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serf's scratchpad

by serf (Chaplain)
on Mar 03, 2005 at 20:08 UTC ( #436355=scratchpad: print w/ replies, xml ) Need Help??

I have been given a new Windows 7 desktop at work and would like to have Perl doing stuff.

I installed Strawberry Perl, which I usually use, and went from there...

One of the things I wanted to be able to do was write GUI applications in Perl, and found to my dismay that a lot of the tools I tried would not build OOTB.

I have found three that do, so I thought I'd share them here in case anybody else is in the same situation.

Installed OK:

Failed to install:

  • Tk (crashed 3 times then failed to install)
  • Win32::GUI this may help
  • Gtk2
  • Qt - I wasn't up for having to install 525MB of libraries to get a little GUI app working!

read this


Why does Deparse do this?

Given:

#!/usr/bin/perl use warnings; use strict 'refs'; use Data::Dumper; my(@array1) = (1, 2, 3, 4); my(@array2) = ('a', 'b', 'c', 'd', 'e', 'f');

If I have this:

push my @array3, @array1, @array2;

I get:

Parentheses missing around "my" list at try.pl line 12.

If I do:

push (my @array3, @array1, @array2);

it doesn't complain...

but if I run the code through -MO=Deparse

It changes the:

push (my @array3, @array1, @array2);

back to:

push my @array3, @array1, @array2;

!!!


I'm trying to get the values out of an enum field in MySQL

At the moment I have:

#!/usr/bin/perl use warnings; use strict; use DBI; my $db_host = "mysql"; my $db_port = "3306"; my $db_user = 'web-user'; my $db_pass = 'pass4monks'; my $db_name = 'order_dev'; my $dbh = DBI->connect( "DBI:mysql:database=$db_name;host=$db_host;port=$db_port", $db_user, $db_pass ) || die ("ERROR: Unable to connect to '$db_name': $DBI::errstr" ); my ($enum_qry) = $dbh->prepare( "SELECT column_type FROM information_schema.columns WHERE table_name = 'orders' AND column_name = 'request_status' LIMIT 1;" ); $enum_qry->execute; my $enum_ref = $enum_qry->fetchrow_hashref; (my $enum_types = $$enum_ref{'column_type'}) =~ s/^enum\((.*)\).*/$1/; foreach my $enum_type ( eval $enum_types ) { print qq[<option value="$enum_type">$enum_type</option>\n]; }
This can be tested without the DB stuff using:
my $enum_types = "'On Order','Waiting, Pending Payment','Dispatched',' +Cancelled','Renewal','Amend\'ed'"; # NB: one value has a , in it and another a ' just to make this challe +nging... ;-) foreach my $enum_type ( eval $enum_types ) { print qq[<option value="$enum_type">$enum_type</option>\n]; }

Consensus is that eval should be spelled 'evil' and should be evoided where possible...

Anno wrote this //g syntax which works fine:

while ( $enum_types =~ m/('(.*?)'|([^']*?))($|,\s*)/g ) { my $match = $3 || $2; print qq[<option value="$match">$match</option>\n] if $match; }

I'm wondering what syntax I'd need to replace the eval using split...

The closest I have at the moment is:

#!/usr/bin/perl use warnings; use strict; my $enum_types = "'On Order','Waiting, Pending Payment','Dispatched',' +Cancelled','Renewal','Amen'ded'"; foreach my $enum_type ( split /(?:^'|','|'$)/, $enum_types ) { print qq[<option value="$enum_type">$enum_type</option>\n]; }

But that also gives me the ^ as a value:

$ ./try.pl <option value=""></option> <option value="On Order">On Order</option> <option value="Waiting, Pending Payment">Waiting, Pending Payment</opt +ion> <option value="Dispatched">Dispatched</option> <option value="Cancelled">Cancelled</option> <option value="Renewal">Renewal</option> <option value="Amen'ded">Amen'ded</option>
Any suggestions?
Read between the lines... ^^^
In the description of "Custom Node Title Definition" in Display Settings it says "Don't use [ nor ]"

I think "Do not use X nor Y" is a double negative where it is not intended...

"Don't use X ... Y" is the same as "Do not use either X or Y" ("Do not use neither..." would be a double negative and incorrect)

The "or" works like a comma in a list of things that have been negated by the "not" in Don't.

It should either be "Use neither X nor Y" or "Don't use X or Y".

Further reading:


Efficient use of space on multiple CDs
Compiling modules for ARM:
my $command = '/usr/local/bin/program_with_multiline_output'; chomp(my(@output) = `$command`); my $output = join($/, grep(/./, @output)); my $returned = $? >> 8; print "Returned: [$returned]\n"; print "Message: [$output]\n";

and all is quiet...
[link://?node_id=3989&BIT=search term|search term] search term If you have a look at Super Search:Ananymous
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