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From: Lewis Not on 22 Jul 2010 12:11
Kenny McCormack <gazelle(a)shell.xmission.com> wrote:
>>if [ $last_seen -gt 0 ] && [ $last_seen -lt $toolate ] ; then
>
>Why?

1) cross-platform compatibility

2) readability

Excellent example, though I would recommend adding quotes, for best
practices, error checking and developing good coding habits, whether
strictly necessary or not:

if [ "$last_seen" -gt 0 ] && [ "$last_seen" -lt "$toolate" ]; then

Lew
From: Chris F.A. Johnson on 22 Jul 2010 19:06
On 2010-07-22, Lewis Not wrote:
> Kenny McCormack <gazelle(a)shell.xmission.com> wrote:
>>>if [ $last_seen -gt 0 ] && [ $last_seen -lt $toolate ] ; then
>>
>>Why?
>
> 1) cross-platform compatibility
>
> 2) readability
>
> Excellent example, though I would recommend adding quotes, for best
> practices, error checking and developing good coding habits, whether
> strictly necessary or not:
>
> if [ "$last_seen" -gt 0 ] && [ "$last_seen" -lt "$toolate" ]; then

I generally don't quote variables in numeric comparisons. If they
don't contain integers, that is a programming error that needs to
be fixed.

--
Chris F.A. Johnson, author <http://shell.cfajohnson.com/>
===================================================================
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)

From: Seebs on 22 Jul 2010 20:51
On 2010-07-22, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote:
> I generally don't quote variables in numeric comparisons. If they
> don't contain integers, that is a programming error that needs to
> be fixed.

But consider the quality of the diagnostic messages you get from
such an error...

-s
--
Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nospam(a)seebs.net
http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures
http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated!
From: Chris F.A. Johnson on 23 Jul 2010 13:25
On 2010-07-23, Seebs wrote:
> On 2010-07-22, Chris F.A. Johnson <cfajohnson(a)gmail.com> wrote:
>> I generally don't quote variables in numeric comparisons. If they
>> don't contain integers, that is a programming error that needs to
>> be fixed.
>
> But consider the quality of the diagnostic messages you get from
> such an error...

You have a point, but either message would be enough to tell me the
problem. (Though I don't think I've ever seen the error; if I am
testing an integer, it's because I have already assigned an integer
to that variable.)

--
Chris F.A. Johnson, author <http://shell.cfajohnson.com/>
===================================================================
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)
Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)

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