Having a script find itself on the file system in Windows XP and other OSs

David Catchpole has asked for the wisdom of the Perl Monks concerning the following question:

I'm a big fan of opening the Command Prompt in Windows and entering a single command line to run a script e.g.

C:\WINDOWS>perl c:\mydocu~1\david\somescript.pl
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Now, problem with this is that it sets as the current working directory the directory (e.g. C:/WINDOWS/) I launched the command from, rather than the directory (e.g. C:/My Documents/David/) where the script resides, which I would like to have on hand in order to play with other files that live in its neighbourhood. I guess I'd also like to have fully portable code that's prepared for any reasonable method of launch, and so I think this is an issue that can't be resolved just by changing my own behaviour. Previously I was using Windows 98SE and I'd gone some way to solving the problem by stripping the script path from

$ENV{"CMDLINE"}
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... but now I'm using Windows XP, which don't got

$ENV{"CMDLINE"}
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or anything similar! Is there any consistent way of getting the full shell command line, or more generally of getting a script to find itself on the file system? Also, what issues does this have for portability to non-Windows OSs?

Comment on Having a script find itself on the file system in Windows XP and other OSs Select or Download Code

Replies are listed 'Best First'.
Re: Having a script find itself on the file system in Windows XP and other OSs by Anonymous Monk on Feb 24, 2004 at 23:24 UTC
Check out `$0`.	[reply] [d/l]
Re: Re: Having a script find itself on the file system in Windows XP and other OSs by David Catchpole (Initiate) on Feb 24, 2004 at 23:39 UTC
Ahhh.... Bugger, now I feel like a dickhead!	[reply]
Re: Having a script find itself on the file system in Windows XP and other OSs by matija (Priest) on Feb 25, 2004 at 08:02 UTC
For simple cases, $0 is the correct answer. For more complex cases, you can use `FindBin` module. FindBin exports the following variables: $Bin - path to bin directory from where script was invoked $Script - basename of script from which perl was invoked $RealBin - $Bin with all links resolved $RealScript - $Script with all links resolved I've seen `FindBin` used in programs which try to work out of the box regardless of the OS they've been run on. MRTG - multi router traffic grapher is one example.	[reply] [d/l] [select]