From: Eric Blake <eblake@redhat.com>
To: Kevin Korb <kmk@sanitarium.net>, dash@vger.kernel.org
Subject: Re: [bug?] echo -n does not work as described
Date: Wed, 11 Nov 2015 20:14:14 -0700 [thread overview]
Message-ID: <56440406.7000201@redhat.com> (raw)
In-Reply-To: <5643F1B2.5050207@sanitarium.net>
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On 11/11/2015 06:56 PM, Kevin Korb wrote:
> I am on dash version 0.5.8.2 on Gentoo Linux (USE=libedit -static).
>
> The echo builtin does not work as described. In the man page:
Which man page? Coreutils'?
Read it further:
> NOTE: your shell may have its own version of echo, which usually super‐
> sedes the version described here. Please refer to your shell's docu‐
> mentation for details about the options it supports.
By the way, 'echo -n' is non-portable, and POSIX says you should use
'printf' instead.
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html
A string to be written to standard output. If the first operand is
-n, or if any of the operands contain a <backslash> character, the
results are implementation-defined.
> $ echo -n testing
> -n testing
Dash's implementation-defined behavior for -n is to treat it the same as
every other string. Thus, this is not a bug in dash, at least according
to POSIX.
> This is causing me problems when I attempt to switch /bin/sh from bash
> to dash.
It's probably not the only bashism you've been relying on. You may want
to try using checkbashisms
(http://sourceforge.net/projects/checkbaskisms/) to help you find other
portability pitfalls.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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next prev parent reply other threads:[~2015-11-12 3:14 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-12 1:56 [bug?] echo -n does not work as described Kevin Korb
2015-11-12 3:14 ` Eric Blake [this message]
2015-11-12 3:40 ` Kevin Korb
2015-11-12 3:46 ` Kevin Korb
2015-11-12 8:35 ` Seb
2015-11-12 16:12 ` Kevin Korb
2015-11-12 21:24 ` Stephane Chazelas
2015-11-12 8:10 ` Bastian Bittorf
2015-11-12 16:11 ` Kevin Korb
2015-11-19 12:36 ` Bastian Bittorf
2015-11-12 10:03 ` Petr Šabata
2015-11-12 16:18 ` Kevin Korb
2015-11-12 16:55 ` Kevin Korb
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