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User Questions
Should I use v5.10 because of named groups?
5 direct replies — Read more / Contribute
by hrcerq
on Apr 13, 2021 at 18:11

    Hello again.

    I've got a script that uses named capture groups to parse file records. The record format is always the same (four fields wide, colon separated), just like a passwd file (except for the number of fields).

    For example:


    You get the idea. At first I used to split it, but later I came to the conclusion that using a regex with named groups could provide a more understandable code. The (simplified) example below might help you get the picture.

    if (/^(?<type>[01]):(?<valid>[01]):(?<name>[^:]+):(?<comment>[^:]+)$/) + { print "Key name: ", $+{name}, "\n"; print "Key Comment: ", $+{comment}, "\n"; print "Not valid\n" unless $+{valid} || !$+{type}; } else { print "Malformed input: $_\n"; }

    Now, I've noticed (according to perlretut) that named capture groups were introduced in Perl 5.10. I don't expect the script to run in older versions, but would it be wise to use v5.10 pragma?

    Would it have any unwanted side effects? I'm not using any of the features of the bundle, just wanted to state that version 5.10 is required. Is that a good idea?

printing metadata Tag using ExifTool
1 direct reply — Read more / Contribute
by g_speran
on Apr 13, 2021 at 15:24

    Hello Perl Monks

    I am trying to use ExifTool to extract some Metadata TAGS. I've searched for a specific use case but was unsuccessful. Ive constructed some simple code to accomplish what I am trying to do, but I am looking for verification that I am doing it correctly to extract the necessary variables or is there a simpler way.

    use Image::ExifTool qw(:Public); use Data::Dumper; $file='d:/60486581538__715F9238-09E5-4806-8146-0626DAFB0E36.JPG'; $ExifTool = new Image::ExifTool; #$ExifTool->Options(DateFormat => '%Y-%m-%d'); $info = $ExifTool->ImageInfo($file,'SubSecCreateDate','LensModel'); #$info = $ExifTool->ImageInfo($file); print "INFO: $info\n"; $createdate=$$info{'SubSecCreateDate'}; $lens=$$info{'LensModel'}; print "\nCreate Date: $createdate\n"; print "Lens Model: $lens\n\n"; print Dumper($info); exit; D:\> INFO: HASH(0x2b9f148) Create Date: 2020:03:02 13:16:55.336-05:00 Lens Model: iPhone 7 back camera 3.99mm f/1.8 $VAR1 = { 'LensModel' => 'iPhone 7 back camera 3.99mm f/1.8', 'SubSecCreateDate' => '2020:03:02 13:16:55.336-05:00' }; D:\>
XML::XPath matching different file extension
1 direct reply — Read more / Contribute
by Anonymous Monk
on Apr 13, 2021 at 11:27
    Hi there Monks!

    I have this line in my code and I am trying to see if there is a way to add more than one file match in this line, the files comes as "*.txt", "*.TXT", "*.png", "*.PNG".
    It breaks if in this line the file extension is "*.TXT" instead of "*.txt".
    my @files = $zip->membersMatching( '.*\.txt' );

    Thanks for looking!
Useless use of string in return statement
7 direct replies — Read more / Contribute
by Bod
on Apr 12, 2021 at 19:06

    Is there something strange about the way return treats conditions?

    I have this and it doesn't work as expected...

    sub get_ids { my ($self, %attrs) = @_; # Do stuff... my %result; # $result{'message'} = ''; if ($self->{'error'}) { $result{'status'} = 'error'; $result{'message'} = $self->{'error'}; } else { $result{'status'} = 'success'; $result{'api-key'} = $self->{'api-public'}; $result{'session'} = $intent_id; } return encode_json(\%result) if lc($attrs{'format'}) eq 'json'; return $result{'message'} or "$result{'api-key'}:$result{'session' +}"; # <- line 229 return "SOMETHING"; }
    If it is called as get_ids( 'format' => 'json' ); it works fine but asking it to return a text string returns undef and warns Useless use of string in void context at line 229. The way I think it should work is that if $result{'message'} evaluates as true, that will get returned but if it evaluates as false then "$result{'api-key'}:$result{'session'}" wil be returned instead.

    Can you explain why this is not behaving as expected?

    As an aside, in searching for an answer I found this post -> Useless use of string in void context
    There it is suggested that Perl reports the wrong line number for this warning so it is quite possible that I'm actually looking in the wrong place!

Strange behavior in File::Find (stopped working for no reason)
2 direct replies — Read more / Contribute
by pvaldes
on Apr 12, 2021 at 12:40

    I'm perplexed. Can you tell me what is wrong with this script?

    #!/usr/bin/perl -w use strict; use warnings; use diagnostics; use File::Find; open (my $t, '>', '/home/myuser/myfilename.sql') or die $!; print $t "blah blah\n"; find( { preprocess => \&hi, wanted => \&work, postprocess => \&bye, fo +llow_skip => 1 }, "."); sub hi { print $t "hi\n"; return;} # works correctly sub bye { print $t "bye\n"; return;} # works correctly sub work { print "my name is: ", $File::Find::name; print $t "I'm a file!"; return;} close $t;

    when I run the script in the current tree directory I would expect a list of filenames being printed in screen and a text file containing:

    blah blah hi I'm a file!I'm a file!I'm a file!... etc bye

    But what I have is: "my name is: ." or "my name is: 1" and a file containing:

    blah blah hi bye I'm a file! <-yep, solitary and in the wrong position

    libfile-find-wanted-perl/testing,testing,now 1.00-1.1 all installed, automatic

    Can somebody tell me what is happening here? Is not a little late for an 1-April Joke?

LinkedIn module
1 direct reply — Read more / Contribute
by Bod
on Apr 12, 2021 at 08:07

    Searching CPAN I was rather surprised that the only general modules for connecting to LinkedIn seem to be WWW::LinkedIn and Net::Linkedin::OAuth2 - both of these date from before Microsoft acquired LinkedIn 5 years ago...unbelievable that it is that long ago!

    Since the 5th April, Hootsuite have reduced the number of scheduled posts permitted on free accounts down to just 5 and we don't use the other features to warrant the paid price tag. We already have an automated Twitter scheduler and I want to add LinkedIn to it so just need something to authenticate, read the timestamp of the latest post and be able to create a post containing media.

    Before I write something to do this, are there any modules available or should I try out the modules above despite their age?

Pushing hash ref onto array ref
2 direct replies — Read more / Contribute
by Bod
on Apr 11, 2021 at 18:18

    A module I am creating has a blessed hash ref as is common. One of the hashes is a reference to an array of anonymous hashes created like so:

    sub new { my $class = shift; my %attrs = @_; my @products = ({ 'id' => 0, 'name' => 'Test', 'description' => 'Some test data', 'qty' => 1, 'price' => 1000, }); $attrs{'trolley'} = \@products; return bless \%attrs, $class; }
    Later on I want to push another anonymous hash onto @products.

    What is the best way to do this?
    Both of these push lines appear to work identically in testing

    sub add_product { my ($self, $product_data) = @_; # create $new_product hasfref push $self->{'trolley'}, $new_product; push @{$self->{'trolley'}}, $new_product; }
    However, I suspect there is some subtle difference between the two which might trip me up in the future!

    Is there a practical difference and is there a 'best' option to use?

Check for another program availability
10 direct replies — Read more / Contribute
by hrcerq
on Apr 10, 2021 at 16:06

    Hi. I need feedback on this... In order to run a Perl program, I must check for the availability of another program (i.e. it's in the PATH). So I've created a subroutine for this (which returns 0 for "not found" and 1 for "found"), and I'm not sure if this is the best option. Here's the code:

    sub available { my $program = shift; for my $pathdir (split /:/, $ENV{PATH}) { return 1 if -x "$pathdir/$program"; } return 0; }

    I'd like to know if it's inefficient, and if there's a core module that already takes care of such tasks. Found nothing related on the FAQs.

pp generated executable can't find or load libraries
5 direct replies — Read more / Contribute
by vexed
on Apr 10, 2021 at 11:21

    Good day Monks,

    I hope you are all well. I am very novice Perl user, in fact I have only used sendEmail.exe by Brandon Zehm, which is a packed Windows executable based on Perl.

    That specific version of sendEmail is old and only supports TLSv1.0

    I have found an updated Perl script patched to used TLSv1.2.

    I have used Par::Packer (installed via cpan)to pack this updated Perl script into an executable, but no matter what I do, the executable keeps asking for Net::SSLeay and IO::Socket::SSL if Perl is not installed. (It works fine if Perl is installed or if I run the .pl script)

    Below is the error message from sendEmail.

    sendEmail.exe: ERROR => No TLS support! SendEmail can't load required libraries. (try installing Net::SSLeay and IO::Socket::SSL)

    Things that I tried:

  • I have used pp with -M Net::SSLeay -M IO::Socket::SSL.
  • I have installed Strawberry Perl 32 bit and 64 bit. (v5.32.1.1)
  • I have used Perl Portable instead. (v5.32.1.1)
  • I have used an older version of Perl. (v5.26.3.1 32 bit Portable)
  • I have made sure the needed packages are installed and up to date.
  • I have tried to use Dependency Walker, but it seems to hang on my workstation (Windows 10 20H2 x64).
  • pp -x fails with this error message: SYSTEM ERROR in executing : 256 at C:/Perl/perl/site/lib/Module/ line 1503.
  • I do not understand why the generated executable is not finding or loading the required libraries.

    Any help is greatly appreciated.

DBD::mysql incorrect string value
3 direct replies — Read more / Contribute
by cormanaz
on Apr 09, 2021 at 20:02
    Hi all. I have some tweets in Russla/Ukrainian/Bulgarian in a database on another machine. I have extracted ones I want to translate using google cloud translate, which is installed on another machine. I loaded them into an array of hashes, dumped them into a Storable file, and moved that to the other machine. I am now trying to load these into a MySQL database and an getting an error I can't figure out on the other machine. Here is the code (I set the die on $sth->execute to print the error and offending values):
    use DBI; use Storable qw(retrieve); $| = 1; my $j = retrieve("/mnt/c/temp/to-translate.sto"); my $dbh = connectdb('****','****','****','****','****'); foreach my $i (0..@$j-1) { my $r; $r->{tid} = $j->[$i]->{id}; $r->{orig} = $j->[$i]->{text}; #print "$r->{tid}\t$r->{orig}\n"; insertsql($dbh,'translate',$r); } sub connectdb { # connects to mysql or PgPP my ($database,$user,$password,$driver,$server) = @_; unless ($driver) { $driver = "mysql"; } unless ($server) { $server = ""; } my $url = "DBI:$driver:$database:$server"; unless ($user) { $user = "root"; $password = "research.HDSHC.mysql"; } my $dbh = DBI->connect( $url, $user, $password ) or die "connectdb + can't connect to mysql: $!\n"; return $dbh; } sub insertsql { my ($dbh,$table,$data,$ignore) = @_; my @qm; my @keys; my @values; my $i = -1; foreach my $k (keys %$data) { if (defined($data->{$k})) { $i++; $keys[$i] = $k; $values[$i] = $data->{$k}; $qm[$i] = '?'; } } my $keylist = join(",",@keys); my $qlist = join(",",@qm); my $sqlstatement = "insert into $table ($keylist) values ($qlist)" +; if ($ignore) { my $sqlstatement = "insert ignore into $table ($keylist) value +s ($qlist)"; } my $sth = $dbh->prepare($sqlstatement); #$sth->execute(@values) || die "putsql could not execute MySQL sta +tement: $sqlstatement $sth->errstr"; $sth->execute(@values) || die $sth->errstr. " ".join(" ",@values); $sth->finish(); return $dbh->{'mysql_insertid'}; }
    The encoding on the original db is utf8, and so are the table and columns on the target db. When it gets to one particular item it croaks:

    Incorrect string value: '\xF0\x9F\x98\x84 "...' for column 'orig' at row 1 530248086468063232 Нужно срочно брать на роботу. Цель для него есть 😄 "Рассекречена личность морпеха застрелившего бин Ладена"  at /home/steve/ line 61.

    Is the problem the emoticon? If so, how can I filter these out?

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