lvalue - howto fix?

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

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Re: lvalue - howto fix? by Nitrox (Chaplain) on Nov 20, 2002 at 20:39 UTC
`$ok = "Y" if ($zipcheck->read($arczip)`== `AZ_OK);` First you need a comparative operator to check AZ_OK, and is AZ_OK a constant you've defined elsewhere? -Nitrox	[reply] [d/l] [select]
Re: lvalue - howto fix? by dreadpiratepeter (Priest) on Nov 20, 2002 at 20:41 UTC
I would think that you want a comparison, not an assignment on line 3. I.e.: `my $ok = "N"; my $zipcheck = Archive::Zip->new(); $ok = "Y" if ($zipcheck->read($arczip) == AZ_OK); unlink $originalfile if ($ok eq 'Y');` [download] Hope this helps, -pete "Worry is like a rocking chair. It gives you something to do, but it doesn't get you anywhere."	[reply] [d/l]
Re: lvalue - howto fix? by BrowserUk (Patriarch) on Nov 20, 2002 at 21:15 UTC
If you enabled warnings (use warnings or -w) perl would prabably have told you what you were doing wrong. Eg. `C:\>perl -we "print 'OK' if (1=1)" Found = in conditional, should be == at -e line 1. Can't modify constant item in scalar assignment at -e line 1, next cha +r ) Execution of -e aborted due to compilation errors. C:\>` [download] Okay you lot, get your wings on the left, halos on the right. It's one size fits all, and "No!", you can't have a different color. Pick up your cloud down the end and "Yes" if you get allocated a grey one they *are* a bit damp under foot, but someone has to get them. Get used to the wings fast cos its an 8 hour day...unless the Govenor calls for a cyclone or hurricane, in which case 16 hour shifts are mandatory. Just be grateful that you arrived just as the tornado season finished. Them buggers are real work.	[reply] [d/l]
Re: Re: lvalue - howto fix? by clairudjinn (Beadle) on Nov 20, 2002 at 23:03 UTC
Just wondering if eq should be used rather than == as AZ_OK looks more character-based than numerical to me...	[reply]
Re: Re: Re: lvalue - howto fix? by Mr. Muskrat (Canon) on Nov 20, 2002 at 23:11 UTC
Actually, AZ_OK is defined as 0.	[reply]
Re: lvalue - howto fix? by pg (Canon) on Nov 20, 2002 at 21:06 UTC
Just want to give you some more extended info on this. Hope those are useful. Although it is not your purpose here, Perl does support l-value functions. An example would be the substr function: `$str = "135"; substr($str, 1, 1) = "234"; print $str; This should give you "12345";` [download] If you are not comparing numbers, but strings, then you should use 'eq', instead of '=='. `$str1 = "01"; $str2 = "1"; print "equal as numbers\n" if ($str1 == $str2); print "equal as strings\n" if ($str1 eq $str2);` [download]	[reply] [d/l] [select]
Re: lvalue - howto fix? by ibanix (Hermit) on Nov 20, 2002 at 23:08 UTC
Everyone else already hit the nail on the head, so I'll just throw out a few useful links: Perl Operators Archive::ZIP Frequently Asked Questions /rgrds <-> In general, we find that those who disparage a given operating system, language, or philosophy have never had to use it in practice. <->	[reply]