Printing of Array Hash is Missing Elements

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

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Re: Printing of Array Hash is Missing Elements by ELISHEVA (Prior) on Sep 28, 2009 at 20:11 UTC
You say you have verified that the hash contains all 40 elements. How? Without seeing that code it is going to be hard for us to guess why print_hash() only prints out 11 elements, but your mystery method prints out 40. That aside, you might want to consider the following changes: slurping: i.e. `@lines = <INFILE>`. This doesn't scale well because you have to hold the entire file into memory. A better approach is to read one line in at a time: `while (my $line=<MYFILE>) { chomp $line; #set up hash entry }` [download] two parameter open: there are some rare circumstances where this can lead to problems. Consider getting in the habit of using the 3 parameter open: `open(MYFILE, '<', $infile)` clearing `@temp` by setting `@temp=()` is unnecessary. split is going to replace the contents of `@temp` anyway. You don't actually need `@temp`. Perl has a wonderful feature that lets you assign array elements to a list of named variables: `my ($vlan_number, $first_octet, $second_octet, $third_octet, $fourth_octet, $subnet_slash, $subnet_dotted, $network, $bldg_name, $description) = split(/,/, $line);` Unless you are absolutely sure that there will never be whitespace on either side of your comma, `split(/\s,\s/, $line)` is a more robust way of splitting a comma delimited list. Assigning `$hashref=\%buildings` at the top, filling `%buildings`, and then printing `$hashref` seems a bit convoluted. You can assign data directly to a hash reference by using `->` operator, so why not just do this: `my $buildings={}; #set up a hash reference while (my $line = <MYFILE>) { #... parse line $buildings->{$bldg_name}{'name'} = $bldg_name; $buildings->{$bldg_name}{'number'} = $vlan_number; #... and so on } # ... more stuff print_hash($buildings);` [download] Best, beth	[reply] [d/l] [select]
Re^2: Printing of Array Hash is Missing Elements by spickles (Scribe) on Sep 28, 2009 at 20:57 UTC
Et al - Thanks for the many suggestions. It's my limited knowledge of perl that results in my current code. I appreciate the overwhelming support from those that do this on a more regular basis. I think that the suggestions I have gotten here will allow me to make my code smaller, more reliable, and easier to understand. It has been particularly the use of multidimensional arrays, hashes and references that has gotten me confused here. I'll clean things up and post back. Thanks again!!	[reply]
Re: Printing of Array Hash is Missing Elements by GrandFather (Saint) on Sep 28, 2009 at 19:56 UTC
How about a little data? Not all the data, just enough to demonstrate the problem. You should also show us a sample of what you get and what you expect for the sample data. At present I can't tell if there should be data for 40 buildings, but you are only seeing output data for 11, or if the problem is that there are 40 columns in the input and only 11 in the output. Although you describe your output file as CSV, it's not using the same format as the original file and doesn't conform to the usual expectations for a CSV file - it may be better thought of as a text or data file to avoid confusion. As an aside, don't globally declare local variables - all your temporary variables should be declared where they are initialized (inside the loop or sub). Use the three parameter version of open and use a lexical variable (my $myFile) instead MYFILE (good to see the open is checked though). Also, use a while loop rather than a for loop for reading input lines. True laziness is hard work	[reply]
Re^2: Printing of Array Hash is Missing Elements by spickles (Scribe) on Sep 28, 2009 at 20:25 UTC
Grandfather - Ok, so I modified some of the data file, as well as the suggestions already posted. It is clear, now, after modifying the building names that the output is only containing unique records. The input is this: VLAN Tag 1st Octet 2nd Octet 3rd Octet 4th Octet Mask + Mask Subnet Building Description 321 10 32 32 0 19 255.255.224.0 10.32.32.0 /19 + Building1 Data VLAN 322 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding1 Data VLAN 323 10 32 128 0 19 255.255.224.0 10.32.128.0 /19 + Building1 Data VLAN 324 10 32 96 0 19 255.255.224.0 10.32.96.0 /19 + Building1 Data VLAN 325 10 32 160 0 19 255.255.224.0 10.32.160.0 /19 + Building1 Data VLAN 326 10 32 192 0 19 255.255.224.0 10.32.192.0 /19 + Building1 Data VLAN 327 10 32 64 0 19 255.255.224.0 10.32.64.0 /19 + Building1 Data VLAN 328 10 32 248 0 22 255.255.252.0 10.32.248.0 /22 + Building1 Data VLAN 329 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding1 Data VLAN 330 10 32 224 0 24 255.255.255.0 10.32.224.0 /24 + Building1 Data VLAN 331 10 32 225 0 24 255.255.255.0 10.32.225.0 /24 + Building2 Data VLAN 332 10 32 228 0 24 255.255.255.0 10.32.228.0 /24 + Building2 Data VLAN 333 10 32 229 0 24 255.255.255.0 10.32.229.0 /24 + Building2 Data VLAN 334 10 32 232 0 24 255.255.255.0 10.32.232.0 /24 + Building2 Data VLAN 335 10 32 233 0 24 255.255.255.0 10.32.233.0 /24 + Building2 Data VLAN 336 10 32 236 0 24 255.255.255.0 10.32.236.0 /24 + Building2 Data VLAN 337 10 32 237 0 24 255.255.255.0 10.32.237.0 /24 + Building2 Data VLAN 338 10 32 240 0 24 255.255.255.0 10.32.240.0 /24 + Building2 Data VLAN 339 10 32 241 0 24 255.255.255.0 10.32.241.0 /24 + Building2 Data VLAN 340 10 32 244 0 24 255.255.255.0 10.32.244.0 /24 + Building2 Data VLAN 341 10 32 245 0 24 255.255.255.0 10.32.245.0 /24 + Building3 Data VLAN 342 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 343 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 344 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 345 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 346 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 347 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 348 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 349 10 32 0 24 255.255.255.0 10.32..0 /24 Bui +lding3 Data VLAN 350 10 32 2 0 23 255.255.254.0 10.32.2.0 /23 B +uilding3 Data VLAN 351 10 32 4 0 23 255.255.254.0 10.32.4.0 /23 B +uilding4 Data VLAN 352 10 32 6 0 23 255.255.254.0 10.32.6.0 /23 B +uilding4 Data VLAN 353 10 32 8 0 23 255.255.254.0 10.32.8.0 /23 B +uilding4 Data VLAN 354 10 32 10 0 23 255.255.254.0 10.32.10.0 /23 + Building4 Data VLAN 355 10 32 12 0 23 255.255.254.0 10.32.12.0 /23 + Building4 Data VLAN 356 10 32 14 0 23 255.255.254.0 10.32.14.0 /23 + Building4 Data VLAN 365 10 33 32 0 24 255.255.255.0 10.33.32.0 /24 + Building4 Data VLAN 606 10 0 249 0 29 255.255.255.248 10.0.249.0 /29 + Building4 Data VLAN [download] The output is: Building name Building VLAN number VLAN Tag VLAN 1st Octet 1st Octet VLAN 2nd Octet 2nd Octet VLAN 3rd Octet 3rd Octet VLAN 4th Octet 4th Octet VLAN Subnet Slash Mask VLAN Subnet Dotted Mask VLAN Network Subnet VLAN Description Description Building name Building1 VLAN number 330 VLAN 1st Octet 10 VLAN 2nd Octet 32 VLAN 3rd Octet 224 VLAN 4th Octet 0 VLAN Subnet Slash 24 VLAN Subnet Dotted 255.255.255.0 VLAN Network 10.32.224.0 /24 VLAN Description Data VLAN Building name Building2 VLAN number 340 VLAN 1st Octet 10 VLAN 2nd Octet 32 VLAN 3rd Octet 244 VLAN 4th Octet 0 VLAN Subnet Slash 24 VLAN Subnet Dotted 255.255.255.0 VLAN Network 10.32.244.0 /24 VLAN Description Data VLAN Building name Building3 VLAN number 350 VLAN 1st Octet 10 VLAN 2nd Octet 32 VLAN 3rd Octet 2 VLAN 4th Octet 0 VLAN Subnet Slash 23 VLAN Subnet Dotted 255.255.254.0 VLAN Network 10.32.2.0 /23 VLAN Description Data VLAN Building name Building4 VLAN number 606 VLAN 1st Octet 10 VLAN 2nd Octet 0 VLAN 3rd Octet 249 VLAN 4th Octet 0 VLAN Subnet Slash 29 VLAN Subnet Dotted 255.255.255.248 VLAN Network 10.0.249.0 /29 VLAN Description Data VLAN [download]	[reply] [d/l] [select]
Re^3: Printing of Array Hash is Missing Elements by ELISHEVA (Prior) on Sep 28, 2009 at 20:45 UTC
Because you are keying your hash by building name, you only get 4 hash entries, one for each unique building name. Each time you add a new line with the same building name, it overwrites the last line you inserted for that building entry. Hence you read in 40 lines but only get out 4. If you want to keep each row separate, I would recommend storing your parsed records in an array of hashes and using a customized sort function. Instead of `$buildings{bldg_name}{first_octet}` do something like this: `my @aBuildings; while (my $line=<MYFILE>) { chomp $line; #... parse line # add a new element to your array of hashes (AoH) my $hLine = { name => $bldg_name number => $vlan_number ... }; push @aBuildings, $hLine; }` [download] Then in your print out you would use a custom sort to sort the array elements by building name: `foreach my $hLine (sort { $a->{name} cmp $b->{name} } @aBuildings) { #print out contents of $hLine }` [download] See sort and perldsc for more information about custom sorting routines and AoH (array of hash) data structures. Best, beth	[reply] [d/l] [select]
Re^3: Printing of Array Hash is Missing Elements by ig (Vicar) on Sep 29, 2009 at 09:29 UTC
Your code splits on commas but your sample data has no commas. To produce all the networks in the format you have shown, sorted by building and VLAN, I might do something like the following: use strict; use warnings; use Data::Dumper; do { print <<EOF; Building name $_->[8] VLAN number $_->[0] VLAN 1st Octet $_->[1] VLAN 2nd Octet $_->[2] VLAN 3rd Octet $_->[3] VLAN 4th Octet $_->[4] VLAN Subnet Slash $_->[5] VLAN Subnet Dotted $_->[6] VLAN Network $_->[7] VLAN Description $_->[9] EOF } for sort { $a->[8] cmp $b->[8] or $a->[0] <=> $b->[0] } map { [ unpack('(A3 x1)6 (A15 x1)2 A11 x1 A*') ] } <DATA>; __DATA__ 321 10 32 32 0 19 255.255.224.0 10.32.32.0 /19 Building1 Da +ta VLAN 322 10 32 0 24 255.255.255.0 10.32..0 /24 Building1 Da +ta VLAN 323 10 32 128 0 19 255.255.224.0 10.32.128.0 /19 Building1 Da +ta VLAN 324 10 32 96 0 19 255.255.224.0 10.32.96.0 /19 Building1 Da +ta VLAN 325 10 32 160 0 19 255.255.224.0 10.32.160.0 /19 Building1 Da +ta VLAN 326 10 32 192 0 19 255.255.224.0 10.32.192.0 /19 Building1 Da +ta VLAN 327 10 32 64 0 19 255.255.224.0 10.32.64.0 /19 Building1 Da +ta VLAN 328 10 32 248 0 22 255.255.252.0 10.32.248.0 /22 Building1 Da +ta VLAN 329 10 32 0 24 255.255.255.0 10.32..0 /24 Building1 Da +ta VLAN 330 10 32 224 0 24 255.255.255.0 10.32.224.0 /24 Building1 Da +ta VLAN 331 10 32 225 0 24 255.255.255.0 10.32.225.0 /24 Building2 Da +ta VLAN 332 10 32 228 0 24 255.255.255.0 10.32.228.0 /24 Building2 Da +ta VLAN 333 10 32 229 0 24 255.255.255.0 10.32.229.0 /24 Building2 Da +ta VLAN 334 10 32 232 0 24 255.255.255.0 10.32.232.0 /24 Building2 Da +ta VLAN 335 10 32 233 0 24 255.255.255.0 10.32.233.0 /24 Building2 Da +ta VLAN 336 10 32 236 0 24 255.255.255.0 10.32.236.0 /24 Building2 Da +ta VLAN 337 10 32 237 0 24 255.255.255.0 10.32.237.0 /24 Building2 Da +ta VLAN 338 10 32 240 0 24 255.255.255.0 10.32.240.0 /24 Building2 Da +ta VLAN 339 10 32 241 0 24 255.255.255.0 10.32.241.0 /24 Building2 Da +ta VLAN 340 10 32 244 0 24 255.255.255.0 10.32.244.0 /24 Building2 Da +ta VLAN 341 10 32 245 0 24 255.255.255.0 10.32.245.0 /24 Building3 Da +ta VLAN 342 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 343 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 344 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 345 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 346 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 347 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 348 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 349 10 32 0 24 255.255.255.0 10.32..0 /24 Building3 Da +ta VLAN 350 10 32 2 0 23 255.255.254.0 10.32.2.0 /23 Building3 Da +ta VLAN 351 10 32 4 0 23 255.255.254.0 10.32.4.0 /23 Building4 Da +ta VLAN 352 10 32 6 0 23 255.255.254.0 10.32.6.0 /23 Building4 Da +ta VLAN 353 10 32 8 0 23 255.255.254.0 10.32.8.0 /23 Building4 Da +ta VLAN 354 10 32 10 0 23 255.255.254.0 10.32.10.0 /23 Building4 Da +ta VLAN 355 10 32 12 0 23 255.255.254.0 10.32.12.0 /23 Building4 Da +ta VLAN 356 10 32 14 0 23 255.255.254.0 10.32.14.0 /23 Building4 Da +ta VLAN 365 10 33 32 0 24 255.255.255.0 10.33.32.0 /24 Building4 Da +ta VLAN 606 10 0 249 0 29 255.255.255.248 10.0.249.0 /29 Building4 Da +ta VLAN [download] But the sorting appears to be unnecessary as the data you have provided is already sorted.	[reply] [d/l]
Re: Printing of Array Hash is Missing Elements by toolic (Bishop) on Sep 28, 2009 at 19:44 UTC
for my $entry (sort keys %buildings) { Try: `for my $entry (sort keys %{ $ref }) {` [download] I would also do: `print_hash(\%buildings);` [download]	[reply] [d/l] [select]
Re: Printing of Array Hash is Missing Elements by jakobi (Pilgrim) on Sep 28, 2009 at 20:18 UTC
If you applied the earlier tips, and the bug's not yet obvious, consider warn's and the perl debugger: Beside the time honored practice of liberally sprinkling warns() to check for "assertions" like `@keys=sort keys %buildings; $#keys+1==40 or warn "NOT forty: $#keys+1\n"` you shouldn't forget the possibilities offered by the perl debugger, esp. when you set the breakpoint near suspected code. Updated to include Dumper: also consider `use Data::Dumper; ...; warn Dumper(...)`; I actually prefer this over interactive debugger use.	[reply] [d/l] [select]


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