Re: [PATCH v2 10/16] engine.pl: delete the captured stderr file if empty

From: Eric Sunshine <sunshine@sunshineco.com>
Date: Jul 20, 2015, 06:40 UTC
Message-ID: <CAPig+cRZgjnxrYRVYCLuzomE=qQtF9N_SE6t5kLcXbdiheNeTg@mail.gmail.com>
In-Reply-To: <FDE2D068444A4350B0C2F25275CBC41D@PhilipOakley>

On Mon, Jul 20, 2015 at 2:16 AM, Philip Oakley <philipoakley@iee.org> wrote:

Show 29 quoted lines

> From: "Eric Sunshine" <sunshine@sunshineco.com>
>> On Sun, Jul 19, 2015 at 4:08 PM, Philip Oakley <philipoakley@iee.org>
>> wrote:
>>> Keep the build clean of extraneous files if it is indeed clean.
>>> Otherwise leave the msvc-build-makedryerrors.txt file both as
>>> a flag for any CI system or for manual debugging.
>>>
>>> Note that the file will contain the new values of the GIT_VERSION
>>> and GITGUI_VERSION if they were generated by the make file. They
>>> are omitted if the release is tagged and indentically defined in
>>> their respective GIT_VERSION_GEN file DEF_VER variables.
>>>
>>> Signed-off-by: Philip Oakley <philipoakley@iee.org>
>>> ---
>>> +# test for an empty Errors file and remove it
>>> +for ($ErrsFile) {unlink $_ if (-f $_) && (!-s $_);}
>>
>> Why the 'for' loop?
>>
>> Also, if you're using the 'for' loop for the $_ side-effect, then why
>> not the simpler:
>
> It was cargo cult programming, with some Google searching to select between
> invocations. Most examples were looping through lists in scripts, hence the
> down select.
>
>>    for ($ErrsFile) { unlink if -f && !-s; }
>
> A lot better. Will fix.

Although that works, I'm not sure that it's really all that desirable due to the unnecessary and potentially confusing 'for' loop. I'd probably just write it as:

    unlink $ErrsFile if -f $ErrsFile && !-s _;

The lone '_' is magical[1] in that it re-uses the stat() information from the -f rather than stat'ing $ErrsFile again. I'd also probably replace !-s ("not non-zero size") with -z ("zero size"):

    unlink $ErrsFile if -f $ErrsFile && -z _;

And, if you're using Perl 5.10 or later, you could use a little syntactic sugar[1] and stack the file test operators up against one another:

    unlink $ErrsFile if -f -z $ErrsFile;

which is the equivalent of the above with the sugar removed.

[1]: http://perldoc.perl.org/functions/-X.html

-- 
-- 
*** Please reply-to-all at all times ***
*** (do not pretend to know who is subscribed and who is not) ***
*** Please avoid top-posting. ***
The msysGit Wiki is here: https://github.com/msysgit/msysgit/wiki - Github accounts are free.

You received this message because you are subscribed to the Google
Groups "msysGit" group.
To post to this group, send email to msysgit@googlegroups.com
To unsubscribe from this group, send email to
msysgit+unsubscribe@googlegroups.com
For more options, and view previous threads, visit this group at
http://groups.google.com/group/msysgit?hl=en_US?hl=en

--- 
You received this message because you are subscribed to the Google Groups "Git for Windows" group.
To unsubscribe from this group and stop receiving emails from it, send an email to msysgit+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.