In general, "if defined($ARGV[0])" is good for checking individual elements. If an element contains the value "0", for example, then it will fail the "if $ARGV[0]" test, even though there IS a value there, which may be valid.
"if defined(@ARGV)" is not really necessary because the only time the value of @ARGV in scalar context will be 0 is if it is empty. -----Original Message----- From: Cliff [mailto:[EMAIL PROTECTED]] Sent: Monday, January 27, 2003 3:37 PM To: Geaslin, Andrew - GPB Cc: [EMAIL PROTECTED] Subject: RE: Detecting $ARGV[0] I also agree that the modules mentioned are great things ... for times when modules are needed. Otherwise, I am a fan of: if (@ARGV) do {blah;} Of course, "defined" is good too, for the pedantic. Sometimes modules are great, sometimes they are overkill ;) -~.-~.-~.-~.-~.-~.-~.-~.-~.-~ -~ -~ Cliff Frensley -~ [EMAIL PROTECTED] -~ Seattle, WA -~ -~ -. On Mon, 27 Jan 2003, Geaslin, Andrew - GPB wrote: > I agree that GetOpt::Std or GetOpt::Long are excellent (I use them often). > But if you want to roll your own you can treat @ARGV like any other array. > > if (@ARGV) > { print "parameters present\n"; > } > else > { print "no parameters\n"; > } > > > > -Andrew > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > There are other caveats to be aware of as well when it comes to writing your > own switches. I would recommend looking into the GetOpt::Std module that > comes standard with Perl. It can do what you want and comes out much > cleaner. > > > > Is there a better way to detect a parameter given in a command line? For > example, to run the script (obviously) c:\>script.pl I have also added > some "switches" to help with setup of the options (like) c:\>script.pl /h > to see a help message > c:\>script.pl /i to generate a new options file, etc. And it is all > working well. > > Question: When NOT using a switch (just running the script), I am getting > a message I would like to supress or preferable fix by using more correct > code... > Use of uninitialized value in string ne at logsaver.pl line 33. > > This is of course because I have not included a /h or /i value. The script > runs, but I would prefer it ran cleanly with no message. > > Code is this.... > # if no parameters passed, skip. If something passed, then do. > if($ARGV[0] ne ""){ do this stuff; } > > Thank you! > > > Glenn Meyer > > > _______________________________________________ > Perl-Win32-Admin mailing list > [EMAIL PROTECTED] > To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs > _______________________________________________ > Perl-Win32-Admin mailing list > [EMAIL PROTECTED] > To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs > _______________________________________________ > Perl-Win32-Admin mailing list > [EMAIL PROTECTED] > To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs > _______________________________________________ Perl-Win32-Admin mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs _______________________________________________ Perl-Win32-Admin mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
