[X-Unix] Login Hooks running items on login a little bit too quickly

[Juan Manuel Palacios]

On Jan 10, 2005, at 10:53 AM, Steven Palm wrote:

>
> On Jan 10, 2005, at 8:36 AM, Our PAl Al wrote:
>> Don't quite fully understand it  but I think I can still use it.
>>
>>  Why do you have the [] around the F in Finder? When I use that line, 
>> it doesn't work.  ps -ax | grep Finder  (without the [] ) works fine.
>
>  Strange, it should... It does work here as well.  The [] denote a 
> "set" of characters, but in this case there is only one so there's no 
> reason to use it.  I suspect it may have been [Ff]inder at some point, 
> matching upper or lower case F in front of inder.  But I'd probably 
> just use grep -i finder in that case, and let it find any combination 
> of upper and lower case. But you always have to be careful to only 
> match what you REALLY want so something else doesn't trip you up.
>

	The purpose of the [ ] around the first letter of Finder is precisely 
to limit the range of matching options of the regular expression. Take 
a look:

$[juan at PowerBook: dports](194/0,1)-> ps -ax | grep Finder
   412  ??  S      1:00.50 
/System/Library/CoreServices/Finder.app/Contents/MacOS/Finder 
-psn_0_786433
  6105 std  S+     0:00.00 grep Finder

	Here the range is open, and all instances of "Finder" are matched, 
including the search itself. With the [ ] around the F the story is 
different:

$[juan at PowerBook: dports](195/0,1)-> ps -ax | grep [F]inder
   412  ??  S      1:00.50 
/System/Library/CoreServices/Finder.app/Contents/MacOS/Finder 
-psn_0_786433

	Only what we're looking for is matched. To get this behavior without 
the [ ] we'd need another, inverse, matching pattern to eliminate 
"grep" from the search results:

$[juan at PowerBook: dports](196/0,1)-> ps -ax | grep Finder | grep -v grep
   412  ??  S      1:00.50 
/System/Library/CoreServices/Finder.app/Contents/MacOS/Finder 
-psn_0_786433

	Now, as to the effect of these differences on the result of $? I think 
you're safe whether you decide to use [F]inder or Finder, in both cases 
$? == 0 is returned, which is what you need for your script. But in any 
case it's usually a good practice to design search patterns that will 
return exactly what you're looking for, unless you're explicitly trying 
to write a wide as possible pattern to get as many matches as possible. 
But that is not the current case.

	Hope that makes it a bit clearer. Regards,...


		Juan