THE UNIX ACRONYM LIST

Acronym	Type	Meaning
.a	Ext	archive
A	HTML	anchor
Aacute	HTML	A with accent acute (also: Oacute etc.)
Acirc	HTML	A with accent circonflexe (also: Ocirc etc.)
ACK	ASCII	acknowledge
adb	Cmd	Algol or absolute or assembly or advanced debugger (see here)
Aelig	HTML	AE ligature (also: aelig)
Agrave	HTML	A with accent grave (also: Ograve etc.)
AIX	OS	Advanced Interactive Executive
ALT	HTML	alternative (image for text-only browsers)
ANSI	Org	American National Standards Institute
ar	Cmd	archiver
ARP	Prot	address resolution protocol
ARPA	Org	Advanced Research Project Agency
as	Cmd	assembler
ASCII	ASCII	American standard code for information interchange
atob	Cmd	ASCII to binary
atof	Fct	ASCII to float
atoi	Fct	ASCII to integer
Auml	HTML	A with umlaut (also: Ouml etc.)
A/UX	OS	Apple Unix
awk	Cmd	Aho, Weinberger, Kernighan (names of program authors)
B	HTML	bold
bash	Cmd	Bourne again shell
bc	Cmd	better or basic calculator (in early Unix versions: B compiler)
BEL	ASCII	bell
bg	Builtin	background
biff	Prot	not an acronym (name of a dog)
bin	Dir	binaries
bootp	Prot	bootstrap protocol
BR	HTML	break (line)
brk	Fct	break
BS	ASCII	backspace
BSD	OS	Berkeley Software Distribution
bsearch	Fct	binary search
bsh	Cmd	Bourne shell (name of program author)
btoa	Cmd	binary to ASCII
.c	Ext	C
.cpp	Ext	C++ ("C plus plus")
.cxx	Ext	C++ (the plus signs are rotated 45 °; found on file systems that don't allow plus signs in file names)
.C	Ext	C++ (on systems where CC is the C++ compiler)
C	Lang	Successor of B (which is the successor of BCPL = Basic Combined Programming Language; see here)
C++	Lang	Successor of C (++ is the C increment operator)
c89	Cmd	1989 (ANSI/ISO-)C compiler
cal	Cmd	calendar
calloc	Fct	count or cleared allocation (?) (see here)
CAN	ASCII	cancel
cat	Cmd	concatenate
cb	Cmd	C beautifier
cc	Cmd	C compiler
Ccedil	HTML	C with cedille (also: ccedil)
cd	Builtin	change directory
CDE	Misc	common desktop environment
chargen	Prot	character generator
chdir	Fct	change directory
chgrp	Cmd	change group
chmod	Cmd	change mode
chown	Cmd	change owner
chsh	Cmd	change shell
ci	Cmd	check in
cmp	Cmd	compare
co	Cmd	check out
.com	TLD	commercial
comm	Cmd	common
cp	Cmd	copy
cpio	Cmd	copy (archive files) in and out (of an archive)
cpp	Cmd	C pre-processor
CR	ASCII	carriage return
crc	Misc	cyclic redundancy check
cron	Cmd	Chronos (greek god)
csh	Cmd	C shell (resembles the syntax of the C programming language)
ctime	Fct	convert time
ctype.h	Hdr	character types
CVS	Misc	concurrent versions system
...d	Cmd	daemon (e. g. inetd = internet daemon)
daemon	Misc	disk and execution monitor
dbx	Cmd	extended debugger (?) or DBX (=extended decibel, noise reduction system; see here)
dc	Cmd	desk calculator
DC1	ASCII	device control 1 (also: DC2, DC3, DC4)
DCE	Misc	distributed computing environment
dd	Cmd	Optinion 1: Dataset Definition (named after the OS/3x0 JCL DD command who's syntax it also ripped off as a joke; see here) Opinion 2: Copy and convert (called dd because cc is the C compiler; see here) Opinions 3-n: data, device, disk, dump in various combinations
DD	HTML	dictionary definition
DEC	Org	Digital Equipment Corporation
DEL	ASCII	delete
dev	Dir	devices
df	Cmd	disk free
DHCP	Prot	dynamic host configuration protocol
diff	Cmd	difference
diff3	Cmd	differences of three files
DIR	HTML	directory
dirname	Cmd	directory name
DIV	HTML	division
DL	HTML	define list
DLE	ASCII	data link escape
DNS	Misc	domain name server
DT	HTML	dictionary term
du	Cmd	disk usage
dup	Fct	duplicate
DVI	Fmt	device independant
DWARF	Fmt	debug with arbitrary record format
ed	Cmd	editor
.edu	TLD	educational
egrep	Cmd	extended grep
ELF	Fmt	extensible linking format
elm	Cmd	electronic mail
EM	ASCII	end of medium
EM	HTML	emphasize
emacs	Cmd	editing macros Sometimes: Eight megabytes and constantly swapping or: Escape Meta Alternate Control Shift or: Emacs makes any computer slow
ENQ	ASCII	enquiry
env	Builtin	environment
EOT	ASCII	end of transmission
eqn	Cmd	equation
errno	Misc	error number
esac	Builtin	case (reversed)
ESC	ASCII	escape
etc	Dir	et cetera
ETB	ASCII	end of transmission block
Eth	HTML	?
ETX	ASCII	end of text
eval	Cmd	evaluate
ex	Cmd	extended editor (?)
exec	Builtin	execute
execl	Fct	execute list
execle	Fct	execl with environment
execlp	Fct	execl with path search
execv	Fct	execute (with arguments passed in a) vector
execve	Fct	execv with environment
execvp	Fct	execv with path search
expr	Cmd	expression
fc	Cmd	fix command
fd	Spc	floppy disk
fd	Dir	file descriptors (as in /dev/fd)
fcntl	Fct	file control
FF	ASCII	form feed
fg	Builtin	foreground
fgrep	Cmd	fixed-string grep
fi	Builtin	if (reversed)
fmt	Cmd	format
fprintf	Fct	file print formatted
FS	ASCII	file separator
fscanf	Fct	file scan formatted
fsck	Cmd	file system check
FSF	Org	Free Software Foundation
fstab	File	file system table
ftio	Cmd	fast tape input/output
ftok	Fct	file token
ftp	Cmd	file transfer protocol
fuser	Cmd	file user
ftw	Fct	file tree walk
g...	Cmd	GNU
getty	Cmd	get tty
GIF	Fmt	graphic interchange format (sometimes: girls in files)
glob	Misc	global (as in "globbing")
GNU	Misc	GNU is not Unix
.gov	TLD	government
grep	Cmd	global regular expression print (from the ed subcommand g/RE/p where RE is a regular expression)
GS	ASCII	group separator
.gz	Ext	GNU zip
.h	Ext	header
H1	HTML	header 1 (also: H2 ... H6)
HALIGN	HTML	horizontal alignment
hd	Spc	hard disk
HP	Org	Hewlett Packard
HPUX	OS	Hewlett-Packard Unix
HR	HTML	horizontal ruler
HREF	HTML	hypertext reference
HT	ASCII	horizontal tabulator
HTML	Fmt	hypertext markup language
http	Prot	hypertext transfer protocol
.i	Ext	intermediate (?)
I	HTML	italic
IBM	Org	International Business Machines
ICMP	Prot	Internet control message protocol
id	Cmd	identity
IEEE	Org	Institute of Electrical and Electronical Engineers
IFS	Env	internal field seperators
IMG	HTML	image
imake	Cmd	interface to make
IMAP2	Prot	interim mail access protocol, version 2
inode	Misc	index node (if anything at all, see here)
ioctl	Fct	input/output control
IP	Prot	Internet protocol
irc	Cmd	internet relay chat
isatty	Fct	is a tty
ISO	Org	not an acronym (from greek "isos"; see here)
Java	Lang	not an acronym (named after the island where coffee comes from)
JPEG	Fmt	joint pictures expert group
jsh	Cmd	job-control shell
KBD	HTML	keyboard
kmem	Spc	kernel memory
ksh	Cmd	Korn shell (from David Korn, program author)
.l	Ext	lex
LANG	Env	language
ld	Cmd	link editor or loader
lex	Cmd	lexical analyser
LF	ASCII	line feed
LI	HTML	list item
lib	Dir	library
lint	Cmd	not an acronym (removes lint from programs)
Linux	OS	from Linus (Torvalds; program author's name) and Unix
lharc	Cmd	Lempl-Huffman archiver (algorithm authors)
ln	Cmd	link
LOGNAME	Env	log-in name
logname	Cmd	log-in name
lorder	Cmd	library order
lp	Spc	line printer
lpc	Cmd	line printer control
lpd	Cmd	line printer daemon
lpp	Dir	licensed program products
lpq	Cmd	line printer queue
lpr	Cmd	line print
lprm	Cmd	line printer remove (from queue)
ls	Cmd	list
m4	Cmd	macro processor version 4 (successor of M3)
malloc	Fct	memory allocation
man	Cmd	manual
mem	Spc	memory
MHS	Misc	message handling system
.mil	TLD	military
MIME	Misc	multi-purpose Internet mail extensions
Minix	OS	miniature Unix
mkfs	Cmd	make file system
mknod	Cmd	make node
motd	File	message or motto of the day
MPEG	Fmt	motion picture expert group
MULTICS	OS	multiplexed information and computing system
mv	Cmd	move
mvdir	Cmd	move directory
mwm	Cmd	Motif window manager
NAK	ASCII	negative acknowledge
nawk	Cmd	new awk
nbsp	HTML	non-breaking space
.net	TLD	network
NFS	Misc	network file system
NIC	Org	Network Information Center
NIS	Misc	network information system
NL	ASCII	new line
nl	Cmd	number lines
nm	Cmd	names
nn	Cmd	no news
nntp	Prot	network news transfer protocol
NOBR	HTML	no break
nohup	Cmd	no hang-up
.nom	TLD	nomenclature
nroff	Cmd	new roff
NTP	Prot	network time protocol
NUL	ASCII	null
.o	Ext	object code
oclock	Cmd	O shaped clock (?)
od	Cmd	octal dump
OL	HTML	ordered list
.org	TLD	organization
OSF	Org	Open Software Foundation
OSI	Org	Open Systems Interconnection
P	HTML	paragraph
passwd	Cmd	password
pax	Cmd	portable archive exchange
PBM	Fmt	portable bitmap
pcc	Cmd	portable C compiler
pclose	Fct	process close
PDP	Misc	programmed data processor (as in PDP-7, PDP-11, see here)
Perl	Lang	practical extraction and report language
pg	Cmd	pager
pgp	Cmd	pretty good privacy
pico	Cmd	pine composer
pine	Cmd	first pine is nearly elm, later pine is no longer elm and finally program for Internet news and e-mail (see here)
ping	Cmd	not an acronym (named after the sound that a sonar makes, see here)
PNG	Fmt	portable network graphics
POP3	Prot	post office protocol version 3
popd	Builtin	pop directory (off stack)
popen	Fct	process open
Posix	Misc	portable operating system interface for Unix
povray	Cmd	persistence of vision raytracer
PPP	Prot	point-to-point protocol
PPTP	Prot	point-to-point tunneling protocol
pr	Cmd	prepare (for printing)
prs	Cmd	print revision summary
printcap	File	printer capability
PRE	HTML	pre-formatted
printf	Fct	print formatted
proc	Dir	processes (/proc pseudo directory)
prof	Cmd	profiler
.ps	Ext	Postscript
ps	Cmd	process status
PS1	Env	prompt string 1 (same for PS2 etc.)
pty	Spc	pseudo tty
pushd	Builtin	push directory
pwd	Cmd	print work directory
qdaemon	Cmd	queue daemon
qsort	Fct	quick sort
r...	Spc	raw (e. g. rfd0 = raw floppy disk 0)
r...	Cmd	remote (e. g. rsh = remote shell)
RAID	Misc	redundant array of inexpensive or independant disks
ranlib	Cmd	(create) random access library
RARP	Prot	reverse ARP
rc	Misc	run commands
rcp	Cmd	remote copy
rcs	Cmd	revision control system
realloc	Fct	re-allocate
.rec	TLD	recreation
regcmp	Fct	regular expression compile
regex	Fct	regular expression execute
RFC	Misc	request for comments
RFD	Misc	request for discussion
RFO	Misc	request for opinions
RIP	Prot	routing information protocol
rlogin	Cmd	remote login
rm	Cmd	remove
rmdel	Cmd	remove delta
rmail	Cmd	restricted mail (see here)
rmdir	Cmd	remove directory
rmt	Cmd	remote magnetic tape
rmt	Spc	raw magnetic tape
rsh	Cmd	remote shell or restricted shell (sometimes Rsh)
roff	Cmd	run-off (similar program)
RS	ASCII	record separator
rz	Cmd	receive Z-modem
.sa	Ext	stub archive
SAMP	HTML	sample
sar	Cmd	system activity report
sbin	Dir	superuser binaries
sbrk	Fct	segment break
scanf	Fct	scan formatted
sccs	Misc	source code control system
SCO	Org	Santa Cruz Operation
SCSI	Misc	small computer systems interface
sdb	Cmd	symbolic debugger
sed	Cmd	stream editor
SGML	Fmt	standard generalized markup language
sh	Cmd	shell
shar	Cmd	shell archive
shtml	Prot	server-parsed HTML
SI	ASCII	shift in
Sinix	OS	Siemens Unix
SIGABRT	Sig	signal: abort
SIGALRM	Sig	signal: alarm clock
SIGBUS	Sig	signal: bus error
SIGCHLD	Sig	signal: (exit of a) child
SIGCONT	Sig	signal: continue
SIGEMT	Sig	signal: EMT instruction
SIGFPE	Sig	signal: floating point exception
SIGHUP	Sig	signal: hangup
SIGILL	Sig	signal: illegal instruction
SIGINT	Sig	signal: interruption
SIGIO	Sig	signal: input/output (possible or completed)
SIGSEGV	Sig	signal: segmentation violation
SIGSYS	Sig	signal: (bad argument to) system call
SIGTERM	Sig	signal: terminate
SIGTTIN	Sig	signal: TTY input
SIGTTOU	Sig	signal: TTY output
SIGTSTP	Sig	Signal: terminal stop
SIGURG	Sig	signal: urgent I/O condition
SIGUSR1	Sig	signal: user-defined signal 1 (also: SIGUSR2)
SIGWINCH	Sig	signal: window (size) changed
SLIP	Prot	serial line Internet protocol
SMTP	Prot	simple mail transfer protocol
SNMP	Prot	simple network management protocol
stdarg.h	Hdr	standard (conforming variable) arguments
stddef.h	Hdr	standard definitions
stdio.h	Hdr	standard input/output
stdlib.h	Hdr	standard library
.so	Ext	shared object
SO	ASCII	shift out
SOH	ASCII	start of header
Spam	Misc	not an acronym (canned beef stew, originally an allusion to ham; used for mass mailings/postings because of a sketch from Monty Python's Flying Circus, see here)
SPC	ASCII	space
spool	Misc	simultaneous peripheral operation on-line
sprintf	Fct	string print formatted
srand	Fct	seed random number generator
SRC	HTML	source
sscanf	Fct	string scan formatted
strcspn	Fct	string character span
strcat	Fct	string concatenate
strchr	Fct	string (find) character
strcmp	Fct	string compare
strcpy	Fct	string copy
strlen	Fct	string length
strpbrk	Fct	string pointer break
strrchr	Fct	string (find from the right) character
strspn	Fct	string span
strstr	Fct	string (find) string
strtol	Fct	string to long
strtok	Fct	string tokenize
stty	Cmd	set tty
STX	ASCII	start of text
su	Cmd	superuser (see here)
SUB	ASCII	substitute
SUB	HTML	subscript
SUP	HTML	superscript
SYN	ASCII	synchronous idle
sync	Cmd	synchronize
SYSV	OS	System V (= roman 5)
SVR4	OS	System V release 4
sz	Cmd	send Z-modem
szlig	HTML	sz ligature
TAB	ASCII	tabulator
tar	Cmd	tape archive(r)
tbl	Cmd	table
Tcl	Lang	tool command language
tclsh	Cmd	Tcl shell
TCP	Prot	transmission control protocol
tcsh	Cmd	Tenex C shell (see here)
TD	HTML	table data
tee	Cmd	T pipe fitting (plumbing device)
telnet	Cmd	terminal over network
termcap	Dir	terminal capability
terminfo	Dir	terminal information
tex	Cmd	tau epsilon chi (greek letters)
tftp	Prot	trivial file transfer protocol
.tgz	Ext	tar gz
TH	HTML	table header
TIFF	Fmt	tagged image file format
Tk	Lang	toolkit
tmp	Dir	temporary
TNS	Prot	transparent network substrate
tr	Cmd	translate
TR	HTML	table row
troff	Cmd	typesetter roff
tsh	Cmd	trusted shell
tsort	Cmd	topological sort
TT	HTML	teletype
ttt	Cmd	tic tac toe
tty	Spc	teletype
TZ	Env	time zone
u	Dir	user
U	HTML	underline
ucb	Dir	University of California at Berkeley
UDP	Prot	user datagram protocol
UL	HTML	unsorted list
ulimit	Cmd	user's limit
umask	Fct	user's (file creation) mask (see here)
uname	Cmd	Unix name (?)
uniq	Cmd	unique
unistd.h	Hdr	Unix standard
Unix	OS	From UNICS, a pun on its predecessor MULTICS (see here)
URL	Misc	uniform resource locator
US	ASCII	unit separator
Usenet	Misc	user's network
USL	Org	Unix System Laboratories
usr	Dir	unix shared resources
utmp	File	temporary file with user information
uucp	Cmd	Unix-to-Unix communication protocol
,v	Ext	version
VALIGN	HTML	vertical alignment
VAR	HTML	variable
var	Dir	variable
varargs.h	Hdr	variable (number of) arguments
vi	Cmd	visual (from the ex subcommand vi that switches into visual mode)
vim	Cmd	vi improved (previously: vi imitation)
vprintf	Fct	varargs print formatted
VT	ASCII	vertical tabulator
VT	Misc	video terminal (as in VT-52, VT-100)
W3C	Org	Word Wide Web Consortium
wall	Cmd	write all
wc	Cmd	word count
wish	Cmd	windowing shell
...wm	Cmd	window manager
WWW	Misc	world wide web
X	Misc	Successor of W (windowing system), usually followed by a version number (e. g. X11)
xargs	Cmd	extended arguments
XBM	Fmt	X bitmap
xdm	Cmd	X display manager
xdpr	Cmd	X dump print
XENIX	OS	Xenos Unix
xfd	Cmd	X font display
xmkmf	Cmd	X make makefile
XMP	HTML	example
XML	Fmt	extensible markup language
XOFF	ASCII	transmission off
XON	ASCII	transmission on
XPM	Fmt	X pixel map
xrdb	Cmd	X resource database
xwd	Cmd	X window dump
xwud	Cmd	X window un-dump
.y	Ext	yacc
yacc	Cmd	yet another compiler compiler
yp	Misc	yellow pages
.Z	Ext	? (not Ziv because compress uses Huffmann encoding)
zip	Cmd	Ziv packer (algorithm author)