echo.1

来自「minix操作系统最新版本（3.1.1）的源代码」· 1 代码 · 共 69 行

.TH ECHO 1
.SH NAME \"	Copyright (C) 1989 by Kenneth Almquist.
echo \- produce message in a shell script
.SH SYNOPSIS
.B echo
[
.B -n
|
.B -e
]
.I args...
.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.
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:
.de i
.IP "\\fB\\$1\\fR" 5
..
.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.
.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.
.SH AUTHOR
Kenneth Almquist.