[pacman-dev] Scripts bombing with no args

[Allan McRae]

On 29/07/11 22:38, Dave Reisner wrote:
> On Fri, Jul 29, 2011 at 07:01:29PM +1000, Allan McRae wrote:
>> On 29/07/11 03:14, Dave Reisner wrote:
>>> On Thu, Jul 28, 2011 at 11:18:15AM -0500, Dan McGee wrote:
>>>> Allan or Dave, mind taking a look at this? We should show usage info,
>>>> as rankmirrors and pacman-key do without args, instead of this silly
>>>> behavior.
>>>>
>>>> -Dan
>>>>
>>>> dmcgee at galway ~/projects/pacman (master)
>>>> $ ./scripts/repo-add
>>>> ==>   ERROR: '' does not have a valid archive extension.
>>>
>>> We never check for $1 being unset before proceeding. Probably my
>>> mistake when I did some refactoring of repo-add.
>>>
>>>> dmcgee at galway ~/projects/pacman (master)
>>>> $ ./scripts/pkgdelta
>>>> ./scripts/pkgdelta: line 147: $1: unbound variable
>>>>
>>>
>>> 'set -u' with 'set -e'? Ugly...
>>
>> Care to explain why?  Using this in our cleanup scripts would have
>> prevented the Arch repos disappearing on more than one occasion....
>>
>
> Because the combination of these two flags causes scripts to fail in
> mysterious and unexpected ways. Also, it won't save you from set but
> empty vars, which I suspect would be just as dangerous as unset vars in
> the situation you allude to. Just validate the user inputs. It makes
> things more obvious to an outside reader of the code, as well as
> consumers of the script.
>

FYI, this is the story I am referring to:

http://archlinux.me/brain0/2009/08/16/shit-happens-when-you-party-naked-or-use-crappy-shell-scripts/

I'm still a fan of keeping set -u and -e...  It may not save you from 
everything, but it does stop some things.

Allan