Basic Unix Commands--2

This quick reference lists commands, including a syntax diagram and brief description. […] indicates an optional part of the command. For more detail, use:

man command

Use  man tcsh for the command language.

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

6. Managing Files

6.1. Looking Up Files

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