freebsd-dev/bin/sh/bltin/echo.1

.\" Copyright (c) 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Kenneth Almquist.
.\" Copyright 1989 by Kenneth Almquist
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)echo.1	8.2 (Berkeley) 5/4/95
.\" $FreeBSD$
.\"
.Dd May 4, 1995
.Dt ECHO 1
.Os
.Sh NAME
.Nm echo
.Nd produce message in a shell script
.Sh SYNOPSIS
.Nm
.Op Fl n | Fl e
.Ar args...
.Sh DESCRIPTION
The
.Nm
utility prints its arguments on the standard output, separated by spaces.
Unless the
.Fl n
option is present, a newline is output following the arguments.
The
.Fl e
option causes
.Nm
to treat the escape sequences specially, as described in the following
paragraph.
The
.Fl e
option is the default, and is provided solely for compatibility with
other systems.
Only one of the options
.Fl n
and
.Fl 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:
.Bl -tag -width indent
.It Li \eb
A backspace character is output.
.It Li \ec
Subsequent output is suppressed.
This is normally used at the end of the
last argument to suppress the trailing newline that
.Nm
would otherwise output.
.It Li \ef
Output a form feed.
.It Li \en
Output a newline character.
.It Li \er
Output a carriage return.
.It Li \et
Output a (horizontal) tab character.
.It Li \ev
Output a vertical tab.
.It Li \e0 Ns Ar digits
Output the character whose value is given by zero to three digits.
If there are zero digits, a
.Dv NUL
character is output.
.It Li \e\e
Output a backslash.
.El
.Sh HINTS
Remember that backslash is special to the shell and needs to be escaped.
To output a message to standard error, say
.Pp
.D1 echo message >&2
.Sh BUGS
The octal character escape mechanism
.Pq Li \e0 Ns Ar digits
differs from the
C language mechanism.
.Pp
There is no way to force
.Nm
to treat its arguments literally, rather than interpreting them as
options and escape sequences.
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.\" Copyright (c) 1991, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" This code is derived from software contributed to Berkeley by`
			`.\" Kenneth Almquist.`
			`.\" Copyright 1989 by Kenneth Almquist`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\" 4. Neither the name of the University nor the names of its contributors`
			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
Merge of 4.4-Lite2 sh source, plus some gcc -Wall cleaning. This is a merge of parallel duplicate work by Steve Price and myself. :-] There are some changes to the build that are my fault... mkinit.c was trying (poorly) to duplicate some of the work that make(1) is designed to do. The Makefile hackery is my fault too, the depend list was incomplete because of some explicit OBJS+= entries, so mkdep wasn't picking up their source file #includes. This closes a pile of /bin/sh PR's, but not all of them.. Submitted by: Steve Price <steve@bonsai.hiwaay.net>, peter 1996-09-01 10:22:36 +00:00			`.\" @(#)echo.1 8.2 (Berkeley) 5/4/95`
$Id$ -> $FreeBSD$ 1999-08-27 23:15:48 +00:00			`.\" $FreeBSD$`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.\"`
Merge of 4.4-Lite2 sh source, plus some gcc -Wall cleaning. This is a merge of parallel duplicate work by Steve Price and myself. :-] There are some changes to the build that are my fault... mkinit.c was trying (poorly) to duplicate some of the work that make(1) is designed to do. The Makefile hackery is my fault too, the depend list was incomplete because of some explicit OBJS+= entries, so mkdep wasn't picking up their source file #includes. This closes a pile of /bin/sh PR's, but not all of them.. Submitted by: Steve Price <steve@bonsai.hiwaay.net>, peter 1996-09-01 10:22:36 +00:00			`.Dd May 4, 1995`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.Dt ECHO 1`
mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 10:04:09 +00:00			`.Os`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.Sh NAME`
			`.Nm echo`
			`.Nd produce message in a shell script`
			`.Sh SYNOPSIS`
Fix for PR#1287. This makes sh behave sensibly in case statements in the face of aliases. Note, bash doesn't do aliases while running scripts, but "real" ksh does.. Also: Reduce redundant .Nm macros in (unused) bltin/echo.1 nuke error2, it's hardly used. More -Wall cleanups dont do certain history operations if NO_HISTORY defined handle quad_t's from resource limits Submitted by: Steve Price <sprice@hiwaay.net> (minor tweaks by me) 1996-09-03 14:16:06 +00:00			`.Nm`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.Op Fl n \| Fl e`
Remove whitespace at EOL. 2001-07-15 07:53:42 +00:00			`.Ar args...`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.Sh DESCRIPTION`
Use `The .Nm utility' 2002-04-16 20:08:06 +00:00			`The`
Fix for PR#1287. This makes sh behave sensibly in case statements in the face of aliases. Note, bash doesn't do aliases while running scripts, but "real" ksh does.. Also: Reduce redundant .Nm macros in (unused) bltin/echo.1 nuke error2, it's hardly used. More -Wall cleanups dont do certain history operations if NO_HISTORY defined handle quad_t's from resource limits Submitted by: Steve Price <sprice@hiwaay.net> (minor tweaks by me) 1996-09-03 14:16:06 +00:00			`.Nm`
Use `The .Nm utility' 2002-04-16 20:08:06 +00:00			`utility prints its arguments on the standard output, separated by spaces.`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`Unless the`
			`.Fl n`
			`option is present, a newline is output following the arguments.`
			`The`
			`.Fl e`
			`option causes`
Fix for PR#1287. This makes sh behave sensibly in case statements in the face of aliases. Note, bash doesn't do aliases while running scripts, but "real" ksh does.. Also: Reduce redundant .Nm macros in (unused) bltin/echo.1 nuke error2, it's hardly used. More -Wall cleanups dont do certain history operations if NO_HISTORY defined handle quad_t's from resource limits Submitted by: Steve Price <sprice@hiwaay.net> (minor tweaks by me) 1996-09-03 14:16:06 +00:00			`.Nm`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`to treat the escape sequences specially, as described in the following`
			`paragraph.`
			`The`
			`.Fl e`
			`option is the default, and is provided solely for compatibility with`
			`other systems.`
			`Only one of the options`
			`.Fl n`
			`and`
			`.Fl e`
			`may be given.`
			`.Pp`
			`If any of the following sequences of characters is encountered during`
Mechanically kill hard sentence breaks. 2004-07-02 21:04:19 +00:00			`output, the sequence is not output.`
			`Instead, the specified action is`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`performed:`
			`.Bl -tag -width indent`
			`.It Li \eb`
			`A backspace character is output.`
			`.It Li \ec`
Mechanically kill hard sentence breaks. 2004-07-02 21:04:19 +00:00			`Subsequent output is suppressed.`
			`This is normally used at the end of the`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`last argument to suppress the trailing newline that`
Fix for PR#1287. This makes sh behave sensibly in case statements in the face of aliases. Note, bash doesn't do aliases while running scripts, but "real" ksh does.. Also: Reduce redundant .Nm macros in (unused) bltin/echo.1 nuke error2, it's hardly used. More -Wall cleanups dont do certain history operations if NO_HISTORY defined handle quad_t's from resource limits Submitted by: Steve Price <sprice@hiwaay.net> (minor tweaks by me) 1996-09-03 14:16:06 +00:00			`.Nm`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`would otherwise output.`
			`.It Li \ef`
			`Output a form feed.`
			`.It Li \en`
			`Output a newline character.`
			`.It Li \er`
			`Output a carriage return.`
			`.It Li \et`
			`Output a (horizontal) tab character.`
			`.It Li \ev`
			`Output a vertical tab.`
			`.It Li \e0 Ns Ar digits`
			`Output the character whose value is given by zero to three digits.`
Capitalize ASCII code names. Approved by: re 2002-12-05 08:50:00 +00:00			`If there are zero digits, a`
			`.Dv NUL`
			`character is output.`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.It Li \e\e`
			`Output a backslash.`
			`.El`
			`.Sh HINTS`
			`Remember that backslash is special to the shell and needs to be escaped.`
			`To output a message to standard error, say`
			`.Pp`
Deal with double whitespace. 2004-07-03 00:06:28 +00:00			`.D1 echo message >&2`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`.Sh BUGS`
			`The octal character escape mechanism`
			`.Pq Li \e0 Ns Ar digits`
			`differs from the`
			`C language mechanism.`
			`.Pp`
			`There is no way to force`
Fix for PR#1287. This makes sh behave sensibly in case statements in the face of aliases. Note, bash doesn't do aliases while running scripts, but "real" ksh does.. Also: Reduce redundant .Nm macros in (unused) bltin/echo.1 nuke error2, it's hardly used. More -Wall cleanups dont do certain history operations if NO_HISTORY defined handle quad_t's from resource limits Submitted by: Steve Price <sprice@hiwaay.net> (minor tweaks by me) 1996-09-03 14:16:06 +00:00			`.Nm`
BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00			`to treat its arguments literally, rather than interpreting them as`
			`options and escape sequences.`