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#119993 - 2004-05-24 01:16 AM Structured EnumKey Loop /w a single EnumKey
Shawn Shawn Administrator Registered: 1999-08-13 Posts: 8611	Someone on korg wrote a non-goto EnumKey loop a while back, that only uses a single EnumKey call, anyone care to give a try. The manual example uses gotos: Code: $Index = 0 :Loop1 $KeyName = ENUMKEY("HKEY_CURRENT_USER\Console\", $Index) If @ERROR = 0 ? "Name found: $KeyName" $Index = $Index + 1 goto Loop1 Endif I know of a structured way using two EnumKeys: Code: $i = 0 $KeyName = EnumKey("HKEY_CURRENT_USER\Software\",$i) While $KeyName ?"Name found: $KeyName" $i=$i+1 $KeyName = EnumKey("HKEY_CURRENT_USER\Software\",$i) Loop But someone wrote a structured way using a single EnumKey ? Anyone ?
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#119994 - 2004-05-24 01:44 AM Re: Structured EnumKey Loop /w a single EnumKey
Chris S. Chris S. MM club member Registered: 2002-03-18 Posts: 2368 Loc: Earth	Does this work? Code: $i = 0 Do $KeyName = EnumKey("HKEY_CURRENT_USER\Software\",$i) "Name found: $KeyName" ? $i=$i+1 Until Not $KeyName
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#119995 - 2004-05-24 02:09 AM Re: Structured EnumKey Loop /w a single EnumKey
Shawn Shawn Administrator Registered: 1999-08-13 Posts: 8611	well, close but no cigar ... if the key really doesn't have any subkeys, it still prints a null subkey plus, it prints a null subkey at the end ... need something eloquent like this, but covers all the bases too.
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#119996 - 2004-05-24 04:05 AM Re: Structured EnumKey Loop /w a single EnumKey
Les Les KiX Master Registered: 2001-06-11 Posts: 12734 Loc: fortfrances.on.ca	Code: Break on $Index = 0 While @Error=0 $KeyName = ENUMKEY("HKEY_CURRENT_USER\Console\", $Index) If @ERROR = 0 ? "Name found: $KeyName" $Index = $Index + 1 Endif Loop _________________________ Give a man a fish and he will be back for more. Slap him with a fish and he will go away forever.
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#119997 - 2004-05-24 05:00 AM Re: Structured EnumKey Loop /w a single EnumKey
Shawn Shawn Administrator Registered: 1999-08-13 Posts: 8611	niiiice ...
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#119998 - 2004-05-24 06:24 AM Re: Structured EnumKey Loop /w a single EnumKey
Sealeopard Sealeopard KiX Master Registered: 2001-04-25 Posts: 11165 Loc: Boston, MA, USA	See also the ArrayEnumKey() UDF in the UDF Forum. You cannot use a single EnumKey() function to enumerate multiple keys, unless you use the EnumKey() function inside a loop. _________________________ There are two types of vessels, submarines and targets.
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#119999 - 2004-05-24 07:30 AM Re: Structured EnumKey Loop /w a single EnumKey
Lonkero Lonkero KiX Master Guru Registered: 2001-06-05 Posts: 22346 Loc: OK	why not: Code: for $i=0 to -1 $keyname = ENUMKEY("HKEY_CURRENT_USER\Console\", $i) if @error $i=-1 else ? "Name found: " $keyname endif Loop _________________________ ! download KiXnet
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#120000 - 2004-05-24 10:51 AM Re: Structured EnumKey Loop /w a single EnumKey
Richard H. Richard H. Administrator Registered: 2000-01-24 Posts: 4946 Loc: Leatherhead, Surrey, UK	A bit over-the-top, but this works: Code: $i = 0 While Execute('$$Key=EnumKey("HKEY_CURRENT_USER\Software\",$$i) Exit Not @@ERROR') "Name found: "+$Key ? $i=$i+1 Loop
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#120001 - 2004-05-24 04:06 PM Re: Structured EnumKey Loop /w a single EnumKey
Richard H. Richard H. Administrator Registered: 2000-01-24 Posts: 4946 Loc: Leatherhead, Surrey, UK	Shawn, I've been racking my brain and I can't think why you want to do this unless it is purely for aesthetic reasons. It's not like having the EnumKey in twice is a processing overhead. In fact the solution I gave above is worse in terms of resources, as the Execute()'ed statement has to be parsed on each loop. It does have a better Golf score however
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#120002 - 2004-05-24 04:15 PM Re: Structured EnumKey Loop /w a single EnumKey
Shawn Shawn Administrator Registered: 1999-08-13 Posts: 8611	It was purely for aesthetic reasons and just on principle. Everytime I had to write an enum loop I always ended-up doing the double enumkey version, always knowing in the back of my mind that this single enumkey version was out there and just seemed more eloquent thats all. I think the single enumkey version is less kludgey and less (down-the-road-changes) error-prone. -Shawn
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#120003 - 2004-05-24 04:23 PM Re: Structured EnumKey Loop /w a single EnumKey
Les Les KiX Master Registered: 2001-06-11 Posts: 12734 Loc: fortfrances.on.ca	I imagine it is also a case of how to avoid GOTOs in the simplest manner. The problem with my method of LOOPing on @Error is that in the real world, @Error may happen at unexpected times and for unexpected reasons. Take MessageBox(), for instance. The post over at http://www.scriptlogic.com/forums/display_message.asp?mid=8877 demonstrates how a successful MessageBox() throws @Error. Code: $rc = Messagebox("Hello World","testing...") $rc = Messagebox("@@Error = "+@error,"testing...") BTW, I think that Ruud should fix that. _________________________ Give a man a fish and he will be back for more. Slap him with a fish and he will go away forever.
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#120004 - 2004-05-24 04:28 PM Re: Structured EnumKey Loop /w a single EnumKey
Shawn Shawn Administrator Registered: 1999-08-13 Posts: 8611	Les - ja - thought same thing when I first read your code - it starts with an "open-ended" check of @ERROR which might cause trouble. Once the loop gets going though, should be perfectly fine.
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#120005 - 2004-05-24 04:39 PM

Re: Structured EnumKey Loop /w a single EnumKey

Richard H. Offline

Administrator

Registered: 2000-01-24
Posts: 4946
Loc: Leatherhead, Surrey, UK

Be careful when using @ERROR at the start of loops if you don't precede it with the function.

Take this for example, exactly the same procedure run twice:
Code:

$Index = 0

While @Error=0

   $KeyName=ENUMKEY("HKEY_CURRENT_USER\Console\", $Index)

   If @ERROR = 0  ?

      "Name found on first pass: $KeyName"

      $Index=$Index+1

   EndIf

Loop

   

$Index = 0

While @Error=0

   $KeyName=ENUMKEY("HKEY_CURRENT_USER\Console\", $Index)

   If @ERROR = 0  ?

      "Name found on second pass: $KeyName"

      $Index=$Index+1

   EndIf

Loop

The problem is that the second pass will not display any results.

The reason is that @ERROR from the first loop is still set, so that the second loop fails instantly.

In a more complex function this can be a bugger to spot.

The solution is to clear the error status before starting the loop:
Code:

$Index=Execute("Exit 0") ; Initialise index and clear error status

While @Error=0

   $KeyName=ENUMKEY("HKEY_CURRENT_USER\Console\", $Index)

   If @ERROR = 0  ?

      "Name found on first pass: $KeyName"

      $Index=$Index+1

   EndIf

Loop

   

$Index=Execute("Exit 0") ; Initialise index and clear error status

While @Error=0

   $KeyName=ENUMKEY("HKEY_CURRENT_USER\Console\", $Index)

   If @ERROR = 0  ?

      "Name found on second pass: $KeyName"

      $Index=$Index+1

   EndIf

Loop

[EDIT]
Spooky. I'll have to type quicker.
[/EDIT]

Edited by Richard H. (2004-05-24 04:42 PM)

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#120006 - 2004-05-24 04:45 PM Re: Structured EnumKey Loop /w a single EnumKey
Les Les KiX Master Registered: 2001-06-11 Posts: 12734 Loc: fortfrances.on.ca	Sorry, just rising to the challenge of your limited scope. You never said it had to be bulletproof. Keeping with the @Error method, someone wrote a one line UDF that clears @Error with an EXIT 0. Useful for times like this. This works too but processes an IF on every LOOP. Code: Break on $i = 0 $KeyName = 'dummy' While $KeyName If $i ?"Name found: $KeyName" EndIf $i=$i+1 $KeyName = EnumKey("HKEY_CURRENT_USER\Software\",$i) Loop _________________________ Give a man a fish and he will be back for more. Slap him with a fish and he will go away forever.
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#120007 - 2004-05-25 05:29 AM Re: Structured EnumKey Loop /w a single EnumKey
Chris S. Chris S. MM club member Registered: 2002-03-18 Posts: 2368 Loc: Earth	I go back to my original sample with a little tweak... Code: $i = 0 Do $KeyName = EnumKey("HKEY_CURRENT_USER\Software\",$i) If Not @ERROR "Name found: $KeyName" ? $i=$i+1 EndIf Until @ERROR ...or, if you'd rather... Code: $i = 0 Do $KeyName = EnumKey("HKEY_CURRENT_USER\Software\",$i) If $KeyName "Name found: $KeyName" ? $i=$i+1 EndIf Until Not $KeyName
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