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User Questions
Looking for something like DBD::HTML::Table
4 direct replies — Read more / Contribute
by talexb
on Feb 26, 2021 at 16:07

    I'm looking into a couple of different solutions for a problem, and one solution involves using an imaginary module called DBD::HTML::Table to load up a web page containing a big table. It would be smart enough to look at the top row for the column names, and the first column for each row's index value.

    I've just had a stroll through, and I didn't see anything like that. Is it cunningly hidden, or does it not exist at all?

    Alex / talexb / Toronto

    Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.

Check whether two numbers are within a range
3 direct replies — Read more / Contribute
by stevieb
on Feb 26, 2021 at 11:07

    Hey Monks, I come here seeking help from our mathematicians again, as I'm feeling apathetic today and am having a brain fart moment.

    My objective is to find out if my car is parked within a 1.1 metre proximity of where it should be. This will identify whether the vehicle is in my garage or not. I then will read the vehicle's charge level, and using an LED strip on the garage wall, indicate the level on that strip, and if it's below a threshold, sound an audible alarm to remind me to plug the car in to recharge it. I will be using motion and sonar proximity sensors to identify when I've come into the house as to turn the warning off if I don't plug the car in (the car will indicate if the charger is plugged in via my software, and I'll disable the alert when this happens too).

    Anyway, with GPS, the fifth decimal place indicates the 1.1 metre area I'm looking to find. My question is, how do I compare the known set location, say 3.1566789, with the actual location of the vehicle, say 3.1565323, and verify whether that they are within at least five decimal places of one another?

    I don't know why I'm having this moment, I know it's a silly, easy thing. It'll likely come to me the second I hit submit. I know I could regex the numbers out, but I'd rather have a math calculation as I want to apply it to other areas.

    I have no code for this simple example, so I'll just post the following to at least make it perlish.

    use 5.10.0; $p=japh;push@a,w();$s=j4;sub n{"8fbac6c6e252"};unshift@a, "b4d6c7ea52a7";$k=crypt($s,$p);$o="aeafa7cfdbd58c";@h= map{sprintf"%x",ord$_}split//,$k;push@a,$o;$a[3]=pop@a; $a[2]=n();sub w{"bcb3d8dec8dd"}$x.=$_ for@a;@b=($x=~m/..?/g); push@z,@h until @z>@b;for(@b){push@japh,hex($_)-hex($z [$n]);$n++;}say map{chr$_}@japh;



Dereferencing in blessed object
2 direct replies — Read more / Contribute
by Bod
on Feb 25, 2021 at 17:58

    I have a bit of a strange problem... I have consulted the very useful assistance haukex and others provided on Re^9: Preparing data for Template.

    The problem is dereferencing an entry in a hash. At first, I thought it was the trouble I always seem to run into when using references. So, I built some test code to check what I was doing and it works as expected.

    use strict; my $val = 'A'; my $vars = { 'test' => $val }; reftest('testing', $vars); sub reftest { my ($value, %vars) = @_; print "$value\n"; print $$vars{'test'}."\n"; } C:\Users\ian\Perl>perl testing A
    The output is exactly as expected.

    But the code on the webserver is structured the same. The only difference is that the subroutine is a method in a blessed object...could this really make a difference?

    The calling code...

    my $vars = { 'testpage' => $data{'testpage'} }; $html->process('index', $vars);

    And the method within the $html object...

    sub process { my ($self, $disp, %v) = @_; my $testpage = $$v{'testpage'}; print "<h1>".$testpage."</h1>\n"; }
    The output is <h1></h1> only.

    I have checked the $data{'testpage'} contains the expected data of either 'A' or 'B'.
    What is causing the lack of dereferencing or what else could I try to debug this problem?

Passing Variables
4 direct replies — Read more / Contribute
by catfish1116
on Feb 25, 2021 at 16:01

    I am running v5.12 and am trying to pass multiple args to a subroutine. Is this possible in v5.12? Here is my code

    ################################################### # # # 2/24/21 # # Program takes finds the average in an # # array and lists out the numbers that were # # above the average found. # # # ################################################### my @numbers = qw(4 12 18 21 35); my $average = &find_average(@numbers); print "The average found for this list is: $average \n " ; my @high_avg = &above_average($average, @numbers); print "The numbers that were found above average are: @high_avg \n" +; sub find_average { my ($sum, $number_count) ; foreach (@_) { $sum += $_; $number_count += 1; } my $avg = $sum / $number_count ; } sub above_average { my $average_num; my @final_list; foreach $_ (@_) { if ($_ > $average_num) { push @final_list, $_ } } }

    Here is the error message I am getting

    Use of uninitialized value $average_num in numeric gt (>) at ./Chapter line 36.

    TIA The Catfish

Move a file to another directory based on regex match
4 direct replies — Read more / Contribute
by DAN0207
on Feb 25, 2021 at 09:43

    I am trying to match the regex of the filename and if it matches i want to move the file into another directory.But when i run the script, i get the error as "move failed: Invalid cross-device link".Please help me.The code is given below:

    #!/usr/bin/perl -w use File::Copy; $InDir = $ARGV[0]; $OutDir = $ARGV[1]; if (!opendir(DIR,$InDir)) { print "Bad Dir $InDir\n"; exit 1;} while(my $Infile = readdir(DIR)) { if ($Infile =~ 'F\d{8}\.\d{4}\+\d{4}\-\d{4}\+\d{4}_.*') { move("$Infile", "$OutDir") or die "move failed: $!"; } elsif ($Infile =~ 'F\d{8}\.\d{6}\+\d{4}\-\d{6}\+\d{4}_.*' ) { < something........> } }
You won't believe what this regular expression does!
4 direct replies — Read more / Contribute
by salva
on Feb 25, 2021 at 05:44
Sending file as "TEXT" or "BLOB"
4 direct replies — Read more / Contribute
by cristofayre
on Feb 24, 2021 at 11:49

    This is partially PERL and partially javascript (Sorry)

    Basically, I want to send an HTTPRequest to the server. If the file =DOES NOT= exist, it throws back an error as a TEXT response. If it DOES exist, it passes back the file as a BLOB. (Not really sure how to send a file as a BLOB from PERL - which is the point of this question)

    ** Using "Content-type: attachment; application/zip" and "content-disposition" to invoke the save dialouge I can just about understand ... but that will not report an error if the file doesn't exist. (The file is accessed by user entering a code number into a form, so a wrong number needs to throw an error warning)

    Here is the basic code:

    CLIENT SIDE: function downFile(){ var formData = new FormData(); formData.set('email','$email'); formData.set('gf_line','$line'); formData.set('code','$code'); var xhttp = new XMLHttpRequest(); xhttp.onreadystatechange = function() { if (this.readyState == 4){ if (this.status == 200) { if (xhttp.responseType == 'text' || xhttp.responseType == +'') { alert('Sorry, but there appears to be an error\\nThis coul +d be:\\n\\n- The email address entered\\ndoes not match the email in +database\\n\\n- The code you entered is incorrect\\n\\nPlease check y +our details, and try again'); window.history.back(); return false; } else if (xhttp.responseType == 'blob'){ // Create a new Blob object using the response data of the + onload object var blob = new Blob([this.response], {type: 'application/z +ip'}); //Create a link element, hide it, direct it towards the bl +ob, and then 'click' it programatically let a = document.createElement("a"); = "display: none"; document.body.appendChild(a); //Create a DOMString representing the blob and point the l +ink element towards it let url = window.URL.createObjectURL(blob); a.href = url; = 'Branded'; //programatically click the link to trigger the download; //release the reference to the file by revoking the Object + URL window.URL.revokeObjectURL(url); } } }"POST", "", true); xhttp.send(formData); } </script> SERVER SIDE: ... .. . if ($inEmail ne $email){ print "content-type: text/html\n\n"; print "500"; # Returned as a "TEXT" response exit; } else{ open FILE, "<", "../data/$user/$dir/$code/$"; binmode FILE; while(<FILE>){ $file.=$_; } close FILE; #print "content-type: text/html\n\n"; #print "content-type: application/zip\n"; #print "content-disposition: attachment; filename='Branded Files'\n\n" +; print $file; # Returned as a "BLOB" response

    Both responses return as text

    The theory is that the code in the else statement will create a fake anchor, load the blob into it, emulate a click and thus invoke the "SAVE" dialogue. Admit this is "copy / paste" so - whilst I understand what it's doing - it's not my code

    In a nutshell, I want an alert if the file does not exist, or a SAVE dialogue if it DOES exist, ideally without navigating away from the page. There may be an easier way to do it, so open to suggestions

ODBC problem
7 direct replies — Read more / Contribute
by Anonymous Monk
on Feb 24, 2021 at 08:47
    Hi, I have to access an old Sage MAS 90 database, I can connect fine with an ODBC query tool using the connection string "Driver={MAS 90 4.0 ODBC Driver};Directory=S:\v440\MAS90" But when I try with Perl I get:
    use strict; use warnings; use DBI; my $dbuser = "user"; my $dbpassword = "password"; # SOTAMAS90 my $CONNECT = 'Driver={MAS 90 4.0 ODBC Driver};Directory=S:\v440\MAS90 +'; my $dbh = DBI->connect("dbi:ODBC:$CONNECT", "$dbuser", "$dbpassword") or die "Cannot connect to $CONNECT: $DBI::errstr\n"; $dbh->disconnect
    It fails with:
    C:\> DBI connect('Driver={MAS 90 4.0 ODBC Driver}','user',...) failed: [Mic +rosoft][ODBC Driver Manager] Data source name not found and no defaul +t driver specified (SQL-IM002) at C:\ line 11. Cannot connect to Driver={MAS 90 4.0 ODBC Driver}: [Microsoft][ODBC Dr +iver Manager] Data source name not found and no default driver specif +ied (SQL-IM002)
    The driver is a 32bit on (if that's relevant) I've also tried using its user DSN name SOTAMAS90 instead but that fails as well. I've never used ODBC before and am not used to working on Windows so any help to helping me connect would be great!
Image rotation with GD: counter or clockwise?
3 direct replies — Read more / Contribute
by Discipulus
on Feb 23, 2021 at 08:29
    Hello folks!

    I'm experimenting with images again but I'm stucked at image rotation using GD. Documentation says:

    > $image->copyRotated($sourceImage,$dstX,$dstY,$srcX,$srcY,$width,$height,$angle) Like copyResized() but the $angle argument specifies an arbitrary amount to rotate the image clockwise (in degrees). In addition, $dstX and $dstY species the center of the destination image, and not the top left corner.

    The following code seems to rotate counter clockwise instead (pass to the following program a jpg image and optionally a degrees value):

    use strict; use warnings; use GD; print "GD version : $GD::VERSION\n"; print "libgd version: ",GD::VERSION_STRING,"\n"; my $original_jpg = $ARGV[0]; my $angle = $ARGV[1] ? $ARGV[1] : 90; my $gd = GD::Image->new( $original_jpg ); my $gdrot = new GD::Image($gd->width, $gd->height ); $gdrot->copyRotated( $gd, # source $gd->width/2, # X center of the destinat +ion image $gd->height/2, # Y center of the destinat +ion image 0, # X specify the upper left + corner of a rectangle in the source image 0, # Y specify the upper left + corner of a rectangle in the source image $gd->width, # final width $gd->height, # final height $angle # rotation angle clockwise + in degrees ); open my $fh,'>', "rotated_".$angle."_".$original_jpg or die $!; binmode $fh; print $fh $gdrot->jpeg;

    Did you see the same result as me? I see the resulting image rotated 90 counter clockwise (I'd say counter documentwise ;). In early tests I got a warning about older version of gdlib (like: libgd 2.0.33 or higher required for copyRotated ) and I upgraded my using cpan client and everything went fine.

    I currently have: GD version   : 2.66 libgd version: 2.2.4

    Any insight appreciated.


    There are no rules, there are no thumbs..
    Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
Assign valuse of array within array to variables
3 direct replies — Read more / Contribute
by g_speran
on Feb 22, 2021 at 20:29

    Good Evening Perl Monks, How can one assign the contents of an array within a multi-dimensional array to a set of variables passed to a subroutine?

    use warnings; use Data::Dumper; my @arr; $arr[0][4] = (["S","M","R","B"]); print Dumper @arr; my ($VAR1,$VAR2,$VAR3,$VAR4) = @{$arr[0][4]}; print "Var1: $VAR1\tVar2: $VAR2\tVar3: $VAR3\tVar4: $VAR4\n"; Testing($arr[0][4]); sub Testing () { my ($VAR5,$VAR6,$VAR7,$VAR8) = @{$_}; print "Var5: $VAR5\tVar6:$VAR6\tVar7: $VAR7\tVar8: $VAR8\n"; }
    OUTPUT ================= main::Testing() called too early to check prototype at C:\temp\arr_ref line 11. $VAR1 = [ undef, undef, undef, undef, [ 'S', 'M', 'R', 'B' ] ]; Var1: S Var2: M Var3: R Var4: B Use of uninitialized value $_ in array dereference at C:\temp\arr_refe line 14. Use of uninitialized value $VAR5 in concatenation (.) or string at C:\ +temp\ line 15. Use of uninitialized value $VAR6 in concatenation (.) or string at C:\ +temp\ line 15. Use of uninitialized value $VAR7 in concatenation (.) or string at C:\ +temp\ line 15. Use of uninitialized value $VAR8 in concatenation (.) or string at C:\ +temp\ line 15. Var5: Var6: Var7: Var8:
    Expecting output ============== Var1: S Var2: M Var3: R Var4: B Var5: S Var6: M Var7: R Var8: B

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