0,0 → 1,113 |
.\" $NetBSD: echo.1,v 1.9 1999/03/22 18:30:47 garbled Exp $ |
.\" |
.\" 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. |
.\" 3. All advertising materials mentioning features or use of this software |
.\" must display the following acknowledgement: |
.\" This product includes software developed by the University of |
.\" California, Berkeley and its contributors. |
.\" 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 8.1 (Berkeley) 5/31/93 |
.\" |
.Dd May 31, 1993 |
.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 |
.Nm |
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 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. |