Variable scope issue

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

Replies are listed 'Best First'.
Re: Variable scope issue by jwkrahn (Abbot) on Jun 26, 2019 at 19:12 UTC
You didn't verify that either `open` succeeded. You didn't `chomp` the value you are using as a file name so it probably failed! `my $score = 100_000; open my $IN, '<', $arq or die "Cannot open '$arq' because: $!"; while ( <$IN> ) { chomp; open my $IN1, '<', $_ or die "Cannot open '$_' because: $!"; while ( <$IN1> ) { my @temp = split /\t/; if ( $temp[ 1 ] < $score ) {` [download]	[reply] [d/l] [select]
Re^2: Variable scope issue by haukex (Archbishop) on Jun 30, 2019 at 10:26 UTC
You didn't verify that either `open` succeeded. You didn't `chomp` the value you are using as a file name... Very good points! ... so it probably failed! Sorry, no - open: "The filename passed to the one- and two-argument forms of open will have leading and trailing whitespace deleted and normal redirection characters honored." Even if the if the second `open` failed, it doesn't explain the warning, as the inner `while` loop would not execute - the same comment applies to LanX's post.	[reply] [d/l] [select]
Re: Variable scope issue by BillKSmith (Monsignor) on Jun 27, 2019 at 15:27 UTC
There does not seem to be anything wrong with the code you posted. I understand it can be difficult to write an SSCCE when you do not know what is wrong. Perhaps this will help. As you can see, the following code does what I think you want without error. Please modify it to demonstrate your error. Post the failing code. Remember, we have to be able to run it and reproduce your error message. >type crickson.pl use strict; use warnings; my $arg = \'$infile1'; my $infile1 = \"one_score\t999"; my $score=100000; open my $IN, '<', $arg or die "error opening list of files"; while (<$IN>) { $_ = eval $_; # Bad practice - Use only for 'in-memory' file. open my $IN1, '<', $_ or die "error opening file $_"; while (local $_ = <$IN1>) { my @temp = split /\t/; if ($temp[1] < $score) { warn "\$temp[1] not defined\n" if !defined $temp[1]; warn "\$score not defined\n" if !defined $score; print "$temp[1] < $score\n"; } } } >perl crickson.pl 999 < 100000 > [download] Bill	[reply] [d/l]
Re: Variable scope issue by LanX (Saint) on Jun 26, 2019 at 17:36 UTC
A guess: I think it's @temp which is undefined because you're messing up $_ twice and your second open fails. Can't test now... Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]
Re^2: Variable scope issue by crickson (Initiate) on Jun 26, 2019 at 17:51 UTC
The second open works and it is not @temp the issue, as I have verified both. It is really $score, as its previous initialization is not considered inside the IF.	[reply]
Re^3: Variable scope issue by GrandFather (Saint) on Jun 26, 2019 at 21:11 UTC
as I have verified both How? Unless there is a substantial bug in the version of Perl you are using, your assertion "as its previous initialization is not considered inside the IF" is wrong. What version of Perl are you using and on what platform? Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply]
Re^3: Variable scope issue by Anonymous Monk on Jun 26, 2019 at 18:14 UTC
show an SSCCE	[reply]
Re: Variable scope issue by Anonymous Monk on Jun 26, 2019 at 17:37 UTC
did you check $temp1?	[reply]
Re^2: Variable scope issue by crickson (Initiate) on Jun 26, 2019 at 17:52 UTC
The temp1 was an issue with the HTML format. I have corrected that.	[reply]