passing parameters from the command line

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

Hi, I'm having a really dumb problem with running scripts from the command line when I have to pass in parameters/options into a script from the command line. My script works perfectly when I type:

c:>perl script.pl <option>
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but when I just run it without the 'perl' command, it always gets a zero-value passed in. As long as there is no need to pass in parameters, no problem, but the

   $option = hex(shift);
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does not work on my system. I'm using WinXP, and believe to have set the correct environment variables . . . anything else to tweak? thanks, TGe

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Re: passing parameters from the command line by GrandFather (Saint) on Dec 08, 2005 at 00:44 UTC
Check that the correct association has been made with '.pl'. Assuming that you are using an ActiveState install of Perl, right click on a .pl file and select "Open With\|Choose Program..." and check that Perl Command Line Interpreter is selected. If not, select it (or browse to perl.exe, probably in c:/Perl/bin) and check the 'Always use the selected program to open this kind of file' check box. FYI, it works fine both ways for me. DWIM is Perl's answer to Gödel	[reply]
Re: passing parameters from the command line by NetWallah (Canon) on Dec 08, 2005 at 05:36 UTC
Expanding on Grandfather's explanation, check the association for ".pl". (In Explorer, do Tools->Folder Options -> File Types, select .pl) The default action should be "Run". Now look at how the executable for "Run" is configured. In my case, it says: `"D:\Perl\PXPerl\bin\perl_pause.bat" "%1"` [download] Notice that only ONE parameter "%1" is being passed, and that is the name of the program. The args you want passed would not work on my system, and I get the results you are getting, and the message "Use of uninitialized value in concatenation (.) or string at ..." when attempting to print $ARGV[0]". The fix is to change the executable line to `"D:\Perl\PXPerl\bin\perl_pause.bat" "%1" %2 %3 %4 %5 %6 %7 %8 %9` [download] You're just jealous cause the voices are only talking to me. No trees were killed in the sending of this message. However, a large number of electrons were terribly inconvenienced.	[reply] [d/l] [select]
Re^2: passing parameters from the command line by TomGeukens (Initiate) on Dec 08, 2005 at 17:33 UTC
Hey Guys, thanks a lot for the information. Messing around with the executable line did the trick!!!	[reply]
Re: passing parameters from the command line by l3v3l (Monk) on Dec 08, 2005 at 00:33 UTC
can you just use: `$opt = $ARGV[0] \|\| "default value for option";` instead of shift or is there something else going on in your script that requires you to use shift?	[reply] [d/l]