[Gllug] $HOSTNAME

[Hari Sekhon]

Hari Sekhon wrote:
> John G Walker wrote:
>> On Tue, 8 Sep 2009 16:32:50 +0100 Stephen Nelson-Smith
>> <sanelson at gmail.com> wrote:
>>
>>  
>>> It's probably safer to use $(hostname -s)
>>>     
>>
>> Safer in what way? I just use the name as a string
> Technically $HOSTNAME can be blank (but usually isn't) but hostname -s 
> seems more likely to return something as it uses the system's 
> gethostname function call which pulls the hostname from sysfs and one 
> would think it's safer but I just tested it and it's not really any 
> safer, you could blank that out too for example or change it to the 
> name of another machine on the network and hostname -s will happily 
> return that or an unknown host error if it's blank or not resolvable.
>
> Some elementary shell scripting will allow you to test for any of this 
> though... and if you're writing anything without such tests then your 
> code simply isn't robust, and shell scripting usually garners 
> criticism from people who aren't very adept at writing it for this 
> very reason. Defensive programming should be employed regardless.
err, quick self correction, it's not sysfs but /proc/sys that that 
function call is pulling the hostname from... got sysfs on the brain...

-h

-- 
Hari Sekhon
http://www.linkedin.com/in/harisekhon

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