| tylan |
| (Starting to like KiXtart) |
| 2007-07-11 07:57 PM |
GOTO is bad, right?
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I know that goto is frowned upon in these forums, so what's the "good coder" way of ending the script immediately? I want to make the script skip over 90% of the code, and resume with the last few lines of code for my admin accounts. I don't want printers installing on servers etc...
Shawn
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| (KiX Supporter) |
| 2007-07-11 08:08 PM |
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Re: GOTO is bad, right?
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Yup goto is bad.
The answer depends on where you "are" in the script (the context/scope):
If you want to quit out of the mainline script - use the quit statement:
Code:
Break On If 1=1 Quit Else ?"Much stuff..." ?"Much stuff..." ?"Much stuff..." Endif Exit 0
If you want to exit out of a "called" script - dont use quit - use exit, like this:
Code:
Break On If 1=1 Exit Else ?"Much stuff..." ?"Much stuff..." ?"Much stuff..." Endif Exit 0
Hope this answers your question.
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Shawn
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| (KiX Supporter) |
| 2007-07-11 08:11 PM |
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Re: GOTO is bad, right?
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You can also use Exit in the mainscript - cause Kixtart knows what is mainline versus called script. If in mainline - exit totally.
| tylan |
| (Starting to like KiXtart) |
| 2007-07-11 08:17 PM |
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Re: GOTO is bad, right?
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I would like to do something like this, but still follow good coding practices...
Code:
IF InGroup("ADMIN_USERS")
GOTO NEAREND
ENDIF
?"Main script"
?"Blah blah blah"
?"etc etc etc"
?"Do stuff and things"
:NEAREND
SHELL "\\somerset-dhcp\audit\scan\scan32.exe"
:END
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Shawn
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| (KiX Supporter) |
| 2007-07-11 08:22 PM |
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Re: GOTO is bad, right?
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Yeah - I hear you. Its these cases that make one want to use goto. We have a similar situation with our login script, maybe do this:
Code:
;; Handle some short code for admins and exit early...
IF InGroup("ADMIN_USERS")
SHELL "\\somerset-dhcp\audit\scan\scan32.exe"
EXIT
ENDIF
;; else the bulk of script ...
?"Main script"
?"Blah blah blah"
?"etc etc etc"
?"Do stuff and things"
EXIT 0
| tylan |
| (Starting to like KiXtart) |
| 2007-07-11 08:26 PM |
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Re: GOTO is bad, right?
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Makes sense. I like that code.
What is EXIT 0? I know what exit means, but what does the zero do?
| tylan |
| (Starting to like KiXtart) |
| 2007-07-11 08:27 PM |
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Re: GOTO is bad, right?
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Never mind. Went to kix help.
If EXIT is followed by a numeric expression, then @ERROR is set to the value of that expression and you can check it in the calling script or batch file.
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Shawn
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| (KiX Supporter) |
| 2007-07-11 08:31 PM |
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Re: GOTO is bad, right?
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If your short-code isn't really that short - but still want to avoid gotos - you can create a FUNCTION (UDF) in your script just for admins, then call it from your IF at the top ... like this:
Code:
IF InGroup("ADMIN_USERS")
AdminLogin()
EXIT
ENDIF
;; much user stuff ...
Function AdminLogin()
;; much admin stuff
EndFunction
| tylan |
| (Starting to like KiXtart) |
| 2007-07-11 08:36 PM |
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Re: GOTO is bad, right?
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As for right now, your example is find. I'll keep in mind the UDF.
Thanks
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Glenn Barnas
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| (KiX Supporter) |
| 2007-07-11 09:30 PM |
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Re: GOTO is bad, right?
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Just FYI
Exit # is the "return code" - it should always be zero unless an error occurred, as it sets the @ERROR macro. This is valid only for user defined functions, or exiting the main script.
If you define a UDF called MyUdf(), you can also set a "return value" by loading the data you want to retun into a variable the same name as the UDF. Thus, if you want to return "42" from your MyUdf calculations, you would put this at the end of your UDF:
Code:
$MyUdf = 42 Exit 0
However, if the calculation failed, you might do this at the point you detected the error:
Code:
$MyUdf = 0 Exit 1
Exiting with 1 is "incorrect function" - a generic error. You can use many other, more meaningful error values. Some common ones are
2 - File Not Found
5 - Access Denied
13 - The data is invalid
50 - the request is not supported
87 - The parameter is incorrect
Glenn
| Les |
| (KiX Master) |
| 2007-07-11 09:41 PM |
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Re: GOTO is bad, right?
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IMHO, Exit should always have a parm follow it. I wrote a FAQ on that topic.
| Witto |
| (MM club member) |
| 2007-07-11 10:40 PM |
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Re: GOTO is bad, right?
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What about
Code:
IF Not InGroup("ADMIN_USERS")
?"Main script"
?"Blah blah blah"
?"etc etc etc"
?"Do stuff and things"
ENDIF
SHELL "\\somerset-dhcp\audit\scan\scan32.exe"
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Lonkero
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| (KiX Master Guru) |
| 2007-07-11 10:59 PM |
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Re: GOTO is bad, right?
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that would do the trick but would require you to remember that endif.
| Witto |
| (MM club member) |
| 2007-07-11 11:10 PM |
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Re: GOTO is bad, right?
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I do not see the difference. The "EndIf" was there. I just added the "Not". By inverting the logic, the Goto is not needed anymore.
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Shawn
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| (KiX Supporter) |
| 2007-07-11 11:27 PM |
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Re: GOTO is bad, right?
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I think he wanted to keep the bulk of his script non-indented. You know - too many wasted bytes and (more importantly) those darn long-lines don't need any help getting longer.
| Les |
| (KiX Master) |
| 2007-07-12 04:06 AM |
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Re: GOTO is bad, right?
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I only indent by two spaces in my scripts. ASE has the vertical indentation lines to help keep track of the indents. Only prob is they are such a light grey that I have to tilt my LCD screen to see them.
Then they have that vertical line at column 83 which is great for knowing where to break those long lines.