range $var[x-y]

Item Count $#var

3.4 foreach Lists

Start foreach Loop foreach var (list)

foreach prompts for commands to repeat for each item in

list (with >), until you type end. Within the loop, $var

stands for the current item in list.

3.5. Command Substitution

Replace Command with its Output on Command Line `…`

3.6 Job Control

Run Command in the Background &

Stop Foreground Job CTRL-Z

List of Background Jobs jobs

Bring Job Forward %[n]

Resume Job in Background %[n] &

4. Processes

Listing ps [-[ef]]

Terminating kill [-9] PID

Timing time command

time is a number up to 4 digits. script is the name of a file

containing the command line(s) to perform.

5. Users

Seeing Who is Logged In who

w

Seeing Your User Name whoami

Standard Commands whereis file

Aliases and Commands which command

Describe Command whatis command

Searching Out Files find dir -name name -print

dir is a directory name within which to search.

name is a filename to search for.

6.2. Finding Changes

Comparing Files diff leftfile rightfile

diff prefixes a less-than (<) to selected lines from leftfile

and a greater-than (>) to lines from rightfile.

6.3. Automating Tasks

Create a Makefile pico Makefile

A makefile consists of macro definitions and targets.

Test Makefile make -n [target]

Run make make [target]

6.4. Managing Disk Usage

Check Quota quota -v

Seeing Disk Usage df

du -s

6.5. Combining and Compressing Files

Create a tarfile tar cf file.tar file1 file2 … fileN

tar combines files but does not compress

Create a zipfile zip filename

Unzip a file unzip filename

7. Printing

7.1 Formatting Output for Printing

Paginate with Page Headers pr filename

in n columns pr -n filename

Format for Laser Printer tex document

7.2 The Printer Queue

Print a File lp [-dpr] filename

lpcae filename

Check Quota lpquot

List Queue lpq

Stop Job lprm

8. Miscellaneous

8.1 Miscellaneous Commands

List Commands for Subject man -k subject

Display Current Date and Time date

Log off exit

Electronic Mail pine

Display Documentation man command

8.2 Control Keys

Abort Program CTRL-C

Backspace (Delete Last Character) CTRL-H

Pause Display on Screen CTRL-S

Resume Display after CTRL-S CTRL-Q

Send Job to Background CTRL-Z followed by bg