This document provides a summary of common Unix commands organized into the following sections: files, file manipulation, directories, processes, users, managing files, printing, and miscellaneous commands. It lists commands and provides a brief description and syntax for each. The document also covers topics like I/O redirection, pipes, grep searching, C-shell features, variables, job control, and control keys.

1. Unix Commands
Unix January 2003
This quick reference lists commands, including a syntax diagram 2. Commands
and brief description. […] indicates an optional part of the 2.1. Command-line Special Characters
command. For more detail, use:
Quotes and Escape
man command Join Words "…"
Use man tcsh for the command language. Suppress Filename, Variable Substitution '…'
Escape Character
1. Files
Separation, Continuation
1.1. Filename Substitution Command Separation ;
Wild Cards ? * Command-Line Continuation (at end of line)
Character Class (c is any single character) [c…]
Range [c-c] 2.2. I/O Redirection and Pipes
Home Directory ~ Standard Output >
Home Directory of Another User ~user (overwrite if exists) >!
List Files in Current Directory ls [-l] Appending to Standard Output >>
List Hidden Files ls -[l]a Standard Input <
Standard Error and Output >&
1.2. File Manipulation Standard Error Separately
Display File Contents cat filename ( command > output ) >& errorfile
Copy cp source destination Pipes/ Pipelines command | filter [ | filter]
Move (Rename) mv oldname newname Filters
Remove (Delete) rm filename Word/Line Count wc [-l]
Create or Modify file pico filename Last n Lines tail [-n]
Sort lines sort [-n]
1.3. File Properties
Multicolumn Output pr -t
Seeing Permissions ls -l filename List Spelling Errors ispell
Changing Permissions chmod nnn filename
chmod c=p…[,c=p…] filename 2.3. Searching with grep
n, a digit from 0 to 7, sets the access level for the user grep Command grep "pattern" filename
(owner), group, and others (public), respectively. c is one of: command | grep "pattern"
u–user; g–group, o–others, or a–all. p is one of: r–read Search Patterns
access, w–write access, or x–execute access. beginning of line ^
Setting Default Permissions umask ugo end of line $
ugo is a (3-digit) number. Each digit restricts the default any single character .
permissions for the user, group, and others, respectively. single character in list or range […]
Changing Modification Time touch filename character not in list or range [^…]
Making Links ln [-s] oldname newname zero or more of preceding char. or pattern *
Seeing File Types ls -F zero or more of any character .*
1.4. Displaying a File with less escapes special meaning
Run less less filename
3. C-Shell Features.
Next line RETURN
Next Page SPACE
3.1 History Substitution
Previous line k Repeat Previous Command !!
Previous Page b Commands Beginning with str !str
Commands Containing str !?str[?]
1.5. Directories All Arguments to Prev. Command !*
Change Directory cd directory
Word Designators
Make New Directory mkdir directory All Arguments :*
Remove Directory rmdir directory Last Argument :$
Print Working (Show Current) Directory pwd First Argument :^
n'th Argument :n

2. Arguments x Through y :x-y Standard Commands whereis file
Modifiers Aliases and Commands which command
Print Command Line :p Describe Command whatis command
Substitute Command Line :[g]s/l/r/ Searching Out Files find dir -name name -print
dir is a directory name within which to search.
3.2 Aliases name is a filename to search for.
alias Command alias name 'definition'
6.2. Finding Changes
definition can contain escaped history substitution event
and Comparing Files diff leftfile rightfile
word designators as placeholders for command-line arguments. diff prefixes a less-than (<) to selected lines from leftfile
and a greater-than (>) to lines from rightfile.
3.3. Variable Substitution
Creating a Variable set var 6.3. Automating Tasks
Assigning a Value set var = value Create a Makefile pico Makefile
Expressing a Value $var A makefile consists of macro definitions and targets.
Displaying a Value echo $var Test Makefile make -n [target]
value is a single word, an expression in quotes, or an Run make make [target]
expression that results in a single word after variable,
6.4. Managing Disk Usage
filename and command substitution takes place.
Assigning a List set var = (list) Check Quota quota -v
list is a space-separated list of words, or an expression that Seeing Disk Usage df
results in a space-separated list. du -s
Selecting the n'th Item $var[n]
6.5. Combining and Compressing Files
Selecting all Items $var
Selecting a Range $var[x-y] Create a tarfile tar cf file.tar file1 file2 … fileN
Item Count $#var tar combines files but does not compress
Create a zipfile zip filename
3.4 foreach Lists Unzip a file unzip filename
Start foreach Loop foreach var (list)
foreach prompts for commands to repeat for each item in 7. Printing
list (with >), until you type end. Within the loop, $var 7.1 Formatting Output for Printing
stands for the current item in list. Paginate with Page Headers pr filename
in n columns pr -n filename
3.5. Command Substitution
Format for Laser Printer tex document
Replace Command with its Output on Command Line `…`
7.2 The Printer Queue
3.6 Job Control
Print a File lp [-dpr] filename
Run Command in the Background & lpcae filename
Stop Foreground Job CTRL-Z Check Quota lpquot
List of Background Jobs jobs List Queue lpq
Bring Job Forward %[n] Stop Job lprm
Resume Job in Background %[n] &
8. Miscellaneous
4. Processes
8.1 Miscellaneous Commands
Listing ps [-[ef]]
Terminating kill [-9] PID List Commands for Subject man -k subject
Timing time command Display Current Date and Time date
time is a number up to 4 digits. script is the name of a file Log off exit
containing the command line(s) to perform. Electronic Mail pine
Display Documentation man command
5. Users
8.2 Control Keys
Seeing Who is Logged In who
Abort Program CTRL-C
w
Backspace (Delete Last Character) CTRL-H
Seeing Your User Name whoami Pause Display on Screen CTRL-S
Resume Display after CTRL-S CTRL-Q
6. Managing Files Send Job to Background CTRL-Z followed by bg
6.1. Looking Up Files

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