| 1 | .\" $NetBSD: echo.1,v 1.13 2003/08/07 09:05:40 agc Exp $
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| 2 | .\"
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| 3 | .\" Copyright (c) 1991, 1993
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| 4 | .\" The Regents of the University of California. All rights reserved.
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| 5 | .\"
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| 6 | .\" This code is derived from software contributed to Berkeley by
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| 7 | .\" Kenneth Almquist.
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| 8 | .\" Copyright 1989 by Kenneth Almquist
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| 9 | .\"
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| 10 | .\" Redistribution and use in source and binary forms, with or without
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| 11 | .\" modification, are permitted provided that the following conditions
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| 12 | .\" are met:
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| 13 | .\" 1. Redistributions of source code must retain the above copyright
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| 14 | .\" notice, this list of conditions and the following disclaimer.
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| 15 | .\" 2. Redistributions in binary form must reproduce the above copyright
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| 16 | .\" notice, this list of conditions and the following disclaimer in the
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| 17 | .\" documentation and/or other materials provided with the distribution.
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| 18 | .\" 3. Neither the name of the University nor the names of its contributors
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| 19 | .\" may be used to endorse or promote products derived from this software
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| 20 | .\" without specific prior written permission.
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| 21 | .\"
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| 22 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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| 23 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 24 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| 25 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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| 26 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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| 27 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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| 28 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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| 29 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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| 30 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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| 31 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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| 32 | .\" SUCH DAMAGE.
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| 33 | .\"
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| 34 | .\" @(#)echo.1 8.1 (Berkeley) 5/31/93
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| 35 | .\"
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| 36 | .Dd May 31, 1993
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| 37 | .Dt ECHO 1
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| 38 | .Os
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| 39 | .Sh NAME
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| 40 | .Nm echo
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| 41 | .Nd produce message in a shell script
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| 42 | .Sh SYNOPSIS
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| 43 | .Nm
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| 44 | .Op Fl n | Fl e
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| 45 | .Ar args ...
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| 46 | .Sh DESCRIPTION
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| 47 | .Nm
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| 48 | prints its arguments on the standard output, separated by spaces.
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| 49 | Unless the
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| 50 | .Fl n
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| 51 | option is present, a newline is output following the arguments.
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| 52 | The
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| 53 | .Fl e
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| 54 | option causes
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| 55 | .Nm
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| 56 | to treat the escape sequences specially, as described in the following
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| 57 | paragraph.
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| 58 | The
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| 59 | .Fl e
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| 60 | option is the default, and is provided solely for compatibility with
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| 61 | other systems.
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| 62 | Only one of the options
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| 63 | .Fl n
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| 64 | and
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| 65 | .Fl e
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| 66 | may be given.
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| 67 | .Pp
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| 68 | If any of the following sequences of characters is encountered during
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| 69 | output, the sequence is not output. Instead, the specified action is
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| 70 | performed:
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| 71 | .Bl -tag -width indent
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| 72 | .It Li \eb
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| 73 | A backspace character is output.
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| 74 | .It Li \ec
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| 75 | Subsequent output is suppressed. This is normally used at the end of the
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| 76 | last argument to suppress the trailing newline that
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| 77 | .Nm
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| 78 | would otherwise output.
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| 79 | .It Li \ef
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| 80 | Output a form feed.
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| 81 | .It Li \en
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| 82 | Output a newline character.
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| 83 | .It Li \er
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| 84 | Output a carriage return.
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| 85 | .It Li \et
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| 86 | Output a (horizontal) tab character.
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| 87 | .It Li \ev
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| 88 | Output a vertical tab.
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| 89 | .It Li \e0 Ns Ar digits
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| 90 | Output the character whose value is given by zero to three digits.
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| 91 | If there are zero digits, a nul character is output.
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| 92 | .It Li \e\e
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| 93 | Output a backslash.
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| 94 | .El
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| 95 | .Sh HINTS
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| 96 | Remember that backslash is special to the shell and needs to be escaped.
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| 97 | To output a message to standard error, say
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| 98 | .Pp
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| 99 | .D1 echo message \*[Gt]\*[Am]2
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| 100 | .Sh BUGS
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| 101 | The octal character escape mechanism
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| 102 | .Pq Li \e0 Ns Ar digits
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| 103 | differs from the
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| 104 | C language mechanism.
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| 105 | .Pp
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| 106 | There is no way to force
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| 107 | .Nm
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| 108 | to treat its arguments literally, rather than interpreting them as
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| 109 | options and escape sequences.
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