ASCII Chart

00000000	nul	00000001	soh	00000010	stx	00000011	etx	00000100	eot	00000101	enq	00000110	ack	00000111	bel
00001000	bs	00001001	tab	00001010	nl	00001011	vt	00001100	ff	00001101	cr	00001110	so	00001111	si
00010000	dle	00010001	dc1	00010010	dc2	00010011	dc3	00010100	dc4	00010101	nak	00010110	syn	00010111	etb
00011000	can	00011001	em	00011010	sub	00011011	esc	00011100	fs	00011101	gs	00011110	rs	00011111	us
00100000	sp	00100001	!	00100010	"	00100011	#	00100100	$	00100101	%	00100110	&	00100111	'
00101000	(	00101001	)	00101010	*	00101011	+	00101100	,	00101101	-	00101110	.	00101111	/
00110000	0	00110001	1	00110010	2	00110011	3	00110100	4	00110101	5	00110110	6	00110111	7
00111000	8	00111001	9	00111010	:	00111011	;	00111100	<	00111101	=	00111110	>	00111111	?
01000000	@	01000001	A	01000010	B	01000011	C	01000100	D	01000101	E	01000110	F	01000111	G
01001000	H	01001001	I	01001010	J	01001011	K	01001100	L	01001101	M	01001110	N	01001111	O
01010000	P	01010001	Q	01010010	R	01010011	S	01010100	T	01010101	U	01010110	V	01010111	W
01011000	X	01011001	Y	01011010	Z	01011011	[	01011100	\	01011101	]	01011110	^	01011111	_
01100000	`	01100001	a	01100010	b	01100011	c	01100100	d	01100101	e	01100110	f	01100111	g
01101000	h	01101001	i	01101010	j	01101011	k	01101100	l	01101101	m	01101110	n	01101111	o
01110000	p	01110001	q	01110010	r	01110011	s	01110100	t	01110101	u	01110110	v	01110111	w
01111000	x	01111001	y	01111010	z	01111011	{	01111100	\|	01111101	}	01111110	~	01111111	del

Octal

000	nul	001	soh	002	stx	003	etx	004	eot	005	enq	006	ack	007	bel
010	bs	011	tab	012	nl	013	vt	014	ff	015	cr	016	so	017	si
020	dle	021	dc1	022	dc2	023	dc3	024	dc4	025	nak	026	syn	027	etb
030	can	031	em	032	sub	033	esc	034	fs	035	gs	036	rs	037	us
040	sp	041	!	042	"	043	#	044	$	045	%	046	&	047	'
050	(	051	)	052	*	053	+	054	,	055	-	056	.	057	/
060	0	061	1	062	2	063	3	064	4	065	5	066	6	067	7
070	8	071	9	072	:	073	;	074	<	075	=	076	>	077	?
100	@	101	A	102	B	103	C	104	D	105	E	106	F	107	G
110	H	111	I	112	J	113	K	114	L	115	M	116	N	117	O
120	P	121	Q	122	R	123	S	124	T	125	U	126	V	127	W
130	X	131	Y	132	Z	133	[	134	\	135	]	136	^	137	_
140	`	141	a	142	b	143	c	144	d	145	e	146	f	147	g
150	h	151	i	152	j	153	k	154	l	155	m	156	n	157	o
160	p	161	q	162	r	163	s	164	t	165	u	166	v	167	w
170	x	171	y	172	z	173	{	174	\|	175	}	176	~	177	del

Decimal

00	nul	01	soh	02	stx	03	etx	04	eot	05	enq	06	ack	07	bel
08	bs	09	tab	10	nl	11	vt	12	ff	13	cr	14	so	15	si
16	dle	17	dc1	18	dc2	19	dc3	20	dc4	21	nak	22	syn	23	etb
24	can	25	em	26	sub	27	esc	28	fs	29	gs	30	rs	31	us
32	sp	33	!	34	"	35	#	36	$	37	%	38	&	39	'
40	(	41	)	42	*	43	+	44	,	45	-	46	.	47	/
48	0	49	1	50	2	51	3	52	4	53	5	54	6	55	7
56	8	57	9	58	:	59	;	60	<	61	=	62	>	63	?
64	@	65	A	66	B	67	C	68	D	69	E	70	F	71	G
72	H	73	I	74	J	75	K	76	L	77	M	78	N	79	O
80	P	81	Q	82	R	83	S	84	T	85	U	86	V	87	W
88	X	89	Y	90	Z	91	[	92	\	93	]	94	^	95	_
96	`	97	a	98	b	99	c	100	d	101	e	102	f	103	g
104	h	105	i	106	j	107	k	108	l	109	m	110	n	111	o
112	p	113	q	114	r	115	s	116	t	117	u	118	v	119	w
120	x	121	y	122	z	123	{	124	\|	125	}	126	~	127	del

Hexadecimal

nul

soh

stx

etx

eot

enq

ack

bel

tab

dle

dc1

dc2

dc3

dc4

nak

syn

etb

can

sub

esc

(

)

;

[

]

{

}

del

The POSIX Classes

Notice that the space character stands on its own and is not included in any basic class.

Most of the control characters should not appear in normal text. The ones that are likely to are:

All but [:word:] are defined in the POSIX standard. [:word:] is not a POSIX class (pace the bash manual) but reflects the fact that in quite a few programming languages the characters in this class are those permitted in identifiers.

The principle governing the classification of characters outside the ASCII range is that the structure of the system as applied to ASCII must be maintained, except that additional classes may be created. The rules for the derived classes must continue to hold, and the basic classes must remain disjoint.

The Control Characters

Class	Definition
[:alpha:]	[:upper:] ∪ [:lower:]
[:alnum:]	[:alpha:] ∪ [:digit:]
[:xdigit:]	[:digit:] ∪ [AaBbCcDdEeFf]
[:graph:]	[:alnum:] ∪ [:punct:]
[:print:]	[:graph:] ∪ Space
[:blank:]	Space ∪ Tab
[:space:]	[:blank:] ∪ [NL VT FF CR]
[:word:]	[:alnum:] ∪ Underscore

The first 31 characters (0-30 decimal, 000-037 octal, 0x00-0x1E hex) together with the last character DEL (decimal 127, octal 177, hex 0x7F) are the "control characters". These were originally used to control teletype machines. Only a few of them are generally meaningful with most devices used today. However, they are often used for other purposes, for example, as commands to programs. When you press the control key on a keyboard at the same time as one of the letters, the code sent to the computer is the corresponding control code. That is, CTRL-A sends 001, CTRL-B sends 002, CTRl-C sends 003, etc.

Control characters are sometimes referred to by names like "Control-A", also written "Ctrl-A" or "^A". The correspondance is as follows: The null character, 0x00, is designated "Control-@". 0x01 is "Control-A", 0x02 is "Control-B", and so on through 0x1A, which is "Control-Z". 0x1B is "Control-[", 0x1C "Control-\", 0x1D "Control-]", 0x1E "Control-^", 0x1F "Control-_", and 0x20 "Control-`". In other words, the control characters are regarded as "Control" versions of the range 0x40-0x60.

ACK	acknowledge
BEL	bell - rings the bell
BS	backspace - moves the cursor or print head back one space
CAN	cancel
CR	carriage return - moves the cursor or print head back to the beginning of the line
DC1	device control 1
DC2	device control 2
DC3	device control 3
DC4	device control 4
DLE	data link escape
EM	end of medium
ENQ	enquiry
EOT	end of transmission
ESC	escape
ETB	end of transmission block
ETX	end of text
FF	form feed - advances the paper to the top of the next page
FS	file separator
GS	group separator
NAK	negative acknowledge
NL	newline. Also known as LF "line feed". Originally, moved the print head or cursor to the next line.
NUL	null
RS	record separator
SI	shift in - switches output device back to default character set
SO	shift out - switches output device to alternate character set
SOH	start of heading
STX	start of text
SUB	substitute
SYN	synchronous idle
TAB	horizontal tab
US	unit separator
VT	vertical tab

The ASCII Code
and the
POSIX character Classes

Binary

Octal

Decimal

Hexadecimal

The POSIX Classes

The Control Characters

000	nul	001	soh	002	stx	003	etx	004	eot	005	enq	006	ack	007	bel
010	bs	011	tab	012	nl	013	vt	014	ff	015	cr	016	so	017	si
020	dle	021	dc1	022	dc2	023	dc3	024	dc4	025	nak	026	syn	027	etb
030	can	031	em	032	sub	033	esc	034	fs	035	gs	036	rs	037	us
040	sp	041	!	042	"	043	#	044	$	045	%	046	&	047	'
050	(	051	)	052	*	053	+	054	,	055	-	056	.	057	/
060	0	061	1	062	2	063	3	064	4	065	5	066	6	067	7
070	8	071	9	072	:	073	;	074	<	075	=	076	>	077	?
100	@	101	A	102	B	103	C	104	D	105	E	106	F	107	G
110	H	111	I	112	J	113	K	114	L	115	M	116	N	117	O
120	P	121	Q	122	R	123	S	124	T	125	U	126	V	127	W
130	X	131	Y	132	Z	133	[	134	\	135	]	136	^	137	_
140	`	141	a	142	b	143	c	144	d	145	e	146	f	147	g
150	h	151	i	152	j	153	k	154	l	155	m	156	n	157	o
160	p	161	q	162	r	163	s	164	t	165	u	166	v	167	w
170	x	171	y	172	z	173	{	174	\|	175	}	176	~	177	del

00	nul	01	soh	02	stx	03	etx	04	eot	05	enq	06	ack	07	bel
08	bs	09	tab	10	nl	11	vt	12	ff	13	cr	14	so	15	si
16	dle	17	dc1	18	dc2	19	dc3	20	dc4	21	nak	22	syn	23	etb
24	can	25	em	26	sub	27	esc	28	fs	29	gs	30	rs	31	us
32	sp	33	!	34	"	35	#	36	$	37	%	38	&	39	'
40	(	41	)	42	*	43	+	44	,	45	-	46	.	47	/
48	0	49	1	50	2	51	3	52	4	53	5	54	6	55	7
56	8	57	9	58	:	59	;	60	<	61	=	62	>	63	?
64	@	65	A	66	B	67	C	68	D	69	E	70	F	71	G
72	H	73	I	74	J	75	K	76	L	77	M	78	N	79	O
80	P	81	Q	82	R	83	S	84	T	85	U	86	V	87	W
88	X	89	Y	90	Z	91	[	92	\	93	]	94	^	95	_
96	`	97	a	98	b	99	c	100	d	101	e	102	f	103	g
104	h	105	i	106	j	107	k	108	l	109	m	110	n	111	o
112	p	113	q	114	r	115	s	116	t	117	u	118	v	119	w
120	x	121	y	122	z	123	{	124	\|	125	}	126	~	127	del

Control Characters	[:cntrl:]
Space
Punctuation	[:punct:]
Digits	[:digit:]
Upper Case Letters	[:upper:]
Lower Case Letters	[:lower:]

0x09	TAB	horizontal tab
0x0A	NL	newline/linefeed
0x0D	CR	carriage return

000	nul	001	soh	002	stx	003	etx	004	eot	005	enq	006	ack	007	bel
010	bs	011	tab	012	nl	013	vt	014	ff	015	cr	016	so	017	si
020	dle	021	dc1	022	dc2	023	dc3	024	dc4	025	nak	026	syn	027	etb
030	can	031	em	032	sub	033	esc	034	fs	035	gs	036	rs	037	us
040	sp	041	!	042	"	043	#	044	$	045	%	046	&	047	'
050	(	051	)	052	*	053	+	054	,	055	-	056	.	057	/
060	0	061	1	062	2	063	3	064	4	065	5	066	6	067	7
070	8	071	9	072	:	073	;	074	<	075	=	076	>	077	?
100	@	101	A	102	B	103	C	104	D	105	E	106	F	107	G
110	H	111	I	112	J	113	K	114	L	115	M	116	N	117	O
120	P	121	Q	122	R	123	S	124	T	125	U	126	V	127	W
130	X	131	Y	132	Z	133	[	134	\	135	]	136	^	137	_
140	`	141	a	142	b	143	c	144	d	145	e	146	f	147	g
150	h	151	i	152	j	153	k	154	l	155	m	156	n	157	o
160	p	161	q	162	r	163	s	164	t	165	u	166	v	167	w
170	x	171	y	172	z	173	{	174	\|	175	}	176	~	177	del

00	nul	01	soh	02	stx	03	etx	04	eot	05	enq	06	ack	07	bel
08	bs	09	tab	10	nl	11	vt	12	ff	13	cr	14	so	15	si
16	dle	17	dc1	18	dc2	19	dc3	20	dc4	21	nak	22	syn	23	etb
24	can	25	em	26	sub	27	esc	28	fs	29	gs	30	rs	31	us
32	sp	33	!	34	"	35	#	36	$	37	%	38	&	39	'
40	(	41	)	42	*	43	+	44	,	45	-	46	.	47	/
48	0	49	1	50	2	51	3	52	4	53	5	54	6	55	7
56	8	57	9	58	:	59	;	60	<	61	=	62	>	63	?
64	@	65	A	66	B	67	C	68	D	69	E	70	F	71	G
72	H	73	I	74	J	75	K	76	L	77	M	78	N	79	O
80	P	81	Q	82	R	83	S	84	T	85	U	86	V	87	W
88	X	89	Y	90	Z	91	[	92	\	93	]	94	^	95	_
96	`	97	a	98	b	99	c	100	d	101	e	102	f	103	g
104	h	105	i	106	j	107	k	108	l	109	m	110	n	111	o
112	p	113	q	114	r	115	s	116	t	117	u	118	v	119	w
120	x	121	y	122	z	123	{	124	\|	125	}	126	~	127	del

The ASCII Codeand thePOSIX character Classes

Binary

Octal

Decimal

Hexadecimal

The POSIX Classes

The Control Characters

The ASCII Code
and the
POSIX character Classes

000	nul	001	soh	002	stx	003	etx	004	eot	005	enq	006	ack	007	bel
010	bs	011	tab	012	nl	013	vt	014	ff	015	cr	016	so	017	si
020	dle	021	dc1	022	dc2	023	dc3	024	dc4	025	nak	026	syn	027	etb
030	can	031	em	032	sub	033	esc	034	fs	035	gs	036	rs	037	us
040	sp	041	!	042	"	043	#	044	$	045	%	046	&	047	'
050	(	051	)	052	*	053	+	054	,	055	-	056	.	057	/
060	0	061	1	062	2	063	3	064	4	065	5	066	6	067	7
070	8	071	9	072	:	073	;	074	<	075	=	076	>	077	?
100	@	101	A	102	B	103	C	104	D	105	E	106	F	107	G
110	H	111	I	112	J	113	K	114	L	115	M	116	N	117	O
120	P	121	Q	122	R	123	S	124	T	125	U	126	V	127	W
130	X	131	Y	132	Z	133	[	134	\	135	]	136	^	137	_
140	`	141	a	142	b	143	c	144	d	145	e	146	f	147	g
150	h	151	i	152	j	153	k	154	l	155	m	156	n	157	o
160	p	161	q	162	r	163	s	164	t	165	u	166	v	167	w
170	x	171	y	172	z	173	{	174	\|	175	}	176	~	177	del

00	nul	01	soh	02	stx	03	etx	04	eot	05	enq	06	ack	07	bel
08	bs	09	tab	10	nl	11	vt	12	ff	13	cr	14	so	15	si
16	dle	17	dc1	18	dc2	19	dc3	20	dc4	21	nak	22	syn	23	etb
24	can	25	em	26	sub	27	esc	28	fs	29	gs	30	rs	31	us
32	sp	33	!	34	"	35	#	36	$	37	%	38	&	39	'
40	(	41	)	42	*	43	+	44	,	45	-	46	.	47	/
48	0	49	1	50	2	51	3	52	4	53	5	54	6	55	7
56	8	57	9	58	:	59	;	60	<	61	=	62	>	63	?
64	@	65	A	66	B	67	C	68	D	69	E	70	F	71	G
72	H	73	I	74	J	75	K	76	L	77	M	78	N	79	O
80	P	81	Q	82	R	83	S	84	T	85	U	86	V	87	W
88	X	89	Y	90	Z	91	[	92	\	93	]	94	^	95	_
96	`	97	a	98	b	99	c	100	d	101	e	102	f	103	g
104	h	105	i	106	j	107	k	108	l	109	m	110	n	111	o
112	p	113	q	114	r	115	s	116	t	117	u	118	v	119	w
120	x	121	y	122	z	123	{	124	\|	125	}	126	~	127	del