Perl hash keys not considered unique

elfstones65 has asked for the wisdom of the Perl Monks concerning the following question:

Hi I seem to have a strange issue where adding a keys into a hash is not being considered as unique
So say I have two files being the keys


$file1 = 'ENV.FILESOURCE.SOURCE.J2018058.N000001';
$file2 = 'ENV.FILESOURCE.SOURCE.J2018059.N000001';



    open LOG, "<$log";
    while (defined($line=<LOG>)) {
        chomp $line;

        if ($line =~/File \[\/opt\/app\/data\/pulsefba\/process/) {
                ($processingFile) = ($line =~ /process\/(.+)]/);
                $files{"$processingFile"} = 1;
        }

        if ($line =~ /Finished/) {
         
                ($currentFile) = ($line =~ /process\/(.+?)]/);
                ($read) = ($line =~ /: Read \[(.+)\] events - Processe
+d /);
                ($processed) = ($line =~ /Processed \[(.+?)\]/);
                ($wrote) = ($line =~ /Wrote \[(.+?)\]/);
                ($skippedRead) = ($line =~ /Skipped Read \[(.+?)\]/);
                ($skippedProcess) = ($line =~ /Skipped Process \[(.+?)
+\]/);
                ($skippedWrite) = ($line =~ /Skipped Write \[(.+?)\]/)
+;
                ($totalCount) = ($line =~ /Total Trailer Count - \[(.+
+?)\]/);

                $files{"$currentFile"}{'read'} = $read;
                $files{"$currentFile"}{'processed'} = $processed;
                $files{"$currentFile"}{'wrote'} = $wrote;
                $files{"$currentFile"}{'skippedRead'} = $skippedRead;
                $files{"$currentFile"}{'skippedProcess'} = $skippedPro
+cess;
                $files{"$currentFile"}{'skippedWrite'} = $skippedWrite
+;
                $files{"$currentFile"}{'totalTrailerCount'} = $totalCo
+unt;


                print "Debug: $currentFile set to Read: $read\n";
                print "File ENV.FILESOURCE.SOURCE.J2018058.N000001 cou
+nt: $files{'ENV.FILESOURCE.SOURCE.J2018058.N000001'}{'read'}\n";
                print "File ENV.FILESOURCE.SOURCE.J2018059.N000001 cou
+nt: $files{'ENV.FILESOURCE.SOURCE.J2018059.N000001'}{'read'}\n";
        }
[download]

While looping through a file Output is like below. How Come is file with the J2018059 getting values in the hash for file J2018058?
Debug: ENV.FILESOURCE.SOURCE.J2018058.N000001 set to Read: 1000
File ENV.FILESOURCE.SOURCE.J2018058.N000001 count: 1000
File ENV.FILESOURCE.SOURCE.J2018059.N000001 count: 1000
Debug: ENV.FILESOURCE.SOURCE.J2018058.N000001set to Read: 2000
File ENV.FILESOURCE.SOURCE.J2018058.N000001 count: 2000
File ENV.FILESOURCE.SOURCE.J2018059.N000001 count: 2000
Debug: ENV.FILESOURCE.SOURCE.J2018058.N000001 set to Read: 3000
File ENV.FILESOURCE.SOURCE.J2018058.N000001 count: 3000
File ENV.FILESOURCE.SOURCE.J2018059.N000001 count: 3000
Debug: ENV.FILESOURCE.SOURCE.J2018058.N000001 set to Read: 4000
File ENV.FILESOURCE.SOURCE.J2018058.N000001 count: 4000
File ENV.FILESOURCE.SOURCE.J2018059.N000001 count: 4000
Debug: ENV.FILESOURCE.SOURCE.J2018058.N000001 set to Read: 5000
File ENV.FILESOURCE.SOURCE.J2018058.N000001 count: 5000
File ENV.FILESOURCE.SOURCE.J2018059.N000001 count: 5000

Comment on Perl hash keys not considered unique Download Code

Replies are listed 'Best First'.
Re: Perl hash keys not considered unique (updated) by haukex (Archbishop) on Apr 23, 2018 at 13:19 UTC
Welcome to the Monastery, elfstones65. In the future, please provide a Short, Self-Contained, Correct Example so that we can download and run the code and more easily see the issue that you are having. Anyway, I assume that when reading your input, you first encounter a line that matches your first regex `/File .../`, and sets `$files{"$processingFile"} = 1;`, so e.g. `$files{"ENV.FILESOURCE.SOURCE.J2018058.N000001"} = 1;`. Then, when your code encounters a line matching `/Finished/` for the same file, you attempt to use `$files{"ENV.FILESOURCE.SOURCE.J2018058.N000001"}` as a hash reference by saying things like `$files{"$currentFile"}{'read'}`. However, `$files{"ENV.FILESOURCE.SOURCE.J2018058.N000001"}` contains the value `1` instead of a hash reference. Now Perl does something interesting: because you're not using strict `'refs'`, it will actually access a hash named `%1` - and it will do this for all files that have the same value in the `%files` hash! So every file's `/Finished/` data is ending up in the same hash, overwriting each other. You can see this yourself if you say `use Data::Dumper; print Dumper(\%1);` - you will see the data from the most recent `Finished` line collected in that hash. See Symbolic references. The best solution here is to Use strict and warnings! This will force you to avoid symbolic references, which is a good practice because it avoids the confusing behavior you're seeing. See also Why it's stupid to `use a variable as a variable name'. <Reveal this spoiler or all in this thread> Update: Several edits to improve the explanation.	[reply] [d/l] [select]
Re^2: Perl hash keys not considered unique (updated) by elfstones65 (Novice) on Apr 23, 2018 at 14:30 UTC
You hit the nail on the head. Trying to have the hash with shall I say multiple levels was the cause. `$files{"$processingFile"} = 1` Simply changing it to `$files{"$processingFile"}{"file"} = $processingFile;` Worked! Such a minor mistake, I was going nuts! Much appreciated.	[reply] [d/l] [select]
Re: Perl hash keys not considered unique by huck (Prior) on Apr 23, 2018 at 13:18 UTC
You are assuming that `$files{'ENV.FILESOURCE.SOURCE.J2018059.N000001'}` and `$files{'ENV.FILESOURCE.SOURCE.J2018058.N000001'}` point to unique hashs. but what if there was somewhere above this section a line that said: `$files{'ENV.FILESOURCE.SOURCE.J2018059.N000001'}=$files{'ENV.FILESOURC +E.SOURCE.J2018058.N000001'};` [download] while there would be an entry in $files for both names, they would both point to the same hash, so modifying either `$files{'ENV.FILESOURCE.SOURCE.J2018059.N000001'}{data}` or `$files{'ENV.FILESOURCE.SOURCE.J2018058.N000001'}{data}` would mean that the same end data location has been modified.	[reply] [d/l] [select]
Re: Perl hash keys not considered unique by Eily (Monsignor) on Apr 24, 2018 at 14:07 UTC
FYI, to avoid having to escape every / in your pattern, you can use the m operator that lets you use another special character as a delimiter for your regex (or a pair of characters if they are symmetric). `$line =~ m<File \[/opt/app/data/pulsefba/process>` Or, since you are searching for a fixed string, index could work as well.	[reply] [d/l]


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