[unix-history] / usr / src / bin / sh / bltin / echo.1

.\" Copyright (c) 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Kenneth Almquist.
.\"
.\" %sccs.include.redist.man%
.\"
.\"	@(#)echo.1	5.1 (Berkeley) %G%
.\"
.TH ECHO 1""
.UC 7
.SH NAME
echo \- produce message in a shell script
.SH SYNOPSIS
.B echo
[
.B -n
|
.B -e
]
.I args...
.SH COPYRIGHT
Copyright 1989 by Kenneth Almquist.
.SH DESCRIPTION
.I Echo
prints its arguments on the standard output, separated by spaces.
Unless the
.B -n
option is present, a newline is output following the arguments.
The
.B -e
option causes
.I echo
to treat the escape sequences specially, as described in the following
paragraph.  The
.B -e
option is the default, and is provided solely for compatibility with
other systems.
Only one of the options
.B -n
and
.B -e
may be given.
.PP
If any of the following sequences of characters is encountered during
output, the sequence is not output.  Instead, the specified action is
performed:
.nr i 0.6i
.de i
.sp
.ti -\\niu
\\$1	\c
.if \w'\\$1'-\\ni .br
..
.in 1.1i
.ta 0.6i
.i \eb
A backspace character is output.
.i \ec
Subsequent output is suppressed.  This is normally used at the end of the
last argument to suppress the trailing newline that
.I echo
would otherwise output.
.i \ef
Output a form feed.
.i \en
Output a newline character.
.i \er
Output a carriage return.
.i \et
Output a (horizontal) tab character.
.i \ev
Output a vertical tab.
.i \e0\fIdigits\fR
Output the character whose value is given by zero to three digits.
If there are zero digits, a nul character is output.
.i \e\e
Output a backslash.
.in -1.1i
.SH HINTS
Remember that backslash is special to the shell and needs to be escaped.
To output a message to standard error, say
.sp
.ti +1i
echo message >&2
.SH BUGS
The octal character escape mechanism (\e0\fIdigits\fR) differs from the
C language mechanism.
.PP
There is no way to force
.I echo
to treat its arguments literally, rather than interpreting them as
options and escape sequences.
Commit	Line	Data
4f637f59 KB	1	.\" Copyright (c) 1991 The Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" This code is derived from software contributed to Berkeley by
	5	.\" Kenneth Almquist.
	6	.\"
	7	.\" %sccs.include.redist.man%
	8	.\"
	9	.\" @(#)echo.1 5.1 (Berkeley) %G%
	10	.\"
	11	.TH ECHO 1""
	12	.UC 7
	13	.SH NAME
	14	echo \- produce message in a shell script
	15	.SH SYNOPSIS
	16	.B echo
	17	[
	18	.B -n
	19	\|
	20	.B -e
	21	]
	22	.I args...
	23	.SH COPYRIGHT
	24	Copyright 1989 by Kenneth Almquist.
	25	.SH DESCRIPTION
	26	.I Echo
	27	prints its arguments on the standard output, separated by spaces.
	28	Unless the
	29	.B -n
	30	option is present, a newline is output following the arguments.
	31	The
	32	.B -e
	33	option causes
	34	.I echo
	35	to treat the escape sequences specially, as described in the following
	36	paragraph. The
	37	.B -e
	38	option is the default, and is provided solely for compatibility with
	39	other systems.
	40	Only one of the options
	41	.B -n
	42	and
	43	.B -e
	44	may be given.
	45	.PP
	46	If any of the following sequences of characters is encountered during
	47	output, the sequence is not output. Instead, the specified action is
	48	performed:
	49	.nr i 0.6i
	50	.de i
	51	.sp
	52	.ti -\\niu
	53	\\$1 \c
	54	.if \w'\\$1'-\\ni .br
	55	..
	56	.in 1.1i
	57	.ta 0.6i
	58	.i \eb
	59	A backspace character is output.
	60	.i \ec
	61	Subsequent output is suppressed. This is normally used at the end of the
	62	last argument to suppress the trailing newline that
	63	.I echo
	64	would otherwise output.
65	.i \ef
66	Output a form feed.
67	.i \en
68	Output a newline character.
69	.i \er
70	Output a carriage return.
71	.i \et
72	Output a (horizontal) tab character.
73	.i \ev
74	Output a vertical tab.
75	.i \e0\fIdigits\fR
76	Output the character whose value is given by zero to three digits.
77	If there are zero digits, a nul character is output.
78	.i \e\e
79	Output a backslash.
80	.in -1.1i
81	.SH HINTS
82	Remember that backslash is special to the shell and needs to be escaped.
83	To output a message to standard error, say
84	.sp
85	.ti +1i
86	echo message >&2
87	.SH BUGS
88	The octal character escape mechanism (\e0\fIdigits\fR) differs from the
89	C language mechanism.
90	.PP
91	There is no way to force
92	.I echo
93	to treat its arguments literally, rather than interpreting them as
94	options and escape sequences.