Re: [PATCH] test-lib.sh: use printf instead of echo

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 20, 2014, 16:42 UTC
Message-ID: <xmqq4n2s255z.fsf@gitster.dls.corp.google.com>
In-Reply-To: <20140320001718.GM15625@google.com>

Jonathan Nieder <jrnieder@gmail.com> writes:

Show 10 quoted lines

> Junio C Hamano wrote:
> ...
>> I am a bit reluctant to name the helper "sane_echo" to declare "echo
>> that interprets backslashes in the string is insane", though.  For
>> these "print a single line" uses, we are only interested in using a
>> subset of the features offered by 'echo', but that does not mean the
>> other features we do not want to trigger in our use is of no use to
>> any sane person.
>
> In a portable script, uncareful use of 'echo' is always insane.

I agree that makes sense and I actually think that it is a bit stronger than that. If a script is meant to be portable, there is no way to use "echo" on a string whose contents is unknown sanely. There is no "careful use is OK".

> In a script tailored to an environment where echo behaves consistently
> it is perfectly reasonable to use 'echo', but that's a different
> story.  In the context of git, saying "Here is the thing you should
> always use instead of echo" is a good thing, in my opinion.

That is true in my opinion, but that thing is also what you should always use instead of "printf '%s\n'". A guideline more useful for the users is "Here is the thing you should always use when literally emitting a single line.", isn't it?