Re: [PATCH 2/5] kbuild: fix warning when domainname is not available

Mike Frysinger
2009-09-14T13:44:16Z

On Mon, Sep 14, 2009 at 04:25, Felipe Contreras wrote:
> On Mon, Sep 14, 2009 at 7:46 AM, Sam Ravnborg wrote:
>> On Mon, Sep 14, 2009 at 01:04:11AM +0300, Felipe Contreras wrote:
>>> On Mon, Sep 14, 2009 at 12:58 AM, Mike Frysinger wrote:
>>> > On Sun, Sep 13, 2009 at 17:42, Felipe Contreras wrote:
>>> >> On Mon, Sep 14, 2009 at 12:12 AM, Mike Frysinger wrote:
>>> >>> On Sun, Sep 13, 2009 at 15:38, Felipe Contreras wrote:
>>> >>>> +  if $domain; then
>>> >>>
>>> >>> is this really correct ?  i think you meant to use:
>>> >>> [ -n "$domain" ]
>>> >>
>>> >> What is the difference?
>>> >>
>>> >> $domain unset
>>> >> test -n "" -> false
>>> >> test -> false
>>> >>
>>> >> $domain is a valid string
>>> >> test -n "string" -> true
>>> >> test "string" -> true
>>> >
>>> > except that you didnt invoke `test` anywhere.  you're executing the
>>> > contents of $domain.
>>>
>>> Ahh, I'll update it to:
>>> [ "$domain" ]
>>
>> Please use [ -n "$domain" ].
>> Be explicit about what you do.
>>
>> [Likewise in c we never omit "int" just because we can].
>
> In fact 'int' is implicit of 'signed int', and 'long' is a shorthand
> of 'signed long int' and so on. Also, AFAIK 'if (foo)' is preferred
> over 'if (foo == true)' or 'if (foo != NULL)' and sometimes even 'if
> (foo >= 0)'.
>
> What's the point of going for the explicit form? Make the code less readable?

your argument here is the opposite of reality. while some of us are
aware of implicit `test`behavior, not everyone is a shell scripting
master. they look at [ "$foo" ] and dont immediately get the
intention. or perhaps someone typoed and didnt actually want -n
semantics. add the whole *3* characters and be done with it.
-mike